diff --git a/libs/gui/CleanSpec.mk b/CleanSpec.mk
similarity index 70%
rename from libs/gui/CleanSpec.mk
rename to CleanSpec.mk
index 5a5144c..1855d26 100644
--- a/libs/gui/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -1,4 +1,4 @@
-# Copyright (C) 2012 The Android Open Source Project
+# Copyright (C) 2018 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -34,19 +34,23 @@
 # made today requires touching the same file, just copy the old
 # touch step and add it to the end of the list.
 #
-# ************************************************
-# NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
-# ************************************************
+# *****************************************************************
+# NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST ABOVE THE BANNER
+# *****************************************************************
 
 # For example:
 #$(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/APPS/AndroidTests_intermediates)
 #$(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/JAVA_LIBRARIES/core_intermediates)
 #$(call add-clean-step, find $(OUT_DIR) -type f -name "IGTalkSession*" -print0 | xargs -0 rm -f)
 #$(call add-clean-step, rm -rf $(PRODUCT_OUT)/data/*)
-
-# ************************************************
-# NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
-# ************************************************
+$(call add-clean-step, find $(PRODUCT_OUT) -type f -name "libdvr.so" -print0 | xargs -0 rm -f)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/SHARED_LIBRARIES/libdvr_intermediates)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/SHARED_LIBRARIES/libdvr_intermediates)
 $(call add-clean-step, find $(PRODUCT_OUT) -type f -name "libgui*" -print0 | xargs -0 rm -f)
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/SHARED_LIBRARIES/libgui_intermediates)
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/SHARED_LIBRARIES/libgui_intermediates)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/bin/thermalserviced)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/etc/init/thermalservice.rc)
+# ******************************************************************
+# NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST ABOVE THIS BANNER
+# ******************************************************************
diff --git a/cmds/surfacereplayer/proto/src/trace.proto b/cmds/surfacereplayer/proto/src/trace.proto
index 68ddeb0..c169b76 100644
--- a/cmds/surfacereplayer/proto/src/trace.proto
+++ b/cmds/surfacereplayer/proto/src/trace.proto
@@ -160,7 +160,7 @@
 message DisplayCreation {
     required int32     id                = 1;
     required string    name              = 2;
-    required int32     type              = 3;
+    optional uint64    display_id        = 3;
     required bool      is_secure         = 4;
 }
 
diff --git a/cmds/surfacereplayer/replayer/trace_creator/trace_creator.py b/cmds/surfacereplayer/replayer/trace_creator/trace_creator.py
index a892e46..d63d97f 100644
--- a/cmds/surfacereplayer/replayer/trace_creator/trace_creator.py
+++ b/cmds/surfacereplayer/replayer/trace_creator/trace_creator.py
@@ -172,7 +172,7 @@
 def display_create(increment):
     increment.display_creation.id = int(input("Enter id: "))
     increment.display_creation.name = str(raw_input("Enter name: "))
-    increment.display_creation.type = int(input("Enter type: "))
+    increment.display_creation.display_id = int(input("Enter display ID: "))
     increment.display_creation.is_secure = bool(input("Enter if secure: "))
 
 def display_delete(increment):
diff --git a/libs/binder/include/binder/IBinder.h b/libs/binder/include/binder/IBinder.h
index 14edcbe..1674516 100644
--- a/libs/binder/include/binder/IBinder.h
+++ b/libs/binder/include/binder/IBinder.h
@@ -47,7 +47,7 @@
  * (method calls, property get and set) is down through a low-level
  * protocol implemented on top of the transact() API.
  */
-class IBinder : public virtual RefBase
+class [[clang::lto_visibility_public]] IBinder : public virtual RefBase
 {
 public:
     enum {
diff --git a/libs/binder/ndk/.clang-format b/libs/binder/ndk/.clang-format
new file mode 100644
index 0000000..9a9d936
--- /dev/null
+++ b/libs/binder/ndk/.clang-format
@@ -0,0 +1,10 @@
+BasedOnStyle: Google
+ColumnLimit: 100
+IndentWidth: 4
+ContinuationIndentWidth: 8
+PointerAlignment: Left
+TabWidth: 4
+AllowShortFunctionsOnASingleLine: Inline
+PointerAlignment: Left
+TabWidth: 4
+UseTab: Never
diff --git a/libs/binder/ndk/ibinder.cpp b/libs/binder/ndk/ibinder.cpp
index e1c2009..f3fb9c3 100644
--- a/libs/binder/ndk/ibinder.cpp
+++ b/libs/binder/ndk/ibinder.cpp
@@ -45,7 +45,7 @@
     return binder != nullptr && binder->findObject(kId) == kValue;
 }
 
-} // namespace ABBinderTag
+}  // namespace ABBinderTag
 
 namespace ABpBinderTag {
 
@@ -60,7 +60,7 @@
     delete static_cast<Value*>(obj);
 };
 
-} // namespace ABpBinderTag
+}  // namespace ABpBinderTag
 
 AIBinder::AIBinder(const AIBinder_Class* clazz) : mClazz(clazz) {}
 AIBinder::~AIBinder() {}
@@ -91,7 +91,7 @@
         return false;
     }
 
-    CHECK(asABpBinder() != nullptr); // ABBinder always has a descriptor
+    CHECK(asABpBinder() != nullptr);  // ABBinder always has a descriptor
 
     String8 descriptor(getBinder()->getInterfaceDescriptor());
     if (descriptor != newDescriptor) {
@@ -107,7 +107,7 @@
 }
 
 ABBinder::ABBinder(const AIBinder_Class* clazz, void* userData)
-      : AIBinder(clazz), BBinder(), mUserData(userData) {
+    : AIBinder(clazz), BBinder(), mUserData(userData) {
     CHECK(clazz != nullptr);
 }
 ABBinder::~ABBinder() {
@@ -136,7 +136,7 @@
 }
 
 ABpBinder::ABpBinder(const ::android::sp<::android::IBinder>& binder)
-      : AIBinder(nullptr /*clazz*/), BpRefBase(binder) {
+    : AIBinder(nullptr /*clazz*/), BpRefBase(binder) {
     CHECK(binder != nullptr);
 }
 ABpBinder::~ABpBinder() {}
@@ -214,10 +214,10 @@
 AIBinder_Class::AIBinder_Class(const char* interfaceDescriptor, AIBinder_Class_onCreate onCreate,
                                AIBinder_Class_onDestroy onDestroy,
                                AIBinder_Class_onTransact onTransact)
-      : onCreate(onCreate),
-        onDestroy(onDestroy),
-        onTransact(onTransact),
-        mInterfaceDescriptor(interfaceDescriptor) {}
+    : onCreate(onCreate),
+      onDestroy(onDestroy),
+      onTransact(onTransact),
+      mInterfaceDescriptor(interfaceDescriptor) {}
 
 AIBinder_Class* AIBinder_Class_define(const char* interfaceDescriptor,
                                       AIBinder_Class_onCreate onCreate,
@@ -239,7 +239,7 @@
 }
 
 AIBinder_DeathRecipient::AIBinder_DeathRecipient(AIBinder_DeathRecipient_onBinderDied onDied)
-      : mOnDied(onDied) {
+    : mOnDied(onDied) {
     CHECK(onDied != nullptr);
 }
 
diff --git a/libs/binder/ndk/ibinder_internal.h b/libs/binder/ndk/ibinder_internal.h
index 5b6bc94..ac592ea 100644
--- a/libs/binder/ndk/ibinder_internal.h
+++ b/libs/binder/ndk/ibinder_internal.h
@@ -49,7 +49,7 @@
         return binder->remoteBinder() != nullptr;
     }
 
-private:
+   private:
     // AIBinder instance is instance of this class for a local object. In order to transact on a
     // remote object, this also must be set for simplicity (although right now, only the
     // interfaceDescriptor from it is used).
@@ -69,7 +69,7 @@
     ::android::status_t onTransact(uint32_t code, const ::android::Parcel& data,
                                    ::android::Parcel* reply, binder_flags_t flags) override;
 
-private:
+   private:
     ABBinder(const AIBinder_Class* clazz, void* userData);
 
     // only thing that should create an ABBinder
@@ -96,7 +96,7 @@
     ::android::sp<::android::IBinder> getBinder() override { return remote(); }
     ABpBinder* asABpBinder() override { return this; }
 
-private:
+   private:
     ABpBinder(const ::android::sp<::android::IBinder>& binder);
 };
 
@@ -110,7 +110,7 @@
     const AIBinder_Class_onDestroy onDestroy;
     const AIBinder_Class_onTransact onTransact;
 
-private:
+   private:
     // This must be a String16 since BBinder virtual getInterfaceDescriptor returns a reference to
     // one.
     const ::android::String16 mInterfaceDescriptor;
@@ -128,14 +128,14 @@
     struct TransferDeathRecipient : ::android::IBinder::DeathRecipient {
         TransferDeathRecipient(const ::android::wp<::android::IBinder>& who, void* cookie,
                                const AIBinder_DeathRecipient_onBinderDied& onDied)
-              : mWho(who), mCookie(cookie), mOnDied(onDied) {}
+            : mWho(who), mCookie(cookie), mOnDied(onDied) {}
 
         void binderDied(const ::android::wp<::android::IBinder>& who) override;
 
         const ::android::wp<::android::IBinder>& getWho() { return mWho; }
         void* getCookie() { return mCookie; }
 
-    private:
+       private:
         ::android::wp<::android::IBinder> mWho;
         void* mCookie;
         const AIBinder_DeathRecipient_onBinderDied& mOnDied;
@@ -145,7 +145,7 @@
     binder_status_t linkToDeath(AIBinder* binder, void* cookie);
     binder_status_t unlinkToDeath(AIBinder* binder, void* cookie);
 
-private:
+   private:
     std::mutex mDeathRecipientsMutex;
     std::vector<::android::sp<TransferDeathRecipient>> mDeathRecipients;
     AIBinder_DeathRecipient_onBinderDied mOnDied;
diff --git a/libs/binder/ndk/include_apex/android/binder_manager.h b/libs/binder/ndk/include_apex/android/binder_manager.h
index b8f38ba..80b6c07 100644
--- a/libs/binder/ndk/include_apex/android/binder_manager.h
+++ b/libs/binder/ndk/include_apex/android/binder_manager.h
@@ -17,11 +17,18 @@
 #pragma once
 
 #include <android/binder_ibinder.h>
+#include <android/binder_status.h>
 
 __BEGIN_DECLS
 
 /**
- * This registers the service with the default service manager under this instance name.
+ * This registers the service with the default service manager under this instance name. This does
+ * not take ownership of binder.
+ *
+ * \param binder object to register globally with the service manager.
+ * \param instance identifier of the service. This will be used to lookup the service.
+ *
+ * \return STATUS_OK on success.
  */
 binder_status_t AServiceManager_addService(AIBinder* binder, const char* instance);
 
@@ -29,6 +36,8 @@
  * Gets a binder object with this specific instance name. Blocks for a couple of seconds waiting on
  * it. This also implicitly calls AIBinder_incStrong (so the caller of this function is responsible
  * for calling AIBinder_decStrong).
+ *
+ * \param instance identifier of the service used to lookup the service.
  */
 __attribute__((warn_unused_result)) AIBinder* AServiceManager_getService(const char* instance);
 
diff --git a/libs/binder/ndk/include_ndk/android/binder_auto_utils.h b/libs/binder/ndk/include_ndk/android/binder_auto_utils.h
index e52a1d6..5c26039 100644
--- a/libs/binder/ndk/include_ndk/android/binder_auto_utils.h
+++ b/libs/binder/ndk/include_ndk/android/binder_auto_utils.h
@@ -31,10 +31,8 @@
 #include <android/binder_status.h>
 
 #include <assert.h>
+
 #include <unistd.h>
-
-#ifdef __cplusplus
-
 #include <cstddef>
 
 namespace ndk {
@@ -43,7 +41,7 @@
  * Represents one strong pointer to an AIBinder object.
  */
 class SpAIBinder {
-public:
+   public:
     /**
      * Takes ownership of one strong refcount of binder.
      */
@@ -107,7 +105,7 @@
      */
     AIBinder** getR() { return &mBinder; }
 
-private:
+   private:
     AIBinder* mBinder = nullptr;
 };
 
@@ -116,7 +114,7 @@
  */
 template <typename T, typename R, R (*Destroy)(T), T DEFAULT>
 class ScopedAResource {
-public:
+   public:
     /**
      * Takes ownership of t.
      */
@@ -167,7 +165,7 @@
     // move-constructing is okay
     ScopedAResource(ScopedAResource&&) = default;
 
-private:
+   private:
     T mT;
 };
 
@@ -175,7 +173,7 @@
  * Convenience wrapper. See AParcel.
  */
 class ScopedAParcel : public ScopedAResource<AParcel*, void, AParcel_delete, nullptr> {
-public:
+   public:
     /**
      * Takes ownership of a.
      */
@@ -188,7 +186,7 @@
  * Convenience wrapper. See AStatus.
  */
 class ScopedAStatus : public ScopedAResource<AStatus*, void, AStatus_delete, nullptr> {
-public:
+   public:
     /**
      * Takes ownership of a.
      */
@@ -206,14 +204,14 @@
  * Convenience wrapper. See AIBinder_DeathRecipient.
  */
 class ScopedAIBinder_DeathRecipient
-      : public ScopedAResource<AIBinder_DeathRecipient*, void, AIBinder_DeathRecipient_delete,
-                               nullptr> {
-public:
+    : public ScopedAResource<AIBinder_DeathRecipient*, void, AIBinder_DeathRecipient_delete,
+                             nullptr> {
+   public:
     /**
      * Takes ownership of a.
      */
     explicit ScopedAIBinder_DeathRecipient(AIBinder_DeathRecipient* a = nullptr)
-          : ScopedAResource(a) {}
+        : ScopedAResource(a) {}
     ~ScopedAIBinder_DeathRecipient() {}
     ScopedAIBinder_DeathRecipient(ScopedAIBinder_DeathRecipient&&) = default;
 };
@@ -222,8 +220,8 @@
  * Convenience wrapper. See AIBinder_Weak.
  */
 class ScopedAIBinder_Weak
-      : public ScopedAResource<AIBinder_Weak*, void, AIBinder_Weak_delete, nullptr> {
-public:
+    : public ScopedAResource<AIBinder_Weak*, void, AIBinder_Weak_delete, nullptr> {
+   public:
     /**
      * Takes ownership of a.
      */
@@ -241,7 +239,7 @@
  * Convenience wrapper for a file descriptor.
  */
 class ScopedFileDescriptor : public ScopedAResource<int, int, close, -1> {
-public:
+   public:
     /**
      * Takes ownership of a.
      */
@@ -250,8 +248,6 @@
     ScopedFileDescriptor(ScopedFileDescriptor&&) = default;
 };
 
-} // namespace ndk
-
-#endif // __cplusplus
+}  // namespace ndk
 
 /** @} */
diff --git a/libs/binder/ndk/include_ndk/android/binder_ibinder.h b/libs/binder/ndk/include_ndk/android/binder_ibinder.h
index c222c16..d711ad8 100644
--- a/libs/binder/ndk/include_ndk/android/binder_ibinder.h
+++ b/libs/binder/ndk/include_ndk/android/binder_ibinder.h
@@ -126,8 +126,9 @@
 /**
  * This is called whenever a new AIBinder object is needed of a specific class.
  *
- * These arguments are passed from AIBinder_new. The return value is stored and can be retrieved
- * using AIBinder_getUserData.
+ * \param args these can be used to construct a new class. These are passed from AIBinder_new.
+ * \return this is the userdata representing the class. It can be retrieved using
+ * AIBinder_getUserData.
  */
 typedef void* (*AIBinder_Class_onCreate)(void* args);
 
@@ -135,23 +136,41 @@
  * This is called whenever an AIBinder object is no longer referenced and needs destroyed.
  *
  * Typically, this just deletes whatever the implementation is.
+ *
+ * \param userData this is the same object returned by AIBinder_Class_onCreate
  */
 typedef void (*AIBinder_Class_onDestroy)(void* userData);
 
 /**
  * This is called whenever a transaction needs to be processed by a local implementation.
+ *
+ * \param binder the object being transacted on.
+ * \param code implementation-specific code representing which transaction should be taken.
+ * \param in the implementation-specific input data to this transaction.
+ * \param out the implementation-specific output data to this transaction.
+ *
+ * \return the implementation-specific output code. This may be forwarded from another service, the
+ * result of a parcel read or write, or another error as is applicable to the specific
+ * implementation. Usually, implementation-specific error codes are written to the output parcel,
+ * and the transaction code is reserved for kernel errors or error codes that have been repeated
+ * from subsequent transactions.
  */
 typedef binder_status_t (*AIBinder_Class_onTransact)(AIBinder* binder, transaction_code_t code,
                                                      const AParcel* in, AParcel* out);
 
 /**
- * An interfaceDescriptor uniquely identifies the type of object that is being created. This is used
- * internally for sanity checks on transactions.
+ * This creates a new instance of a class of binders which can be instantiated. This is called one
+ * time during library initialization and cleaned up when the process exits or execs.
  *
- * None of these parameters can be nullptr.
+ * None of these parameters can be null.
  *
- * This is created one time during library initialization and cleaned up when the process exits or
- * execs.
+ * \param interfaceDescriptor this is a unique identifier for the class. This is used internally for
+ * sanity checks on transactions.
+ * \param onCreate see AIBinder_Class_onCreate.
+ * \param onDestroy see AIBinder_Class_onDestroy.
+ * \param onTransact see AIBinder_Class_onTransact.
+ *
+ * \return the class object representing these parameters or null on error.
  */
 __attribute__((warn_unused_result)) AIBinder_Class* AIBinder_Class_define(
         const char* interfaceDescriptor, AIBinder_Class_onCreate onCreate,
@@ -174,12 +193,21 @@
  * hypothetical removeCallback function, the remote process would have no way to determine that
  * these two objects are actually equal using the AIBinder pointer alone (which they should be able
  * to do). Also see the suggested memory ownership model suggested above.
+ *
+ * \param clazz the type of the object to be created.
+ * \param args the args to pass to AIBinder_onCreate for that class.
+ *
+ * \return a binder object representing the newly instantiated object.
  */
 __attribute__((warn_unused_result)) AIBinder* AIBinder_new(const AIBinder_Class* clazz, void* args)
         __INTRODUCED_IN(29);
 
 /**
  * If this is hosted in a process other than the current one.
+ *
+ * \param binder the binder being queried.
+ *
+ * \return true if the AIBinder represents an object in another process.
  */
 bool AIBinder_isRemote(const AIBinder* binder) __INTRODUCED_IN(29);
 
@@ -189,13 +217,21 @@
  * this is automatically updated to reflect the current alive status of this binder. This will be
  * updated as the result of a transaction made using AIBinder_transact, but it will also be updated
  * based on the results of bookkeeping or other transactions made internally.
+ *
+ * \param binder the binder being queried.
+ *
+ * \return true if the binder is alive.
  */
 bool AIBinder_isAlive(const AIBinder* binder) __INTRODUCED_IN(29);
 
 /**
- * Built-in transaction for all binder objects. This sends a transaction which will immediately
+ * Built-in transaction for all binder objects. This sends a transaction that will immediately
  * return. Usually this is used to make sure that a binder is alive, as a placeholder call, or as a
  * sanity check.
+ *
+ * \param binder the binder being queried.
+ *
+ * \return STATUS_OK if the ping succeeds.
  */
 binder_status_t AIBinder_ping(AIBinder* binder) __INTRODUCED_IN(29);
 
@@ -209,6 +245,12 @@
  * identification and holding user data.
  *
  * If binder is local, this will return STATUS_INVALID_OPERATION.
+ *
+ * \param binder the binder object you want to receive death notifications from.
+ * \param recipient the callback that will receive notifications when/if the binder dies.
+ * \param cookie the value that will be passed to the death recipient on death.
+ *
+ * \return STATUS_OK on success.
  */
 binder_status_t AIBinder_linkToDeath(AIBinder* binder, AIBinder_DeathRecipient* recipient,
                                      void* cookie) __INTRODUCED_IN(29);
@@ -217,22 +259,37 @@
  * Stops registration for the associated binder dying. Does not delete the recipient. This function
  * may return a binder transaction failure and in case the death recipient cannot be found, it
  * returns STATUS_NAME_NOT_FOUND.
+ *
+ * \param binder the binder object to remove a previously linked death recipient from.
+ * \param recipient the callback to remove.
+ * \param cookie the cookie used to link to death.
+ *
+ * \return STATUS_OK on success. STATUS_NAME_NOT_FOUND if the binder cannot be found to be unlinked.
  */
 binder_status_t AIBinder_unlinkToDeath(AIBinder* binder, AIBinder_DeathRecipient* recipient,
                                        void* cookie) __INTRODUCED_IN(29);
 
 /**
  * This can only be called if a strong reference to this object already exists in process.
+ *
+ * \param binder the binder object to add a refcount to.
  */
 void AIBinder_incStrong(AIBinder* binder) __INTRODUCED_IN(29);
 
 /**
  * This will delete the object and call onDestroy once the refcount reaches zero.
+ *
+ * \param binder the binder object to remove a refcount from.
  */
 void AIBinder_decStrong(AIBinder* binder) __INTRODUCED_IN(29);
 
 /**
  * For debugging only!
+ *
+ * \param binder the binder object to retrieve the refcount of.
+ *
+ * \return the number of strong-refs on this binder in this process. If binder is null, this will be
+ * -1.
  */
 int32_t AIBinder_debugGetRefCount(AIBinder* binder) __INTRODUCED_IN(29);
 
@@ -244,17 +301,32 @@
  *
  * This returns true if the class association succeeds. If it fails, no change is made to the
  * binder object.
+ *
+ * \param binder the object to attach the class to.
+ * \param clazz the clazz to attach to binder.
+ *
+ * \return true if the binder has the class clazz and if the association was successful.
  */
 bool AIBinder_associateClass(AIBinder* binder, const AIBinder_Class* clazz) __INTRODUCED_IN(29);
 
 /**
  * Returns the class that this binder was constructed with or associated with.
+ *
+ * \param binder the object that is being queried.
+ *
+ * \return the class that this binder is associated with. If this binder wasn't created with
+ * AIBinder_new, and AIBinder_associateClass hasn't been called, then this will return null.
  */
 const AIBinder_Class* AIBinder_getClass(AIBinder* binder) __INTRODUCED_IN(29);
 
 /**
  * Value returned by onCreate for a local binder. For stateless classes (if onCreate returns
- * nullptr), this also returns nullptr. For a remote binder, this will always return nullptr.
+ * null), this also returns null. For a remote binder, this will always return null.
+ *
+ * \param binder the object that is being queried.
+ *
+ * \return the userdata returned from AIBinder_onCreate when this object was created. This may be
+ * null for stateless objects. For remote objects, this is always null.
  */
 void* AIBinder_getUserData(AIBinder* binder) __INTRODUCED_IN(29);
 
@@ -278,6 +350,12 @@
  * ownership is passed to the caller. At this point, the parcel can be filled out and passed to
  * AIBinder_transact. Alternatively, if there is an error while filling out the parcel, it can be
  * deleted with AParcel_delete.
+ *
+ * \param binder the binder object to start a transaction on.
+ * \param in out parameter for input data to the transaction.
+ *
+ * \return STATUS_OK on success. This will return STATUS_INVALID_OPERATION if the binder has not yet
+ * been associated with a class (see AIBinder_new and AIBinder_associateClass).
  */
 binder_status_t AIBinder_prepareTransaction(AIBinder* binder, AParcel** in) __INTRODUCED_IN(29);
 
@@ -292,6 +370,16 @@
  *
  * This does not affect the ownership of binder. The out parcel's ownership is passed to the caller
  * and must be released with AParcel_delete when finished reading.
+ *
+ * \param binder the binder object to transact on.
+ * \param code the implementation-specific code representing which transaction should be taken.
+ * \param in the implementation-specific input data to this transaction.
+ * \param out the implementation-specific output data to this transaction.
+ * \param flags possible flags to alter the way in which the transaction is conducted or 0.
+ *
+ * \return the result from the kernel or from the remote process. Usually, implementation-specific
+ * error codes are written to the output parcel, and the transaction code is reserved for kernel
+ * errors or error codes that have been repeated from subsequent transactions.
  */
 binder_status_t AIBinder_transact(AIBinder* binder, transaction_code_t code, AParcel** in,
                                   AParcel** out, binder_flags_t flags) __INTRODUCED_IN(29);
@@ -299,29 +387,45 @@
 /**
  * This does not take any ownership of the input binder, but it can be used to retrieve it if
  * something else in some process still holds a reference to it.
+ *
+ * \param binder object to create a weak pointer to.
+ *
+ * \return object representing a weak pointer to binder (or null if binder is null).
  */
 __attribute__((warn_unused_result)) AIBinder_Weak* AIBinder_Weak_new(AIBinder* binder)
         __INTRODUCED_IN(29);
 
 /**
  * Deletes the weak reference. This will have no impact on the lifetime of the binder.
+ *
+ * \param weakBinder object created with AIBinder_Weak_new.
  */
 void AIBinder_Weak_delete(AIBinder_Weak* weakBinder) __INTRODUCED_IN(29);
 
 /**
  * If promotion succeeds, result will have one strong refcount added to it. Otherwise, this returns
- * nullptr.
+ * null.
+ *
+ * \param weakBinder weak pointer to attempt retrieving the original object from.
+ *
+ * \return an AIBinder object with one refcount given to the caller or null.
  */
 __attribute__((warn_unused_result)) AIBinder* AIBinder_Weak_promote(AIBinder_Weak* weakBinder)
         __INTRODUCED_IN(29);
 
 /**
  * This function is executed on death receipt. See AIBinder_linkToDeath/AIBinder_unlinkToDeath.
+ *
+ * \param cookie the cookie passed to AIBinder_linkToDeath.
  */
 typedef void (*AIBinder_DeathRecipient_onBinderDied)(void* cookie) __INTRODUCED_IN(29);
 
 /**
  * Creates a new binder death recipient. This can be attached to multiple different binder objects.
+ *
+ * \param onBinderDied the callback to call when this death recipient is invoked.
+ *
+ * \return the newly constructed object (or null if onBinderDied is null).
  */
 __attribute__((warn_unused_result)) AIBinder_DeathRecipient* AIBinder_DeathRecipient_new(
         AIBinder_DeathRecipient_onBinderDied onBinderDied) __INTRODUCED_IN(29);
@@ -329,10 +433,12 @@
 /**
  * Deletes a binder death recipient. It is not necessary to call AIBinder_unlinkToDeath before
  * calling this as these will all be automatically unlinked.
+ *
+ * \param recipient the binder to delete (previously created with AIBinder_DeathRecipient_new).
  */
 void AIBinder_DeathRecipient_delete(AIBinder_DeathRecipient* recipient) __INTRODUCED_IN(29);
 
-#endif //__ANDROID_API__ >= __ANDROID_API_Q__
+#endif  //__ANDROID_API__ >= __ANDROID_API_Q__
 __END_DECLS
 
 /** @} */
diff --git a/libs/binder/ndk/include_ndk/android/binder_ibinder_jni.h b/libs/binder/ndk/include_ndk/android/binder_ibinder_jni.h
index 81fb3c5..124f36c 100644
--- a/libs/binder/ndk/include_ndk/android/binder_ibinder_jni.h
+++ b/libs/binder/ndk/include_ndk/android/binder_ibinder_jni.h
@@ -39,6 +39,12 @@
  * If either env or the binder is null, null is returned. If this binder object was originally an
  * AIBinder object, the original object is returned. The returned object has one refcount
  * associated with it, and so this should be accompanied with an AIBinder_decStrong call.
+ *
+ * \param env Java environment.
+ * \param binder android.os.IBinder java object.
+ *
+ * \return an AIBinder object representing the Java binder object. If either parameter is null, or
+ * the Java object is of the wrong type, this will return null.
  */
 __attribute__((warn_unused_result)) AIBinder* AIBinder_fromJavaBinder(JNIEnv* env, jobject binder)
         __INTRODUCED_IN(29);
@@ -48,11 +54,16 @@
  *
  * If either env or the binder is null, null is returned. If this binder object was originally an
  * IBinder object, the original java object will be returned.
+ *
+ * \param env Java environment.
+ * \param binder the object to convert.
+ *
+ * \return an android.os.IBinder object or null if the parameters were null.
  */
 __attribute__((warn_unused_result)) jobject AIBinder_toJavaBinder(JNIEnv* env, AIBinder* binder)
         __INTRODUCED_IN(29);
 
-#endif //__ANDROID_API__ >= __ANDROID_API_Q__
+#endif  //__ANDROID_API__ >= __ANDROID_API_Q__
 __END_DECLS
 
 /** @} */
diff --git a/libs/binder/ndk/include_ndk/android/binder_interface_utils.h b/libs/binder/ndk/include_ndk/android/binder_interface_utils.h
index e37c388..1532725 100644
--- a/libs/binder/ndk/include_ndk/android/binder_interface_utils.h
+++ b/libs/binder/ndk/include_ndk/android/binder_interface_utils.h
@@ -32,8 +32,6 @@
 
 #include <assert.h>
 
-#ifdef __cplusplus
-
 #include <memory>
 #include <mutex>
 
@@ -46,7 +44,7 @@
  * construct this object is with SharedRefBase::make.
  */
 class SharedRefBase {
-public:
+   public:
     SharedRefBase() {}
     virtual ~SharedRefBase() {
         std::call_once(mFlagThis, [&]() {
@@ -83,7 +81,7 @@
         return t->template ref<T>();
     }
 
-private:
+   private:
     std::once_flag mFlagThis;
     std::weak_ptr<SharedRefBase> mThis;
 };
@@ -92,7 +90,7 @@
  * wrapper analog to IInterface
  */
 class ICInterface : public SharedRefBase {
-public:
+   public:
     ICInterface() {}
     virtual ~ICInterface() {}
 
@@ -113,7 +111,7 @@
  */
 template <typename INTERFACE>
 class BnCInterface : public INTERFACE {
-public:
+   public:
     BnCInterface() {}
     virtual ~BnCInterface() {}
 
@@ -121,15 +119,15 @@
 
     bool isRemote() override { return true; }
 
-protected:
+   protected:
     /**
      * This function should only be called by asBinder. Otherwise, there is a possibility of
      * multiple AIBinder* objects being created for the same instance of an object.
      */
     virtual SpAIBinder createBinder() = 0;
 
-private:
-    std::mutex mMutex; // for asBinder
+   private:
+    std::mutex mMutex;  // for asBinder
     ScopedAIBinder_Weak mWeakBinder;
 };
 
@@ -138,7 +136,7 @@
  */
 template <typename INTERFACE>
 class BpCInterface : public INTERFACE {
-public:
+   public:
     BpCInterface(const SpAIBinder& binder) : mBinder(binder) {}
     virtual ~BpCInterface() {}
 
@@ -146,7 +144,7 @@
 
     bool isRemote() override { return AIBinder_isRemote(mBinder.get()); }
 
-private:
+   private:
     SpAIBinder mBinder;
 };
 
@@ -171,8 +169,6 @@
     return mBinder;
 }
 
-} // namespace ndk
-
-#endif // __cplusplus
+}  // namespace ndk
 
 /** @} */
diff --git a/libs/binder/ndk/include_ndk/android/binder_parcel.h b/libs/binder/ndk/include_ndk/android/binder_parcel.h
index a303f4a..a5842f7 100644
--- a/libs/binder/ndk/include_ndk/android/binder_parcel.h
+++ b/libs/binder/ndk/include_ndk/android/binder_parcel.h
@@ -47,6 +47,9 @@
 
 /**
  * Cleans up a parcel.
+ *
+ * \param parcel A parcel returned by AIBinder_prepareTransaction or AIBinder_transact when a
+ * transaction is being aborted.
  */
 void AParcel_delete(AParcel* parcel) __INTRODUCED_IN(29);
 
@@ -59,6 +62,11 @@
  * See also AParcel_readString.
  *
  * If allocation fails, null should be returned.
+ *
+ * \param stringData some external representation of a string
+ * \param length the length of the buffer needed to fill (including the null-terminator)
+ *
+ * \return a buffer of size 'length' or null if allocation failed.
  */
 typedef char* (*AParcel_stringAllocator)(void* stringData, size_t length);
 
@@ -66,6 +74,11 @@
  * This is called to allocate an array of size 'length'.
  *
  * See also AParcel_readStringArray
+ *
+ * \param arrayData some external representation of an array
+ * \param length the length to allocate this array to
+ *
+ * \return true if allocation succeeded
  */
 typedef bool (*AParcel_stringArrayAllocator)(void* arrayData, size_t length);
 
@@ -79,6 +92,13 @@
  * greater than 0.
  *
  * See also AParcel_readStringArray
+ *
+ * \param arrayData some external representation of an array.
+ * \param index the index at which a string should be allocated.
+ * \param length the length of the string to be allocated at this index. See also
+ * AParcel_stringAllocator. This includes the length required for a null-terminator.
+ *
+ * \return a buffer of size 'length' or null if allocation failed.
  */
 typedef char* (*AParcel_stringArrayElementAllocator)(void* arrayData, size_t index, size_t length);
 
@@ -86,6 +106,14 @@
  * This returns the length and buffer of an array at a specific index in an arrayData object.
  *
  * See also AParcel_writeStringArray
+ *
+ * \param arrayData some external representation of an array.
+ * \param index the index at which a string should be allocated.
+ * \param outLength an out parameter for the length of the string (not including the
+ * null-terminator)
+ *
+ * \param a null-terminated buffer of size 'outLength + 1' representing the string at the provided
+ * index including the null-terminator.
  */
 typedef const char* (*AParcel_stringArrayElementGetter)(const void* arrayData, size_t index,
                                                         size_t* outLength);
@@ -99,6 +127,11 @@
  * returned.
  *
  * See also AParcel_readInt32Array
+ *
+ * \param arrayData some external representation of an array of int32_t.
+ * \param length the length to allocate arrayData to.
+ *
+ * \return a buffer of int32_t of size 'length'.
  */
 typedef int32_t* (*AParcel_int32ArrayAllocator)(void* arrayData, size_t length);
 
@@ -110,6 +143,11 @@
  * returned.
  *
  * See also AParcel_readUint32Array
+ *
+ * \param arrayData some external representation of an array of uint32_t.
+ * \param length the length to allocate arrayData to.
+ *
+ * \return a buffer of uint32_t of size 'length'.
  */
 typedef uint32_t* (*AParcel_uint32ArrayAllocator)(void* arrayData, size_t length);
 
@@ -121,6 +159,11 @@
  * returned.
  *
  * See also AParcel_readInt64Array
+ *
+ * \param arrayData some external representation of an array of int64_t.
+ * \param length the length to allocate arrayData to.
+ *
+ * \return a buffer of int64_t of size 'length'.
  */
 typedef int64_t* (*AParcel_int64ArrayAllocator)(void* arrayData, size_t length);
 
@@ -132,6 +175,11 @@
  * returned.
  *
  * See also AParcel_readUint64Array
+ *
+ * \param arrayData some external representation of an array of uint64_t.
+ * \param length the length to allocate arrayData to.
+ *
+ * \return a buffer of uint64_t of size 'length'.
  */
 typedef uint64_t* (*AParcel_uint64ArrayAllocator)(void* arrayData, size_t length);
 
@@ -143,6 +191,11 @@
  * returned.
  *
  * See also AParcel_readFloatArray
+ *
+ * \param arrayData some external representation of an array of float.
+ * \param length the length to allocate arrayData to.
+ *
+ * \return a buffer of float of size 'length'.
  */
 typedef float* (*AParcel_floatArrayAllocator)(void* arrayData, size_t length);
 
@@ -154,6 +207,11 @@
  * returned.
  *
  * See also AParcel_readDoubleArray
+ *
+ * \param arrayData some external representation of an array of double.
+ * \param length the length to allocate arrayData to.
+ *
+ * \return a buffer of double of size 'length'.
  */
 typedef double* (*AParcel_doubleArrayAllocator)(void* arrayData, size_t length);
 
@@ -162,6 +220,11 @@
  * a success.
  *
  * See also AParcel_readBoolArray
+ *
+ * \param arrayData some external representation of an array of bool.
+ * \param length the length to allocate arrayData to.
+ *
+ * \return whether the allocation succeeded.
  */
 typedef bool (*AParcel_boolArrayAllocator)(void* arrayData, size_t length);
 
@@ -169,6 +232,11 @@
  * This is called to get the underlying data from an arrayData object at index.
  *
  * See also AParcel_writeBoolArray
+ *
+ * \param arrayData some external representation of an array of bool.
+ * \param index the index of the value to be retrieved.
+ *
+ * \return the value of the array at index index.
  */
 typedef bool (*AParcel_boolArrayGetter)(const void* arrayData, size_t index);
 
@@ -176,6 +244,10 @@
  * This is called to set an underlying value in an arrayData object at index.
  *
  * See also AParcel_readBoolArray
+ *
+ * \param arrayData some external representation of an array of bool.
+ * \param index the index of the value to be set.
+ * \param value the value to set at index index.
  */
 typedef void (*AParcel_boolArraySetter)(void* arrayData, size_t index, bool value);
 
@@ -187,6 +259,11 @@
  * returned.
  *
  * See also AParcel_readCharArray
+ *
+ * \param arrayData some external representation of an array of char16_t.
+ * \param length the length to allocate arrayData to.
+ *
+ * \return a buffer of char16_t of size 'length'.
  */
 typedef char16_t* (*AParcel_charArrayAllocator)(void* arrayData, size_t length);
 
@@ -198,19 +275,36 @@
  * returned.
  *
  * See also AParcel_readByteArray
+ *
+ * \param arrayData some external representation of an array of int8_t.
+ * \param length the length to allocate arrayData to.
+ *
+ * \return a buffer of int8_t of size 'length'.
  */
 typedef int8_t* (*AParcel_byteArrayAllocator)(void* arrayData, size_t length);
 
 // @END-PRIMITIVE-VECTOR-GETTERS
 
 /**
- * Writes an AIBinder to the next location in a non-null parcel. Can be null.
+ * Writes an AIBinder to the next location in a non-null parcel. Can be null. This does not take any
+ * refcounts of ownership of the binder from the client.
+ *
+ * \param parcel the parcel to write to.
+ * \param binder the value to write to the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeStrongBinder(AParcel* parcel, AIBinder* binder) __INTRODUCED_IN(29);
 
 /**
  * Reads an AIBinder from the next location in a non-null parcel. This will fail if the binder is
  * non-null. One strong ref-count of ownership is passed to the caller of this function.
+ *
+ * \param parcel the parcel to read from.
+ * \param binder the out parameter for what is read from the parcel. This will not be null on
+ * success.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_readStrongBinder(const AParcel* parcel, AIBinder** binder)
         __INTRODUCED_IN(29);
@@ -218,6 +312,12 @@
 /**
  * Reads an AIBinder from the next location in a non-null parcel. This may read a null. One strong
  * ref-count of ownership is passed to the caller of this function.
+ *
+ * \param parcel the parcel to read from.
+ * \param binder the out parameter for what is read from the parcel. This may be null even on
+ * success.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_readNullableStrongBinder(const AParcel* parcel, AIBinder** binder)
         __INTRODUCED_IN(29);
@@ -227,6 +327,11 @@
  * of fd.
  *
  * This corresponds to the SDK's android.os.ParcelFileDescriptor.
+ *
+ * \param parcel the parcel to write to.
+ * \param fd the value to write to the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeParcelFileDescriptor(AParcel* parcel, int fd);
 
@@ -236,6 +341,11 @@
  * The returned fd must be closed.
  *
  * This corresponds to the SDK's android.os.ParcelFileDescriptor.
+ *
+ * \param parcel the parcel to read from.
+ * \param binder the out parameter for what is read from the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_readParcelFileDescriptor(const AParcel* parcel, int* fd);
 
@@ -247,6 +357,11 @@
  * status will be returned from this method and nothing will be written to the parcel. If either
  * this happens or if writing the status object itself fails, the return value from this function
  * should be propagated to the client, and AParcel_readStatusHeader shouldn't be called.
+ *
+ * \param parcel the parcel to write to.
+ * \param status the value to write to the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeStatusHeader(AParcel* parcel, const AStatus* status)
         __INTRODUCED_IN(29);
@@ -254,12 +369,24 @@
 /**
  * Reads an AStatus from the next location in a non-null parcel. Ownership is passed to the caller
  * of this function.
+ *
+ * \param parcel the parcel to read from.
+ * \param status the out parameter for what is read from the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_readStatusHeader(const AParcel* parcel, AStatus** status)
         __INTRODUCED_IN(29);
 
 /**
  * Writes utf-8 string value to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param string the null-terminated string to write to the parcel. The buffer including the null
+ * terminator should be of size 'length' + 1.
+ * \param length the length of the string to be written.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeString(AParcel* parcel, const char* string, size_t length)
         __INTRODUCED_IN(29);
@@ -270,6 +397,12 @@
  * Data is passed to the string allocator once the string size is known. This size includes the
  * space for the null-terminator of this string. This allocator returns a buffer which is used as
  * the output buffer from this read.
+ *
+ * \param parcel the parcel to read from.
+ * \param stringData some external representation of a string.
+ * \param allocator allocator that will be called once the size of the string is known.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_readString(const AParcel* parcel, void* stringData,
                                    AParcel_stringAllocator allocator) __INTRODUCED_IN(29);
@@ -280,6 +413,14 @@
  * length is the length of the array. AParcel_stringArrayElementGetter will be called for all
  * indices in range [0, length) with the arrayData provided here. The string length and buffer
  * returned from this function will be used to fill out the data from the parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param arrayData some external representation of an array.
+ * \param length the length of the array to be written.
+ * \param getter the callback that will be called for every index of the array to retrieve the
+ * corresponding string buffer.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeStringArray(AParcel* parcel, const void* arrayData, size_t length,
                                          AParcel_stringArrayElementGetter getter)
@@ -293,6 +434,15 @@
  * length), AParcel_stringArrayElementAllocator will be called with the length of the string to be
  * read from the parcel. The resultant buffer from each of these calls will be filled according to
  * the contents of the string that is read.
+ *
+ * \param parcel the parcel to read from.
+ * \param arrayData some external representation of an array.
+ * \param allocator the callback that will be called with arrayData once the size of the output
+ * array is known.
+ * \param elementAllocator the callback that will be called on every index of arrayData to allocate
+ * the string at that location.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readStringArray(const AParcel* parcel, void* arrayData,
                                         AParcel_stringArrayAllocator allocator,
@@ -302,128 +452,254 @@
 // @START-PRIMITIVE-READ-WRITE
 /**
  * Writes int32_t value to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param value the value to write to the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeInt32(AParcel* parcel, int32_t value) __INTRODUCED_IN(29);
 
 /**
  * Writes uint32_t value to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param value the value to write to the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeUint32(AParcel* parcel, uint32_t value) __INTRODUCED_IN(29);
 
 /**
  * Writes int64_t value to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param value the value to write to the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeInt64(AParcel* parcel, int64_t value) __INTRODUCED_IN(29);
 
 /**
  * Writes uint64_t value to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param value the value to write to the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeUint64(AParcel* parcel, uint64_t value) __INTRODUCED_IN(29);
 
 /**
  * Writes float value to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param value the value to write to the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeFloat(AParcel* parcel, float value) __INTRODUCED_IN(29);
 
 /**
  * Writes double value to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param value the value to write to the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeDouble(AParcel* parcel, double value) __INTRODUCED_IN(29);
 
 /**
  * Writes bool value to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param value the value to write to the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeBool(AParcel* parcel, bool value) __INTRODUCED_IN(29);
 
 /**
  * Writes char16_t value to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param value the value to write to the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeChar(AParcel* parcel, char16_t value) __INTRODUCED_IN(29);
 
 /**
  * Writes int8_t value to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param value the value to write to the parcel.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeByte(AParcel* parcel, int8_t value) __INTRODUCED_IN(29);
 
 /**
  * Reads into int32_t value from the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to read from.
+ * \param value the value to read from the parcel.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readInt32(const AParcel* parcel, int32_t* value) __INTRODUCED_IN(29);
 
 /**
  * Reads into uint32_t value from the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to read from.
+ * \param value the value to read from the parcel.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readUint32(const AParcel* parcel, uint32_t* value) __INTRODUCED_IN(29);
 
 /**
  * Reads into int64_t value from the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to read from.
+ * \param value the value to read from the parcel.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readInt64(const AParcel* parcel, int64_t* value) __INTRODUCED_IN(29);
 
 /**
  * Reads into uint64_t value from the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to read from.
+ * \param value the value to read from the parcel.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readUint64(const AParcel* parcel, uint64_t* value) __INTRODUCED_IN(29);
 
 /**
  * Reads into float value from the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to read from.
+ * \param value the value to read from the parcel.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readFloat(const AParcel* parcel, float* value) __INTRODUCED_IN(29);
 
 /**
  * Reads into double value from the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to read from.
+ * \param value the value to read from the parcel.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readDouble(const AParcel* parcel, double* value) __INTRODUCED_IN(29);
 
 /**
  * Reads into bool value from the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to read from.
+ * \param value the value to read from the parcel.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readBool(const AParcel* parcel, bool* value) __INTRODUCED_IN(29);
 
 /**
  * Reads into char16_t value from the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to read from.
+ * \param value the value to read from the parcel.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readChar(const AParcel* parcel, char16_t* value) __INTRODUCED_IN(29);
 
 /**
  * Reads into int8_t value from the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to read from.
+ * \param value the value to read from the parcel.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readByte(const AParcel* parcel, int8_t* value) __INTRODUCED_IN(29);
 
 /**
  * Writes an array of int32_t to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param arrayData an array of size 'length'.
+ * \param length the length of arrayData.
+ *
+ * \return STATUS_OK on successful write.
  */
-binder_status_t AParcel_writeInt32Array(AParcel* parcel, const int32_t* value, size_t length)
+binder_status_t AParcel_writeInt32Array(AParcel* parcel, const int32_t* arrayData, size_t length)
         __INTRODUCED_IN(29);
 
 /**
  * Writes an array of uint32_t to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param arrayData an array of size 'length'.
+ * \param length the length of arrayData.
+ *
+ * \return STATUS_OK on successful write.
  */
-binder_status_t AParcel_writeUint32Array(AParcel* parcel, const uint32_t* value, size_t length)
+binder_status_t AParcel_writeUint32Array(AParcel* parcel, const uint32_t* arrayData, size_t length)
         __INTRODUCED_IN(29);
 
 /**
  * Writes an array of int64_t to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param arrayData an array of size 'length'.
+ * \param length the length of arrayData.
+ *
+ * \return STATUS_OK on successful write.
  */
-binder_status_t AParcel_writeInt64Array(AParcel* parcel, const int64_t* value, size_t length)
+binder_status_t AParcel_writeInt64Array(AParcel* parcel, const int64_t* arrayData, size_t length)
         __INTRODUCED_IN(29);
 
 /**
  * Writes an array of uint64_t to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param arrayData an array of size 'length'.
+ * \param length the length of arrayData.
+ *
+ * \return STATUS_OK on successful write.
  */
-binder_status_t AParcel_writeUint64Array(AParcel* parcel, const uint64_t* value, size_t length)
+binder_status_t AParcel_writeUint64Array(AParcel* parcel, const uint64_t* arrayData, size_t length)
         __INTRODUCED_IN(29);
 
 /**
  * Writes an array of float to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param arrayData an array of size 'length'.
+ * \param length the length of arrayData.
+ *
+ * \return STATUS_OK on successful write.
  */
-binder_status_t AParcel_writeFloatArray(AParcel* parcel, const float* value, size_t length)
+binder_status_t AParcel_writeFloatArray(AParcel* parcel, const float* arrayData, size_t length)
         __INTRODUCED_IN(29);
 
 /**
  * Writes an array of double to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param arrayData an array of size 'length'.
+ * \param length the length of arrayData.
+ *
+ * \return STATUS_OK on successful write.
  */
-binder_status_t AParcel_writeDoubleArray(AParcel* parcel, const double* value, size_t length)
+binder_status_t AParcel_writeDoubleArray(AParcel* parcel, const double* arrayData, size_t length)
         __INTRODUCED_IN(29);
 
 /**
@@ -431,20 +707,39 @@
  *
  * getter(arrayData, i) will be called for each i in [0, length) in order to get the underlying
  * values to write to the parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param arrayData some external representation of an array.
+ * \param length the length of arrayData.
+ * \param getter the callback to retrieve data at specific locations in the array.
+ *
+ * \return STATUS_OK on successful write.
  */
 binder_status_t AParcel_writeBoolArray(AParcel* parcel, const void* arrayData, size_t length,
                                        AParcel_boolArrayGetter getter) __INTRODUCED_IN(29);
 
 /**
  * Writes an array of char16_t to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param arrayData an array of size 'length'.
+ * \param length the length of arrayData.
+ *
+ * \return STATUS_OK on successful write.
  */
-binder_status_t AParcel_writeCharArray(AParcel* parcel, const char16_t* value, size_t length)
+binder_status_t AParcel_writeCharArray(AParcel* parcel, const char16_t* arrayData, size_t length)
         __INTRODUCED_IN(29);
 
 /**
  * Writes an array of int8_t to the next location in a non-null parcel.
+ *
+ * \param parcel the parcel to write to.
+ * \param arrayData an array of size 'length'.
+ * \param length the length of arrayData.
+ *
+ * \return STATUS_OK on successful write.
  */
-binder_status_t AParcel_writeByteArray(AParcel* parcel, const int8_t* value, size_t length)
+binder_status_t AParcel_writeByteArray(AParcel* parcel, const int8_t* arrayData, size_t length)
         __INTRODUCED_IN(29);
 
 /**
@@ -453,6 +748,12 @@
  * First, allocator will be called with the length of the array. If the allocation succeeds and the
  * length is greater than zero, the buffer returned by the allocator will be filled with the
  * corresponding data
+ *
+ * \param parcel the parcel to read from.
+ * \param arrayData some external representation of an array.
+ * \param allocator the callback that will be called to allocate the array.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readInt32Array(const AParcel* parcel, void* arrayData,
                                        AParcel_int32ArrayAllocator allocator) __INTRODUCED_IN(29);
@@ -463,6 +764,12 @@
  * First, allocator will be called with the length of the array. If the allocation succeeds and the
  * length is greater than zero, the buffer returned by the allocator will be filled with the
  * corresponding data
+ *
+ * \param parcel the parcel to read from.
+ * \param arrayData some external representation of an array.
+ * \param allocator the callback that will be called to allocate the array.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readUint32Array(const AParcel* parcel, void* arrayData,
                                         AParcel_uint32ArrayAllocator allocator) __INTRODUCED_IN(29);
@@ -473,6 +780,12 @@
  * First, allocator will be called with the length of the array. If the allocation succeeds and the
  * length is greater than zero, the buffer returned by the allocator will be filled with the
  * corresponding data
+ *
+ * \param parcel the parcel to read from.
+ * \param arrayData some external representation of an array.
+ * \param allocator the callback that will be called to allocate the array.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readInt64Array(const AParcel* parcel, void* arrayData,
                                        AParcel_int64ArrayAllocator allocator) __INTRODUCED_IN(29);
@@ -483,6 +796,12 @@
  * First, allocator will be called with the length of the array. If the allocation succeeds and the
  * length is greater than zero, the buffer returned by the allocator will be filled with the
  * corresponding data
+ *
+ * \param parcel the parcel to read from.
+ * \param arrayData some external representation of an array.
+ * \param allocator the callback that will be called to allocate the array.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readUint64Array(const AParcel* parcel, void* arrayData,
                                         AParcel_uint64ArrayAllocator allocator) __INTRODUCED_IN(29);
@@ -493,6 +812,12 @@
  * First, allocator will be called with the length of the array. If the allocation succeeds and the
  * length is greater than zero, the buffer returned by the allocator will be filled with the
  * corresponding data
+ *
+ * \param parcel the parcel to read from.
+ * \param arrayData some external representation of an array.
+ * \param allocator the callback that will be called to allocate the array.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readFloatArray(const AParcel* parcel, void* arrayData,
                                        AParcel_floatArrayAllocator allocator) __INTRODUCED_IN(29);
@@ -503,6 +828,12 @@
  * First, allocator will be called with the length of the array. If the allocation succeeds and the
  * length is greater than zero, the buffer returned by the allocator will be filled with the
  * corresponding data
+ *
+ * \param parcel the parcel to read from.
+ * \param arrayData some external representation of an array.
+ * \param allocator the callback that will be called to allocate the array.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readDoubleArray(const AParcel* parcel, void* arrayData,
                                         AParcel_doubleArrayAllocator allocator) __INTRODUCED_IN(29);
@@ -512,6 +843,14 @@
  *
  * First, allocator will be called with the length of the array. Then, for every i in [0, length),
  * setter(arrayData, i, x) will be called where x is the value at the associated index.
+ *
+ * \param parcel the parcel to read from.
+ * \param arrayData some external representation of an array.
+ * \param allocator the callback that will be called to allocate the array.
+ * \param setter the callback that will be called to set a value at a specific location in the
+ * array.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readBoolArray(const AParcel* parcel, void* arrayData,
                                       AParcel_boolArrayAllocator allocator,
@@ -523,6 +862,12 @@
  * First, allocator will be called with the length of the array. If the allocation succeeds and the
  * length is greater than zero, the buffer returned by the allocator will be filled with the
  * corresponding data
+ *
+ * \param parcel the parcel to read from.
+ * \param arrayData some external representation of an array.
+ * \param allocator the callback that will be called to allocate the array.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readCharArray(const AParcel* parcel, void* arrayData,
                                       AParcel_charArrayAllocator allocator) __INTRODUCED_IN(29);
@@ -533,13 +878,19 @@
  * First, allocator will be called with the length of the array. If the allocation succeeds and the
  * length is greater than zero, the buffer returned by the allocator will be filled with the
  * corresponding data
+ *
+ * \param parcel the parcel to read from.
+ * \param arrayData some external representation of an array.
+ * \param allocator the callback that will be called to allocate the array.
+ *
+ * \return STATUS_OK on successful read.
  */
 binder_status_t AParcel_readByteArray(const AParcel* parcel, void* arrayData,
                                       AParcel_byteArrayAllocator allocator) __INTRODUCED_IN(29);
 
 // @END-PRIMITIVE-READ-WRITE
 
-#endif //__ANDROID_API__ >= __ANDROID_API_Q__
+#endif  //__ANDROID_API__ >= __ANDROID_API_Q__
 __END_DECLS
 
 /** @} */
diff --git a/libs/binder/ndk/include_ndk/android/binder_parcel_utils.h b/libs/binder/ndk/include_ndk/android/binder_parcel_utils.h
index 3fcb121..2ccbe5a 100644
--- a/libs/binder/ndk/include_ndk/android/binder_parcel_utils.h
+++ b/libs/binder/ndk/include_ndk/android/binder_parcel_utils.h
@@ -28,8 +28,6 @@
 
 #include <android/binder_parcel.h>
 
-#ifdef __cplusplus
-
 #include <string>
 #include <vector>
 
@@ -298,6 +296,9 @@
                                    AParcel_stdVectorStringElementAllocator);
 }
 
+/**
+ * Convenience API for writing the size of a vector.
+ */
 template <typename T>
 static inline binder_status_t AParcel_writeVectorSize(AParcel* parcel, const std::vector<T>& vec) {
     if (vec.size() > INT32_MAX) {
@@ -307,6 +308,9 @@
     return AParcel_writeInt32(parcel, static_cast<int32_t>(vec.size()));
 }
 
+/**
+ * Convenience API for resizing a vector.
+ */
 template <typename T>
 static inline binder_status_t AParcel_resizeVector(const AParcel* parcel, std::vector<T>* vec) {
     int32_t size;
@@ -319,8 +323,6 @@
     return STATUS_OK;
 }
 
-} // namespace ndk
-
-#endif // __cplusplus
+}  // namespace ndk
 
 /** @} */
diff --git a/libs/binder/ndk/include_ndk/android/binder_status.h b/libs/binder/ndk/include_ndk/android/binder_status.h
index 2d8b7fa..2671b9b 100644
--- a/libs/binder/ndk/include_ndk/android/binder_status.h
+++ b/libs/binder/ndk/include_ndk/android/binder_status.h
@@ -35,7 +35,7 @@
 enum {
     STATUS_OK = 0,
 
-    STATUS_UNKNOWN_ERROR = (-2147483647 - 1), // INT32_MIN value
+    STATUS_UNKNOWN_ERROR = (-2147483647 - 1),  // INT32_MIN value
     STATUS_NO_MEMORY = -ENOMEM,
     STATUS_INVALID_OPERATION = -ENOSYS,
     STATUS_BAD_VALUE = -EINVAL,
@@ -95,24 +95,39 @@
  * along with service specific errors.
  *
  * It is not required to be used in order to parcel/receive transactions, but it is required in
- * order to be compatible with standard AIDL transactions.
+ * order to be compatible with standard AIDL transactions since it is written as the header to the
+ * out parcel for transactions which get executed (don't fail during unparceling of input arguments
+ * or sooner).
  */
 struct AStatus;
 typedef struct AStatus AStatus;
 
 /**
  * New status which is considered a success.
+ *
+ * \return a newly constructed status object that the caller owns.
  */
 __attribute__((warn_unused_result)) AStatus* AStatus_newOk() __INTRODUCED_IN(29);
 
 /**
  * New status with exception code.
+ *
+ * \param exception the code that this status should represent. If this is EX_NONE, then this
+ * constructs an non-error status object.
+ *
+ * \return a newly constructed status object that the caller owns.
  */
 __attribute__((warn_unused_result)) AStatus* AStatus_fromExceptionCode(binder_exception_t exception)
         __INTRODUCED_IN(29);
 
 /**
  * New status with exception code and message.
+ *
+ * \param exception the code that this status should represent. If this is EX_NONE, then this
+ * constructs an non-error status object.
+ * \param message the error message to associate with this status object.
+ *
+ * \return a newly constructed status object that the caller owns.
  */
 __attribute__((warn_unused_result)) AStatus* AStatus_fromExceptionCodeWithMessage(
         binder_exception_t exception, const char* message) __INTRODUCED_IN(29);
@@ -121,6 +136,10 @@
  * New status with a service speciic error.
  *
  * This is considered to be EX_TRANSACTION_FAILED with extra information.
+ *
+ * \param serviceSpecific an implementation defined error code.
+ *
+ * \return a newly constructed status object that the caller owns.
  */
 __attribute__((warn_unused_result)) AStatus* AStatus_fromServiceSpecificError(
         int32_t serviceSpecific) __INTRODUCED_IN(29);
@@ -129,6 +148,11 @@
  * New status with a service specific error and message.
  *
  * This is considered to be EX_TRANSACTION_FAILED with extra information.
+ *
+ * \param serviceSpecific an implementation defined error code.
+ * \param message the error message to associate with this status object.
+ *
+ * \return a newly constructed status object that the caller owns.
  */
 __attribute__((warn_unused_result)) AStatus* AStatus_fromServiceSpecificErrorWithMessage(
         int32_t serviceSpecific, const char* message) __INTRODUCED_IN(29);
@@ -137,6 +161,10 @@
  * New status with binder_status_t. This is typically for low level failures when a binder_status_t
  * is returned by an API on AIBinder or AParcel, and that is to be returned from a method returning
  * an AStatus instance.
+ *
+ * \param a low-level error to associate with this status object.
+ *
+ * \return a newly constructed status object that the caller owns.
  */
 __attribute__((warn_unused_result)) AStatus* AStatus_fromStatus(binder_status_t status)
         __INTRODUCED_IN(29);
@@ -144,11 +172,19 @@
 /**
  * Whether this object represents a successful transaction. If this function returns true, then
  * AStatus_getExceptionCode will return EX_NONE.
+ *
+ * \param status the status being queried.
+ *
+ * \return whether the status represents a successful transaction. For more details, see below.
  */
 bool AStatus_isOk(const AStatus* status) __INTRODUCED_IN(29);
 
 /**
  * The exception that this status object represents.
+ *
+ * \param status the status being queried.
+ *
+ * \return the exception code that this object represents.
  */
 binder_exception_t AStatus_getExceptionCode(const AStatus* status) __INTRODUCED_IN(29);
 
@@ -157,6 +193,10 @@
  * non-zero result if AStatus_getExceptionCode returns EX_SERVICE_SPECIFIC. If this function returns
  * 0, the status object may still represent a different exception or status. To find out if this
  * transaction as a whole is okay, use AStatus_isOk instead.
+ *
+ * \param status the status being queried.
+ *
+ * \return the service-specific error code if the exception code is EX_SERVICE_SPECIFIC or 0.
  */
 int32_t AStatus_getServiceSpecificError(const AStatus* status) __INTRODUCED_IN(29);
 
@@ -165,6 +205,10 @@
  * if AStatus_getExceptionCode returns EX_TRANSACTION_FAILED. If this function return 0, the status
  * object may represent a different exception or a service specific error. To find out if this
  * transaction as a whole is okay, use AStatus_isOk instead.
+ *
+ * \param status the status being queried.
+ *
+ * \return the status code if the exception code is EX_TRANSACTION_FAILED or 0.
  */
 binder_status_t AStatus_getStatus(const AStatus* status) __INTRODUCED_IN(29);
 
@@ -173,15 +217,21 @@
  * message, this will return an empty string.
  *
  * The returned string has the lifetime of the status object passed into this function.
+ *
+ * \param status the status being queried.
+ *
+ * \return the message associated with this error.
  */
 const char* AStatus_getMessage(const AStatus* status) __INTRODUCED_IN(29);
 
 /**
  * Deletes memory associated with the status instance.
+ *
+ * \param status the status to delete, returned from AStatus_newOk or one of the AStatus_from* APIs.
  */
 void AStatus_delete(AStatus* status) __INTRODUCED_IN(29);
 
-#endif //__ANDROID_API__ >= __ANDROID_API_Q__
+#endif  //__ANDROID_API__ >= __ANDROID_API_Q__
 __END_DECLS
 
 /** @} */
diff --git a/libs/binder/ndk/parcel.cpp b/libs/binder/ndk/parcel.cpp
index 3b44a62..8e5b477 100644
--- a/libs/binder/ndk/parcel.cpp
+++ b/libs/binder/ndk/parcel.cpp
@@ -332,8 +332,8 @@
 // This implements AParcel_stringAllocator for a string using an array, index, and element
 // allocator.
 struct StringArrayElementAllocationAdapter {
-    void* arrayData; // stringData from the NDK
-    size_t index;    // index into the string array
+    void* arrayData;  // stringData from the NDK
+    size_t index;     // index into the string array
     AParcel_stringArrayElementAllocator elementAllocator;
 
     static char* Allocator(void* stringData, size_t length) {
@@ -463,28 +463,30 @@
     return PruneStatusT(status);
 }
 
-binder_status_t AParcel_writeInt32Array(AParcel* parcel, const int32_t* value, size_t length) {
-    return WriteArray<int32_t>(parcel, value, length);
+binder_status_t AParcel_writeInt32Array(AParcel* parcel, const int32_t* arrayData, size_t length) {
+    return WriteArray<int32_t>(parcel, arrayData, length);
 }
 
-binder_status_t AParcel_writeUint32Array(AParcel* parcel, const uint32_t* value, size_t length) {
-    return WriteArray<uint32_t>(parcel, value, length);
+binder_status_t AParcel_writeUint32Array(AParcel* parcel, const uint32_t* arrayData,
+                                         size_t length) {
+    return WriteArray<uint32_t>(parcel, arrayData, length);
 }
 
-binder_status_t AParcel_writeInt64Array(AParcel* parcel, const int64_t* value, size_t length) {
-    return WriteArray<int64_t>(parcel, value, length);
+binder_status_t AParcel_writeInt64Array(AParcel* parcel, const int64_t* arrayData, size_t length) {
+    return WriteArray<int64_t>(parcel, arrayData, length);
 }
 
-binder_status_t AParcel_writeUint64Array(AParcel* parcel, const uint64_t* value, size_t length) {
-    return WriteArray<uint64_t>(parcel, value, length);
+binder_status_t AParcel_writeUint64Array(AParcel* parcel, const uint64_t* arrayData,
+                                         size_t length) {
+    return WriteArray<uint64_t>(parcel, arrayData, length);
 }
 
-binder_status_t AParcel_writeFloatArray(AParcel* parcel, const float* value, size_t length) {
-    return WriteArray<float>(parcel, value, length);
+binder_status_t AParcel_writeFloatArray(AParcel* parcel, const float* arrayData, size_t length) {
+    return WriteArray<float>(parcel, arrayData, length);
 }
 
-binder_status_t AParcel_writeDoubleArray(AParcel* parcel, const double* value, size_t length) {
-    return WriteArray<double>(parcel, value, length);
+binder_status_t AParcel_writeDoubleArray(AParcel* parcel, const double* arrayData, size_t length) {
+    return WriteArray<double>(parcel, arrayData, length);
 }
 
 binder_status_t AParcel_writeBoolArray(AParcel* parcel, const void* arrayData, size_t length,
@@ -492,12 +494,12 @@
     return WriteArray<bool>(parcel, arrayData, length, getter, &Parcel::writeBool);
 }
 
-binder_status_t AParcel_writeCharArray(AParcel* parcel, const char16_t* value, size_t length) {
-    return WriteArray<char16_t>(parcel, value, length);
+binder_status_t AParcel_writeCharArray(AParcel* parcel, const char16_t* arrayData, size_t length) {
+    return WriteArray<char16_t>(parcel, arrayData, length);
 }
 
-binder_status_t AParcel_writeByteArray(AParcel* parcel, const int8_t* value, size_t length) {
-    return WriteArray<int8_t>(parcel, value, length);
+binder_status_t AParcel_writeByteArray(AParcel* parcel, const int8_t* arrayData, size_t length) {
+    return WriteArray<int8_t>(parcel, arrayData, length);
 }
 
 binder_status_t AParcel_readInt32Array(const AParcel* parcel, void* arrayData,
diff --git a/libs/binder/ndk/parcel_internal.h b/libs/binder/ndk/parcel_internal.h
index d69971f..f292309 100644
--- a/libs/binder/ndk/parcel_internal.h
+++ b/libs/binder/ndk/parcel_internal.h
@@ -29,7 +29,7 @@
 
     AParcel(const AIBinder* binder) : AParcel(binder, new ::android::Parcel, true /*owns*/) {}
     AParcel(const AIBinder* binder, ::android::Parcel* parcel, bool owns)
-          : mBinder(binder), mParcel(parcel), mOwns(owns) {}
+        : mBinder(binder), mParcel(parcel), mOwns(owns) {}
 
     ~AParcel() {
         if (mOwns) {
@@ -43,7 +43,7 @@
 
     const AIBinder* getBinder() { return mBinder; }
 
-private:
+   private:
     // This object is associated with a calls to a specific AIBinder object. This is used for sanity
     // checking to make sure that a parcel is one that is expected.
     const AIBinder* mBinder;
diff --git a/libs/binder/ndk/runtests.sh b/libs/binder/ndk/runtests.sh
index 2257eb2..a0c49fb 100755
--- a/libs/binder/ndk/runtests.sh
+++ b/libs/binder/ndk/runtests.sh
@@ -22,12 +22,13 @@
 set -ex
 
 function run_libbinder_ndk_test() {
-	adb shell /data/nativetest64/libbinder_ndk_test_server/libbinder_ndk_test_server &
-	local pid=$!
-	trap "kill $pid" ERR
-	adb shell /data/nativetest64/libbinder_ndk_test_client/libbinder_ndk_test_client
-	trap '' ERR
-	kill $pid
+    adb shell /data/nativetest64/libbinder_ndk_test_server/libbinder_ndk_test_server &
+
+    # avoid getService 1s delay for most runs, non-critical
+    sleep 0.1
+
+    adb shell /data/nativetest64/libbinder_ndk_test_client/libbinder_ndk_test_client; \
+        adb shell killall libbinder_ndk_test_server
 }
 
 [ "$1" != "--skip-build" ] && $ANDROID_BUILD_TOP/build/soong/soong_ui.bash --make-mode \
@@ -40,4 +41,5 @@
 # very simple unit tests, tests things outside of the NDK as well
 run_libbinder_ndk_test
 
-atest android.binder.cts.NdkBinderTest
+# CTS tests (much more comprehensive, new tests should ideally go here)
+atest android.binder.cts
diff --git a/libs/binder/ndk/scripts/gen_parcel_helper.py b/libs/binder/ndk/scripts/gen_parcel_helper.py
index 0e10220..bb76254 100755
--- a/libs/binder/ndk/scripts/gen_parcel_helper.py
+++ b/libs/binder/ndk/scripts/gen_parcel_helper.py
@@ -69,6 +69,11 @@
     for pretty, cpp in data_types:
         header += "/**\n"
         header += " * Writes " + cpp + " value to the next location in a non-null parcel.\n"
+        header += " *\n"
+        header += " * \\param parcel the parcel to write to.\n"
+        header += " * \\param value the value to write to the parcel.\n"
+        header += " *\n"
+        header += " * \\return STATUS_OK on successful write.\n"
         header += " */\n"
         header += "binder_status_t AParcel_write" + pretty + "(AParcel* parcel, " + cpp + " value) __INTRODUCED_IN(29);\n\n"
         source += "binder_status_t AParcel_write" + pretty + "(AParcel* parcel, " + cpp + " value) {\n"
@@ -79,6 +84,11 @@
     for pretty, cpp in data_types:
         header += "/**\n"
         header += " * Reads into " + cpp + " value from the next location in a non-null parcel.\n"
+        header += " *\n"
+        header += " * \\param parcel the parcel to read from.\n"
+        header += " * \\param value the value to read from the parcel.\n"
+        header += " *\n"
+        header += " * \\return STATUS_OK on successful read.\n"
         header += " */\n"
         header += "binder_status_t AParcel_read" + pretty + "(const AParcel* parcel, " + cpp + "* value) __INTRODUCED_IN(29);\n\n"
         source += "binder_status_t AParcel_read" + pretty + "(const AParcel* parcel, " + cpp + "* value) {\n"
@@ -89,9 +99,9 @@
     for pretty, cpp in data_types:
         nca = pretty in non_contiguously_addressable
 
-        arg_types = "const " + cpp + "* value, size_t length"
+        arg_types = "const " + cpp + "* arrayData, size_t length"
         if nca: arg_types = "const void* arrayData, size_t length, AParcel_" + pretty.lower() + "ArrayGetter getter"
-        args = "value, length"
+        args = "arrayData, length"
         if nca: args = "arrayData, length, getter, &Parcel::write" + pretty
 
         header += "/**\n"
@@ -100,6 +110,17 @@
             header += " *\n"
             header += " * getter(arrayData, i) will be called for each i in [0, length) in order to get the underlying values to write "
             header += "to the parcel.\n"
+        header += " *\n"
+        header += " * \\param parcel the parcel to write to.\n"
+        if nca:
+            header += " * \\param arrayData some external representation of an array.\n"
+            header += " * \\param length the length of arrayData.\n"
+            header += " * \\param getter the callback to retrieve data at specific locations in the array.\n"
+        else:
+            header += " * \\param arrayData an array of size 'length'.\n"
+            header += " * \\param length the length of arrayData.\n"
+        header += " *\n"
+        header += " * \\return STATUS_OK on successful write.\n"
         header += " */\n"
         header += "binder_status_t AParcel_write" + pretty + "Array(AParcel* parcel, " + arg_types + ") __INTRODUCED_IN(29);\n\n"
         source += "binder_status_t AParcel_write" + pretty + "Array(AParcel* parcel, " + arg_types + ") {\n"
@@ -121,6 +142,11 @@
             pre_header += "a success.\n"
             pre_header += " *\n"
             pre_header += " * See also " + read_func + "\n"
+            pre_header += " *\n"
+            pre_header += " * \\param arrayData some external representation of an array of " + cpp + ".\n"
+            pre_header += " * \\param length the length to allocate arrayData to.\n"
+            pre_header += " *\n"
+            pre_header += " * \\return whether the allocation succeeded.\n"
             pre_header += " */\n"
             pre_header += "typedef bool (*" + allocator_type + ")(void* arrayData, size_t length);\n\n"
 
@@ -128,6 +154,11 @@
             pre_header += " * This is called to get the underlying data from an arrayData object at index.\n"
             pre_header += " *\n"
             pre_header += " * See also " + write_func + "\n"
+            pre_header += " *\n"
+            pre_header += " * \\param arrayData some external representation of an array of " + cpp + ".\n"
+            pre_header += " * \\param index the index of the value to be retrieved.\n"
+            pre_header += " *\n"
+            pre_header += " * \\return the value of the array at index index.\n"
             pre_header += " */\n"
             pre_header += "typedef " + cpp + " (*" + getter_type + ")(const void* arrayData, size_t index);\n\n"
 
@@ -135,6 +166,10 @@
             pre_header += " * This is called to set an underlying value in an arrayData object at index.\n"
             pre_header += " *\n"
             pre_header += " * See also " + read_func + "\n"
+            pre_header += " *\n"
+            pre_header += " * \\param arrayData some external representation of an array of " + cpp + ".\n"
+            pre_header += " * \\param index the index of the value to be set.\n"
+            pre_header += " * \\param value the value to set at index index.\n"
             pre_header += " */\n"
             pre_header += "typedef void (*" + setter_type + ")(void* arrayData, size_t index, " + cpp + " value);\n\n"
         else:
@@ -146,6 +181,11 @@
             pre_header += "returned.\n"
             pre_header += " *\n"
             pre_header += " * See also " + read_func + "\n"
+            pre_header += " *\n"
+            pre_header += " * \\param arrayData some external representation of an array of " + cpp + ".\n"
+            pre_header += " * \\param length the length to allocate arrayData to.\n"
+            pre_header += " *\n"
+            pre_header += " * \\return a buffer of " + cpp + " of size 'length'.\n"
             pre_header += " */\n"
             pre_header += "typedef " + cpp + "* (*" + allocator_type + ")(void* arrayData, size_t length);\n\n"
 
@@ -166,6 +206,14 @@
         else:
             header += " * First, allocator will be called with the length of the array. If the allocation succeeds and the "
             header += "length is greater than zero, the buffer returned by the allocator will be filled with the corresponding data\n"
+        header += " *\n"
+        header += " * \\param parcel the parcel to read from.\n"
+        header += " * \\param arrayData some external representation of an array.\n"
+        header += " * \\param allocator the callback that will be called to allocate the array.\n"
+        if nca:
+            header += " * \\param setter the callback that will be called to set a value at a specific location in the array.\n"
+        header += " *\n"
+        header += " * \\return STATUS_OK on successful read.\n"
         header += " */\n"
         header += "binder_status_t " + read_func + "(" + read_type_args + ") __INTRODUCED_IN(29);\n\n"
         source += "binder_status_t " + read_func + "(" + read_type_args + ") {\n"
diff --git a/libs/binder/ndk/status_internal.h b/libs/binder/ndk/status_internal.h
index 8c32baf..d39f0d8 100644
--- a/libs/binder/ndk/status_internal.h
+++ b/libs/binder/ndk/status_internal.h
@@ -22,13 +22,13 @@
 #include <utils/Errors.h>
 
 struct AStatus {
-    AStatus() {} // ok
+    AStatus() {}  // ok
     AStatus(::android::binder::Status&& status) : mStatus(std::move(status)) {}
 
     ::android::binder::Status* get() { return &mStatus; }
     const ::android::binder::Status* get() const { return &mStatus; }
 
-private:
+   private:
     ::android::binder::Status mStatus;
 };
 
diff --git a/libs/binder/ndk/test/Android.bp b/libs/binder/ndk/test/Android.bp
index 8e40a01..b29b6e7 100644
--- a/libs/binder/ndk/test/Android.bp
+++ b/libs/binder/ndk/test/Android.bp
@@ -14,9 +14,6 @@
  * limitations under the License.
  */
 
-// This test is a unit test of the low-level API that is presented here.
-// Actual users should use AIDL to generate these complicated stubs.
-
 cc_defaults {
     name: "test_libbinder_ndk_defaults",
     shared_libs: [
@@ -55,6 +52,9 @@
     ],
 }
 
+// This test is a unit test of the low-level API that is presented here,
+// specifically the parts which are outside of the NDK. Actual users should
+// also instead use AIDL to generate these stubs. See android.binder.cts.
 cc_test {
     name: "libbinder_ndk_test_client",
     defaults: ["test_libbinder_ndk_test_defaults"],
diff --git a/libs/binder/ndk/test/iface.cpp b/libs/binder/ndk/test/iface.cpp
index 0dc3cc4..6ef964e 100644
--- a/libs/binder/ndk/test/iface.cpp
+++ b/libs/binder/ndk/test/iface.cpp
@@ -18,10 +18,13 @@
 #include <android/binder_manager.h>
 #include <iface/iface.h>
 
+#include <android/binder_auto_utils.h>
+
 using ::android::sp;
 using ::android::wp;
 
 const char* IFoo::kSomeInstanceName = "libbinder_ndk-test-IFoo";
+const char* IFoo::kInstanceNameToDieFor = "libbinder_ndk-test-IFoo-to-die";
 const char* kIFooDescriptor = "my-special-IFoo-class";
 
 struct IFoo_Class_Data {
@@ -49,12 +52,18 @@
     switch (code) {
         case IFoo::DOFOO: {
             int32_t valueIn;
+            int32_t valueOut;
             stat = AParcel_readInt32(in, &valueIn);
             if (stat != STATUS_OK) break;
-            int32_t valueOut = foo->doubleNumber(valueIn);
+            stat = foo->doubleNumber(valueIn, &valueOut);
+            if (stat != STATUS_OK) break;
             stat = AParcel_writeInt32(out, valueOut);
             break;
         }
+        case IFoo::DIE: {
+            stat = foo->die();
+            break;
+        }
     }
 
     return stat;
@@ -64,29 +73,43 @@
                                                      IFoo_Class_onDestroy, IFoo_Class_onTransact);
 
 class BpFoo : public IFoo {
-public:
+   public:
     BpFoo(AIBinder* binder) : mBinder(binder) {}
     virtual ~BpFoo() { AIBinder_decStrong(mBinder); }
 
-    virtual int32_t doubleNumber(int32_t in) {
+    virtual binder_status_t doubleNumber(int32_t in, int32_t* out) {
+        binder_status_t stat = STATUS_OK;
+
         AParcel* parcelIn;
-        CHECK(STATUS_OK == AIBinder_prepareTransaction(mBinder, &parcelIn));
+        stat = AIBinder_prepareTransaction(mBinder, &parcelIn);
+        if (stat != STATUS_OK) return stat;
 
-        CHECK(STATUS_OK == AParcel_writeInt32(parcelIn, in));
+        stat = AParcel_writeInt32(parcelIn, in);
+        if (stat != STATUS_OK) return stat;
 
-        AParcel* parcelOut;
-        CHECK(STATUS_OK ==
-              AIBinder_transact(mBinder, IFoo::DOFOO, &parcelIn, &parcelOut, 0 /*flags*/));
+        ::ndk::ScopedAParcel parcelOut;
+        stat = AIBinder_transact(mBinder, IFoo::DOFOO, &parcelIn, parcelOut.getR(), 0 /*flags*/);
+        if (stat != STATUS_OK) return stat;
 
-        int32_t out;
-        CHECK(STATUS_OK == AParcel_readInt32(parcelOut, &out));
+        stat = AParcel_readInt32(parcelOut.get(), out);
+        if (stat != STATUS_OK) return stat;
 
-        AParcel_delete(parcelOut);
-
-        return out;
+        return stat;
     }
 
-private:
+    virtual binder_status_t die() {
+        binder_status_t stat = STATUS_OK;
+
+        AParcel* parcelIn;
+        stat = AIBinder_prepareTransaction(mBinder, &parcelIn);
+
+        ::ndk::ScopedAParcel parcelOut;
+        stat = AIBinder_transact(mBinder, IFoo::DIE, &parcelIn, parcelOut.getR(), 0 /*flags*/);
+
+        return stat;
+    }
+
+   private:
     // Always assumes one refcount
     AIBinder* mBinder;
 };
@@ -117,8 +140,8 @@
     return status;
 }
 
-sp<IFoo> IFoo::getService(const char* instance) {
-    AIBinder* binder = AServiceManager_getService(instance); // maybe nullptr
+sp<IFoo> IFoo::getService(const char* instance, AIBinder** outBinder) {
+    AIBinder* binder = AServiceManager_getService(instance);  // maybe nullptr
     if (binder == nullptr) {
         return nullptr;
     }
@@ -128,14 +151,19 @@
         return nullptr;
     }
 
+    if (outBinder != nullptr) {
+        AIBinder_incStrong(binder);
+        *outBinder = binder;
+    }
+
     if (AIBinder_isRemote(binder)) {
-        sp<IFoo> ret = new BpFoo(binder); // takes ownership of binder
+        sp<IFoo> ret = new BpFoo(binder);  // takes ownership of binder
         return ret;
     }
 
     IFoo_Class_Data* data = static_cast<IFoo_Class_Data*>(AIBinder_getUserData(binder));
 
-    CHECK(data != nullptr); // always created with non-null data
+    CHECK(data != nullptr);  // always created with non-null data
 
     sp<IFoo> ret = data->foo;
 
@@ -143,7 +171,6 @@
     CHECK(held == binder);
     AIBinder_decStrong(held);
 
-    // IFoo only keeps a weak reference to AIBinder, so we can drop this
     AIBinder_decStrong(binder);
     return ret;
 }
diff --git a/libs/binder/ndk/test/include/iface/iface.h b/libs/binder/ndk/test/include/iface/iface.h
index 4c61e9d..cdf5493 100644
--- a/libs/binder/ndk/test/include/iface/iface.h
+++ b/libs/binder/ndk/test/include/iface/iface.h
@@ -19,22 +19,33 @@
 #include <android/binder_ibinder.h>
 #include <utils/RefBase.h>
 
+// warning: it is recommended to use AIDL output instead of this. binder_ibinder_utils.h and some of
+// the other niceties make sure that, for instance, binder proxies are always the same. They also
+// don't use internal Android APIs like refbase which are used here only for convenience.
+
 class IFoo : public virtual ::android::RefBase {
-public:
+   public:
     static const char* kSomeInstanceName;
+    static const char* kInstanceNameToDieFor;
+
     static AIBinder_Class* kClass;
 
     // Takes ownership of IFoo
     binder_status_t addService(const char* instance);
-    static ::android::sp<IFoo> getService(const char* instance);
+    static ::android::sp<IFoo> getService(const char* instance, AIBinder** outBinder = nullptr);
 
     enum Call {
         DOFOO = FIRST_CALL_TRANSACTION + 0,
+        DIE = FIRST_CALL_TRANSACTION + 1,
     };
 
     virtual ~IFoo();
-    virtual int32_t doubleNumber(int32_t in) = 0;
 
-private:
-    AIBinder_Weak* mWeakBinder = nullptr; // maybe owns AIBinder
+    virtual binder_status_t doubleNumber(int32_t in, int32_t* out) = 0;
+    virtual binder_status_t die() = 0;
+
+   private:
+    // this variable is only when IFoo is local (since this test combines 'IFoo' and 'BnFoo'), not
+    // for BpFoo.
+    AIBinder_Weak* mWeakBinder = nullptr;
 };
diff --git a/libs/binder/ndk/test/main_client.cpp b/libs/binder/ndk/test/main_client.cpp
index 6945cac..c159d71 100644
--- a/libs/binder/ndk/test/main_client.cpp
+++ b/libs/binder/ndk/test/main_client.cpp
@@ -21,6 +21,10 @@
 #include <gtest/gtest.h>
 #include <iface/iface.h>
 
+#include <chrono>
+#include <condition_variable>
+#include <mutex>
+
 using ::android::sp;
 
 constexpr char kExistingNonNdkService[] = "SurfaceFlinger";
@@ -34,7 +38,47 @@
 TEST(NdkBinder, DoubleNumber) {
     sp<IFoo> foo = IFoo::getService(IFoo::kSomeInstanceName);
     ASSERT_NE(foo, nullptr);
-    EXPECT_EQ(2, foo->doubleNumber(1));
+
+    int32_t out;
+    EXPECT_EQ(STATUS_OK, foo->doubleNumber(1, &out));
+    EXPECT_EQ(2, out);
+}
+
+void LambdaOnDeath(void* cookie) {
+    auto onDeath = static_cast<std::function<void(void)>*>(cookie);
+    (*onDeath)();
+};
+TEST(NdkBinder, DeathRecipient) {
+    using namespace std::chrono_literals;
+
+    AIBinder* binder;
+    sp<IFoo> foo = IFoo::getService(IFoo::kInstanceNameToDieFor, &binder);
+    ASSERT_NE(nullptr, foo.get());
+    ASSERT_NE(nullptr, binder);
+
+    std::mutex deathMutex;
+    std::condition_variable deathCv;
+    bool deathRecieved = false;
+
+    std::function<void(void)> onDeath = [&] {
+        std::cerr << "Binder died (as requested)." << std::endl;
+        deathRecieved = true;
+        deathCv.notify_one();
+    };
+
+    AIBinder_DeathRecipient* recipient = AIBinder_DeathRecipient_new(LambdaOnDeath);
+
+    EXPECT_EQ(STATUS_OK, AIBinder_linkToDeath(binder, recipient, static_cast<void*>(&onDeath)));
+
+    // the binder driver should return this if the service dies during the transaction
+    EXPECT_EQ(STATUS_DEAD_OBJECT, foo->die());
+
+    std::unique_lock<std::mutex> lock(deathMutex);
+    EXPECT_TRUE(deathCv.wait_for(lock, 1s, [&] { return deathRecieved; }));
+    EXPECT_TRUE(deathRecieved);
+
+    AIBinder_DeathRecipient_delete(recipient);
+    AIBinder_decStrong(binder);
 }
 
 TEST(NdkBinder, RetrieveNonNdkService) {
@@ -52,9 +96,6 @@
 }
 
 TEST(NdkBinder, LinkToDeath) {
-    ABinderProcess_setThreadPoolMaxThreadCount(1); // to recieve death notifications
-    ABinderProcess_startThreadPool();
-
     AIBinder* binder = AServiceManager_getService(kExistingNonNdkService);
     ASSERT_NE(nullptr, binder);
 
@@ -72,9 +113,14 @@
 }
 
 class MyTestFoo : public IFoo {
-    int32_t doubleNumber(int32_t in) override {
-        LOG(INFO) << "doubleNumber " << in;
-        return 2 * in;
+    binder_status_t doubleNumber(int32_t in, int32_t* out) override {
+        *out = 2 * in;
+        LOG(INFO) << "doubleNumber (" << in << ") => " << *out;
+        return STATUS_OK;
+    }
+    binder_status_t die() override {
+        ADD_FAILURE() << "die called on local instance";
+        return STATUS_OK;
     }
 };
 
@@ -87,7 +133,9 @@
     sp<IFoo> getFoo = IFoo::getService(kInstanceName);
     EXPECT_EQ(foo.get(), getFoo.get());
 
-    EXPECT_EQ(2, getFoo->doubleNumber(1));
+    int32_t out;
+    EXPECT_EQ(STATUS_OK, getFoo->doubleNumber(1, &out));
+    EXPECT_EQ(2, out);
 }
 
 TEST(NdkBinder, EqualityOfRemoteBinderPointer) {
@@ -132,6 +180,15 @@
     EXPECT_EQ(IFoo::getService(kInstanceName1), IFoo::getService(kInstanceName2));
 }
 
+int main(int argc, char* argv[]) {
+    ::testing::InitGoogleTest(&argc, argv);
+
+    ABinderProcess_setThreadPoolMaxThreadCount(1);  // to recieve death notifications/callbacks
+    ABinderProcess_startThreadPool();
+
+    return RUN_ALL_TESTS();
+}
+
 #include <android/binder_auto_utils.h>
 #include <android/binder_interface_utils.h>
 #include <android/binder_parcel_utils.h>
diff --git a/libs/binder/ndk/test/main_server.cpp b/libs/binder/ndk/test/main_server.cpp
index 0718a69..a6e17e8 100644
--- a/libs/binder/ndk/test/main_server.cpp
+++ b/libs/binder/ndk/test/main_server.cpp
@@ -21,23 +21,37 @@
 using ::android::sp;
 
 class MyFoo : public IFoo {
-    int32_t doubleNumber(int32_t in) override {
-        LOG(INFO) << "doubling " << in;
-        return 2 * in;
+    binder_status_t doubleNumber(int32_t in, int32_t* out) override {
+        *out = 2 * in;
+        LOG(INFO) << "doubleNumber (" << in << ") => " << *out;
+        return STATUS_OK;
+    }
+
+    binder_status_t die() override {
+        LOG(FATAL) << "IFoo::die called!";
+        return STATUS_UNKNOWN_ERROR;
     }
 };
 
-int main() {
+int service(const char* instance) {
     ABinderProcess_setThreadPoolMaxThreadCount(0);
 
     // Strong reference to MyFoo kept by service manager.
-    binder_status_t status = (new MyFoo)->addService(IFoo::kSomeInstanceName);
+    binder_status_t status = (new MyFoo)->addService(instance);
 
     if (status != STATUS_OK) {
-        LOG(FATAL) << "Could not register: " << status;
+        LOG(FATAL) << "Could not register: " << status << " " << instance;
     }
 
     ABinderProcess_joinThreadPool();
 
-    return 1;
+    return 1;  // should not return
+}
+
+int main() {
+    if (fork() == 0) {
+        return service(IFoo::kInstanceNameToDieFor);
+    }
+
+    return service(IFoo::kSomeInstanceName);
 }
diff --git a/libs/graphicsenv/GraphicsEnv.cpp b/libs/graphicsenv/GraphicsEnv.cpp
index 97b4828..afa32b6 100644
--- a/libs/graphicsenv/GraphicsEnv.cpp
+++ b/libs/graphicsenv/GraphicsEnv.cpp
@@ -68,8 +68,7 @@
 }
 
 void GraphicsEnv::setAngleInfo(const std::string path, const std::string appName,
-                               const std::string appPref, bool developerOptIn,
-                               const int rulesFd, const long rulesOffset,
+                               bool developerOptIn, const int rulesFd, const long rulesOffset,
                                const long rulesLength) {
     if (!mAnglePath.empty()) {
         ALOGV("ignoring attempt to change ANGLE path from '%s' to '%s'", mAnglePath.c_str(),
@@ -87,14 +86,6 @@
         mAngleAppName = appName;
     }
 
-    if (!mAngleAppPref.empty()) {
-        ALOGV("ignoring attempt to change ANGLE application opt-in from '%s' to '%s'",
-              mAngleAppPref.c_str(), appPref.c_str());
-    } else {
-        ALOGV("setting ANGLE application opt-in to '%s'", appPref.c_str());
-        mAngleAppPref = appPref;
-    }
-
     mAngleDeveloperOptIn = developerOptIn;
 
     ALOGV("setting ANGLE rules file descriptor to '%i'", rulesFd);
@@ -128,11 +119,6 @@
     return mAngleDeveloperOptIn;
 }
 
-const char* GraphicsEnv::getAngleAppPref() {
-    if (mAngleAppPref.empty()) return nullptr;
-    return mAngleAppPref.c_str();
-}
-
 int GraphicsEnv::getAngleRulesFd() {
     return mAngleRulesFd;
 }
diff --git a/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h b/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h
index 528c260..20e4d66 100644
--- a/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h
+++ b/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h
@@ -44,9 +44,8 @@
     // (libraries must be stored uncompressed and page aligned); such elements
     // in the search path must have a '!' after the zip filename, e.g.
     //     /system/app/ANGLEPrebuilt/ANGLEPrebuilt.apk!/lib/arm64-v8a
-    void setAngleInfo(const std::string path, const std::string appName, const std::string appPref,
-                      bool devOptIn, const int rulesFd, const long rulesOffset,
-                      const long rulesLength);
+    void setAngleInfo(const std::string path, const std::string appName, bool devOptIn,
+                      const int rulesFd, const long rulesOffset, const long rulesLength);
     android_namespace_t* getAngleNamespace();
     const char* getAngleAppName();
     const char* getAngleAppPref();
@@ -70,7 +69,6 @@
     std::string mDriverPath;
     std::string mAnglePath;
     std::string mAngleAppName;
-    std::string mAngleAppPref;
     bool mAngleDeveloperOptIn;
     int mAngleRulesFd;
     long mAngleRulesOffset;
diff --git a/libs/renderengine/gl/GLES20RenderEngine.cpp b/libs/renderengine/gl/GLES20RenderEngine.cpp
index 026b151..70a4322 100644
--- a/libs/renderengine/gl/GLES20RenderEngine.cpp
+++ b/libs/renderengine/gl/GLES20RenderEngine.cpp
@@ -385,17 +385,9 @@
     // mColorBlindnessCorrection = M;
 
     if (mUseColorManagement) {
-        ColorSpace srgb(ColorSpace::sRGB());
-        ColorSpace displayP3(ColorSpace::DisplayP3());
-        ColorSpace bt2020(ColorSpace::BT2020());
-
-        // Compute sRGB to Display P3 transform matrix.
-        // NOTE: For now, we are limiting output wide color space support to
-        // Display-P3 only.
-        mSrgbToDisplayP3 = mat4(ColorSpaceConnector(srgb, displayP3).getTransform());
-
-        // Compute Display P3 to sRGB transform matrix.
-        mDisplayP3ToSrgb = mat4(ColorSpaceConnector(displayP3, srgb).getTransform());
+        const ColorSpace srgb(ColorSpace::sRGB());
+        const ColorSpace displayP3(ColorSpace::DisplayP3());
+        const ColorSpace bt2020(ColorSpace::BT2020());
 
         // no chromatic adaptation needed since all color spaces use D65 for their white points.
         mSrgbToXyz = mat4(srgb.getRGBtoXYZ());
@@ -404,6 +396,20 @@
         mXyzToSrgb = mat4(srgb.getXYZtoRGB());
         mXyzToDisplayP3 = mat4(displayP3.getXYZtoRGB());
         mXyzToBt2020 = mat4(bt2020.getXYZtoRGB());
+
+        // Compute sRGB to Display P3 and BT2020 transform matrix.
+        // NOTE: For now, we are limiting output wide color space support to
+        // Display-P3 and BT2020 only.
+        mSrgbToDisplayP3 = mXyzToDisplayP3 * mSrgbToXyz;
+        mSrgbToBt2020 = mXyzToBt2020 * mSrgbToXyz;
+
+        // Compute Display P3 to sRGB and BT2020 transform matrix.
+        mDisplayP3ToSrgb = mXyzToSrgb * mDisplayP3ToXyz;
+        mDisplayP3ToBt2020 = mXyzToBt2020 * mDisplayP3ToXyz;
+
+        // Compute BT2020 to sRGB and Display P3 transform matrix
+        mBt2020ToSrgb = mXyzToSrgb * mBt2020ToXyz;
+        mBt2020ToDisplayP3 = mXyzToDisplayP3 * mBt2020ToXyz;
     }
 }
 
@@ -793,6 +799,13 @@
                 static_cast<Dataspace>(mOutputDataSpace & Dataspace::TRANSFER_MASK);
         bool needsXYZConversion = needsXYZTransformMatrix();
 
+        // NOTE: if the input standard of the input dataspace is not STANDARD_DCI_P3 or
+        // STANDARD_BT2020, it will be  treated as STANDARD_BT709
+        if (inputStandard != Dataspace::STANDARD_DCI_P3 &&
+            inputStandard != Dataspace::STANDARD_BT2020) {
+            inputStandard = Dataspace::STANDARD_BT709;
+        }
+
         if (needsXYZConversion) {
             // The supported input color spaces are standard RGB, Display P3 and BT2020.
             switch (inputStandard) {
@@ -827,13 +840,33 @@
             // - scRGB non-linear
             // - sRGB
             // - Display P3
+            // - BT2020
             // The output data spaces could be
             // - sRGB
             // - Display P3
-            if (outputStandard == Dataspace::STANDARD_BT709) {
-                managedState.outputTransformMatrix = mDisplayP3ToSrgb;
-            } else if (outputStandard == Dataspace::STANDARD_DCI_P3) {
-                managedState.outputTransformMatrix = mSrgbToDisplayP3;
+            // - BT2020
+            switch (outputStandard) {
+                case Dataspace::STANDARD_BT2020:
+                    if (inputStandard == Dataspace::STANDARD_BT709) {
+                        managedState.outputTransformMatrix = mSrgbToBt2020;
+                    } else if (inputStandard == Dataspace::STANDARD_DCI_P3) {
+                        managedState.outputTransformMatrix = mDisplayP3ToBt2020;
+                    }
+                    break;
+                case Dataspace::STANDARD_DCI_P3:
+                    if (inputStandard == Dataspace::STANDARD_BT709) {
+                        managedState.outputTransformMatrix = mSrgbToDisplayP3;
+                    } else if (inputStandard == Dataspace::STANDARD_BT2020) {
+                        managedState.outputTransformMatrix = mBt2020ToDisplayP3;
+                    }
+                    break;
+                default:
+                    if (inputStandard == Dataspace::STANDARD_DCI_P3) {
+                        managedState.outputTransformMatrix = mDisplayP3ToSrgb;
+                    } else if (inputStandard == Dataspace::STANDARD_BT2020) {
+                        managedState.outputTransformMatrix = mBt2020ToSrgb;
+                    }
+                    break;
             }
         }
 
diff --git a/libs/renderengine/gl/GLES20RenderEngine.h b/libs/renderengine/gl/GLES20RenderEngine.h
index 6ea8523..148df2f 100644
--- a/libs/renderengine/gl/GLES20RenderEngine.h
+++ b/libs/renderengine/gl/GLES20RenderEngine.h
@@ -132,14 +132,18 @@
     GLuint mVpHeight;
     Description mState;
 
-    mat4 mSrgbToDisplayP3;
-    mat4 mDisplayP3ToSrgb;
     mat4 mSrgbToXyz;
-    mat4 mBt2020ToXyz;
     mat4 mDisplayP3ToXyz;
+    mat4 mBt2020ToXyz;
     mat4 mXyzToSrgb;
     mat4 mXyzToDisplayP3;
     mat4 mXyzToBt2020;
+    mat4 mSrgbToDisplayP3;
+    mat4 mSrgbToBt2020;
+    mat4 mDisplayP3ToSrgb;
+    mat4 mDisplayP3ToBt2020;
+    mat4 mBt2020ToSrgb;
+    mat4 mBt2020ToDisplayP3;
 
     bool mRenderToFbo = false;
     int32_t mSurfaceHeight = 0;
diff --git a/libs/vr/CleanSpec.mk b/libs/vr/CleanSpec.mk
deleted file mode 100644
index a17c9b2..0000000
--- a/libs/vr/CleanSpec.mk
+++ /dev/null
@@ -1,52 +0,0 @@
-# Copyright (C) 2012 The Android Open Source Project
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-
-# If you don't need to do a full clean build but would like to touch
-# a file or delete some intermediate files, add a clean step to the end
-# of the list.  These steps will only be run once, if they haven't been
-# run before.
-#
-# E.g.:
-#     $(call add-clean-step, touch -c external/sqlite/sqlite3.h)
-#     $(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/STATIC_LIBRARIES/libz_intermediates)
-#
-# Always use "touch -c" and "rm -f" or "rm -rf" to gracefully deal with
-# files that are missing or have been moved.
-#
-# Use $(PRODUCT_OUT) to get to the "out/target/product/blah/" directory.
-# Use $(OUT_DIR) to refer to the "out" directory.
-#
-# If you need to re-do something that's already mentioned, just copy
-# the command and add it to the bottom of the list.  E.g., if a change
-# that you made last week required touching a file and a change you
-# made today requires touching the same file, just copy the old
-# touch step and add it to the end of the list.
-#
-# ************************************************
-# NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
-# ************************************************
-
-# For example:
-#$(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/APPS/AndroidTests_intermediates)
-#$(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/JAVA_LIBRARIES/core_intermediates)
-#$(call add-clean-step, find $(OUT_DIR) -type f -name "IGTalkSession*" -print0 | xargs -0 rm -f)
-#$(call add-clean-step, rm -rf $(PRODUCT_OUT)/data/*)
-
-# ************************************************
-# NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
-# ************************************************
-$(call add-clean-step, find $(PRODUCT_OUT) -type f -name "libdvr.so" -print0 | xargs -0 rm -f)
-$(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/SHARED_LIBRARIES/libdvr_intermediates)
-$(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/SHARED_LIBRARIES/libdvr_intermediates)
diff --git a/libs/vr/libbufferhubqueue/buffer_hub_queue_client.cpp b/libs/vr/libbufferhubqueue/buffer_hub_queue_client.cpp
index e1c1aa9..b8e2f9d 100644
--- a/libs/vr/libbufferhubqueue/buffer_hub_queue_client.cpp
+++ b/libs/vr/libbufferhubqueue/buffer_hub_queue_client.cpp
@@ -69,7 +69,7 @@
       .data = {.u64 = Stuff(-1, BufferHubQueue::kEpollQueueEventIndex)}};
   ret = epoll_fd_.Control(EPOLL_CTL_ADD, event_fd(), &event);
   if (ret < 0) {
-    ALOGE("BufferHubQueue::Initialize: Failed to add event fd to epoll set: %s",
+    ALOGE("%s: Failed to add event fd to epoll set: %s", __FUNCTION__,
           strerror(-ret));
   }
 }
@@ -77,7 +77,7 @@
 Status<void> BufferHubQueue::ImportQueue() {
   auto status = InvokeRemoteMethod<BufferHubRPC::GetQueueInfo>();
   if (!status) {
-    ALOGE("BufferHubQueue::ImportQueue: Failed to import queue: %s",
+    ALOGE("%s: Failed to import queue: %s", __FUNCTION__,
           status.GetErrorMessage().c_str());
     return ErrorStatus(status.error());
   } else {
@@ -136,9 +136,7 @@
       consumer_queue->GetChannel()->TakeChannelParcelable());
 
   if (!queue_parcelable.IsValid()) {
-    ALOGE(
-        "BufferHubQueue::CreateConsumerQueueParcelable: Failed to create "
-        "consumer queue parcelable.");
+    ALOGE("%s: Failed to create consumer queue parcelable.", __FUNCTION__);
     return ErrorStatus(EINVAL);
   }
 
@@ -169,8 +167,7 @@
     }
 
     if (ret < 0 && ret != -EINTR) {
-      ALOGE("BufferHubQueue::WaitForBuffers: Failed to wait for buffers: %s",
-            strerror(-ret));
+      ALOGE("%s: Failed to wait for buffers: %s", __FUNCTION__, strerror(-ret));
       return false;
     }
 
@@ -264,14 +261,14 @@
     // wait will be tried again to acquire the newly imported buffer.
     auto buffer_status = OnBufferAllocated();
     if (!buffer_status) {
-      ALOGE("BufferHubQueue::HandleQueueEvent: Failed to import buffer: %s",
+      ALOGE("%s: Failed to import buffer: %s", __FUNCTION__,
             buffer_status.GetErrorMessage().c_str());
     }
   } else if (events & EPOLLHUP) {
-    ALOGD_IF(TRACE, "BufferHubQueue::HandleQueueEvent: hang up event!");
+    ALOGD_IF(TRACE, "%s: hang up event!", __FUNCTION__);
     hung_up_ = true;
   } else {
-    ALOGW("BufferHubQueue::HandleQueueEvent: Unknown epoll events=%x", events);
+    ALOGW("%s: Unknown epoll events=%x", __FUNCTION__, events);
   }
 
   return {};
@@ -279,12 +276,11 @@
 
 Status<void> BufferHubQueue::AddBuffer(
     const std::shared_ptr<BufferHubBase>& buffer, size_t slot) {
-  ALOGD_IF(TRACE, "BufferHubQueue::AddBuffer: buffer_id=%d slot=%zu",
-           buffer->id(), slot);
+  ALOGD_IF(TRACE, "%s: buffer_id=%d slot=%zu", __FUNCTION__, buffer->id(),
+           slot);
 
   if (is_full()) {
-    ALOGE("BufferHubQueue::AddBuffer queue is at maximum capacity: %zu",
-          capacity_);
+    ALOGE("%s: queue is at maximum capacity: %zu", __FUNCTION__, capacity_);
     return ErrorStatus(E2BIG);
   }
 
@@ -303,7 +299,7 @@
     const int ret =
         epoll_fd_.Control(EPOLL_CTL_ADD, event_source.event_fd, &event);
     if (ret < 0) {
-      ALOGE("BufferHubQueue::AddBuffer: Failed to add buffer to epoll set: %s",
+      ALOGE("%s: Failed to add buffer to epoll set: %s", __FUNCTION__,
             strerror(-ret));
       return ErrorStatus(-ret);
     }
@@ -315,17 +311,15 @@
 }
 
 Status<void> BufferHubQueue::RemoveBuffer(size_t slot) {
-  ALOGD_IF(TRACE, "BufferHubQueue::RemoveBuffer: slot=%zu", slot);
+  ALOGD_IF(TRACE, "%s: slot=%zu", __FUNCTION__, slot);
 
   if (buffers_[slot]) {
     for (const auto& event_source : buffers_[slot]->GetEventSources()) {
       const int ret =
           epoll_fd_.Control(EPOLL_CTL_DEL, event_source.event_fd, nullptr);
       if (ret < 0) {
-        ALOGE(
-            "BufferHubQueue::RemoveBuffer: Failed to remove buffer from epoll "
-            "set: %s",
-            strerror(-ret));
+        ALOGE("%s: Failed to remove buffer from epoll set: %s", __FUNCTION__,
+              strerror(-ret));
         return ErrorStatus(-ret);
       }
     }
@@ -345,23 +339,31 @@
   if (!is_full()) {
     available_buffers_.push(std::move(entry));
 
+    // Find and remove the enqueued buffer from unavailable_buffers_slot if
+    // exist.
+    auto enqueued_buffer_iter = std::find_if(
+        unavailable_buffers_slot_.begin(), unavailable_buffers_slot_.end(),
+        [&entry](size_t slot) -> bool { return slot == entry.slot; });
+    if (enqueued_buffer_iter != unavailable_buffers_slot_.end()) {
+      unavailable_buffers_slot_.erase(enqueued_buffer_iter);
+    }
+
     // Trigger OnBufferAvailable callback if registered.
     if (on_buffer_available_)
       on_buffer_available_();
 
     return {};
   } else {
-    ALOGE("BufferHubQueue::Enqueue: Buffer queue is full!");
+    ALOGE("%s: Buffer queue is full!", __FUNCTION__);
     return ErrorStatus(E2BIG);
   }
 }
 
 Status<std::shared_ptr<BufferHubBase>> BufferHubQueue::Dequeue(int timeout,
                                                                size_t* slot) {
-  ALOGD_IF(TRACE, "BufferHubQueue::Dequeue: count=%zu, timeout=%d", count(),
-           timeout);
+  ALOGD_IF(TRACE, "%s: count=%zu, timeout=%d", __FUNCTION__, count(), timeout);
 
-  PDX_TRACE_FORMAT("BufferHubQueue::Dequeue|count=%zu|", count());
+  PDX_TRACE_FORMAT("%s|count=%zu|", __FUNCTION__, count());
 
   if (count() == 0) {
     if (!WaitForBuffers(timeout))
@@ -376,6 +378,7 @@
   *slot = entry.slot;
 
   available_buffers_.pop();
+  unavailable_buffers_slot_.push_back(*slot);
 
   return {std::move(buffer)};
 }
@@ -564,7 +567,7 @@
   auto status =
       InvokeRemoteMethod<BufferHubRPC::ProducerQueueRemoveBuffer>(slot);
   if (!status) {
-    ALOGE("ProducerQueue::RemoveBuffer: Failed to remove producer buffer: %s",
+    ALOGE("%s: Failed to remove producer buffer: %s", __FUNCTION__,
           status.GetErrorMessage().c_str());
     return status.error_status();
   }
@@ -580,31 +583,81 @@
 
 pdx::Status<std::shared_ptr<BufferProducer>> ProducerQueue::Dequeue(
     int timeout, size_t* slot, DvrNativeBufferMetadata* out_meta,
-    pdx::LocalHandle* release_fence) {
+    pdx::LocalHandle* release_fence, bool gain_posted_buffer) {
   ATRACE_NAME("ProducerQueue::Dequeue");
   if (slot == nullptr || out_meta == nullptr || release_fence == nullptr) {
-    ALOGE("ProducerQueue::Dequeue: Invalid parameter.");
+    ALOGE("%s: Invalid parameter.", __FUNCTION__);
     return ErrorStatus(EINVAL);
   }
 
-  auto status = BufferHubQueue::Dequeue(timeout, slot);
-  if (!status)
-    return status.error_status();
-
-  auto buffer = std::static_pointer_cast<BufferProducer>(status.take());
-  const int ret = buffer->GainAsync(out_meta, release_fence);
+  std::shared_ptr<BufferProducer> buffer;
+  Status<std::shared_ptr<BufferHubBase>> dequeue_status =
+      BufferHubQueue::Dequeue(timeout, slot);
+  if (dequeue_status.ok()) {
+    buffer = std::static_pointer_cast<BufferProducer>(dequeue_status.take());
+  } else {
+    if (gain_posted_buffer) {
+      Status<std::shared_ptr<BufferProducer>> dequeue_unacquired_status =
+          ProducerQueue::DequeueUnacquiredBuffer(slot);
+      if (!dequeue_unacquired_status.ok()) {
+        ALOGE("%s: DequeueUnacquiredBuffer returned error: %d", __FUNCTION__,
+              dequeue_unacquired_status.error());
+        return dequeue_unacquired_status.error_status();
+      }
+      buffer = dequeue_unacquired_status.take();
+    } else {
+      return dequeue_status.error_status();
+    }
+  }
+  const int ret =
+      buffer->GainAsync(out_meta, release_fence, gain_posted_buffer);
   if (ret < 0 && ret != -EALREADY)
     return ErrorStatus(-ret);
 
   return {std::move(buffer)};
 }
 
+Status<std::shared_ptr<BufferProducer>> ProducerQueue::DequeueUnacquiredBuffer(
+    size_t* slot) {
+  if (unavailable_buffers_slot_.size() < 1) {
+    ALOGE(
+        "%s: Failed to dequeue un-acquired buffer. All buffer(s) are in "
+        "acquired state if exist.",
+        __FUNCTION__);
+    return ErrorStatus(ENOMEM);
+  }
+
+  // Find the first buffer that is not in acquired state from
+  // unavailable_buffers_slot_.
+  for (auto iter = unavailable_buffers_slot_.begin();
+       iter != unavailable_buffers_slot_.end(); iter++) {
+    std::shared_ptr<BufferProducer> buffer = ProducerQueue::GetBuffer(*iter);
+    if (buffer == nullptr) {
+      ALOGE("%s failed. Buffer slot %d is  null.", __FUNCTION__,
+            static_cast<int>(*slot));
+      return ErrorStatus(EIO);
+    }
+    if (!BufferHubDefs::IsBufferAcquired(buffer->buffer_state())) {
+      *slot = *iter;
+      unavailable_buffers_slot_.erase(iter);
+      unavailable_buffers_slot_.push_back(*slot);
+      ALOGD("%s: Producer queue dequeue unacquired buffer in slot %d",
+            __FUNCTION__, static_cast<int>(*slot));
+      return {std::move(buffer)};
+    }
+  }
+  ALOGE(
+      "%s: Failed to dequeue un-acquired buffer. No un-acquired buffer exist.",
+      __FUNCTION__);
+  return ErrorStatus(EBUSY);
+}
+
 pdx::Status<ProducerQueueParcelable> ProducerQueue::TakeAsParcelable() {
   if (capacity() != 0) {
     ALOGE(
-        "ProducerQueue::TakeAsParcelable: producer queue can only be taken out"
-        " as a parcelable when empty. Current queue capacity: %zu",
-        capacity());
+        "%s: producer queue can only be taken out as a parcelable when empty. "
+        "Current queue capacity: %zu",
+        __FUNCTION__, capacity());
     return ErrorStatus(EINVAL);
   }
 
@@ -628,17 +681,16 @@
     : BufferHubQueue(std::move(handle)) {
   auto status = ImportQueue();
   if (!status) {
-    ALOGE("ConsumerQueue::ConsumerQueue: Failed to import queue: %s",
+    ALOGE("%s: Failed to import queue: %s", __FUNCTION__,
           status.GetErrorMessage().c_str());
     Close(-status.error());
   }
 
   auto import_status = ImportBuffers();
   if (import_status) {
-    ALOGI("ConsumerQueue::ConsumerQueue: Imported %zu buffers.",
-          import_status.get());
+    ALOGI("%s: Imported %zu buffers.", __FUNCTION__, import_status.get());
   } else {
-    ALOGE("ConsumerQueue::ConsumerQueue: Failed to import buffers: %s",
+    ALOGE("%s: Failed to import buffers: %s", __FUNCTION__,
           import_status.GetErrorMessage().c_str());
   }
 }
@@ -647,14 +699,11 @@
   auto status = InvokeRemoteMethod<BufferHubRPC::ConsumerQueueImportBuffers>();
   if (!status) {
     if (status.error() == EBADR) {
-      ALOGI(
-          "ConsumerQueue::ImportBuffers: Queue is silent, no buffers "
-          "imported.");
+      ALOGI("%s: Queue is silent, no buffers imported.", __FUNCTION__);
       return {0};
     } else {
-      ALOGE(
-          "ConsumerQueue::ImportBuffers: Failed to import consumer buffer: %s",
-          status.GetErrorMessage().c_str());
+      ALOGE("%s: Failed to import consumer buffer: %s", __FUNCTION__,
+            status.GetErrorMessage().c_str());
       return status.error_status();
     }
   }
@@ -665,13 +714,13 @@
 
   auto buffer_handle_slots = status.take();
   for (auto& buffer_handle_slot : buffer_handle_slots) {
-    ALOGD_IF(TRACE, "ConsumerQueue::ImportBuffers: buffer_handle=%d",
+    ALOGD_IF(TRACE, ": buffer_handle=%d", __FUNCTION__,
              buffer_handle_slot.first.value());
 
     std::unique_ptr<BufferConsumer> buffer_consumer =
         BufferConsumer::Import(std::move(buffer_handle_slot.first));
     if (!buffer_consumer) {
-      ALOGE("ConsumerQueue::ImportBuffers: Failed to import buffer: slot=%zu",
+      ALOGE("%s: Failed to import buffer: slot=%zu", __FUNCTION__,
             buffer_handle_slot.second);
       last_error = ErrorStatus(EPIPE);
       continue;
@@ -680,7 +729,7 @@
     auto add_status =
         AddBuffer(std::move(buffer_consumer), buffer_handle_slot.second);
     if (!add_status) {
-      ALOGE("ConsumerQueue::ImportBuffers: Failed to add buffer: %s",
+      ALOGE("%s: Failed to add buffer: %s", __FUNCTION__,
             add_status.GetErrorMessage().c_str());
       last_error = add_status;
     } else {
@@ -696,8 +745,8 @@
 
 Status<void> ConsumerQueue::AddBuffer(
     const std::shared_ptr<BufferConsumer>& buffer, size_t slot) {
-  ALOGD_IF(TRACE, "ConsumerQueue::AddBuffer: queue_id=%d buffer_id=%d slot=%zu",
-           id(), buffer->id(), slot);
+  ALOGD_IF(TRACE, "%s: queue_id=%d buffer_id=%d slot=%zu", __FUNCTION__, id(),
+           buffer->id(), slot);
   return BufferHubQueue::AddBuffer(buffer, slot);
 }
 
@@ -706,9 +755,9 @@
     LocalHandle* acquire_fence) {
   if (user_metadata_size != user_metadata_size_) {
     ALOGE(
-        "ConsumerQueue::Dequeue: Metadata size (%zu) for the dequeuing buffer "
-        "does not match metadata size (%zu) for the queue.",
-        user_metadata_size, user_metadata_size_);
+        "%s: Metadata size (%zu) for the dequeuing buffer does not match "
+        "metadata size (%zu) for the queue.",
+        __FUNCTION__, user_metadata_size, user_metadata_size_);
     return ErrorStatus(EINVAL);
   }
 
@@ -723,7 +772,7 @@
     if (metadata_src) {
       memcpy(meta, metadata_src, user_metadata_size);
     } else {
-      ALOGW("ConsumerQueue::Dequeue: no user-defined metadata.");
+      ALOGW("%s: no user-defined metadata.", __FUNCTION__);
     }
   }
 
@@ -735,7 +784,7 @@
     pdx::LocalHandle* acquire_fence) {
   ATRACE_NAME("ConsumerQueue::Dequeue");
   if (slot == nullptr || out_meta == nullptr || acquire_fence == nullptr) {
-    ALOGE("ConsumerQueue::Dequeue: Invalid parameter.");
+    ALOGE("%s: Invalid parameter.", __FUNCTION__);
     return ErrorStatus(EINVAL);
   }
 
@@ -752,19 +801,18 @@
 }
 
 Status<void> ConsumerQueue::OnBufferAllocated() {
-  ALOGD_IF(TRACE, "ConsumerQueue::OnBufferAllocated: queue_id=%d", id());
+  ALOGD_IF(TRACE, "%s: queue_id=%d", __FUNCTION__, id());
 
   auto status = ImportBuffers();
   if (!status) {
-    ALOGE("ConsumerQueue::OnBufferAllocated: Failed to import buffers: %s",
+    ALOGE("%s: Failed to import buffers: %s", __FUNCTION__,
           status.GetErrorMessage().c_str());
     return ErrorStatus(status.error());
   } else if (status.get() == 0) {
-    ALOGW("ConsumerQueue::OnBufferAllocated: No new buffers allocated!");
+    ALOGW("%s: No new buffers allocated!", __FUNCTION__);
     return ErrorStatus(ENOBUFS);
   } else {
-    ALOGD_IF(TRACE,
-             "ConsumerQueue::OnBufferAllocated: Imported %zu consumer buffers.",
+    ALOGD_IF(TRACE, "%s: Imported %zu consumer buffers.", __FUNCTION__,
              status.get());
     return {};
   }
diff --git a/libs/vr/libbufferhubqueue/include/private/dvr/buffer_hub_queue_client.h b/libs/vr/libbufferhubqueue/include/private/dvr/buffer_hub_queue_client.h
index c69002d..def7c6b 100644
--- a/libs/vr/libbufferhubqueue/include/private/dvr/buffer_hub_queue_client.h
+++ b/libs/vr/libbufferhubqueue/include/private/dvr/buffer_hub_queue_client.h
@@ -57,10 +57,10 @@
   uint32_t default_width() const { return default_width_; }
 
   // Returns the default buffer height of this buffer queue.
-  uint32_t default_height() const { return static_cast<uint32_t>(default_height_); }
+  uint32_t default_height() const { return default_height_; }
 
   // Returns the default buffer format of this buffer queue.
-  uint32_t default_format() const { return static_cast<uint32_t>(default_format_); }
+  uint32_t default_format() const { return default_format_; }
 
   // Creates a new consumer in handle form for immediate transport over RPC.
   pdx::Status<pdx::LocalChannelHandle> CreateConsumerQueueHandle(
@@ -208,6 +208,14 @@
   // Size of the metadata that buffers in this queue cary.
   size_t user_metadata_size_{0};
 
+  // Buffers and related data that are available for dequeue.
+  std::priority_queue<Entry, std::vector<Entry>, EntryComparator>
+      available_buffers_;
+
+  // Slot of the buffers that are not available for normal dequeue. For example,
+  // the slot of posted or acquired buffers in the perspective of a producer.
+  std::vector<size_t> unavailable_buffers_slot_;
+
  private:
   void Initialize();
 
@@ -252,10 +260,6 @@
   // queue regardless of its queue position or presence in the ring buffer.
   std::array<std::shared_ptr<BufferHubBase>, kMaxQueueCapacity> buffers_;
 
-  // Buffers and related data that are available for dequeue.
-  std::priority_queue<Entry, std::vector<Entry>, EntryComparator>
-      available_buffers_;
-
   // Keeps track with how many buffers have been added into the queue.
   size_t capacity_{0};
 
@@ -349,11 +353,30 @@
   // Dequeue a producer buffer to write. The returned buffer in |Gain|'ed mode,
   // and caller should call Post() once it's done writing to release the buffer
   // to the consumer side.
+  // @return a buffer in gained state, which was originally in released state.
   pdx::Status<std::shared_ptr<BufferProducer>> Dequeue(
       int timeout, size_t* slot, pdx::LocalHandle* release_fence);
+
+  // Dequeue a producer buffer to write. The returned buffer in |Gain|'ed mode,
+  // and caller should call Post() once it's done writing to release the buffer
+  // to the consumer side.
+  //
+  // @param timeout to dequeue a buffer.
+  // @param slot is the slot of the output BufferProducer.
+  // @param release_fence for gaining a buffer.
+  // @param out_meta metadata of the output buffer.
+  // @param gain_posted_buffer whether to gain posted buffer if no released
+  //     buffer is available to gain.
+  // @return a buffer in gained state, which was originally in released state if
+  //     gain_posted_buffer is false, or in posted/released state if
+  //     gain_posted_buffer is true.
+  // TODO(b/112007999): gain_posted_buffer true is only used to prevent
+  // libdvrtracking from starving when there are non-responding clients. This
+  // gain_posted_buffer param can be removed once libdvrtracking start to use
+  // the new AHardwareBuffer API.
   pdx::Status<std::shared_ptr<BufferProducer>> Dequeue(
       int timeout, size_t* slot, DvrNativeBufferMetadata* out_meta,
-      pdx::LocalHandle* release_fence);
+      pdx::LocalHandle* release_fence, bool gain_posted_buffer = false);
 
   // Enqueues a producer buffer in the queue.
   pdx::Status<void> Enqueue(const std::shared_ptr<BufferProducer>& buffer,
@@ -374,6 +397,16 @@
   // arguments as the constructors.
   explicit ProducerQueue(pdx::LocalChannelHandle handle);
   ProducerQueue(const ProducerQueueConfig& config, const UsagePolicy& usage);
+
+  // Dequeue a producer buffer to write. The returned buffer in |Gain|'ed mode,
+  // and caller should call Post() once it's done writing to release the buffer
+  // to the consumer side.
+  //
+  // @param slot the slot of the returned buffer.
+  // @return a buffer in gained state, which was originally in posted state or
+  //     released state.
+  pdx::Status<std::shared_ptr<BufferProducer>> DequeueUnacquiredBuffer(
+      size_t* slot);
 };
 
 class ConsumerQueue : public BufferHubQueue {
diff --git a/libs/vr/libbufferhubqueue/tests/buffer_hub_queue-test.cpp b/libs/vr/libbufferhubqueue/tests/buffer_hub_queue-test.cpp
index 046df54..c58f55f 100644
--- a/libs/vr/libbufferhubqueue/tests/buffer_hub_queue-test.cpp
+++ b/libs/vr/libbufferhubqueue/tests/buffer_hub_queue-test.cpp
@@ -1,5 +1,6 @@
 #include <base/logging.h>
 #include <binder/Parcel.h>
+#include <dvr/dvr_api.h>
 #include <private/dvr/buffer_hub_client.h>
 #include <private/dvr/buffer_hub_queue_client.h>
 
@@ -122,6 +123,147 @@
   }
 }
 
+TEST_F(BufferHubQueueTest,
+       TestDequeuePostedBufferIfNoAvailableReleasedBuffer_withBufferConsumer) {
+  ASSERT_TRUE(CreateQueues(config_builder_.Build(), UsagePolicy{}));
+
+  // Allocate 3 buffers to use.
+  const size_t test_queue_capacity = 3;
+  for (int64_t i = 0; i < test_queue_capacity; i++) {
+    AllocateBuffer();
+  }
+  EXPECT_EQ(producer_queue_->capacity(), test_queue_capacity);
+
+  size_t producer_slot, consumer_slot;
+  LocalHandle fence;
+  DvrNativeBufferMetadata mi, mo;
+
+  // Producer posts 2 buffers and remember their posted sequence.
+  std::deque<size_t> posted_slots;
+  for (int64_t i = 0; i < 2; i++) {
+    auto p1_status =
+        producer_queue_->Dequeue(kTimeoutMs, &producer_slot, &mo, &fence, true);
+    EXPECT_TRUE(p1_status.ok());
+    auto p1 = p1_status.take();
+    ASSERT_NE(p1, nullptr);
+
+    // Producer should not be gaining posted buffer when there are still
+    // available buffers to gain.
+    auto found_iter =
+        std::find(posted_slots.begin(), posted_slots.end(), producer_slot);
+    EXPECT_EQ(found_iter, posted_slots.end());
+    posted_slots.push_back(producer_slot);
+
+    // Producer posts the buffer.
+    mi.index = i;
+    EXPECT_EQ(0, p1->PostAsync(&mi, LocalHandle()));
+  }
+
+  // Consumer acquires one buffer.
+  auto c1_status =
+      consumer_queue_->Dequeue(kTimeoutMs, &consumer_slot, &mo, &fence);
+  EXPECT_TRUE(c1_status.ok());
+  auto c1 = c1_status.take();
+  ASSERT_NE(c1, nullptr);
+  // Consumer should get the oldest posted buffer. No checks here.
+  // posted_slots[0] should be in acquired state now.
+  EXPECT_EQ(mo.index, 0);
+  // Consumer releases the buffer.
+  EXPECT_EQ(c1->ReleaseAsync(&mi, LocalHandle()), 0);
+  // posted_slots[0] should be in released state now.
+
+  // Producer gain and post 2 buffers.
+  for (int64_t i = 0; i < 2; i++) {
+    auto p1_status =
+        producer_queue_->Dequeue(kTimeoutMs, &producer_slot, &mo, &fence, true);
+    EXPECT_TRUE(p1_status.ok());
+    auto p1 = p1_status.take();
+    ASSERT_NE(p1, nullptr);
+
+    // The gained buffer should be the one in released state or the one haven't
+    // been use.
+    EXPECT_NE(posted_slots[1], producer_slot);
+
+    mi.index = i + 2;
+    EXPECT_EQ(0, p1->PostAsync(&mi, LocalHandle()));
+  }
+
+  // Producer gains a buffer.
+  auto p1_status =
+      producer_queue_->Dequeue(kTimeoutMs, &producer_slot, &mo, &fence, true);
+  EXPECT_TRUE(p1_status.ok());
+  auto p1 = p1_status.take();
+  ASSERT_NE(p1, nullptr);
+
+  // The gained buffer should be the oldest posted buffer.
+  EXPECT_EQ(posted_slots[1], producer_slot);
+
+  // Producer posts the buffer.
+  mi.index = 4;
+  EXPECT_EQ(0, p1->PostAsync(&mi, LocalHandle()));
+}
+
+TEST_F(BufferHubQueueTest,
+       TestDequeuePostedBufferIfNoAvailableReleasedBuffer_noBufferConsumer) {
+  ASSERT_TRUE(CreateQueues(config_builder_.Build(), UsagePolicy{}));
+
+  // Allocate 4 buffers to use.
+  const size_t test_queue_capacity = 4;
+  for (int64_t i = 0; i < test_queue_capacity; i++) {
+    AllocateBuffer();
+  }
+  EXPECT_EQ(producer_queue_->capacity(), test_queue_capacity);
+
+  // Post all allowed buffers and remember their posted sequence.
+  std::deque<size_t> posted_slots;
+  for (int64_t i = 0; i < test_queue_capacity; i++) {
+    size_t slot;
+    LocalHandle fence;
+    DvrNativeBufferMetadata mi, mo;
+
+    // Producer gains a buffer.
+    auto p1_status =
+        producer_queue_->Dequeue(kTimeoutMs, &slot, &mo, &fence, true);
+    EXPECT_TRUE(p1_status.ok());
+    auto p1 = p1_status.take();
+    ASSERT_NE(p1, nullptr);
+
+    // Producer should not be gaining posted buffer when there are still
+    // available buffers to gain.
+    auto found_iter = std::find(posted_slots.begin(), posted_slots.end(), slot);
+    EXPECT_EQ(found_iter, posted_slots.end());
+    posted_slots.push_back(slot);
+
+    // Producer posts the buffer.
+    mi.index = i;
+    EXPECT_EQ(p1->PostAsync(&mi, LocalHandle()), 0);
+  }
+
+  // Gain posted buffers in sequence.
+  const int64_t nb_dequeue_all_times = 2;
+  for (int j = 0; j < nb_dequeue_all_times; ++j) {
+    for (int i = 0; i < test_queue_capacity; ++i) {
+      size_t slot;
+      LocalHandle fence;
+      DvrNativeBufferMetadata mi, mo;
+
+      // Producer gains a buffer.
+      auto p1_status =
+          producer_queue_->Dequeue(kTimeoutMs, &slot, &mo, &fence, true);
+      EXPECT_TRUE(p1_status.ok());
+      auto p1 = p1_status.take();
+      ASSERT_NE(p1, nullptr);
+
+      // The gained buffer should be the oldest posted buffer.
+      EXPECT_EQ(posted_slots[i], slot);
+
+      // Producer posts the buffer.
+      mi.index = i + test_queue_capacity * (j + 1);
+      EXPECT_EQ(p1->PostAsync(&mi, LocalHandle()), 0);
+    }
+  }
+}
+
 TEST_F(BufferHubQueueTest, TestProducerConsumer) {
   const size_t kBufferCount = 16;
   size_t slot;
@@ -245,8 +387,8 @@
 
   for (size_t i = 0; i < kBufferCount; i++) {
     Entry* entry = &buffers[i];
-    auto producer_status = producer_queue_->Dequeue(
-        kTimeoutMs, &entry->slot, &mo, &entry->fence);
+    auto producer_status =
+        producer_queue_->Dequeue(kTimeoutMs, &entry->slot, &mo, &entry->fence);
     ASSERT_TRUE(producer_status.ok());
     entry->buffer = producer_status.take();
     ASSERT_NE(nullptr, entry->buffer);
diff --git a/libs/vr/libpdx/status_tests.cpp b/libs/vr/libpdx/status_tests.cpp
index d4e697c..772c529 100644
--- a/libs/vr/libpdx/status_tests.cpp
+++ b/libs/vr/libpdx/status_tests.cpp
@@ -2,6 +2,8 @@
 
 #include <gtest/gtest.h>
 
+#include <memory>
+
 using android::pdx::ErrorStatus;
 using android::pdx::Status;
 
@@ -84,8 +86,8 @@
   Status<std::unique_ptr<int>> status1;
   Status<std::unique_ptr<int>> status2;
 
-  status1 = Status<std::unique_ptr<int>>{std::unique_ptr<int>{new int{11}}};
-  status2 = Status<std::unique_ptr<int>>{std::unique_ptr<int>{new int{12}}};
+  status1 = Status<std::unique_ptr<int>>{std::make_unique<int>(int{11})};
+  status2 = Status<std::unique_ptr<int>>{std::make_unique<int>(int{12})};
   EXPECT_FALSE(status1.empty());
   EXPECT_FALSE(status2.empty());
   EXPECT_TRUE(status1.ok());
@@ -114,7 +116,7 @@
 }
 
 TEST(Status, Take) {
-  Status<std::unique_ptr<int>> status{std::unique_ptr<int>{new int{123}}};
+  Status<std::unique_ptr<int>> status{std::make_unique<int>(int{123})};
   EXPECT_FALSE(status.empty());
   EXPECT_NE(nullptr, status.get());
 
diff --git a/opengl/libs/EGL/Loader.cpp b/opengl/libs/EGL/Loader.cpp
index a150db1..0c43b83 100644
--- a/opengl/libs/EGL/Loader.cpp
+++ b/opengl/libs/EGL/Loader.cpp
@@ -42,18 +42,6 @@
   android_namespace_t* android_get_exported_namespace(const char*);
 
   // TODO(ianelliott@): Get this from an ANGLE header:
-  typedef enum ANGLEPreference {
-      ANGLE_NO_PREFERENCE = 0,
-      ANGLE_PREFER_NATIVE = 1,
-      ANGLE_PREFER_ANGLE = 2,
-  } ANGLEPreference;
-
-  // TODO(ianelliott@): Get this from an ANGLE header:
-  typedef bool (*fpANGLEUseForApplication)(const char* appName, const char* deviceMfr,
-                                           const char* deviceModel, ANGLEPreference developerOption,
-                                           ANGLEPreference appPreference);
-
-  // TODO(ianelliott@): Get this from an ANGLE header:
   typedef bool (*fpANGLEGetUtilityAPI)(unsigned int* versionToUse);
 
   // TODO(ianelliott@): Get this from an ANGLE header:
@@ -522,16 +510,56 @@
     return nullptr;
 }
 
-static ANGLEPreference getAnglePref(const char* app_pref) {
-    if (app_pref == nullptr)
-        return ANGLE_NO_PREFERENCE;
 
-    if (strcmp(app_pref, "angle") == 0) {
-        return ANGLE_PREFER_ANGLE;
-    } else if (strcmp(app_pref, "native") == 0) {
-        return ANGLE_PREFER_NATIVE;
+static bool check_angle_rules(void* so, const char* app_name) {
+    bool use_angle = false;
+    const int rules_fd = android::GraphicsEnv::getInstance().getAngleRulesFd();
+    const long rules_offset = android::GraphicsEnv::getInstance().getAngleRulesOffset();
+    const long rules_length = android::GraphicsEnv::getInstance().getAngleRulesLength();
+
+    std::string app_name_str = app_name ? app_name : "";
+    char manufacturer[PROPERTY_VALUE_MAX];
+    char model[PROPERTY_VALUE_MAX];
+    property_get("ro.product.manufacturer", manufacturer, "UNSET");
+    property_get("ro.product.model", model, "UNSET");
+
+    fpANGLEGetUtilityAPI ANGLEGetUtilityAPI =
+            (fpANGLEGetUtilityAPI)dlsym(so, "ANGLEGetUtilityAPI");
+
+    if (ANGLEGetUtilityAPI) {
+
+        // Negotiate the interface version by requesting most recent known to the platform
+        unsigned int versionToUse = 1;
+        if ((ANGLEGetUtilityAPI)(&versionToUse)) {
+
+            // Add and remove versions below as needed
+            switch(versionToUse) {
+            case 1: {
+                ALOGV("Using version 1 of ANGLE opt-in/out logic interface");
+                fpAndroidUseANGLEForApplication AndroidUseANGLEForApplication =
+                        (fpAndroidUseANGLEForApplication)dlsym(so, "AndroidUseANGLEForApplication");
+
+                if (AndroidUseANGLEForApplication) {
+                    use_angle = (AndroidUseANGLEForApplication)(rules_fd, rules_offset,
+                                                                rules_length, app_name_str.c_str(),
+                                                                manufacturer, model);
+                } else {
+                    ALOGW("Cannot find AndroidUseANGLEForApplication in ANGLE feature-support library");
+                }
+            }
+            break;
+            default:
+                ALOGW("Cannot find supported version of ANGLE feature-support library, found version %u", versionToUse);
+            }
+        } else {
+            ALOGW("Cannot use ANGLE feature-support library, it is older than supported by EGL, requested version %u", versionToUse);
+        }
+    } else {
+        ALOGW("Cannot find ANGLEGetUtilityAPI function");
     }
-    return ANGLE_NO_PREFERENCE;
+
+    ALOGV("Close temporarily-loaded ANGLE opt-in/out logic");
+    return use_angle;
 }
 
 static void* load_angle(const char* kind, android_namespace_t* ns, egl_connection_t* cnx) {
@@ -543,15 +571,10 @@
     char prop[PROPERTY_VALUE_MAX];
 
     const char* app_name = android::GraphicsEnv::getInstance().getAngleAppName();
-    const char* app_pref = android::GraphicsEnv::getInstance().getAngleAppPref();
     bool developer_opt_in = android::GraphicsEnv::getInstance().getAngleDeveloperOptIn();
-    const int rules_fd = android::GraphicsEnv::getInstance().getAngleRulesFd();
-    const long rules_offset = android::GraphicsEnv::getInstance().getAngleRulesOffset();
-    const long rules_length = android::GraphicsEnv::getInstance().getAngleRulesLength();
 
     // Determine whether or not to use ANGLE:
-    ANGLEPreference developer_option = developer_opt_in ? ANGLE_PREFER_ANGLE : ANGLE_NO_PREFERENCE;
-    bool use_angle = (developer_option == ANGLE_PREFER_ANGLE);
+    bool use_angle = developer_opt_in;
 
     if (use_angle) {
         ALOGV("User set \"Developer Options\" to force the use of ANGLE");
@@ -560,59 +583,11 @@
     } else {
         // The "Developer Options" value wasn't set to force the use of ANGLE.  Need to temporarily
         // load ANGLE and call the updatable opt-in/out logic:
-        std::string app_name_str = app_name ? app_name : "";
-        char manufacturer[PROPERTY_VALUE_MAX];
-        char model[PROPERTY_VALUE_MAX];
-        property_get("ro.product.manufacturer", manufacturer, "UNSET");
-        property_get("ro.product.model", model, "UNSET");
 
         cnx->featureSo = load_angle_from_namespace("feature_support", ns);
         if (cnx->featureSo) {
             ALOGV("loaded ANGLE's opt-in/out logic from namespace");
-            bool use_version0_API = false;
-            bool use_version1_API = false;
-            fpANGLEGetUtilityAPI ANGLEGetUtilityAPI =
-                    (fpANGLEGetUtilityAPI)dlsym(cnx->featureSo, "ANGLEGetUtilityAPI");
-            if (ANGLEGetUtilityAPI) {
-                unsigned int versionToUse = 1;
-                if ((ANGLEGetUtilityAPI)(&versionToUse)) {
-                    if (versionToUse == 1) {
-                        use_version1_API = true;
-                    } else {
-                        use_version0_API = true;
-                    }
-                }
-            } else {
-                use_version0_API = true;
-                ALOGV("Cannot find ANGLEGetUtilityAPI in library");
-            }
-            if (use_version1_API) {
-                // Use the new version 1 API to determine if the
-                // application should use the ANGLE or the native driver.
-                fpAndroidUseANGLEForApplication AndroidUseANGLEForApplication =
-                        (fpAndroidUseANGLEForApplication)dlsym(cnx->featureSo, "AndroidUseANGLEForApplication");
-                if (AndroidUseANGLEForApplication) {
-                    use_angle = (AndroidUseANGLEForApplication)(rules_fd, rules_offset,
-                                                                rules_length, app_name_str.c_str(),
-                                                                manufacturer, model);
-                } else {
-                    ALOGW("Cannot find AndroidUseANGLEForApplication in library");
-                }
-            } else if (use_version0_API) {
-                // Use the old version 0 API to determine if the
-                // application should use the ANGLE or the native driver.
-                fpANGLEUseForApplication ANGLEUseForApplication =
-                        (fpANGLEUseForApplication)dlsym(cnx->featureSo, "ANGLEUseForApplication");
-                if (ANGLEUseForApplication) {
-                    ANGLEPreference app_preference =
-                            getAnglePref(android::GraphicsEnv::getInstance().getAngleAppPref());
-                    use_angle = (ANGLEUseForApplication)(app_name_str.c_str(), manufacturer, model,
-                                                         developer_option, app_preference);
-                    ALOGV("Result of opt-in/out logic is %s", use_angle ? "true" : "false");
-                } else {
-                    ALOGW("Cannot find ANGLEUseForApplication in library");
-                }
-            }
+            use_angle = check_angle_rules(cnx->featureSo, app_name);
         } else {
             // We weren't able to load and call the updateable opt-in/out logic.
             // If we can't load the library, there is no ANGLE available.
diff --git a/services/gpuservice/Android.bp b/services/gpuservice/Android.bp
new file mode 100644
index 0000000..250bbee
--- /dev/null
+++ b/services/gpuservice/Android.bp
@@ -0,0 +1,74 @@
+filegroup {
+    name: "gpuservice_sources",
+    srcs: [
+        "GpuService.cpp",
+    ],
+}
+
+filegroup {
+    name: "gpuservice_binary_sources",
+    srcs: ["main_gpuservice.cpp"],
+}
+
+cc_defaults {
+    name: "gpuservice_defaults",
+    cflags: [
+        "-DLOG_TAG=\"GpuService\"",
+        "-Wall",
+        "-Werror",
+        "-Wformat",
+        "-Wthread-safety",
+        "-Wunused",
+        "-Wunreachable-code",
+    ],
+    cppflags: ["-std=c++1z"],
+    srcs: [
+        ":gpuservice_sources",
+    ],
+    include_dirs: [
+        "frameworks/native/vulkan/vkjson",
+        "frameworks/native/vulkan/include",
+    ],
+    shared_libs: [
+        "libbinder",
+        "liblog",
+        "libutils",
+        "libvulkan",
+    ],
+    static_libs: [
+        "libvkjson",
+    ],
+}
+
+cc_defaults {
+    name: "gpuservice_production_defaults",
+    defaults: ["gpuservice_defaults"],
+    cflags: [
+        "-fvisibility=hidden",
+        "-fwhole-program-vtables", // requires ThinLTO
+    ],
+    lto: {
+        thin: true,
+    },
+}
+
+cc_defaults {
+    name: "gpuservice_binary",
+    defaults: ["gpuservice_defaults"],
+    whole_static_libs: [
+        "libsigchain",
+    ],
+    shared_libs: [
+        "libbinder",
+        "liblog",
+        "libutils",
+    ],
+    ldflags: ["-Wl,--export-dynamic"],
+}
+
+cc_binary {
+    name: "gpuservice",
+    defaults: ["gpuservice_binary"],
+    init_rc: ["gpuservice.rc"],
+    srcs: [":gpuservice_binary_sources"],
+}
diff --git a/services/surfaceflinger/GpuService.cpp b/services/gpuservice/GpuService.cpp
similarity index 83%
rename from services/surfaceflinger/GpuService.cpp
rename to services/gpuservice/GpuService.cpp
index 71052fb..e4ca6bc 100644
--- a/services/surfaceflinger/GpuService.cpp
+++ b/services/gpuservice/GpuService.cpp
@@ -23,10 +23,7 @@
 
 namespace android {
 
-// ----------------------------------------------------------------------------
-
-class BpGpuService : public BpInterface<IGpuService>
-{
+class BpGpuService : public BpInterface<IGpuService> {
 public:
     explicit BpGpuService(const sp<IBinder>& impl) : BpInterface<IGpuService>(impl) {}
 };
@@ -34,19 +31,15 @@
 IMPLEMENT_META_INTERFACE(GpuService, "android.ui.IGpuService");
 
 status_t BnGpuService::onTransact(uint32_t code, const Parcel& data,
-        Parcel* reply, uint32_t flags)
-{
+        Parcel* reply, uint32_t flags) {
     status_t status;
     switch (code) {
     case SHELL_COMMAND_TRANSACTION: {
         int in = data.readFileDescriptor();
         int out = data.readFileDescriptor();
         int err = data.readFileDescriptor();
-        int argc = data.readInt32();
-        Vector<String16> args;
-        for (int i = 0; i < argc && data.dataAvail() > 0; i++) {
-           args.add(data.readString16());
-        }
+        std::vector<String16> args;
+        data.readString16Vector(&args);
         sp<IBinder> unusedCallback;
         sp<IResultReceiver> resultReceiver;
         if ((status = data.readNullableStrongBinder(&unusedCallback)) != OK)
@@ -64,20 +57,17 @@
     }
 }
 
-// ----------------------------------------------------------------------------
-
 namespace {
     status_t cmd_help(int out);
     status_t cmd_vkjson(int out, int err);
 }
 
-const char* const GpuService::SERVICE_NAME = "gpu";
+const char* const GpuService::SERVICE_NAME = "gpuservice";
 
-GpuService::GpuService() {}
+GpuService::GpuService() = default;
 
 status_t GpuService::shellCommand(int /*in*/, int out, int err,
-        Vector<String16>& args)
-{
+                                  std::vector<String16>& args) {
     ALOGV("GpuService::shellCommand");
     for (size_t i = 0, n = args.size(); i < n; i++)
         ALOGV("  arg[%zu]: '%s'", i, String8(args[i]).string());
@@ -93,8 +83,6 @@
     return BAD_VALUE;
 }
 
-// ----------------------------------------------------------------------------
-
 namespace {
 
 status_t cmd_help(int out) {
diff --git a/services/surfaceflinger/GpuService.h b/services/gpuservice/GpuService.h
similarity index 80%
rename from services/surfaceflinger/GpuService.h
rename to services/gpuservice/GpuService.h
index b8c28d2..e2b396e 100644
--- a/services/surfaceflinger/GpuService.h
+++ b/services/gpuservice/GpuService.h
@@ -17,6 +17,8 @@
 #ifndef ANDROID_GPUSERVICE_H
 #define ANDROID_GPUSERVICE_H
 
+#include <vector>
+
 #include <binder/IInterface.h>
 #include <cutils/compiler.h>
 
@@ -34,22 +36,21 @@
 class BnGpuService: public BnInterface<IGpuService> {
 protected:
     virtual status_t shellCommand(int in, int out, int err,
-        Vector<String16>& args) = 0;
+                                  std::vector<String16>& args) = 0;
 
-    virtual status_t onTransact(uint32_t code, const Parcel& data,
+    status_t onTransact(uint32_t code, const Parcel& data,
             Parcel* reply, uint32_t flags = 0) override;
 };
 
-class GpuService : public BnGpuService
-{
+class GpuService : public BnGpuService {
 public:
     static const char* const SERVICE_NAME ANDROID_API;
 
     GpuService() ANDROID_API;
 
 protected:
-    virtual status_t shellCommand(int in, int out, int err,
-        Vector<String16>& args) override;
+    status_t shellCommand(int in, int out, int err,
+                          std::vector<String16>& args) override;
 };
 
 } // namespace android
diff --git a/services/gpuservice/gpuservice.rc b/services/gpuservice/gpuservice.rc
new file mode 100644
index 0000000..d23cf46
--- /dev/null
+++ b/services/gpuservice/gpuservice.rc
@@ -0,0 +1,4 @@
+service gpuservice /system/bin/gpuservice
+    class core
+    user gpu_service
+    group graphics
diff --git a/services/gpuservice/main_gpuservice.cpp b/services/gpuservice/main_gpuservice.cpp
new file mode 100644
index 0000000..64aafca
--- /dev/null
+++ b/services/gpuservice/main_gpuservice.cpp
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <binder/IPCThreadState.h>
+#include <binder/IServiceManager.h>
+#include <binder/ProcessState.h>
+#include <sys/resource.h>
+#include "GpuService.h"
+
+using namespace android;
+
+int main(int /* argc */, char** /* argv */) {
+    signal(SIGPIPE, SIG_IGN);
+
+    // publish GpuService
+    sp<GpuService> gpuservice = new GpuService();
+    sp<IServiceManager> sm(defaultServiceManager());
+    sm->addService(String16(GpuService::SERVICE_NAME), gpuservice, false);
+
+    // limit the number of binder threads to 4.
+    ProcessState::self()->setThreadPoolMaxThreadCount(4);
+
+    // start the thread pool
+    sp<ProcessState> ps(ProcessState::self());
+    ps->startThreadPool();
+    ps->giveThreadPoolName();
+    IPCThreadState::self()->joinThreadPool();
+
+    return 0;
+}
diff --git a/services/surfaceflinger/Android.bp b/services/surfaceflinger/Android.bp
index 16003a2..e8092a9 100644
--- a/services/surfaceflinger/Android.bp
+++ b/services/surfaceflinger/Android.bp
@@ -19,10 +19,6 @@
         "-DGL_GLEXT_PROTOTYPES",
         "-DEGL_EGLEXT_PROTOTYPES",
     ],
-    include_dirs: [
-        "frameworks/native/vulkan/vkjson",
-        "frameworks/native/vulkan/include",
-    ],
     shared_libs: [
         "android.frameworks.vr.composer@1.0",
         "android.hardware.configstore-utils",
@@ -59,13 +55,11 @@
         "libtimestats_proto",
         "libui",
         "libutils",
-        "libvulkan",
     ],
     static_libs: [
         "librenderengine",
         "libserviceutils",
         "libtrace_proto",
-        "libvkjson",
         "libvr_manager",
         "libvrflinger",
     ],
@@ -132,7 +126,6 @@
         "Effects/Daltonizer.cpp",
         "EventLog/EventLog.cpp",
         "FrameTracker.cpp",
-        "GpuService.cpp",
         "Layer.cpp",
         "LayerBE.cpp",
         "LayerProtoHelper.cpp",
diff --git a/services/surfaceflinger/BufferLayer.cpp b/services/surfaceflinger/BufferLayer.cpp
index 440f1e2..641bd8d 100644
--- a/services/surfaceflinger/BufferLayer.cpp
+++ b/services/surfaceflinger/BufferLayer.cpp
@@ -229,15 +229,14 @@
             getBE().compositionInfo.mBuffer->getPixelFormat() == HAL_PIXEL_FORMAT_RGBA_1010102);
 }
 
-void BufferLayer::setPerFrameData(const sp<const DisplayDevice>& display) {
+void BufferLayer::setPerFrameData(DisplayId displayId, const ui::Transform& transform,
+                                  const Rect& viewport, int32_t supportedPerFrameMetadata) {
     // Apply this display's projection's viewport to the visible region
     // before giving it to the HWC HAL.
-    const ui::Transform& tr = display->getTransform();
-    const auto& viewport = display->getViewport();
-    Region visible = tr.transform(visibleRegion.intersect(viewport));
-    const auto displayId = display->getId();
+    Region visible = transform.transform(visibleRegion.intersect(viewport));
+
     if (!hasHwcLayer(displayId)) {
-        ALOGE("[%s] failed to setPerFrameData: no HWC layer found (%d)",
+        ALOGE("[%s] failed to setPerFrameData: no HWC layer found for display %" PRIu64,
               mName.string(), displayId);
         return;
     }
@@ -290,7 +289,7 @@
     }
 
     const HdrMetadata& metadata = getDrawingHdrMetadata();
-    error = hwcLayer->setPerFrameMetadata(display->getSupportedPerFrameMetadata(), metadata);
+    error = hwcLayer->setPerFrameMetadata(supportedPerFrameMetadata, metadata);
     if (error != HWC2::Error::None && error != HWC2::Error::Unsupported) {
         ALOGE("[%s] Failed to set hdrMetadata: %s (%d)", mName.string(),
               to_string(error).c_str(), static_cast<int32_t>(error));
@@ -303,10 +302,10 @@
     }
     getBE().compositionInfo.hwc.dataspace = mCurrentDataSpace;
     getBE().compositionInfo.hwc.hdrMetadata = getDrawingHdrMetadata();
-    getBE().compositionInfo.hwc.supportedPerFrameMetadata = display->getSupportedPerFrameMetadata();
+    getBE().compositionInfo.hwc.supportedPerFrameMetadata = supportedPerFrameMetadata;
     getBE().compositionInfo.hwc.colorTransform = getColorTransform();
 
-    setHwcLayerBuffer(display);
+    setHwcLayerBuffer(displayId);
 }
 
 bool BufferLayer::onPreComposition(nsecs_t refreshStartTime) {
@@ -318,10 +317,10 @@
     return hasReadyFrame();
 }
 
-bool BufferLayer::onPostComposition(const std::shared_ptr<FenceTime>& glDoneFence,
+bool BufferLayer::onPostComposition(const std::optional<DisplayId>& displayId,
+                                    const std::shared_ptr<FenceTime>& glDoneFence,
                                     const std::shared_ptr<FenceTime>& presentFence,
                                     const CompositorTiming& compositorTiming) {
-
     // mFrameLatencyNeeded is true when a new frame was latched for the
     // composition.
     if (!mFrameLatencyNeeded) return false;
@@ -352,11 +351,10 @@
     if (presentFence->isValid()) {
         mTimeStats.setPresentFence(layerID, mCurrentFrameNumber, presentFence);
         mFrameTracker.setActualPresentFence(std::shared_ptr<FenceTime>(presentFence));
-    } else if (mFlinger->getHwComposer().isConnected(HWC_DISPLAY_PRIMARY)) {
+    } else if (displayId && mFlinger->getHwComposer().isConnected(*displayId)) {
         // The HWC doesn't support present fences, so use the refresh
         // timestamp instead.
-        const nsecs_t actualPresentTime =
-                mFlinger->getHwComposer().getRefreshTimestamp(HWC_DISPLAY_PRIMARY);
+        const nsecs_t actualPresentTime = mFlinger->getHwComposer().getRefreshTimestamp(*displayId);
         mTimeStats.setPresentTime(layerID, mCurrentFrameNumber, actualPresentTime);
         mFrameTracker.setActualPresentTime(actualPresentTime);
     }
diff --git a/services/surfaceflinger/BufferLayer.h b/services/surfaceflinger/BufferLayer.h
index d000d85..b3ea7e6 100644
--- a/services/surfaceflinger/BufferLayer.h
+++ b/services/surfaceflinger/BufferLayer.h
@@ -80,10 +80,12 @@
 
     bool isHdrY410() const override;
 
-    void setPerFrameData(const sp<const DisplayDevice>& displayDevice) override;
+    void setPerFrameData(DisplayId displayId, const ui::Transform& transform, const Rect& viewport,
+                         int32_t supportedPerFrameMetadata) override;
 
     bool onPreComposition(nsecs_t refreshStartTime) override;
-    bool onPostComposition(const std::shared_ptr<FenceTime>& glDoneFence,
+    bool onPostComposition(const std::optional<DisplayId>& displayId,
+                           const std::shared_ptr<FenceTime>& glDoneFence,
                            const std::shared_ptr<FenceTime>& presentFence,
                            const CompositorTiming& compositorTiming) override;
 
@@ -145,7 +147,7 @@
     virtual status_t updateActiveBuffer() = 0;
     virtual status_t updateFrameNumber(nsecs_t latchTime) = 0;
 
-    virtual void setHwcLayerBuffer(const sp<const DisplayDevice>& display) = 0;
+    virtual void setHwcLayerBuffer(DisplayId displayId) = 0;
 
     // -----------------------------------------------------------------------
 
diff --git a/services/surfaceflinger/BufferQueueLayer.cpp b/services/surfaceflinger/BufferQueueLayer.cpp
index c130bc5..5dea3c8 100644
--- a/services/surfaceflinger/BufferQueueLayer.cpp
+++ b/services/surfaceflinger/BufferQueueLayer.cpp
@@ -325,8 +325,7 @@
     return NO_ERROR;
 }
 
-void BufferQueueLayer::setHwcLayerBuffer(const sp<const DisplayDevice>& display) {
-    const auto displayId = display->getId();
+void BufferQueueLayer::setHwcLayerBuffer(DisplayId displayId) {
     auto& hwcInfo = getBE().mHwcLayers[displayId];
     auto& hwcLayer = hwcInfo.layer;
 
@@ -353,6 +352,11 @@
 void BufferQueueLayer::onFrameAvailable(const BufferItem& item) {
     // Add this buffer from our internal queue tracker
     { // Autolock scope
+        // Report the timestamp to the Scheduler.
+        if (mFlinger->mUseScheduler) {
+            mFlinger->mScheduler->addNewFrameTimestamp(item.mTimestamp, item.mIsAutoTimestamp);
+        }
+
         Mutex::Autolock lock(mQueueItemLock);
         // Reset the frame number tracker when we receive the first buffer after
         // a frame number reset
diff --git a/services/surfaceflinger/BufferQueueLayer.h b/services/surfaceflinger/BufferQueueLayer.h
index c9ebe04..74dd21e 100644
--- a/services/surfaceflinger/BufferQueueLayer.h
+++ b/services/surfaceflinger/BufferQueueLayer.h
@@ -94,8 +94,7 @@
     status_t updateActiveBuffer() override;
     status_t updateFrameNumber(nsecs_t latchTime) override;
 
-    void setHwcLayerBuffer(const sp<const DisplayDevice>& display) override;
-    // -----------------------------------------------------------------------
+    void setHwcLayerBuffer(DisplayId displayId) override;
 
     // -----------------------------------------------------------------------
     // Interface implementation for BufferLayerConsumer::ContentsChangedListener
diff --git a/services/surfaceflinger/BufferStateLayer.cpp b/services/surfaceflinger/BufferStateLayer.cpp
index 73098bf..8d59841 100644
--- a/services/surfaceflinger/BufferStateLayer.cpp
+++ b/services/surfaceflinger/BufferStateLayer.cpp
@@ -497,8 +497,7 @@
     return NO_ERROR;
 }
 
-void BufferStateLayer::setHwcLayerBuffer(const sp<const DisplayDevice>& display) {
-    const auto displayId = display->getId();
+void BufferStateLayer::setHwcLayerBuffer(DisplayId displayId) {
     auto& hwcInfo = getBE().mHwcLayers[displayId];
     auto& hwcLayer = hwcInfo.layer;
 
diff --git a/services/surfaceflinger/BufferStateLayer.h b/services/surfaceflinger/BufferStateLayer.h
index 0c6eaf5..381cd28 100644
--- a/services/surfaceflinger/BufferStateLayer.h
+++ b/services/surfaceflinger/BufferStateLayer.h
@@ -121,8 +121,8 @@
     status_t updateActiveBuffer() override;
     status_t updateFrameNumber(nsecs_t latchTime) override;
 
-    void setHwcLayerBuffer(const sp<const DisplayDevice>& display) override;
-    // -----------------------------------------------------------------------
+    void setHwcLayerBuffer(DisplayId displayId) override;
+
 private:
     void onFirstRef() override;
 
diff --git a/services/surfaceflinger/ColorLayer.cpp b/services/surfaceflinger/ColorLayer.cpp
index 263f872..ad716ef 100644
--- a/services/surfaceflinger/ColorLayer.cpp
+++ b/services/surfaceflinger/ColorLayer.cpp
@@ -57,13 +57,12 @@
     return !isHiddenByPolicy() && getAlpha() > 0.0f;
 }
 
-void ColorLayer::setPerFrameData(const sp<const DisplayDevice>& display) {
-    const ui::Transform& tr = display->getTransform();
-    const auto& viewport = display->getViewport();
-    Region visible = tr.transform(visibleRegion.intersect(viewport));
-    const auto displayId = display->getId();
+void ColorLayer::setPerFrameData(DisplayId displayId, const ui::Transform& transform,
+                                 const Rect& viewport, int32_t /* supportedPerFrameMetadata */) {
+    Region visible = transform.transform(visibleRegion.intersect(viewport));
+
     if (!hasHwcLayer(displayId)) {
-        ALOGE("[%s] failed to setPerFrameData: no HWC layer found (%d)",
+        ALOGE("[%s] failed to setPerFrameData: no HWC layer found for display %" PRIu64,
               mName.string(), displayId);
         return;
     }
diff --git a/services/surfaceflinger/ColorLayer.h b/services/surfaceflinger/ColorLayer.h
index 2c10357..d1b1697 100644
--- a/services/surfaceflinger/ColorLayer.h
+++ b/services/surfaceflinger/ColorLayer.h
@@ -33,7 +33,10 @@
                         bool useIdentityTransform);
     bool isVisible() const override;
 
-    void setPerFrameData(const sp<const DisplayDevice>& display) override;
+    void setPerFrameData(DisplayId displayId, const ui::Transform& transform, const Rect& viewport,
+                         int32_t supportedPerFrameMetadata) override;
+
+    bool onPreComposition(nsecs_t /*refreshStartTime*/) override { return false; }
 
 protected:
     FloatRect computeCrop(const sp<const DisplayDevice>& /*display*/) const override { return {}; }
diff --git a/services/surfaceflinger/ContainerLayer.cpp b/services/surfaceflinger/ContainerLayer.cpp
index 44e843e..ca49f6c 100644
--- a/services/surfaceflinger/ContainerLayer.cpp
+++ b/services/surfaceflinger/ContainerLayer.cpp
@@ -32,6 +32,6 @@
     return !isHiddenByPolicy();
 }
 
-void ContainerLayer::setPerFrameData(const sp<const DisplayDevice>&) {}
+void ContainerLayer::setPerFrameData(DisplayId, const ui::Transform&, const Rect&, int32_t) {}
 
 } // namespace android
diff --git a/services/surfaceflinger/ContainerLayer.h b/services/surfaceflinger/ContainerLayer.h
index 8eddc7f..413844b 100644
--- a/services/surfaceflinger/ContainerLayer.h
+++ b/services/surfaceflinger/ContainerLayer.h
@@ -33,9 +33,12 @@
                 bool useIdentityTransform) override;
     bool isVisible() const override;
 
-    void setPerFrameData(const sp<const DisplayDevice>& display) override;
+    void setPerFrameData(DisplayId displayId, const ui::Transform& transform, const Rect& viewport,
+                         int32_t supportedPerFrameMetadata) override;
 
     bool isCreatedFromMainThread() const override { return true; }
+
+    bool onPreComposition(nsecs_t /*refreshStartTime*/) override { return false; }
 };
 
 } // namespace android
diff --git a/services/surfaceflinger/DisplayDevice.cpp b/services/surfaceflinger/DisplayDevice.cpp
index 91b18c9..7c5c1bc 100644
--- a/services/surfaceflinger/DisplayDevice.cpp
+++ b/services/surfaceflinger/DisplayDevice.cpp
@@ -212,15 +212,14 @@
 
 DisplayDeviceCreationArgs::DisplayDeviceCreationArgs(const sp<SurfaceFlinger>& flinger,
                                                      const wp<IBinder>& displayToken,
-                                                     DisplayDevice::DisplayType type, int32_t id)
-      : flinger(flinger), displayToken(displayToken), type(type), id(id) {}
+                                                     const std::optional<DisplayId>& displayId)
+      : flinger(flinger), displayToken(displayToken), displayId(displayId) {}
 
 DisplayDevice::DisplayDevice(DisplayDeviceCreationArgs&& args)
       : lastCompositionHadVisibleLayers(false),
         mFlinger(args.flinger),
-        mType(args.type),
-        mId(args.id),
         mDisplayToken(args.displayToken),
+        mId(args.displayId),
         mNativeWindow(args.nativeWindow),
         mDisplaySurface(args.displaySurface),
         mSurface{std::move(args.renderSurface)},
@@ -228,6 +227,7 @@
         mDisplayHeight(args.displayHeight),
         mDisplayInstallOrientation(args.displayInstallOrientation),
         mPageFlipCount(0),
+        mIsVirtual(args.isVirtual),
         mIsSecure(args.isSecure),
         mLayerStack(NO_LAYER_STACK),
         mOrientation(),
@@ -240,7 +240,8 @@
         mHasHdr10(false),
         mHasHLG(false),
         mHasDolbyVision(false),
-        mSupportedPerFrameMetadata(args.supportedPerFrameMetadata) {
+        mSupportedPerFrameMetadata(args.supportedPerFrameMetadata),
+        mIsPrimary(args.isPrimary) {
     populateColorModes(args.hwcColorModes);
 
     ALOGE_IF(!mNativeWindow, "No native window was set for display");
@@ -293,16 +294,12 @@
 DisplayDevice::~DisplayDevice() = default;
 
 void DisplayDevice::disconnect(HWComposer& hwc) {
-    if (mId >= 0) {
-        hwc.disconnectDisplay(mId);
-        mId = -1;
+    if (mId) {
+        hwc.disconnectDisplay(*mId);
+        mId.reset();
     }
 }
 
-bool DisplayDevice::isValid() const {
-    return mFlinger != nullptr;
-}
-
 int DisplayDevice::getWidth() const {
     return mDisplayWidth;
 }
@@ -334,9 +331,11 @@
 
 status_t DisplayDevice::prepareFrame(HWComposer& hwc,
         std::vector<CompositionInfo>& compositionData) {
-    status_t error = hwc.prepare(*this, compositionData);
-    if (error != NO_ERROR) {
-        return error;
+    if (mId) {
+        status_t error = hwc.prepare(*mId, compositionData);
+        if (error != NO_ERROR) {
+            return error;
+        }
     }
 
     DisplaySurface::CompositionType compositionType;
@@ -600,7 +599,7 @@
 
     // need to take care of primary display rotation for mGlobalTransform
     // for case if the panel is not installed aligned with device orientation
-    if (mType == DisplayType::DISPLAY_PRIMARY) {
+    if (isPrimary()) {
         DisplayDevice::orientationToTransfrom(
                 (orientation + mDisplayInstallOrientation) % (DisplayState::eOrientation270 + 1),
                 w, h, &R);
@@ -648,7 +647,7 @@
 }
 
 std::string DisplayDevice::getDebugName() const {
-    const auto id = mId >= 0 ? base::StringPrintf("%d, ", mId) : std::string();
+    const auto id = mId ? base::StringPrintf("%" PRIu64 ", ", *mId) : std::string();
     return base::StringPrintf("DisplayDevice{%s%s%s\"%s\"}", id.c_str(),
                               isPrimary() ? "primary, " : "", isVirtual() ? "virtual, " : "",
                               mDisplayName.c_str());
diff --git a/services/surfaceflinger/DisplayDevice.h b/services/surfaceflinger/DisplayDevice.h
index 152d0ec..9ec7666 100644
--- a/services/surfaceflinger/DisplayDevice.h
+++ b/services/surfaceflinger/DisplayDevice.h
@@ -20,6 +20,7 @@
 #include <stdlib.h>
 
 #include <memory>
+#include <optional>
 #include <string>
 #include <unordered_map>
 
@@ -37,6 +38,7 @@
 #include <utils/String8.h>
 #include <utils/Timers.h>
 
+#include "DisplayHardware/DisplayIdentification.h"
 #include "RenderArea.h"
 
 struct ANativeWindow;
@@ -66,25 +68,15 @@
     Region undefinedRegion;
     bool lastCompositionHadVisibleLayers;
 
-    enum DisplayType {
-        DISPLAY_ID_INVALID = -1,
-        DISPLAY_PRIMARY     = HWC_DISPLAY_PRIMARY,
-        DISPLAY_EXTERNAL    = HWC_DISPLAY_EXTERNAL,
-        DISPLAY_VIRTUAL     = HWC_DISPLAY_VIRTUAL,
-        NUM_BUILTIN_DISPLAY_TYPES = HWC_NUM_PHYSICAL_DISPLAY_TYPES,
-    };
-
     enum {
         NO_LAYER_STACK = 0xFFFFFFFF,
     };
 
     explicit DisplayDevice(DisplayDeviceCreationArgs&& args);
-
     ~DisplayDevice();
 
-    // whether this is a valid object. An invalid DisplayDevice is returned
-    // when an non existing id is requested
-    bool isValid() const;
+    bool isVirtual() const { return mIsVirtual; }
+    bool isPrimary() const { return mIsPrimary; }
 
     // isSecure indicates whether this display can be trusted to display
     // secure surfaces.
@@ -118,11 +110,9 @@
     bool                    needsFiltering() const { return mNeedsFiltering; }
 
     uint32_t                getLayerStack() const { return mLayerStack; }
-    int32_t                 getDisplayType() const { return mType; }
-    bool                    isPrimary() const { return mType == DISPLAY_PRIMARY; }
-    bool                    isVirtual() const { return mType == DISPLAY_VIRTUAL; }
-    int32_t                 getId() const { return mId; }
-    const wp<IBinder>&      getDisplayToken() const { return mDisplayToken; }
+
+    const std::optional<DisplayId>& getId() const { return mId; }
+    const wp<IBinder>& getDisplayToken() const { return mDisplayToken; }
 
     int32_t getSupportedPerFrameMetadata() const { return mSupportedPerFrameMetadata; }
 
@@ -207,13 +197,10 @@
     void dump(String8& result) const;
 
 private:
-    /*
-     *  Constants, set during initialization
-     */
-    sp<SurfaceFlinger> mFlinger;
-    DisplayType mType;
-    int32_t mId;
-    wp<IBinder> mDisplayToken;
+    const sp<SurfaceFlinger> mFlinger;
+    const wp<IBinder> mDisplayToken;
+
+    std::optional<DisplayId> mId;
 
     // ANativeWindow this display is rendering into
     sp<ANativeWindow> mNativeWindow;
@@ -225,7 +212,9 @@
     const int       mDisplayInstallOrientation;
     mutable uint32_t mPageFlipCount;
     std::string     mDisplayName;
-    bool            mIsSecure;
+
+    const bool mIsVirtual;
+    const bool mIsSecure;
 
     /*
      * Can only accessed from the main thread, these members
@@ -299,13 +288,16 @@
             const ui::ColorMode mode, const ui::RenderIntent intent);
 
     std::unordered_map<ColorModeKey, ColorModeValue> mColorModes;
+
+    // TODO(b/74619554): Remove special cases for primary display.
+    const bool mIsPrimary;
 };
 
 struct DisplayDeviceState {
-    bool isVirtual() const { return type >= DisplayDevice::DISPLAY_VIRTUAL; }
+    bool isVirtual() const { return !displayId.has_value(); }
 
     int32_t sequenceId = sNextSequenceId++;
-    DisplayDevice::DisplayType type = DisplayDevice::DISPLAY_ID_INVALID;
+    std::optional<DisplayId> displayId;
     sp<IGraphicBufferProducer> surface;
     uint32_t layerStack = DisplayDevice::NO_LAYER_STACK;
     Rect viewport;
@@ -324,13 +316,13 @@
     // We use a constructor to ensure some of the values are set, without
     // assuming a default value.
     DisplayDeviceCreationArgs(const sp<SurfaceFlinger>& flinger, const wp<IBinder>& displayToken,
-                              DisplayDevice::DisplayType type, int32_t id);
+                              const std::optional<DisplayId>& displayId);
 
     const sp<SurfaceFlinger> flinger;
     const wp<IBinder> displayToken;
-    const DisplayDevice::DisplayType type;
-    const int32_t id;
+    const std::optional<DisplayId> displayId;
 
+    bool isVirtual{false};
     bool isSecure{false};
     sp<ANativeWindow> nativeWindow;
     sp<DisplaySurface> displaySurface;
@@ -343,6 +335,7 @@
     int32_t supportedPerFrameMetadata{0};
     std::unordered_map<ui::ColorMode, std::vector<ui::RenderIntent>> hwcColorModes;
     int initialPowerMode{HWC_POWER_MODE_NORMAL};
+    bool isPrimary{false};
 };
 
 class DisplayRenderArea : public RenderArea {
diff --git a/services/surfaceflinger/DisplayHardware/DisplayIdentification.cpp b/services/surfaceflinger/DisplayHardware/DisplayIdentification.cpp
index dcc4138..ec240f3 100644
--- a/services/surfaceflinger/DisplayHardware/DisplayIdentification.cpp
+++ b/services/surfaceflinger/DisplayHardware/DisplayIdentification.cpp
@@ -33,6 +33,9 @@
 
 constexpr size_t kEdidHeaderLength = 5;
 
+constexpr uint16_t kFallbackEdidManufacturerId = 0;
+constexpr uint16_t kVirtualEdidManufacturerId = 0xffffu;
+
 std::optional<uint8_t> getEdidDescriptorType(const byte_view& view) {
     if (view.size() < kEdidHeaderLength || view[0] || view[1] || view[2] || view[4]) {
         return {};
@@ -165,7 +168,8 @@
     return a && b && c ? std::make_optional(PnpId{a, b, c}) : std::nullopt;
 }
 
-std::optional<DisplayId> generateDisplayId(uint8_t port, const DisplayIdentificationData& data) {
+std::optional<DisplayIdentificationInfo> parseDisplayIdentificationData(
+        uint8_t port, const DisplayIdentificationData& data) {
     if (!isEdid(data)) {
         ALOGE("Display identification data has unknown format.");
         return {};
@@ -179,7 +183,16 @@
     // Hash display name instead of using product code or serial number, since the latter have been
     // observed to change on some displays with multiple inputs.
     const auto hash = static_cast<uint32_t>(std::hash<std::string_view>()(edid->displayName));
-    return getEdidDisplayId(port, edid->manufacturerId, hash);
+    return DisplayIdentificationInfo{getEdidDisplayId(port, edid->manufacturerId, hash),
+                                     std::string(edid->displayName)};
+}
+
+DisplayId getFallbackDisplayId(uint8_t port) {
+    return getEdidDisplayId(port, kFallbackEdidManufacturerId, 0);
+}
+
+DisplayId getVirtualDisplayId(uint32_t id) {
+    return getEdidDisplayId(0, kVirtualEdidManufacturerId, id);
 }
 
 } // namespace android
diff --git a/services/surfaceflinger/DisplayHardware/DisplayIdentification.h b/services/surfaceflinger/DisplayHardware/DisplayIdentification.h
index 379f2d3..1f2e789 100644
--- a/services/surfaceflinger/DisplayHardware/DisplayIdentification.h
+++ b/services/surfaceflinger/DisplayHardware/DisplayIdentification.h
@@ -19,6 +19,7 @@
 #include <array>
 #include <cstdint>
 #include <optional>
+#include <string>
 #include <string_view>
 #include <vector>
 
@@ -27,6 +28,11 @@
 using DisplayId = uint64_t;
 using DisplayIdentificationData = std::vector<uint8_t>;
 
+struct DisplayIdentificationInfo {
+    DisplayId id;
+    std::string name;
+};
+
 // NUL-terminated plug and play ID.
 using PnpId = std::array<char, 4>;
 
@@ -40,6 +46,10 @@
 std::optional<Edid> parseEdid(const DisplayIdentificationData&);
 std::optional<PnpId> getPnpId(uint16_t manufacturerId);
 
-std::optional<DisplayId> generateDisplayId(uint8_t port, const DisplayIdentificationData&);
+std::optional<DisplayIdentificationInfo> parseDisplayIdentificationData(
+        uint8_t port, const DisplayIdentificationData&);
+
+DisplayId getFallbackDisplayId(uint8_t port);
+DisplayId getVirtualDisplayId(uint32_t id);
 
 } // namespace android
diff --git a/services/surfaceflinger/DisplayHardware/FramebufferSurface.cpp b/services/surfaceflinger/DisplayHardware/FramebufferSurface.cpp
index e6d7834..f3f8d9d 100644
--- a/services/surfaceflinger/DisplayHardware/FramebufferSurface.cpp
+++ b/services/surfaceflinger/DisplayHardware/FramebufferSurface.cpp
@@ -52,26 +52,25 @@
  *
  */
 
-FramebufferSurface::FramebufferSurface(HWComposer& hwc, int disp,
-        const sp<IGraphicBufferConsumer>& consumer) :
-    ConsumerBase(consumer),
-    mDisplayType(disp),
-    mCurrentBufferSlot(-1),
-    mCurrentBuffer(),
-    mCurrentFence(Fence::NO_FENCE),
-    mHwc(hwc),
-    mHasPendingRelease(false),
-    mPreviousBufferSlot(BufferQueue::INVALID_BUFFER_SLOT),
-    mPreviousBuffer()
-{
-    ALOGV("Creating for display %d", disp);
+FramebufferSurface::FramebufferSurface(HWComposer& hwc, DisplayId displayId,
+                                       const sp<IGraphicBufferConsumer>& consumer)
+      : ConsumerBase(consumer),
+        mDisplayId(displayId),
+        mCurrentBufferSlot(-1),
+        mCurrentBuffer(),
+        mCurrentFence(Fence::NO_FENCE),
+        mHwc(hwc),
+        mHasPendingRelease(false),
+        mPreviousBufferSlot(BufferQueue::INVALID_BUFFER_SLOT),
+        mPreviousBuffer() {
+    ALOGV("Creating for display %" PRIu64, displayId);
 
     mName = "FramebufferSurface";
     mConsumer->setConsumerName(mName);
     mConsumer->setConsumerUsageBits(GRALLOC_USAGE_HW_FB |
                                        GRALLOC_USAGE_HW_RENDER |
                                        GRALLOC_USAGE_HW_COMPOSER);
-    const auto& activeConfig = mHwc.getActiveConfig(disp);
+    const auto& activeConfig = mHwc.getActiveConfig(displayId);
     mConsumer->setDefaultBufferSize(activeConfig->getWidth(),
             activeConfig->getHeight());
     mConsumer->setMaxAcquiredBufferCount(
@@ -142,8 +141,7 @@
     mHwcBufferCache.getHwcBuffer(mCurrentBufferSlot, mCurrentBuffer,
             &outSlot, &outBuffer);
     outDataspace = static_cast<Dataspace>(item.mDataSpace);
-    status_t result =
-            mHwc.setClientTarget(mDisplayType, outSlot, outFence, outBuffer, outDataspace);
+    status_t result = mHwc.setClientTarget(mDisplayId, outSlot, outFence, outBuffer, outDataspace);
     if (result != NO_ERROR) {
         ALOGE("error posting framebuffer: %d", result);
         return result;
@@ -161,7 +159,7 @@
 
 void FramebufferSurface::onFrameCommitted() {
     if (mHasPendingRelease) {
-        sp<Fence> fence = mHwc.getPresentFence(mDisplayType);
+        sp<Fence> fence = mHwc.getPresentFence(mDisplayId);
         if (fence->isValid()) {
             status_t result = addReleaseFence(mPreviousBufferSlot,
                     mPreviousBuffer, fence);
diff --git a/services/surfaceflinger/DisplayHardware/FramebufferSurface.h b/services/surfaceflinger/DisplayHardware/FramebufferSurface.h
index 0fd8e9e..2431dfd 100644
--- a/services/surfaceflinger/DisplayHardware/FramebufferSurface.h
+++ b/services/surfaceflinger/DisplayHardware/FramebufferSurface.h
@@ -17,6 +17,7 @@
 #ifndef ANDROID_SF_FRAMEBUFFER_SURFACE_H
 #define ANDROID_SF_FRAMEBUFFER_SURFACE_H
 
+#include "DisplayIdentification.h"
 #include "DisplaySurface.h"
 #include "HWComposerBufferCache.h"
 
@@ -38,7 +39,8 @@
 class FramebufferSurface : public ConsumerBase,
                            public DisplaySurface {
 public:
-    FramebufferSurface(HWComposer& hwc, int disp, const sp<IGraphicBufferConsumer>& consumer);
+    FramebufferSurface(HWComposer& hwc, DisplayId displayId,
+                       const sp<IGraphicBufferConsumer>& consumer);
 
     virtual status_t beginFrame(bool mustRecompose);
     virtual status_t prepareFrame(CompositionType compositionType);
@@ -63,8 +65,7 @@
     status_t nextBuffer(uint32_t& outSlot, sp<GraphicBuffer>& outBuffer,
             sp<Fence>& outFence, ui::Dataspace& outDataspace);
 
-    // mDisplayType must match one of the HWC display types
-    int mDisplayType;
+    const DisplayId mDisplayId;
 
     // mCurrentBufferIndex is the slot index of the current buffer or
     // INVALID_BUFFER_SLOT to indicate that either there is no current buffer
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index d827fd2..4c472b8 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -58,15 +58,15 @@
     ALOGE("%s failed for HWC display %" PRIu64 ": %s", __FUNCTION__, hwcDisplayId, msg)
 
 #define LOG_DISPLAY_ERROR(displayId, msg) \
-    ALOGE("%s failed for display %d: %s", __FUNCTION__, displayId, msg)
+    ALOGE("%s failed for display %" PRIu64 ": %s", __FUNCTION__, displayId, msg)
 
-#define LOG_HWC_ERROR(what, error, displayId)                                     \
-    ALOGE("%s: %s failed for display %d: %s (%d)", __FUNCTION__, what, displayId, \
+#define LOG_HWC_ERROR(what, error, displayId)                                              \
+    ALOGE("%s: %s failed for display %" PRIu64 ": %s (%d)", __FUNCTION__, what, displayId, \
           to_string(error).c_str(), static_cast<int32_t>(error))
 
 #define RETURN_IF_INVALID_DISPLAY(displayId, ...)            \
     do {                                                     \
-        if (!isValidDisplay(displayId)) {                    \
+        if (mDisplayData.count(displayId) == 0) {            \
             LOG_DISPLAY_ERROR(displayId, "Invalid display"); \
             return __VA_ARGS__;                              \
         }                                                    \
@@ -92,7 +92,9 @@
 HWComposer::HWComposer(std::unique_ptr<android::Hwc2::Composer> composer)
       : mHwcDevice(std::make_unique<HWC2::Device>(std::move(composer))) {}
 
-HWComposer::~HWComposer() = default;
+HWComposer::~HWComposer() {
+    mDisplayData.clear();
+}
 
 void HWComposer::registerCallback(HWC2::ComposerCallback* callback,
                                   int32_t sequenceId) {
@@ -116,11 +118,6 @@
     return mHwcDevice->getCapabilities().count(capability) > 0;
 }
 
-bool HWComposer::isValidDisplay(int32_t displayId) const {
-    return static_cast<size_t>(displayId) < mDisplayData.size() &&
-            mDisplayData[displayId].hwcDisplay;
-}
-
 void HWComposer::validateChange(HWC2::Composition from, HWC2::Composition to) {
     bool valid = true;
     switch (from) {
@@ -146,52 +143,50 @@
     }
 }
 
-std::optional<DisplayId> HWComposer::onHotplug(hwc2_display_t hwcDisplayId, int32_t displayType,
-                                               HWC2::Connection connection) {
-    if (displayType >= HWC_NUM_PHYSICAL_DISPLAY_TYPES) {
-        ALOGE("Invalid display type of %d", displayType);
-        return {};
-    }
+std::optional<DisplayIdentificationInfo> HWComposer::onHotplug(hwc2_display_t hwcDisplayId,
+                                                               HWC2::Connection connection) {
+    std::optional<DisplayIdentificationInfo> info;
 
-    ALOGV("hotplug: %" PRIu64 ", %s %s", hwcDisplayId,
-          displayType == DisplayDevice::DISPLAY_PRIMARY ? "primary" : "external",
-          to_string(connection).c_str());
-    mHwcDevice->onHotplug(hwcDisplayId, connection);
-
-    std::optional<DisplayId> displayId;
-
-    if (connection == HWC2::Connection::Connected) {
-        uint8_t port;
-        DisplayIdentificationData data;
-        if (getDisplayIdentificationData(hwcDisplayId, &port, &data)) {
-            displayId = generateDisplayId(port, data);
-            ALOGE_IF(!displayId, "Failed to generate stable ID for display %" PRIu64, hwcDisplayId);
+    if (const auto displayId = toPhysicalDisplayId(hwcDisplayId)) {
+        info = DisplayIdentificationInfo{*displayId, std::string()};
+    } else {
+        if (connection == HWC2::Connection::Disconnected) {
+            ALOGE("Ignoring disconnection of invalid HWC display %" PRIu64, hwcDisplayId);
+            return {};
         }
+
+        info = onHotplugConnect(hwcDisplayId);
+        if (!info) return {};
     }
 
+    ALOGV("%s: %s %s display %" PRIu64 " with HWC ID %" PRIu64, __FUNCTION__,
+          to_string(connection).c_str(),
+          hwcDisplayId == mInternalHwcDisplayId ? "internal" : "external", info->id, hwcDisplayId);
+
+    mHwcDevice->onHotplug(hwcDisplayId, connection);
+
     // Disconnect is handled through HWComposer::disconnectDisplay via
     // SurfaceFlinger's onHotplugReceived callback handling
     if (connection == HWC2::Connection::Connected) {
-        mDisplayData[displayType].hwcDisplay = mHwcDevice->getDisplayById(hwcDisplayId);
-        mHwcDisplaySlots[hwcDisplayId] = displayType;
+        mDisplayData[info->id].hwcDisplay = mHwcDevice->getDisplayById(hwcDisplayId);
+        mPhysicalDisplayIdMap[hwcDisplayId] = info->id;
     }
 
-    return displayId;
+    return info;
 }
 
-bool HWComposer::onVsync(hwc2_display_t hwcDisplayId, int64_t timestamp, int32_t* outDisplayId) {
-    const auto it = mHwcDisplaySlots.find(hwcDisplayId);
-    if (it == mHwcDisplaySlots.end()) {
-        LOG_HWC_DISPLAY_ERROR(hwcDisplayId, "Invalid display");
+bool HWComposer::onVsync(hwc2_display_t hwcDisplayId, int64_t timestamp) {
+    const auto displayId = toPhysicalDisplayId(hwcDisplayId);
+    if (!displayId) {
+        LOG_HWC_DISPLAY_ERROR(hwcDisplayId, "Invalid HWC display");
         return false;
     }
 
-    const int32_t displayId = it->second;
-    RETURN_IF_INVALID_DISPLAY(displayId, false);
+    RETURN_IF_INVALID_DISPLAY(*displayId, false);
 
-    const auto& displayData = mDisplayData[displayId];
+    const auto& displayData = mDisplayData[*displayId];
     if (displayData.isVirtual) {
-        LOG_DISPLAY_ERROR(displayId, "Invalid operation on virtual display");
+        LOG_DISPLAY_ERROR(*displayId, "Invalid operation on virtual display");
         return false;
     }
 
@@ -202,31 +197,26 @@
         // with the same timestamp when turning the display off and on. This
         // is a bug in the HWC implementation, but filter the extra events
         // out here so they don't cause havoc downstream.
-        if (timestamp == mLastHwVSync[displayId]) {
-            ALOGW("Ignoring duplicate VSYNC event from HWC (t=%" PRId64 ")",
-                    timestamp);
+        if (timestamp == mLastHwVSync[*displayId]) {
+            ALOGW("Ignoring duplicate VSYNC event from HWC for display %" PRIu64 " (t=%" PRId64 ")",
+                  *displayId, timestamp);
             return false;
         }
 
-        mLastHwVSync[displayId] = timestamp;
+        mLastHwVSync[*displayId] = timestamp;
     }
 
-    if (outDisplayId) {
-        *outDisplayId = displayId;
-    }
-
-    char tag[16];
-    snprintf(tag, sizeof(tag), "HW_VSYNC_%1u", displayId);
-    ATRACE_INT(tag, ++mVSyncCounts[displayId] & 1);
+    const auto tag = "HW_VSYNC_" + std::to_string(*displayId);
+    ATRACE_INT(tag.c_str(), ++mVSyncCounts[*displayId] & 1);
 
     return true;
 }
 
-status_t HWComposer::allocateVirtualDisplay(uint32_t width, uint32_t height,
-        ui::PixelFormat* format, int32_t *outId) {
+std::optional<DisplayId> HWComposer::allocateVirtualDisplay(uint32_t width, uint32_t height,
+                                                            ui::PixelFormat* format) {
     if (mRemainingHwcVirtualDisplays == 0) {
         ALOGE("%s: No remaining virtual displays", __FUNCTION__);
-        return NO_MEMORY;
+        return {};
     }
 
     if (SurfaceFlinger::maxVirtualDisplaySize != 0 &&
@@ -234,41 +224,33 @@
          height > SurfaceFlinger::maxVirtualDisplaySize)) {
         ALOGE("%s: Display size %ux%u exceeds maximum dimension of %" PRIu64, __FUNCTION__, width,
               height, SurfaceFlinger::maxVirtualDisplaySize);
-        return INVALID_OPERATION;
+        return {};
     }
-
     HWC2::Display* display;
     auto error = mHwcDevice->createVirtualDisplay(width, height, format,
             &display);
     if (error != HWC2::Error::None) {
         ALOGE("%s: Failed to create HWC virtual display", __FUNCTION__);
-        return NO_MEMORY;
+        return {};
     }
 
-    size_t displaySlot = 0;
-    if (!mFreeDisplaySlots.empty()) {
-        displaySlot = *mFreeDisplaySlots.begin();
-        mFreeDisplaySlots.erase(displaySlot);
-    } else if (mDisplayData.size() < INT32_MAX) {
-        // Don't bother allocating a slot larger than we can return
-        displaySlot = mDisplayData.size();
-        mDisplayData.resize(displaySlot + 1);
+    DisplayId displayId;
+    if (mFreeVirtualDisplayIds.empty()) {
+        displayId = getVirtualDisplayId(mNextVirtualDisplayId++);
     } else {
-        ALOGE("%s: Unable to allocate a display slot", __FUNCTION__);
-        return NO_MEMORY;
+        displayId = *mFreeVirtualDisplayIds.begin();
+        mFreeVirtualDisplayIds.erase(displayId);
     }
 
-    auto& displayData = mDisplayData[displaySlot];
+    auto& displayData = mDisplayData[displayId];
     displayData.hwcDisplay = display;
     displayData.isVirtual = true;
 
     --mRemainingHwcVirtualDisplays;
-    *outId = static_cast<int32_t>(displaySlot);
-
-    return NO_ERROR;
+    return displayId;
 }
 
-HWC2::Layer* HWComposer::createLayer(int32_t displayId) {
+HWC2::Layer* HWComposer::createLayer(DisplayId displayId) {
     RETURN_IF_INVALID_DISPLAY(displayId, nullptr);
 
     auto display = mDisplayData[displayId].hwcDisplay;
@@ -278,7 +260,7 @@
     return layer;
 }
 
-void HWComposer::destroyLayer(int32_t displayId, HWC2::Layer* layer) {
+void HWComposer::destroyLayer(DisplayId displayId, HWC2::Layer* layer) {
     RETURN_IF_INVALID_DISPLAY(displayId);
 
     auto display = mDisplayData[displayId].hwcDisplay;
@@ -286,7 +268,8 @@
     RETURN_IF_HWC_ERROR(error, displayId);
 }
 
-nsecs_t HWComposer::getRefreshTimestamp(int32_t displayId) const {
+nsecs_t HWComposer::getRefreshTimestamp(DisplayId displayId) const {
+    RETURN_IF_INVALID_DISPLAY(displayId, 0);
     // this returns the last refresh timestamp.
     // if the last one is not available, we estimate it based on
     // the refresh period and whatever closest timestamp we have.
@@ -296,17 +279,17 @@
     return now - ((now - mLastHwVSync[displayId]) % vsyncPeriod);
 }
 
-bool HWComposer::isConnected(int32_t displayId) const {
+bool HWComposer::isConnected(DisplayId displayId) const {
     RETURN_IF_INVALID_DISPLAY(displayId, false);
-    return mDisplayData[displayId].hwcDisplay->isConnected();
+    return mDisplayData.at(displayId).hwcDisplay->isConnected();
 }
 
-std::vector<std::shared_ptr<const HWC2::Display::Config>>
-        HWComposer::getConfigs(int32_t displayId) const {
+std::vector<std::shared_ptr<const HWC2::Display::Config>> HWComposer::getConfigs(
+        DisplayId displayId) const {
     RETURN_IF_INVALID_DISPLAY(displayId, {});
 
-    auto& displayData = mDisplayData[displayId];
-    auto configs = mDisplayData[displayId].hwcDisplay->getConfigs();
+    const auto& displayData = mDisplayData.at(displayId);
+    auto configs = displayData.hwcDisplay->getConfigs();
     if (displayData.configMap.empty()) {
         for (size_t i = 0; i < configs.size(); ++i) {
             displayData.configMap[i] = configs[i];
@@ -315,12 +298,12 @@
     return configs;
 }
 
-std::shared_ptr<const HWC2::Display::Config>
-        HWComposer::getActiveConfig(int32_t displayId) const {
+std::shared_ptr<const HWC2::Display::Config> HWComposer::getActiveConfig(
+        DisplayId displayId) const {
     RETURN_IF_INVALID_DISPLAY(displayId, nullptr);
 
     std::shared_ptr<const HWC2::Display::Config> config;
-    auto error = mDisplayData[displayId].hwcDisplay->getActiveConfig(&config);
+    auto error = mDisplayData.at(displayId).hwcDisplay->getActiveConfig(&config);
     if (error == HWC2::Error::BadConfig) {
         LOG_DISPLAY_ERROR(displayId, "No active config");
         return nullptr;
@@ -336,11 +319,11 @@
     return config;
 }
 
-int HWComposer::getActiveConfigIndex(int32_t displayId) const {
+int HWComposer::getActiveConfigIndex(DisplayId displayId) const {
     RETURN_IF_INVALID_DISPLAY(displayId, -1);
 
     int index;
-    auto error = mDisplayData[displayId].hwcDisplay->getActiveConfigIndex(&index);
+    auto error = mDisplayData.at(displayId).hwcDisplay->getActiveConfigIndex(&index);
     if (error == HWC2::Error::BadConfig) {
         LOG_DISPLAY_ERROR(displayId, "No active config");
         return -1;
@@ -356,17 +339,17 @@
     return index;
 }
 
-std::vector<ui::ColorMode> HWComposer::getColorModes(int32_t displayId) const {
+std::vector<ui::ColorMode> HWComposer::getColorModes(DisplayId displayId) const {
     RETURN_IF_INVALID_DISPLAY(displayId, {});
 
     std::vector<ui::ColorMode> modes;
-    auto error = mDisplayData[displayId].hwcDisplay->getColorModes(&modes);
+    auto error = mDisplayData.at(displayId).hwcDisplay->getColorModes(&modes);
     RETURN_IF_HWC_ERROR(error, displayId, {});
     return modes;
 }
 
-status_t HWComposer::setActiveColorMode(int32_t displayId, ui::ColorMode mode,
-        ui::RenderIntent renderIntent) {
+status_t HWComposer::setActiveColorMode(DisplayId displayId, ui::ColorMode mode,
+                                        ui::RenderIntent renderIntent) {
     RETURN_IF_INVALID_DISPLAY(displayId, BAD_INDEX);
 
     auto& displayData = mDisplayData[displayId];
@@ -379,8 +362,7 @@
     return NO_ERROR;
 }
 
-
-void HWComposer::setVsyncEnabled(int32_t displayId, HWC2::Vsync enabled) {
+void HWComposer::setVsyncEnabled(DisplayId displayId, HWC2::Vsync enabled) {
     RETURN_IF_INVALID_DISPLAY(displayId);
     auto& displayData = mDisplayData[displayId];
 
@@ -401,37 +383,30 @@
 
         displayData.vsyncEnabled = enabled;
 
-        char tag[16];
-        snprintf(tag, sizeof(tag), "HW_VSYNC_ON_%1u", displayId);
-        ATRACE_INT(tag, enabled == HWC2::Vsync::Enable ? 1 : 0);
+        const auto tag = "HW_VSYNC_ON_" + std::to_string(displayId);
+        ATRACE_INT(tag.c_str(), enabled == HWC2::Vsync::Enable ? 1 : 0);
     }
 }
 
-status_t HWComposer::setClientTarget(int32_t displayId, uint32_t slot,
-        const sp<Fence>& acquireFence, const sp<GraphicBuffer>& target,
-        ui::Dataspace dataspace) {
+status_t HWComposer::setClientTarget(DisplayId displayId, uint32_t slot,
+                                     const sp<Fence>& acquireFence, const sp<GraphicBuffer>& target,
+                                     ui::Dataspace dataspace) {
     RETURN_IF_INVALID_DISPLAY(displayId, BAD_INDEX);
 
-    ALOGV("setClientTarget for display %d", displayId);
+    ALOGV("setClientTarget for display %" PRIu64, displayId);
     auto& hwcDisplay = mDisplayData[displayId].hwcDisplay;
     auto error = hwcDisplay->setClientTarget(slot, target, acquireFence, dataspace);
     RETURN_IF_HWC_ERROR(error, displayId, BAD_VALUE);
     return NO_ERROR;
 }
 
-status_t HWComposer::prepare(DisplayDevice& display,
-        std::vector<CompositionInfo>& compositionData) {
+status_t HWComposer::prepare(DisplayId displayId, std::vector<CompositionInfo>& compositionData) {
     ATRACE_CALL();
 
-    Mutex::Autolock _l(mDisplayLock);
-    const auto displayId = display.getId();
-    if (displayId == DisplayDevice::DISPLAY_ID_INVALID) {
-        ALOGV("Skipping HWComposer prepare for non-HWC display");
-        return NO_ERROR;
-    }
-
     RETURN_IF_INVALID_DISPLAY(displayId, BAD_INDEX);
 
+    Mutex::Autolock _l(mDisplayLock);
+
     auto& displayData = mDisplayData[displayId];
     auto& hwcDisplay = displayData.hwcDisplay;
     if (!hwcDisplay->isConnected()) {
@@ -501,7 +476,8 @@
                     changedTypes[&*hwcLayer]);
             compositionInfo.compositionType = changedTypes[&*hwcLayer];
             compositionInfo.layer->mLayer->setCompositionType(displayId,
-                    compositionInfo.compositionType, false);
+                                                              compositionInfo.compositionType,
+                                                              false);
         }
 
         switch (compositionInfo.compositionType) {
@@ -540,49 +516,48 @@
     return NO_ERROR;
 }
 
-bool HWComposer::hasDeviceComposition(int32_t displayId) const {
-    if (displayId == DisplayDevice::DISPLAY_ID_INVALID) {
+bool HWComposer::hasDeviceComposition(const std::optional<DisplayId>& displayId) const {
+    if (!displayId) {
         // Displays without a corresponding HWC display are never composed by
         // the device
         return false;
     }
 
-    RETURN_IF_INVALID_DISPLAY(displayId, false);
-    return mDisplayData[displayId].hasDeviceComposition;
+    RETURN_IF_INVALID_DISPLAY(*displayId, false);
+    return mDisplayData.at(*displayId).hasDeviceComposition;
 }
 
-bool HWComposer::hasFlipClientTargetRequest(int32_t displayId) const {
-    if (displayId == DisplayDevice::DISPLAY_ID_INVALID) {
+bool HWComposer::hasFlipClientTargetRequest(const std::optional<DisplayId>& displayId) const {
+    if (!displayId) {
         // Displays without a corresponding HWC display are never composed by
         // the device
         return false;
     }
 
-    RETURN_IF_INVALID_DISPLAY(displayId, false);
-    return ((static_cast<uint32_t>(mDisplayData[displayId].displayRequests) &
+    RETURN_IF_INVALID_DISPLAY(*displayId, false);
+    return ((static_cast<uint32_t>(mDisplayData.at(*displayId).displayRequests) &
              static_cast<uint32_t>(HWC2::DisplayRequest::FlipClientTarget)) != 0);
 }
 
-bool HWComposer::hasClientComposition(int32_t displayId) const {
-    if (displayId == DisplayDevice::DISPLAY_ID_INVALID) {
+bool HWComposer::hasClientComposition(const std::optional<DisplayId>& displayId) const {
+    if (!displayId) {
         // Displays without a corresponding HWC display are always composed by
         // the client
         return true;
     }
 
-    RETURN_IF_INVALID_DISPLAY(displayId, true);
-    return mDisplayData[displayId].hasClientComposition;
+    RETURN_IF_INVALID_DISPLAY(*displayId, true);
+    return mDisplayData.at(*displayId).hasClientComposition;
 }
 
-sp<Fence> HWComposer::getPresentFence(int32_t displayId) const {
+sp<Fence> HWComposer::getPresentFence(DisplayId displayId) const {
     RETURN_IF_INVALID_DISPLAY(displayId, Fence::NO_FENCE);
-    return mDisplayData[displayId].lastPresentFence;
+    return mDisplayData.at(displayId).lastPresentFence;
 }
 
-sp<Fence> HWComposer::getLayerReleaseFence(int32_t displayId,
-        HWC2::Layer* layer) const {
+sp<Fence> HWComposer::getLayerReleaseFence(DisplayId displayId, HWC2::Layer* layer) const {
     RETURN_IF_INVALID_DISPLAY(displayId, Fence::NO_FENCE);
-    auto displayFences = mDisplayData[displayId].releaseFences;
+    auto displayFences = mDisplayData.at(displayId).releaseFences;
     if (displayFences.count(layer) == 0) {
         ALOGV("getLayerReleaseFence: Release fence not found");
         return Fence::NO_FENCE;
@@ -590,7 +565,7 @@
     return displayFences[layer];
 }
 
-status_t HWComposer::presentAndGetReleaseFences(int32_t displayId) {
+status_t HWComposer::presentAndGetReleaseFences(DisplayId displayId) {
     ATRACE_CALL();
 
     RETURN_IF_INVALID_DISPLAY(displayId, BAD_INDEX);
@@ -618,8 +593,7 @@
     return NO_ERROR;
 }
 
-status_t HWComposer::setPowerMode(int32_t displayId, int32_t intMode) {
-    ALOGV("setPowerMode(%d, %d)", displayId, intMode);
+status_t HWComposer::setPowerMode(DisplayId displayId, int32_t intMode) {
     RETURN_IF_INVALID_DISPLAY(displayId, BAD_INDEX);
 
     const auto& displayData = mDisplayData[displayId];
@@ -675,7 +649,7 @@
     return NO_ERROR;
 }
 
-status_t HWComposer::setActiveConfig(int32_t displayId, size_t configId) {
+status_t HWComposer::setActiveConfig(DisplayId displayId, size_t configId) {
     RETURN_IF_INVALID_DISPLAY(displayId, BAD_INDEX);
 
     auto& displayData = mDisplayData[displayId];
@@ -689,8 +663,7 @@
     return NO_ERROR;
 }
 
-status_t HWComposer::setColorTransform(int32_t displayId,
-        const mat4& transform) {
+status_t HWComposer::setColorTransform(DisplayId displayId, const mat4& transform) {
     RETURN_IF_INVALID_DISPLAY(displayId, BAD_INDEX);
 
     auto& displayData = mDisplayData[displayId];
@@ -702,26 +675,34 @@
     return NO_ERROR;
 }
 
-void HWComposer::disconnectDisplay(int32_t displayId) {
+void HWComposer::disconnectDisplay(DisplayId displayId) {
     RETURN_IF_INVALID_DISPLAY(displayId);
     auto& displayData = mDisplayData[displayId];
 
     // If this was a virtual display, add its slot back for reuse by future
     // virtual displays
     if (displayData.isVirtual) {
-        mFreeDisplaySlots.insert(displayId);
+        mFreeVirtualDisplayIds.insert(displayId);
         ++mRemainingHwcVirtualDisplays;
     }
 
     const auto hwcDisplayId = displayData.hwcDisplay->getId();
-    mHwcDisplaySlots.erase(hwcDisplayId);
-    displayData = DisplayData();
+    mPhysicalDisplayIdMap.erase(hwcDisplayId);
+    mDisplayData.erase(displayId);
+    mVSyncCounts.erase(displayId);
+
+    // TODO(b/74619554): Select internal/external display from remaining displays.
+    if (hwcDisplayId == mInternalHwcDisplayId) {
+        mInternalHwcDisplayId.reset();
+    } else if (hwcDisplayId == mExternalHwcDisplayId) {
+        mExternalHwcDisplayId.reset();
+    }
 
     mHwcDevice->destroyDisplay(hwcDisplayId);
 }
 
-status_t HWComposer::setOutputBuffer(int32_t displayId,
-        const sp<Fence>& acquireFence, const sp<GraphicBuffer>& buffer) {
+status_t HWComposer::setOutputBuffer(DisplayId displayId, const sp<Fence>& acquireFence,
+                                     const sp<GraphicBuffer>& buffer) {
     RETURN_IF_INVALID_DISPLAY(displayId, BAD_INDEX);
     const auto& displayData = mDisplayData[displayId];
 
@@ -735,13 +716,12 @@
     return NO_ERROR;
 }
 
-void HWComposer::clearReleaseFences(int32_t displayId) {
+void HWComposer::clearReleaseFences(DisplayId displayId) {
     RETURN_IF_INVALID_DISPLAY(displayId);
     mDisplayData[displayId].releaseFences.clear();
 }
 
-status_t HWComposer::getHdrCapabilities(
-        int32_t displayId, HdrCapabilities* outCapabilities) {
+status_t HWComposer::getHdrCapabilities(DisplayId displayId, HdrCapabilities* outCapabilities) {
     RETURN_IF_INVALID_DISPLAY(displayId, BAD_INDEX);
 
     auto& hwcDisplay = mDisplayData[displayId].hwcDisplay;
@@ -750,22 +730,22 @@
     return NO_ERROR;
 }
 
-int32_t HWComposer::getSupportedPerFrameMetadata(int32_t displayId) const {
+int32_t HWComposer::getSupportedPerFrameMetadata(DisplayId displayId) const {
     RETURN_IF_INVALID_DISPLAY(displayId, 0);
-    return mDisplayData[displayId].hwcDisplay->getSupportedPerFrameMetadata();
+    return mDisplayData.at(displayId).hwcDisplay->getSupportedPerFrameMetadata();
 }
 
-std::vector<ui::RenderIntent> HWComposer::getRenderIntents(int32_t displayId,
-        ui::ColorMode colorMode) const {
+std::vector<ui::RenderIntent> HWComposer::getRenderIntents(DisplayId displayId,
+                                                           ui::ColorMode colorMode) const {
     RETURN_IF_INVALID_DISPLAY(displayId, {});
 
     std::vector<ui::RenderIntent> renderIntents;
-    auto error = mDisplayData[displayId].hwcDisplay->getRenderIntents(colorMode, &renderIntents);
+    auto error = mDisplayData.at(displayId).hwcDisplay->getRenderIntents(colorMode, &renderIntents);
     RETURN_IF_HWC_ERROR(error, displayId, {});
     return renderIntents;
 }
 
-mat4 HWComposer::getDataspaceSaturationMatrix(int32_t displayId, ui::Dataspace dataspace) {
+mat4 HWComposer::getDataspaceSaturationMatrix(DisplayId displayId, ui::Dataspace dataspace) {
     RETURN_IF_INVALID_DISPLAY(displayId, {});
 
     mat4 matrix;
@@ -806,12 +786,67 @@
     result.append(mHwcDevice->dump().c_str());
 }
 
-std::optional<hwc2_display_t>
-HWComposer::getHwcDisplayId(int32_t displayId) const {
-    if (!isValidDisplay(displayId)) {
+std::optional<DisplayId> HWComposer::toPhysicalDisplayId(hwc2_display_t hwcDisplayId) const {
+    if (const auto it = mPhysicalDisplayIdMap.find(hwcDisplayId);
+        it != mPhysicalDisplayIdMap.end()) {
+        return it->second;
+    }
+    return {};
+}
+
+std::optional<hwc2_display_t> HWComposer::fromPhysicalDisplayId(DisplayId displayId) const {
+    if (const auto it = mDisplayData.find(displayId);
+        it != mDisplayData.end() && !it->second.isVirtual) {
+        return it->second.hwcDisplay->getId();
+    }
+    return {};
+}
+
+std::optional<DisplayIdentificationInfo> HWComposer::onHotplugConnect(hwc2_display_t hwcDisplayId) {
+    if (isUsingVrComposer() && mInternalHwcDisplayId) {
+        ALOGE("Ignoring connection of external display %" PRIu64 " in VR mode", hwcDisplayId);
         return {};
     }
-    return mDisplayData[displayId].hwcDisplay->getId();
+
+    uint8_t port;
+    DisplayIdentificationData data;
+    const bool hasMultiDisplaySupport = getDisplayIdentificationData(hwcDisplayId, &port, &data);
+
+    if (mPhysicalDisplayIdMap.empty()) {
+        mHasMultiDisplaySupport = hasMultiDisplaySupport;
+        ALOGI("Switching to %s multi-display mode",
+              hasMultiDisplaySupport ? "generalized" : "legacy");
+    } else if (mHasMultiDisplaySupport && !hasMultiDisplaySupport) {
+        ALOGE("Ignoring connection of display %" PRIu64 " without identification data",
+              hwcDisplayId);
+        return {};
+    }
+
+    std::optional<DisplayIdentificationInfo> info;
+
+    if (mHasMultiDisplaySupport) {
+        info = parseDisplayIdentificationData(port, data);
+        ALOGE_IF(!info, "Failed to parse identification data for display %" PRIu64, hwcDisplayId);
+    } else if (mInternalHwcDisplayId && mExternalHwcDisplayId) {
+        ALOGE("Ignoring connection of tertiary display %" PRIu64, hwcDisplayId);
+        return {};
+    } else {
+        ALOGW_IF(hasMultiDisplaySupport, "Ignoring identification data for display %" PRIu64,
+                 hwcDisplayId);
+        port = mInternalHwcDisplayId ? HWC_DISPLAY_EXTERNAL : HWC_DISPLAY_PRIMARY;
+    }
+
+    if (!mInternalHwcDisplayId) {
+        mInternalHwcDisplayId = hwcDisplayId;
+    } else if (!mExternalHwcDisplayId) {
+        mExternalHwcDisplayId = hwcDisplayId;
+    }
+
+    if (info) return info;
+
+    return DisplayIdentificationInfo{getFallbackDisplayId(port),
+                                     hwcDisplayId == mInternalHwcDisplayId ? "Internal display"
+                                                                           : "External display"};
 }
 
 } // namespace android
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 4777ca9..5074c2c 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -34,7 +34,8 @@
 
 #include <memory>
 #include <optional>
-#include <set>
+#include <unordered_map>
+#include <unordered_set>
 #include <vector>
 
 #include "DisplayIdentification.h"
@@ -82,101 +83,94 @@
 
     bool hasCapability(HWC2::Capability capability) const;
 
-    // Attempts to allocate a virtual display. If the virtual display is created
-    // on the HWC device, outId will contain its HWC ID.
-    status_t allocateVirtualDisplay(uint32_t width, uint32_t height,
-            ui::PixelFormat* format, int32_t* outId);
+    // Attempts to allocate a virtual display and returns its ID if created on the HWC device.
+    std::optional<DisplayId> allocateVirtualDisplay(uint32_t width, uint32_t height,
+                                                    ui::PixelFormat* format);
 
     // Attempts to create a new layer on this display
-    HWC2::Layer* createLayer(int32_t displayId);
+    HWC2::Layer* createLayer(DisplayId displayId);
     // Destroy a previously created layer
-    void destroyLayer(int32_t displayId, HWC2::Layer* layer);
+    void destroyLayer(DisplayId displayId, HWC2::Layer* layer);
 
     // Asks the HAL what it can do
-    status_t prepare(DisplayDevice& display,
-            std::vector<CompositionInfo>& compositionData);
+    status_t prepare(DisplayId displayId, std::vector<CompositionInfo>& compositionData);
 
-    status_t setClientTarget(int32_t displayId, uint32_t slot,
-            const sp<Fence>& acquireFence,
-            const sp<GraphicBuffer>& target, ui::Dataspace dataspace);
+    status_t setClientTarget(DisplayId displayId, uint32_t slot, const sp<Fence>& acquireFence,
+                             const sp<GraphicBuffer>& target, ui::Dataspace dataspace);
 
     // Present layers to the display and read releaseFences.
-    status_t presentAndGetReleaseFences(int32_t displayId);
+    status_t presentAndGetReleaseFences(DisplayId displayId);
 
     // set power mode
-    status_t setPowerMode(int32_t displayId, int mode);
+    status_t setPowerMode(DisplayId displayId, int mode);
 
     // set active config
-    status_t setActiveConfig(int32_t displayId, size_t configId);
+    status_t setActiveConfig(DisplayId displayId, size_t configId);
 
     // Sets a color transform to be applied to the result of composition
-    status_t setColorTransform(int32_t displayId, const mat4& transform);
+    status_t setColorTransform(DisplayId displayId, const mat4& transform);
 
     // reset state when an external, non-virtual display is disconnected
-    void disconnectDisplay(int32_t displayId);
+    void disconnectDisplay(DisplayId displayId);
 
     // does this display have layers handled by HWC
-    bool hasDeviceComposition(int32_t displayId) const;
+    bool hasDeviceComposition(const std::optional<DisplayId>& displayId) const;
 
     // does this display have pending request to flip client target
-    bool hasFlipClientTargetRequest(int32_t displayId) const;
+    bool hasFlipClientTargetRequest(const std::optional<DisplayId>& displayId) const;
 
     // does this display have layers handled by GLES
-    bool hasClientComposition(int32_t displayId) const;
+    bool hasClientComposition(const std::optional<DisplayId>& displayId) const;
 
     // get the present fence received from the last call to present.
-    sp<Fence> getPresentFence(int32_t displayId) const;
+    sp<Fence> getPresentFence(DisplayId displayId) const;
 
     // Get last release fence for the given layer
-    sp<Fence> getLayerReleaseFence(int32_t displayId,
-            HWC2::Layer* layer) const;
+    sp<Fence> getLayerReleaseFence(DisplayId displayId, HWC2::Layer* layer) const;
 
     // Set the output buffer and acquire fence for a virtual display.
     // Returns INVALID_OPERATION if displayId is not a virtual display.
-    status_t setOutputBuffer(int32_t displayId, const sp<Fence>& acquireFence,
-            const sp<GraphicBuffer>& buf);
+    status_t setOutputBuffer(DisplayId displayId, const sp<Fence>& acquireFence,
+                             const sp<GraphicBuffer>& buffer);
 
     // After SurfaceFlinger has retrieved the release fences for all the frames,
     // it can call this to clear the shared pointers in the release fence map
-    void clearReleaseFences(int32_t displayId);
+    void clearReleaseFences(DisplayId displayId);
 
     // Fetches the HDR capabilities of the given display
-    status_t getHdrCapabilities(int32_t displayId, HdrCapabilities* outCapabilities);
+    status_t getHdrCapabilities(DisplayId displayId, HdrCapabilities* outCapabilities);
 
-    int32_t getSupportedPerFrameMetadata(int32_t displayId) const;
+    int32_t getSupportedPerFrameMetadata(DisplayId displayId) const;
 
     // Returns the available RenderIntent of the given display.
-    std::vector<ui::RenderIntent> getRenderIntents(int32_t displayId, ui::ColorMode colorMode) const;
+    std::vector<ui::RenderIntent> getRenderIntents(DisplayId displayId,
+                                                   ui::ColorMode colorMode) const;
 
-    mat4 getDataspaceSaturationMatrix(int32_t displayId, ui::Dataspace dataspace);
+    mat4 getDataspaceSaturationMatrix(DisplayId displayId, ui::Dataspace dataspace);
 
     // Events handling ---------------------------------------------------------
 
-    // Returns true if successful, false otherwise. The
-    // DisplayDevice::DisplayType of the display is returned as an output param.
-    bool onVsync(hwc2_display_t hwcDisplayId, int64_t timestamp, int32_t* outDisplay);
-    std::optional<DisplayId> onHotplug(hwc2_display_t hwcDisplayId, int32_t displayType,
-                                       HWC2::Connection connection);
+    // Returns stable display ID (and display name on connection of new or previously disconnected
+    // display), or std::nullopt if hotplug event was ignored.
+    std::optional<DisplayIdentificationInfo> onHotplug(hwc2_display_t hwcDisplayId,
+                                                       HWC2::Connection connection);
 
-    void setVsyncEnabled(int32_t displayId, HWC2::Vsync enabled);
+    bool onVsync(hwc2_display_t hwcDisplayId, int64_t timestamp);
+    void setVsyncEnabled(DisplayId displayId, HWC2::Vsync enabled);
 
-    // Query display parameters.  Pass in a display index (e.g.
-    // HWC_DISPLAY_PRIMARY).
-    nsecs_t getRefreshTimestamp(int32_t displayId) const;
-    bool isConnected(int32_t displayId) const;
+    nsecs_t getRefreshTimestamp(DisplayId displayId) const;
+    bool isConnected(DisplayId displayId) const;
 
     // Non-const because it can update configMap inside of mDisplayData
-    std::vector<std::shared_ptr<const HWC2::Display::Config>>
-            getConfigs(int32_t displayId) const;
+    std::vector<std::shared_ptr<const HWC2::Display::Config>> getConfigs(DisplayId displayId) const;
 
-    std::shared_ptr<const HWC2::Display::Config>
-            getActiveConfig(int32_t displayId) const;
-    int getActiveConfigIndex(int32_t displayId) const;
+    std::shared_ptr<const HWC2::Display::Config> getActiveConfig(DisplayId displayId) const;
+    int getActiveConfigIndex(DisplayId displayId) const;
 
-    std::vector<ui::ColorMode> getColorModes(int32_t displayId) const;
+    std::vector<ui::ColorMode> getColorModes(DisplayId displayId) const;
 
-    status_t setActiveColorMode(int32_t displayId, ui::ColorMode mode,
-            ui::RenderIntent renderIntent);
+    status_t setActiveColorMode(DisplayId displayId, ui::ColorMode mode,
+                                ui::RenderIntent renderIntent);
 
     bool isUsingVrComposer() const;
 
@@ -185,12 +179,19 @@
 
     android::Hwc2::Composer* getComposer() const { return mHwcDevice->getComposer(); }
 
-    std::optional<hwc2_display_t> getHwcDisplayId(int32_t displayId) const;
+    // TODO(b/74619554): Remove special cases for internal/external display.
+    std::optional<hwc2_display_t> getInternalHwcDisplayId() const { return mInternalHwcDisplayId; }
+    std::optional<hwc2_display_t> getExternalHwcDisplayId() const { return mExternalHwcDisplayId; }
+
+    std::optional<DisplayId> toPhysicalDisplayId(hwc2_display_t hwcDisplayId) const;
+    std::optional<hwc2_display_t> fromPhysicalDisplayId(DisplayId displayId) const;
+
 private:
     // For unit tests
     friend TestableSurfaceFlinger;
 
-    bool isValidDisplay(int32_t displayId) const;
+    std::optional<DisplayIdentificationInfo> onHotplugConnect(hwc2_display_t hwcDisplayId);
+
     static void validateChange(HWC2::Composition from, HWC2::Composition to);
 
     struct cb_context;
@@ -215,21 +216,30 @@
         HWC2::Error presentError;
     };
 
-    std::unique_ptr<HWC2::Device>   mHwcDevice;
-    std::vector<DisplayData> mDisplayData{HWC_NUM_PHYSICAL_DISPLAY_TYPES};
-    std::set<size_t>                mFreeDisplaySlots;
-    std::unordered_map<hwc2_display_t, int32_t> mHwcDisplaySlots;
+    std::unordered_map<DisplayId, DisplayData> mDisplayData;
+
+    // This must be destroyed before mDisplayData, because destructor may call back into HWComposer
+    // and look up DisplayData.
+    std::unique_ptr<HWC2::Device> mHwcDevice;
+
+    std::unordered_map<hwc2_display_t, DisplayId> mPhysicalDisplayIdMap;
+    std::optional<hwc2_display_t> mInternalHwcDisplayId;
+    std::optional<hwc2_display_t> mExternalHwcDisplayId;
+    bool mHasMultiDisplaySupport = false;
+
     // protect mDisplayData from races between prepare and dump
     mutable Mutex mDisplayLock;
 
     cb_context* mCBContext = nullptr;
-    size_t mVSyncCounts[HWC_NUM_PHYSICAL_DISPLAY_TYPES]{0, 0};
+    std::unordered_map<DisplayId, size_t> mVSyncCounts;
+
+    std::unordered_set<uint32_t> mFreeVirtualDisplayIds;
+    uint32_t mNextVirtualDisplayId = 0;
     uint32_t mRemainingHwcVirtualDisplays{mHwcDevice->getMaxVirtualDisplayCount()};
 
     // protected by mLock
     mutable Mutex mLock;
-    mutable std::unordered_map<int32_t, nsecs_t> mLastHwVSync{
-            {{HWC_DISPLAY_PRIMARY, 0}, {HWC_DISPLAY_EXTERNAL, 0}}};
+    mutable std::unordered_map<DisplayId, nsecs_t> mLastHwVSync;
 
     // thread-safe
     mutable Mutex mVsyncLock;
diff --git a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
index c111a27..27d3dc5 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
@@ -48,34 +48,34 @@
     }
 }
 
-VirtualDisplaySurface::VirtualDisplaySurface(HWComposer& hwc, int32_t dispId,
-        const sp<IGraphicBufferProducer>& sink,
-        const sp<IGraphicBufferProducer>& bqProducer,
-        const sp<IGraphicBufferConsumer>& bqConsumer,
-        const std::string& name)
-:   ConsumerBase(bqConsumer),
-    mHwc(hwc),
-    mDisplayId(dispId),
-    mDisplayName(name),
-    mSource{},
-    mDefaultOutputFormat(HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED),
-    mOutputFormat(HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED),
-    mOutputUsage(GRALLOC_USAGE_HW_COMPOSER),
-    mProducerSlotSource(0),
-    mProducerBuffers(),
-    mQueueBufferOutput(),
-    mSinkBufferWidth(0),
-    mSinkBufferHeight(0),
-    mCompositionType(COMPOSITION_UNKNOWN),
-    mFbFence(Fence::NO_FENCE),
-    mOutputFence(Fence::NO_FENCE),
-    mFbProducerSlot(BufferQueue::INVALID_BUFFER_SLOT),
-    mOutputProducerSlot(BufferQueue::INVALID_BUFFER_SLOT),
-    mDbgState(DBG_STATE_IDLE),
-    mDbgLastCompositionType(COMPOSITION_UNKNOWN),
-    mMustRecompose(false),
-    mForceHwcCopy(SurfaceFlinger::useHwcForRgbToYuv)
-{
+VirtualDisplaySurface::VirtualDisplaySurface(HWComposer& hwc,
+                                             const std::optional<DisplayId>& displayId,
+                                             const sp<IGraphicBufferProducer>& sink,
+                                             const sp<IGraphicBufferProducer>& bqProducer,
+                                             const sp<IGraphicBufferConsumer>& bqConsumer,
+                                             const std::string& name)
+      : ConsumerBase(bqConsumer),
+        mHwc(hwc),
+        mDisplayId(displayId),
+        mDisplayName(name),
+        mSource{},
+        mDefaultOutputFormat(HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED),
+        mOutputFormat(HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED),
+        mOutputUsage(GRALLOC_USAGE_HW_COMPOSER),
+        mProducerSlotSource(0),
+        mProducerBuffers(),
+        mQueueBufferOutput(),
+        mSinkBufferWidth(0),
+        mSinkBufferHeight(0),
+        mCompositionType(COMPOSITION_UNKNOWN),
+        mFbFence(Fence::NO_FENCE),
+        mOutputFence(Fence::NO_FENCE),
+        mFbProducerSlot(BufferQueue::INVALID_BUFFER_SLOT),
+        mOutputProducerSlot(BufferQueue::INVALID_BUFFER_SLOT),
+        mDbgState(DBG_STATE_IDLE),
+        mDbgLastCompositionType(COMPOSITION_UNKNOWN),
+        mMustRecompose(false),
+        mForceHwcCopy(SurfaceFlinger::useHwcForRgbToYuv) {
     mSource[SOURCE_SINK] = sink;
     mSource[SOURCE_SCRATCH] = bqProducer;
 
@@ -116,8 +116,9 @@
 }
 
 status_t VirtualDisplaySurface::beginFrame(bool mustRecompose) {
-    if (mDisplayId < 0)
+    if (!mDisplayId) {
         return NO_ERROR;
+    }
 
     mMustRecompose = mustRecompose;
 
@@ -129,8 +130,9 @@
 }
 
 status_t VirtualDisplaySurface::prepareFrame(CompositionType compositionType) {
-    if (mDisplayId < 0)
+    if (!mDisplayId) {
         return NO_ERROR;
+    }
 
     VDS_LOGW_IF(mDbgState != DBG_STATE_BEGUN,
             "Unexpected prepareFrame() in %s state", dbgStateStr());
@@ -177,8 +179,9 @@
 }
 
 status_t VirtualDisplaySurface::advanceFrame() {
-    if (mDisplayId < 0)
+    if (!mDisplayId) {
         return NO_ERROR;
+    }
 
     if (mCompositionType == COMPOSITION_HWC) {
         VDS_LOGW_IF(mDbgState != DBG_STATE_PREPARED,
@@ -211,7 +214,7 @@
 
     // At this point we know the output buffer acquire fence,
     // so update HWC state with it.
-    mHwc.setOutputBuffer(mDisplayId, mOutputFence, outBuffer);
+    mHwc.setOutputBuffer(*mDisplayId, mOutputFence, outBuffer);
 
     status_t result = NO_ERROR;
     if (fbBuffer != nullptr) {
@@ -221,22 +224,23 @@
                 &hwcSlot, &hwcBuffer);
 
         // TODO: Correctly propagate the dataspace from GL composition
-        result = mHwc.setClientTarget(mDisplayId, hwcSlot, mFbFence,
-                hwcBuffer, ui::Dataspace::UNKNOWN);
+        result = mHwc.setClientTarget(*mDisplayId, hwcSlot, mFbFence, hwcBuffer,
+                                      ui::Dataspace::UNKNOWN);
     }
 
     return result;
 }
 
 void VirtualDisplaySurface::onFrameCommitted() {
-    if (mDisplayId < 0)
+    if (!mDisplayId) {
         return;
+    }
 
     VDS_LOGW_IF(mDbgState != DBG_STATE_HWC,
             "Unexpected onFrameCommitted() in %s state", dbgStateStr());
     mDbgState = DBG_STATE_IDLE;
 
-    sp<Fence> retireFence = mHwc.getPresentFence(mDisplayId);
+    sp<Fence> retireFence = mHwc.getPresentFence(*mDisplayId);
     if (mCompositionType == COMPOSITION_MIXED && mFbProducerSlot >= 0) {
         // release the scratch buffer back to the pool
         Mutex::Autolock lock(mMutex);
@@ -291,8 +295,9 @@
 
 status_t VirtualDisplaySurface::requestBuffer(int pslot,
         sp<GraphicBuffer>* outBuf) {
-    if (mDisplayId < 0)
+    if (!mDisplayId) {
         return mSource[SOURCE_SINK]->requestBuffer(pslot, outBuf);
+    }
 
     VDS_LOGW_IF(mDbgState != DBG_STATE_GLES,
             "Unexpected requestBuffer pslot=%d in %s state",
@@ -313,7 +318,7 @@
 
 status_t VirtualDisplaySurface::dequeueBuffer(Source source,
         PixelFormat format, uint64_t usage, int* sslot, sp<Fence>* fence) {
-    LOG_FATAL_IF(mDisplayId < 0, "mDisplayId=%d but should not be < 0.", mDisplayId);
+    LOG_FATAL_IF(!mDisplayId);
 
     status_t result =
             mSource[source]->dequeueBuffer(sslot, fence, mSinkBufferWidth, mSinkBufferHeight,
@@ -359,7 +364,7 @@
                                               PixelFormat format, uint64_t usage,
                                               uint64_t* outBufferAge,
                                               FrameEventHistoryDelta* outTimestamps) {
-    if (mDisplayId < 0) {
+    if (!mDisplayId) {
         return mSource[SOURCE_SINK]->dequeueBuffer(pslot, fence, w, h, format, usage, outBufferAge,
                                                    outTimestamps);
     }
@@ -446,8 +451,9 @@
 
 status_t VirtualDisplaySurface::queueBuffer(int pslot,
         const QueueBufferInput& input, QueueBufferOutput* output) {
-    if (mDisplayId < 0)
+    if (!mDisplayId) {
         return mSource[SOURCE_SINK]->queueBuffer(pslot, input, output);
+    }
 
     VDS_LOGW_IF(mDbgState != DBG_STATE_GLES,
             "Unexpected queueBuffer(pslot=%d) in %s state", pslot,
@@ -504,8 +510,9 @@
 
 status_t VirtualDisplaySurface::cancelBuffer(int pslot,
         const sp<Fence>& fence) {
-    if (mDisplayId < 0)
+    if (!mDisplayId) {
         return mSource[SOURCE_SINK]->cancelBuffer(mapProducer2SourceSlot(SOURCE_SINK, pslot), fence);
+    }
 
     VDS_LOGW_IF(mDbgState != DBG_STATE_GLES,
             "Unexpected cancelBuffer(pslot=%d) in %s state", pslot,
@@ -616,6 +623,8 @@
 }
 
 status_t VirtualDisplaySurface::refreshOutputBuffer() {
+    LOG_FATAL_IF(!mDisplayId);
+
     if (mOutputProducerSlot >= 0) {
         mSource[SOURCE_SINK]->cancelBuffer(
                 mapProducer2SourceSlot(SOURCE_SINK, mOutputProducerSlot),
@@ -633,8 +642,8 @@
     // until after GLES calls queueBuffer(). So here we just set the buffer
     // (for use in HWC prepare) but not the fence; we'll call this again with
     // the proper fence once we have it.
-    result = mHwc.setOutputBuffer(mDisplayId, Fence::NO_FENCE,
-            mProducerBuffers[mOutputProducerSlot]);
+    result = mHwc.setOutputBuffer(*mDisplayId, Fence::NO_FENCE,
+                                  mProducerBuffers[mOutputProducerSlot]);
 
     return result;
 }
diff --git a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
index 4bd4d0f..33678df 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
@@ -17,8 +17,10 @@
 #ifndef ANDROID_SF_VIRTUAL_DISPLAY_SURFACE_H
 #define ANDROID_SF_VIRTUAL_DISPLAY_SURFACE_H
 
+#include <optional>
 #include <string>
 
+#include "DisplayIdentification.h"
 #include "DisplaySurface.h"
 #include "HWComposerBufferCache.h"
 
@@ -75,11 +77,10 @@
                               public BnGraphicBufferProducer,
                               private ConsumerBase {
 public:
-    VirtualDisplaySurface(HWComposer& hwc, int32_t dispId,
-            const sp<IGraphicBufferProducer>& sink,
-            const sp<IGraphicBufferProducer>& bqProducer,
-            const sp<IGraphicBufferConsumer>& bqConsumer,
-            const std::string& name);
+    VirtualDisplaySurface(HWComposer& hwc, const std::optional<DisplayId>& displayId,
+                          const sp<IGraphicBufferProducer>& sink,
+                          const sp<IGraphicBufferProducer>& bqProducer,
+                          const sp<IGraphicBufferConsumer>& bqConsumer, const std::string& name);
 
     //
     // DisplaySurface interface
@@ -154,7 +155,7 @@
     // Immutable after construction
     //
     HWComposer& mHwc;
-    const int32_t mDisplayId;
+    const std::optional<DisplayId> mDisplayId;
     const std::string mDisplayName;
     sp<IGraphicBufferProducer> mSource[2]; // indexed by SOURCE_*
     uint32_t mDefaultOutputFormat;
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index f29dfc0..f41a753 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -196,9 +196,9 @@
 // h/w composer set-up
 // ---------------------------------------------------------------------------
 
-bool Layer::createHwcLayer(HWComposer* hwc, int32_t displayId) {
+bool Layer::createHwcLayer(HWComposer* hwc, DisplayId displayId) {
     LOG_ALWAYS_FATAL_IF(getBE().mHwcLayers.count(displayId) != 0,
-                        "Already have a layer for display %d", displayId);
+                        "Already have a layer for display %" PRIu64, displayId);
     auto layer = std::shared_ptr<HWC2::Layer>(
             hwc->createLayer(displayId),
             [hwc, displayId](HWC2::Layer* layer) {
@@ -214,7 +214,7 @@
     return true;
 }
 
-bool Layer::destroyHwcLayer(int32_t displayId) {
+bool Layer::destroyHwcLayer(DisplayId displayId) {
     if (getBE().mHwcLayers.count(displayId) == 0) {
         return false;
     }
@@ -461,12 +461,13 @@
 
 void Layer::setGeometry(const sp<const DisplayDevice>& display, uint32_t z) {
     const auto displayId = display->getId();
-    if (!hasHwcLayer(displayId)) {
-        ALOGE("[%s] failed to setGeometry: no HWC layer found (%d)",
-              mName.string(), displayId);
+    LOG_ALWAYS_FATAL_IF(!displayId);
+    if (!hasHwcLayer(*displayId)) {
+        ALOGE("[%s] failed to setGeometry: no HWC layer found for display %" PRIu64, mName.string(),
+              *displayId);
         return;
     }
-    auto& hwcInfo = getBE().mHwcLayers[displayId];
+    auto& hwcInfo = getBE().mHwcLayers[*displayId];
 
     // enable this layer
     hwcInfo.forceClientComposition = false;
@@ -618,7 +619,7 @@
     if (orientation & ui::Transform::ROT_INVALID) {
         // we can only handle simple transformation
         hwcInfo.forceClientComposition = true;
-        getBE().mHwcLayers[displayId].compositionType = HWC2::Composition::Client;
+        getBE().mHwcLayers[*displayId].compositionType = HWC2::Composition::Client;
     } else {
         auto transform = static_cast<HWC2::Transform>(orientation);
         hwcInfo.transform = transform;
@@ -632,18 +633,18 @@
     }
 }
 
-void Layer::forceClientComposition(int32_t displayId) {
+void Layer::forceClientComposition(DisplayId displayId) {
     if (getBE().mHwcLayers.count(displayId) == 0) {
-        ALOGE("forceClientComposition: no HWC layer found (%d)", displayId);
+        ALOGE("forceClientComposition: no HWC layer found (display %" PRIu64 ")", displayId);
         return;
     }
 
     getBE().mHwcLayers[displayId].forceClientComposition = true;
 }
 
-bool Layer::getForceClientComposition(int32_t displayId) {
+bool Layer::getForceClientComposition(DisplayId displayId) {
     if (getBE().mHwcLayers.count(displayId) == 0) {
-        ALOGE("getForceClientComposition: no HWC layer found (%d)", displayId);
+        ALOGE("getForceClientComposition: no HWC layer found (display %" PRIu64 ")", displayId);
         return false;
     }
 
@@ -652,7 +653,7 @@
 
 void Layer::updateCursorPosition(const sp<const DisplayDevice>& display) {
     const auto displayId = display->getId();
-    if (getBE().mHwcLayers.count(displayId) == 0 ||
+    if (getBE().mHwcLayers.count(*displayId) == 0 ||
         getCompositionType(displayId) != HWC2::Composition::Cursor) {
         return;
     }
@@ -675,8 +676,8 @@
     auto position = displayTransform.transform(frame);
 
     auto error =
-            (getBE().mHwcLayers[displayId].layer)->setCursorPosition(
-                    position.left, position.top);
+            getBE().mHwcLayers[*displayId].layer->setCursorPosition(position.left, position.top);
+
     ALOGE_IF(error != HWC2::Error::None,
              "[%s] Failed to set cursor position "
              "to (%d, %d): %s (%d)",
@@ -708,7 +709,7 @@
     clearWithOpenGL(renderArea, 0, 0, 0, 0);
 }
 
-void Layer::setCompositionType(int32_t displayId, HWC2::Composition type, bool callIntoHwc) {
+void Layer::setCompositionType(DisplayId displayId, HWC2::Composition type, bool callIntoHwc) {
     if (getBE().mHwcLayers.count(displayId) == 0) {
         ALOGE("setCompositionType called without a valid HWC layer");
         return;
@@ -731,16 +732,20 @@
     }
 }
 
-HWC2::Composition Layer::getCompositionType(int32_t displayId) const {
-    if (getBE().mHwcLayers.count(displayId) == 0) {
+HWC2::Composition Layer::getCompositionType(const std::optional<DisplayId>& displayId) const {
+    if (!displayId) {
         // If we're querying the composition type for a display that does not
         // have a HWC counterpart, then it will always be Client
         return HWC2::Composition::Client;
     }
-    return getBE().mHwcLayers[displayId].compositionType;
+    if (getBE().mHwcLayers.count(*displayId) == 0) {
+        ALOGE("getCompositionType called with an invalid HWC layer");
+        return HWC2::Composition::Invalid;
+    }
+    return getBE().mHwcLayers.at(*displayId).compositionType;
 }
 
-void Layer::setClearClientTarget(int32_t displayId, bool clear) {
+void Layer::setClearClientTarget(DisplayId displayId, bool clear) {
     if (getBE().mHwcLayers.count(displayId) == 0) {
         ALOGE("setClearClientTarget called without a valid HWC layer");
         return;
@@ -748,7 +753,7 @@
     getBE().mHwcLayers[displayId].clearClientTarget = clear;
 }
 
-bool Layer::getClearClientTarget(int32_t displayId) const {
+bool Layer::getClearClientTarget(DisplayId displayId) const {
     if (getBE().mHwcLayers.count(displayId) == 0) {
         ALOGE("getClearClientTarget called without a valid HWC layer");
         return false;
@@ -1416,7 +1421,7 @@
     result.append("-----------------------------\n");
 }
 
-void Layer::miniDump(String8& result, int32_t displayId) const {
+void Layer::miniDump(String8& result, DisplayId displayId) const {
     if (getBE().mHwcLayers.count(displayId) == 0) {
         return;
     }
@@ -1980,7 +1985,7 @@
     }
 }
 
-void Layer::writeToProto(LayerProto* layerInfo, int32_t displayId) {
+void Layer::writeToProto(LayerProto* layerInfo, DisplayId displayId) {
     if (!hasHwcLayer(displayId)) {
         return;
     }
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 12671ff..ced6532 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -38,6 +38,7 @@
 
 #include <cstdint>
 #include <list>
+#include <optional>
 #include <vector>
 
 #include "Client.h"
@@ -351,7 +352,7 @@
     void writeToProto(LayerProto* layerInfo,
                       LayerVector::StateSet stateSet = LayerVector::StateSet::Drawing);
 
-    void writeToProto(LayerProto* layerInfo, int32_t displayId);
+    void writeToProto(LayerProto* layerInfo, DisplayId displayId);
 
     virtual Geometry getActiveGeometry(const Layer::State& s) const { return s.active_legacy; }
     virtual uint32_t getActiveWidth(const Layer::State& s) const { return s.active_legacy.w; }
@@ -377,16 +378,17 @@
     virtual bool isHdrY410() const { return false; }
 
     void setGeometry(const sp<const DisplayDevice>& display, uint32_t z);
-    void forceClientComposition(int32_t displayId);
-    bool getForceClientComposition(int32_t displayId);
-    virtual void setPerFrameData(const sp<const DisplayDevice>& display) = 0;
+    void forceClientComposition(DisplayId displayId);
+    bool getForceClientComposition(DisplayId displayId);
+    virtual void setPerFrameData(DisplayId displayId, const ui::Transform& transform,
+                                 const Rect& viewport, int32_t supportedPerFrameMetadata) = 0;
 
     // callIntoHwc exists so we can update our local state and call
     // acceptDisplayChanges without unnecessarily updating the device's state
-    void setCompositionType(int32_t displayId, HWC2::Composition type, bool callIntoHwc = true);
-    HWC2::Composition getCompositionType(int32_t displayId) const;
-    void setClearClientTarget(int32_t displayId, bool clear);
-    bool getClearClientTarget(int32_t displayId) const;
+    void setCompositionType(DisplayId displayId, HWC2::Composition type, bool callIntoHwc = true);
+    HWC2::Composition getCompositionType(const std::optional<DisplayId>& displayId) const;
+    void setClearClientTarget(DisplayId displayId, bool clear);
+    bool getClearClientTarget(DisplayId displayId) const;
     void updateCursorPosition(const sp<const DisplayDevice>& display);
 
     /*
@@ -401,13 +403,14 @@
      * called before composition.
      * returns true if the layer has pending updates.
      */
-    virtual bool onPreComposition(nsecs_t /*refreshStartTime*/) { return true; }
+    virtual bool onPreComposition(nsecs_t refreshStartTime) = 0;
 
     /*
      * called after composition.
      * returns true if the layer latched a new buffer this frame.
      */
-    virtual bool onPostComposition(const std::shared_ptr<FenceTime>& /*glDoneFence*/,
+    virtual bool onPostComposition(const std::optional<DisplayId>& /*displayId*/,
+                                   const std::shared_ptr<FenceTime>& /*glDoneFence*/,
                                    const std::shared_ptr<FenceTime>& /*presentFence*/,
                                    const CompositorTiming& /*compositorTiming*/) {
         return false;
@@ -492,24 +495,24 @@
 
     // -----------------------------------------------------------------------
 
-    bool createHwcLayer(HWComposer* hwc, int32_t displayId);
-    bool destroyHwcLayer(int32_t displayId);
+    bool createHwcLayer(HWComposer* hwc, DisplayId displayId);
+    bool destroyHwcLayer(DisplayId displayId);
     void destroyAllHwcLayers();
 
-    bool hasHwcLayer(int32_t displayId) { return getBE().mHwcLayers.count(displayId) > 0; }
+    bool hasHwcLayer(DisplayId displayId) { return getBE().mHwcLayers.count(displayId) > 0; }
 
-    HWC2::Layer* getHwcLayer(int32_t displayId) {
-        if (getBE().mHwcLayers.count(displayId) == 0) {
+    HWC2::Layer* getHwcLayer(DisplayId displayId) {
+        if (!hasHwcLayer(displayId)) {
             return nullptr;
         }
         return getBE().mHwcLayers[displayId].layer.get();
     }
 
-    bool setHwcLayer(int32_t hwcId) {
-        if (getBE().mHwcLayers.count(hwcId) == 0) {
+    bool setHwcLayer(DisplayId displayId) {
+        if (!hasHwcLayer(displayId)) {
             return false;
         }
-        getBE().compositionInfo.hwc.hwcLayer = getBE().mHwcLayers[hwcId].layer;
+        getBE().compositionInfo.hwc.hwcLayer = getBE().mHwcLayers[displayId].layer;
         return true;
     }
 
@@ -524,7 +527,7 @@
 
     /* always call base class first */
     static void miniDumpHeader(String8& result);
-    void miniDump(String8& result, int32_t displayId) const;
+    void miniDump(String8& result, DisplayId displayId) const;
     void dumpFrameStats(String8& result) const;
     void dumpFrameEvents(String8& result);
     void clearFrameStats();
diff --git a/services/surfaceflinger/LayerBE.h b/services/surfaceflinger/LayerBE.h
index 463c46c..3f5134e 100644
--- a/services/surfaceflinger/LayerBE.h
+++ b/services/surfaceflinger/LayerBE.h
@@ -24,6 +24,7 @@
 #include <renderengine/Texture.h>
 #include <ui/Region.h>
 
+#include "DisplayHardware/DisplayIdentification.h"
 #include "DisplayHardware/HWComposer.h"
 #include "DisplayHardware/HWComposerBufferCache.h"
 #include "SurfaceFlinger.h"
@@ -41,7 +42,7 @@
     std::shared_ptr<LayerBE> layer;
     struct {
         std::shared_ptr<HWC2::Layer> hwcLayer;
-        int32_t displayId = -1;
+        DisplayId displayId;
         sp<Fence> fence;
         HWC2::BlendMode blendMode = HWC2::BlendMode::Invalid;
         Rect displayFrame;
@@ -123,12 +124,11 @@
         HWC2::Transform transform;
     };
 
-
     // A layer can be attached to multiple displays when operating in mirror mode
     // (a.k.a: when several displays are attached with equal layerStack). In this
     // case we need to keep track. In non-mirror mode, a layer will have only one
-    // HWCInfo. This map key is a display layerStack.
-    std::unordered_map<int32_t, HWCInfo> mHwcLayers;
+    // HWCInfo.
+    std::unordered_map<DisplayId, HWCInfo> mHwcLayers;
 
     CompositionInfo compositionInfo;
 };
diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index 18a8bb1..4286cc9 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -14,11 +14,14 @@
  * limitations under the License.
  */
 
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+
 #include "Scheduler.h"
 
 #include <cinttypes>
 #include <cstdint>
 #include <memory>
+#include <numeric>
 
 #include <android/hardware/configstore/1.0/ISurfaceFlingerConfigs.h>
 #include <android/hardware/configstore/1.1/ISurfaceFlingerConfigs.h>
@@ -27,6 +30,7 @@
 
 #include <gui/ISurfaceComposer.h>
 #include <ui/DisplayStatInfo.h>
+#include <utils/Trace.h>
 
 #include "DispSync.h"
 #include "DispSyncSource.h"
@@ -196,4 +200,58 @@
     mPrimaryDispSync->setIgnorePresentFences(ignore);
 }
 
+void Scheduler::makeHWSyncAvailable(bool makeAvailable) {
+    std::lock_guard<std::mutex> lock(mHWVsyncLock);
+    mHWVsyncAvailable = makeAvailable;
+}
+
+void Scheduler::addNewFrameTimestamp(const nsecs_t newFrameTimestamp, bool isAutoTimestamp) {
+    ATRACE_INT("AutoTimestamp", isAutoTimestamp);
+    // Video does not have timestamp automatically set, so we discard timestamps that are
+    // coming in from other sources for now.
+    if (isAutoTimestamp) {
+        return;
+    }
+    int64_t differenceMs = (newFrameTimestamp - mPreviousFrameTimestamp) / 1000000;
+    mPreviousFrameTimestamp = newFrameTimestamp;
+
+    if (differenceMs < 10 || differenceMs > 100) {
+        // Dismiss noise.
+        return;
+    }
+    ATRACE_INT("TimestampDiff", differenceMs);
+
+    mTimeDifferences[mCounter % ARRAY_SIZE] = differenceMs;
+    mCounter++;
+    nsecs_t average = calculateAverage();
+    ATRACE_INT("TimestampAverage", average);
+
+    // TODO(b/113612090): This are current numbers from trial and error while running videos
+    // from YouTube at 24, 30, and 60 fps.
+    if (average > 14 && average < 18) {
+        ATRACE_INT("FPS", 60);
+    } else if (average > 31 && average < 34) {
+        ATRACE_INT("FPS", 30);
+        updateFrameSkipping(1);
+        return;
+    } else if (average > 39 && average < 42) {
+        ATRACE_INT("FPS", 24);
+    }
+    updateFrameSkipping(0);
+}
+
+nsecs_t Scheduler::calculateAverage() const {
+    nsecs_t sum = std::accumulate(mTimeDifferences.begin(), mTimeDifferences.end(), 0);
+    return (sum / ARRAY_SIZE);
+}
+
+void Scheduler::updateFrameSkipping(const int64_t skipCount) {
+    ATRACE_INT("FrameSkipCount", skipCount);
+    if (mSkipCount != skipCount) {
+        // Only update DispSync if it hasn't been updated yet.
+        mPrimaryDispSync->setRefreshSkipCount(skipCount);
+        mSkipCount = skipCount;
+    }
+}
+
 } // namespace android
diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index fdafe58..dd1f24b 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -102,6 +102,8 @@
     void addResyncSample(const nsecs_t timestamp);
     void addPresentFence(const std::shared_ptr<FenceTime>& fenceTime);
     void setIgnorePresentFences(bool ignore);
+    void makeHWSyncAvailable(bool makeAvailable);
+    void addNewFrameTimestamp(const nsecs_t newFrameTimestamp, bool isAutoTimestamp);
 
 protected:
     virtual std::unique_ptr<EventThread> makeEventThread(
@@ -110,6 +112,9 @@
             impl::EventThread::InterceptVSyncsCallback interceptCallback);
 
 private:
+    nsecs_t calculateAverage() const;
+    void updateFrameSkipping(const int64_t skipCount);
+
     // TODO(b/113612090): Instead of letting BufferQueueLayer to access mDispSync directly, it
     // should make request to Scheduler to compute next refresh.
     friend class BufferQueueLayer;
@@ -133,6 +138,18 @@
 
     std::unique_ptr<DispSync> mPrimaryDispSync;
     std::unique_ptr<EventControlThread> mEventControlThread;
+
+    // TODO(b/113612090): The following set of variables needs to be revised. For now, this is
+    // a proof of concept. We turn on frame skipping if the difference between the timestamps
+    // is between 32 and 34ms. We expect this currently for 30fps videos, so we render them at 30Hz.
+    nsecs_t mPreviousFrameTimestamp = 0;
+    // Keeping track of whether we are skipping the refresh count. If we want to
+    // simulate 30Hz rendering, we skip every other frame, and this variable is set
+    // to 1.
+    int64_t mSkipCount = 0;
+    static constexpr size_t ARRAY_SIZE = 30;
+    std::array<int64_t, ARRAY_SIZE> mTimeDifferences;
+    size_t mCounter = 0;
 };
 
-} // namespace android
\ No newline at end of file
+} // namespace android
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index c15bdb2..368b9b8 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -105,8 +105,6 @@
 
 #include <layerproto/LayerProtoParser.h>
 
-#define DISPLAY_COUNT       1
-
 namespace android {
 
 using namespace android::hardware::configstore;
@@ -173,6 +171,11 @@
     bool mLocked;
 };
 
+// Currently we only support V0_SRGB and DISPLAY_P3 as composition preference.
+bool validateCompositionDataspace(Dataspace dataspace) {
+    return dataspace == Dataspace::V0_SRGB || dataspace == Dataspace::DISPLAY_P3;
+}
+
 }  // namespace anonymous
 
 // ---------------------------------------------------------------------------
@@ -191,7 +194,6 @@
 bool SurfaceFlinger::hasSyncFramework;
 bool SurfaceFlinger::useVrFlinger;
 int64_t SurfaceFlinger::maxFrameBufferAcquiredBuffers;
-// TODO(courtneygo): Rename hasWideColorDisplay to clarify its actual meaning.
 bool SurfaceFlinger::hasWideColorDisplay;
 int SurfaceFlinger::primaryDisplayOrientation = DisplayState::eOrientationDefault;
 bool SurfaceFlinger::useColorManagement;
@@ -247,7 +249,6 @@
         mLayersRemoved(false),
         mLayersAdded(false),
         mBootTime(systemTime()),
-        mDisplayTokens(),
         mVisibleRegionsDirty(false),
         mGeometryInvalid(false),
         mAnimCompositionPending(false),
@@ -313,6 +314,8 @@
                     wideColorGamutCompositionPixelFormat = tmpWideColorGamutPixelFormat;
                 });
     }
+    mDefaultCompositionDataspace = defaultCompositionDataspace;
+    mWideColorGamutCompositionDataspace = wideColorGamutCompositionDataspace;
 
     useContextPriority = getBool<ISurfaceFlingerConfigs,
                                  &ISurfaceFlingerConfigs::useContextPriority>(true);
@@ -482,40 +485,49 @@
     sp<BBinder> token = new DisplayToken(this);
 
     Mutex::Autolock _l(mStateLock);
-    DisplayDeviceState info;
-    info.type = DisplayDevice::DISPLAY_VIRTUAL;
-    info.displayName = displayName;
-    info.isSecure = secure;
-    mCurrentState.displays.add(token, info);
-    mInterceptor->saveDisplayCreation(info);
+    // Display ID is assigned when virtual display is allocated by HWC.
+    DisplayDeviceState state;
+    state.isSecure = secure;
+    state.displayName = displayName;
+    mCurrentState.displays.add(token, state);
+    mInterceptor->saveDisplayCreation(state);
     return token;
 }
 
 void SurfaceFlinger::destroyDisplay(const sp<IBinder>& displayToken) {
     Mutex::Autolock _l(mStateLock);
 
-    ssize_t idx = mCurrentState.displays.indexOfKey(displayToken);
-    if (idx < 0) {
+    ssize_t index = mCurrentState.displays.indexOfKey(displayToken);
+    if (index < 0) {
         ALOGE("destroyDisplay: Invalid display token %p", displayToken.get());
         return;
     }
 
-    const DisplayDeviceState& info(mCurrentState.displays.valueAt(idx));
-    if (!info.isVirtual()) {
+    const DisplayDeviceState& state = mCurrentState.displays.valueAt(index);
+    if (!state.isVirtual()) {
         ALOGE("destroyDisplay called for non-virtual display");
         return;
     }
-    mInterceptor->saveDisplayDeletion(info.sequenceId);
-    mCurrentState.displays.removeItemsAt(idx);
+    mInterceptor->saveDisplayDeletion(state.sequenceId);
+    mCurrentState.displays.removeItemsAt(index);
     setTransactionFlags(eDisplayTransactionNeeded);
 }
 
 sp<IBinder> SurfaceFlinger::getBuiltInDisplay(int32_t id) {
-    if (uint32_t(id) >= DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES) {
-        ALOGE("getDefaultDisplay: id=%d is not a valid default display id", id);
+    std::optional<DisplayId> displayId;
+
+    if (id == HWC_DISPLAY_PRIMARY) {
+        displayId = getInternalDisplayId();
+    } else if (id == HWC_DISPLAY_EXTERNAL) {
+        displayId = getExternalDisplayId();
+    }
+
+    if (!displayId) {
+        ALOGE("%s: Invalid display %d", __FUNCTION__, id);
         return nullptr;
     }
-    return mDisplayTokens[id];
+
+    return getPhysicalDisplayToken(*displayId);
 }
 
 status_t SurfaceFlinger::getColorManagement(bool* outGetColorManagement) const {
@@ -598,8 +610,10 @@
 
     // start the EventThread
     if (mUseScheduler) {
-        mScheduler = getFactory().createScheduler(
-                [this](bool enabled) { setVsyncEnabled(HWC_DISPLAY_PRIMARY, enabled); });
+        mScheduler = getFactory().createScheduler([this](bool enabled) {
+            setVsyncEnabled(EventThread::DisplayType::Primary, enabled);
+        });
+
         mAppConnectionHandle =
                 mScheduler->createConnection("appConnection", SurfaceFlinger::vsyncPhaseOffsetNs,
                                              [this] { resyncWithRateLimit(); },
@@ -659,7 +673,7 @@
     processDisplayHotplugEventsLocked();
     const auto display = getDefaultDisplayDeviceLocked();
     LOG_ALWAYS_FATAL_IF(!display, "Missing internal display after registering composer callback.");
-    LOG_ALWAYS_FATAL_IF(!getHwComposer().isConnected(display->getId()),
+    LOG_ALWAYS_FATAL_IF(!getHwComposer().isConnected(*display->getId()),
                         "Internal display is disconnected.");
 
     // make the default display GLContext current so that we can create textures
@@ -682,7 +696,7 @@
         };
         mVrFlinger = dvr::VrFlinger::Create(getHwComposer().getComposer(),
                                             getHwComposer()
-                                                    .getHwcDisplayId(display->getId())
+                                                    .fromPhysicalDisplayId(*display->getId())
                                                     .value_or(0),
                                             vrFlingerRequestDisplayCallback);
         if (!mVrFlinger) {
@@ -691,7 +705,7 @@
     }
 
     mEventControlThread = getFactory().createEventControlThread(
-            [this](bool enabled) { setVsyncEnabled(HWC_DISPLAY_PRIMARY, enabled); });
+            [this](bool enabled) { setVsyncEnabled(EventThread::DisplayType::Primary, enabled); });
 
     // initialize our drawing state
     mDrawingState = mCurrentState;
@@ -717,8 +731,8 @@
     // and apply this saturation matrix on Display P3 content. Unless the risk of applying
     // such saturation matrix on Display P3 is understood fully, the API should always return
     // identify matrix.
-    mEnhancedSaturationMatrix = getBE().mHwc->getDataspaceSaturationMatrix(display->getId(),
-            Dataspace::SRGB_LINEAR);
+    mEnhancedSaturationMatrix =
+            getHwComposer().getDataspaceSaturationMatrix(*display->getId(), Dataspace::SRGB_LINEAR);
 
     // we will apply this on Display P3.
     if (mEnhancedSaturationMatrix != mat4()) {
@@ -805,16 +819,9 @@
         return BAD_VALUE;
     }
 
-    int32_t type = NAME_NOT_FOUND;
-    for (int i = 0; i < DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES; ++i) {
-        if (displayToken == mDisplayTokens[i]) {
-            type = i;
-            break;
-        }
-    }
-
-    if (type < 0) {
-        return type;
+    const auto displayId = getPhysicalDisplayId(displayToken);
+    if (!displayId) {
+        return NAME_NOT_FOUND;
     }
 
     // TODO: Not sure if display density should handled by SF any longer
@@ -838,7 +845,7 @@
 
     ConditionalLock _l(mStateLock,
             std::this_thread::get_id() != mMainThreadId);
-    for (const auto& hwConfig : getHwComposer().getConfigs(type)) {
+    for (const auto& hwConfig : getHwComposer().getConfigs(*displayId)) {
         DisplayInfo info = DisplayInfo();
 
         float xdpi = hwConfig->getDpiX();
@@ -850,7 +857,7 @@
         info.viewportW = info.w;
         info.viewportH = info.h;
 
-        if (type == DisplayDevice::DISPLAY_PRIMARY) {
+        if (displayId == getInternalDisplayId()) {
             // The density of the device is provided by a build property
             float density = Density::getBuildDensity() / 160.0f;
             if (density == 0) {
@@ -906,7 +913,7 @@
         // All non-virtual displays are currently considered secure.
         info.secure = true;
 
-        if (type == DisplayDevice::DISPLAY_PRIMARY &&
+        if (displayId == getInternalDisplayId() &&
             primaryDisplayOrientation & DisplayState::eOrientationSwapMask) {
             std::swap(info.w, info.h);
         }
@@ -922,7 +929,6 @@
         return BAD_VALUE;
     }
 
-    // FIXME for now we always return stats for the primary display.
     if (mUseScheduler) {
         mScheduler->getDisplayStatInfo(stats);
     } else {
@@ -943,18 +949,21 @@
 }
 
 void SurfaceFlinger::setActiveConfigInternal(const sp<DisplayDevice>& display, int mode) {
+    if (display->isVirtual()) {
+        ALOGE("%s: Invalid operation on virtual display", __FUNCTION__);
+        return;
+    }
+
     int currentMode = display->getActiveConfig();
     if (mode == currentMode) {
         return;
     }
 
-    if (display->isVirtual()) {
-        ALOGW("Trying to set config for virtual display");
-        return;
-    }
+    const auto displayId = display->getId();
+    LOG_ALWAYS_FATAL_IF(!displayId);
 
     display->setActiveConfig(mode);
-    getHwComposer().setActiveConfig(display->getDisplayType(), mode);
+    getHwComposer().setActiveConfig(*displayId, mode);
 }
 
 status_t SurfaceFlinger::setActiveConfig(const sp<IBinder>& displayToken, int mode) {
@@ -979,29 +988,23 @@
 
     return NO_ERROR;
 }
+
 status_t SurfaceFlinger::getDisplayColorModes(const sp<IBinder>& displayToken,
                                               Vector<ColorMode>* outColorModes) {
     if (!displayToken || !outColorModes) {
         return BAD_VALUE;
     }
 
-    int32_t type = NAME_NOT_FOUND;
-    for (int i = 0; i < DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES; ++i) {
-        if (displayToken == mDisplayTokens[i]) {
-            type = i;
-            break;
-        }
-    }
-
-    if (type < 0) {
-        return type;
+    const auto displayId = getPhysicalDisplayId(displayToken);
+    if (!displayId) {
+        return NAME_NOT_FOUND;
     }
 
     std::vector<ColorMode> modes;
     {
         ConditionalLock _l(mStateLock,
                 std::this_thread::get_id() != mMainThreadId);
-        modes = getHwComposer().getColorModes(type);
+        modes = getHwComposer().getColorModes(*displayId);
     }
     outColorModes->clear();
     std::copy(modes.cbegin(), modes.cend(), std::back_inserter(*outColorModes));
@@ -1018,6 +1021,11 @@
 
 void SurfaceFlinger::setActiveColorModeInternal(const sp<DisplayDevice>& display, ColorMode mode,
                                                 Dataspace dataSpace, RenderIntent renderIntent) {
+    if (display->isVirtual()) {
+        ALOGE("%s: Invalid operation on virtual display", __FUNCTION__);
+        return;
+    }
+
     ColorMode currentMode = display->getActiveColorMode();
     Dataspace currentDataSpace = display->getCompositionDataSpace();
     RenderIntent currentRenderIntent = display->getActiveRenderIntent();
@@ -1027,19 +1035,17 @@
         return;
     }
 
-    if (display->isVirtual()) {
-        ALOGW("Trying to set config for virtual display");
-        return;
-    }
-
     display->setActiveColorMode(mode);
     display->setCompositionDataSpace(dataSpace);
     display->setActiveRenderIntent(renderIntent);
-    getHwComposer().setActiveColorMode(display->getDisplayType(), mode, renderIntent);
 
-    ALOGV("Set active color mode: %s (%d), active render intent: %s (%d), type=%d",
+    const auto displayId = display->getId();
+    LOG_ALWAYS_FATAL_IF(!displayId);
+    getHwComposer().setActiveColorMode(*displayId, mode, renderIntent);
+
+    ALOGV("Set active color mode: %s (%d), active render intent: %s (%d), display=%" PRIu64,
           decodeColorMode(mode).c_str(), mode, decodeRenderIntent(renderIntent).c_str(),
-          renderIntent, display->getDisplayType());
+          renderIntent, *displayId);
 }
 
 status_t SurfaceFlinger::setActiveColorMode(const sp<IBinder>& displayToken, ColorMode mode) {
@@ -1170,9 +1176,9 @@
         Dataspace* outDataspace, ui::PixelFormat* outPixelFormat,
         Dataspace* outWideColorGamutDataspace,
         ui::PixelFormat* outWideColorGamutPixelFormat) const {
-    *outDataspace = defaultCompositionDataspace;
+    *outDataspace = mDefaultCompositionDataspace;
     *outPixelFormat = defaultCompositionPixelFormat;
-    *outWideColorGamutDataspace = wideColorGamutCompositionDataspace;
+    *outWideColorGamutDataspace = mWideColorGamutCompositionDataspace;
     *outWideColorGamutPixelFormat = wideColorGamutCompositionPixelFormat;
     return NO_ERROR;
 }
@@ -1249,18 +1255,22 @@
 
     if (makeAvailable) {
         mHWVsyncAvailable = true;
+        // TODO(b/113612090): This is silly, but necessary evil until we turn on the flag for good.
+        if (mUseScheduler) {
+            mScheduler->makeHWSyncAvailable(true);
+        }
     } else if (!mHWVsyncAvailable) {
         // Hardware vsync is not currently available, so abort the resync
         // attempt for now
         return;
     }
 
-    const auto displayId = DisplayDevice::DISPLAY_PRIMARY;
-    if (!getHwComposer().isConnected(displayId)) {
+    const auto displayId = getInternalDisplayId();
+    if (!displayId || !getHwComposer().isConnected(*displayId)) {
         return;
     }
 
-    const auto activeConfig = getHwComposer().getActiveConfig(displayId);
+    const auto activeConfig = getHwComposer().getActiveConfig(*displayId);
     const nsecs_t period = activeConfig->getVsyncPeriod();
 
     if (mUseScheduler) {
@@ -1311,12 +1321,11 @@
         return;
     }
 
-    int32_t type;
-    if (!getBE().mHwc->onVsync(hwcDisplayId, timestamp, &type)) {
+    if (!getHwComposer().onVsync(hwcDisplayId, timestamp)) {
         return;
     }
 
-    if (type != DisplayDevice::DISPLAY_PRIMARY) {
+    if (hwcDisplayId != getHwComposer().getInternalHwcDisplayId()) {
         // For now, we don't do anything with external display vsyncs.
         return;
     }
@@ -1379,11 +1388,13 @@
     repaintEverything();
 }
 
-void SurfaceFlinger::setVsyncEnabled(int disp, int enabled) {
+void SurfaceFlinger::setVsyncEnabled(EventThread::DisplayType /*displayType*/, bool enabled) {
     ATRACE_CALL();
     Mutex::Autolock lock(mStateLock);
-    getHwComposer().setVsyncEnabled(disp,
-            enabled ? HWC2::Vsync::Enable : HWC2::Vsync::Disable);
+    if (const auto displayId = getInternalDisplayId()) {
+        getHwComposer().setVsyncEnabled(*displayId,
+                                        enabled ? HWC2::Vsync::Enable : HWC2::Vsync::Disable);
+    }
 }
 
 // Note: it is assumed the caller holds |mStateLock| when this is called
@@ -1454,7 +1465,7 @@
     setPowerModeInternal(display, currentDisplayPowerMode, /*stateLockHeld*/ true);
 
     // Reset the timing values to account for the period of the swapped in HWC
-    const auto activeConfig = getHwComposer().getActiveConfig(display->getId());
+    const auto activeConfig = getHwComposer().getActiveConfig(*display->getId());
     const nsecs_t period = activeConfig->getVsyncPeriod();
     mAnimFrameTracker.setDisplayRefreshPeriod(period);
 
@@ -1595,24 +1606,25 @@
         mGeometryInvalid = false;
         for (const auto& [token, display] : mDisplays) {
             const auto displayId = display->getId();
-            if (displayId >= 0) {
-                const Vector<sp<Layer>>& currentLayers(
-                        display->getVisibleLayersSortedByZ());
-                for (size_t i = 0; i < currentLayers.size(); i++) {
-                    const auto& layer = currentLayers[i];
+            if (!displayId) {
+                continue;
+            }
 
-                    if (!layer->hasHwcLayer(displayId)) {
-                        if (!layer->createHwcLayer(getBE().mHwc.get(), displayId)) {
-                            layer->forceClientComposition(displayId);
-                            continue;
-                        }
-                    }
+            const Vector<sp<Layer>>& currentLayers = display->getVisibleLayersSortedByZ();
+            for (size_t i = 0; i < currentLayers.size(); i++) {
+                const auto& layer = currentLayers[i];
 
-                    layer->setGeometry(display, i);
-                    if (mDebugDisableHWC || mDebugRegion) {
-                        layer->forceClientComposition(displayId);
+                if (!layer->hasHwcLayer(*displayId)) {
+                    if (!layer->createHwcLayer(&getHwComposer(), *displayId)) {
+                        layer->forceClientComposition(*displayId);
+                        continue;
                     }
                 }
+
+                layer->setGeometry(display, i);
+                if (mDebugDisableHWC || mDebugRegion) {
+                    layer->forceClientComposition(*displayId);
+                }
             }
         }
     }
@@ -1620,41 +1632,43 @@
     // Set the per-frame data
     for (const auto& [token, display] : mDisplays) {
         const auto displayId = display->getId();
-        if (displayId < 0) {
+        if (!displayId) {
             continue;
         }
 
         if (mDrawingState.colorMatrixChanged) {
             display->setColorTransform(mDrawingState.colorMatrix);
-            status_t result = getBE().mHwc->setColorTransform(displayId, mDrawingState.colorMatrix);
-            ALOGE_IF(result != NO_ERROR, "Failed to set color transform on "
-                    "display %d: %d", displayId, result);
+            status_t result =
+                    getHwComposer().setColorTransform(*displayId, mDrawingState.colorMatrix);
+            ALOGE_IF(result != NO_ERROR, "Failed to set color transform on display %" PRIu64 ": %d",
+                     *displayId, result);
         }
         for (auto& layer : display->getVisibleLayersSortedByZ()) {
             if (layer->isHdrY410()) {
-                layer->forceClientComposition(displayId);
+                layer->forceClientComposition(*displayId);
             } else if ((layer->getDataSpace() == Dataspace::BT2020_PQ ||
                         layer->getDataSpace() == Dataspace::BT2020_ITU_PQ) &&
                     !display->hasHDR10Support()) {
-                layer->forceClientComposition(displayId);
+                layer->forceClientComposition(*displayId);
             } else if ((layer->getDataSpace() == Dataspace::BT2020_HLG ||
                         layer->getDataSpace() == Dataspace::BT2020_ITU_HLG) &&
                     !display->hasHLGSupport()) {
-                layer->forceClientComposition(displayId);
+                layer->forceClientComposition(*displayId);
             }
 
             // TODO(b/111562338) remove when composer 2.3 is shipped.
             if (layer->hasColorTransform()) {
-                layer->forceClientComposition(displayId);
+                layer->forceClientComposition(*displayId);
             }
 
-            if (layer->getForceClientComposition(displayId)) {
+            if (layer->getForceClientComposition(*displayId)) {
                 ALOGV("[%s] Requesting Client composition", layer->getName().string());
-                layer->setCompositionType(displayId, HWC2::Composition::Client);
+                layer->setCompositionType(*displayId, HWC2::Composition::Client);
                 continue;
             }
 
-            layer->setPerFrameData(display);
+            layer->setPerFrameData(*displayId, display->getTransform(), display->getViewport(),
+                                   display->getSupportedPerFrameMetadata());
         }
 
         if (useColorManagement) {
@@ -1674,10 +1688,14 @@
         for (auto& layer : display->getVisibleLayersSortedByZ()) {
             const auto displayId = display->getId();
             layer->getBE().compositionInfo.compositionType = layer->getCompositionType(displayId);
-            if (!layer->setHwcLayer(displayId)) {
-                ALOGV("Need to create HWCLayer for %s", layer->getName().string());
+
+            if (displayId) {
+                if (!layer->setHwcLayer(*displayId)) {
+                    ALOGV("Need to create HWCLayer for %s", layer->getName().string());
+                }
+                layer->getBE().compositionInfo.hwc.displayId = *displayId;
             }
-            layer->getBE().compositionInfo.hwc.displayId = displayId;
+
             getBE().mCompositionInfo[token].push_back(layer->getBE().compositionInfo);
             layer->getBE().compositionInfo.hwc.hwcLayer = nullptr;
         }
@@ -1837,7 +1855,7 @@
 
     getBE().mDisplayTimeline.updateSignalTimes();
     mPreviousPresentFence =
-            display ? getHwComposer().getPresentFence(display->getId()) : Fence::NO_FENCE;
+            display ? getHwComposer().getPresentFence(*display->getId()) : Fence::NO_FENCE;
     auto presentFenceTime = std::make_shared<FenceTime>(mPreviousPresentFence);
     getBE().mDisplayTimeline.push(presentFenceTime);
 
@@ -1860,8 +1878,8 @@
     }
 
     mDrawingState.traverseInZOrder([&](Layer* layer) {
-        bool frameLatched = layer->onPostComposition(glCompositionDoneFenceTime,
-                presentFenceTime, compositorTiming);
+        bool frameLatched = layer->onPostComposition(display->getId(), glCompositionDoneFenceTime,
+                                                     presentFenceTime, compositorTiming);
         if (frameLatched) {
             recordBufferingStats(layer->getName().string(),
                     layer->getOccupancyHistory(false));
@@ -1881,7 +1899,7 @@
     }
 
     if (!hasSyncFramework) {
-        if (display && getHwComposer().isConnected(display->getId()) && display->isPoweredOn()) {
+        if (display && getHwComposer().isConnected(*display->getId()) && display->isPoweredOn()) {
             if (mUseScheduler) {
                 mScheduler->enableHardwareVsync();
             } else {
@@ -1896,10 +1914,10 @@
         if (presentFenceTime->isValid()) {
             mAnimFrameTracker.setActualPresentFence(
                     std::move(presentFenceTime));
-        } else if (display && getHwComposer().isConnected(display->getId())) {
+        } else if (display && getHwComposer().isConnected(*display->getId())) {
             // The HWC doesn't support present fences, so use the refresh
             // timestamp instead.
-            const nsecs_t presentTime = getHwComposer().getRefreshTimestamp(display->getId());
+            const nsecs_t presentTime = getHwComposer().getRefreshTimestamp(*display->getId());
             mAnimFrameTracker.setActualPresentTime(presentTime);
         }
         mAnimFrameTracker.advanceFrame();
@@ -1912,8 +1930,7 @@
 
     mTimeStats.setPresentFenceGlobal(presentFenceTime);
 
-    if (display && getHwComposer().isConnected(display->getId()) &&
-        display->getPowerMode() == HWC_POWER_MODE_OFF) {
+    if (display && getHwComposer().isConnected(*display->getId()) && !display->isPoweredOn()) {
         return;
     }
 
@@ -1967,6 +1984,7 @@
 
                 mDrawingState.traverseInZOrder([&](Layer* layer) {
                     bool hwcLayerDestroyed = false;
+                    const auto displayId = display->getId();
                     if (layer->belongsToDisplay(display->getLayerStack(), display->isPrimary())) {
                         Region drawRegion(tr.transform(
                                 layer->visibleNonTransparentRegion));
@@ -1976,13 +1994,13 @@
                         } else {
                             // Clear out the HWC layer if this layer was
                             // previously visible, but no longer is
-                            hwcLayerDestroyed = layer->destroyHwcLayer(display->getId());
+                            hwcLayerDestroyed = displayId && layer->destroyHwcLayer(*displayId);
                         }
                     } else {
                         // WM changes display->layerStack upon sleep/awake.
                         // Here we make sure we delete the HWC layers even if
                         // WM changed their layer stack.
-                        hwcLayerDestroyed = layer->destroyHwcLayer(display->getId());
+                        hwcLayerDestroyed = displayId && layer->destroyHwcLayer(*displayId);
                     }
 
                     // If a layer is not going to get a release fence because
@@ -2107,12 +2125,11 @@
     //   emit any black frames until a layer is added to the layer stack.
     bool mustRecompose = dirty && !(empty && wasEmpty);
 
-    ALOGV_IF(display->getDisplayType() == DisplayDevice::DISPLAY_VIRTUAL,
-            "id[%d]: %s composition (%sdirty %sempty %swasEmpty)", display->getId(),
-            mustRecompose ? "doing" : "skipping",
-            dirty ? "+" : "-",
-            empty ? "+" : "-",
-            wasEmpty ? "+" : "-");
+    const char flagPrefix[] = {'-', '+'};
+    static_cast<void>(flagPrefix);
+    ALOGV_IF(display->isVirtual(), "%s: %s composition for %s (%cdirty %cempty %cwasEmpty)",
+             __FUNCTION__, mustRecompose ? "doing" : "skipping", display->getDebugName().c_str(),
+             flagPrefix[dirty], flagPrefix[empty], flagPrefix[wasEmpty]);
 
     display->beginFrame(mustRecompose);
 
@@ -2129,10 +2146,8 @@
 
     status_t result = display->prepareFrame(getHwComposer(),
                                             getBE().mCompositionInfo[display->getDisplayToken()]);
-    ALOGE_IF(result != NO_ERROR,
-             "prepareFrame for display %d failed:"
-             " %d (%s)",
-             display->getId(), result, strerror(-result));
+    ALOGE_IF(result != NO_ERROR, "prepareFrame failed for %s: %d (%s)",
+             display->getDebugName().c_str(), result, strerror(-result));
 }
 
 void SurfaceFlinger::doComposition(const sp<DisplayDevice>& display, bool repaintEverything) {
@@ -2155,8 +2170,9 @@
 void SurfaceFlinger::postFrame()
 {
     // |mStateLock| not needed as we are on the main thread
-    if (getBE().mHwc->isConnected(HWC_DISPLAY_PRIMARY)) {
-        uint32_t flipCount = getDefaultDisplayDeviceLocked()->getPageFlipCount();
+    const auto display = getDefaultDisplayDeviceLocked();
+    if (display && getHwComposer().isConnected(*display->getId())) {
+        uint32_t flipCount = display->getPageFlipCount();
         if (flipCount % LOG_FRAME_STATS_PERIOD == 0) {
             logFrameStats();
         }
@@ -2172,8 +2188,8 @@
 
     if (display->isPoweredOn()) {
         const auto displayId = display->getId();
-        if (displayId >= 0) {
-            getBE().mHwc->presentAndGetReleaseFences(displayId);
+        if (displayId) {
+            getHwComposer().presentAndGetReleaseFences(*displayId);
         }
         display->onSwapBuffersCompleted();
         display->makeCurrent();
@@ -2183,9 +2199,9 @@
             // The layer buffer from the previous frame (if any) is released
             // by HWC only when the release fence from this frame (if any) is
             // signaled.  Always get the release fence from HWC first.
-            auto hwcLayer = layer->getHwcLayer(displayId);
-            if (displayId >= 0) {
-                releaseFence = getBE().mHwc->getLayerReleaseFence(displayId, hwcLayer);
+            if (displayId && layer->hasHwcLayer(*displayId)) {
+                releaseFence = getHwComposer().getLayerReleaseFence(*displayId,
+                                                                    layer->getHwcLayer(*displayId));
             }
 
             // If the layer was client composited in the previous frame, we
@@ -2205,14 +2221,15 @@
         // display->getVisibleLayersSortedByZ.  The best we can do is to
         // supply them with the present fence.
         if (!display->getLayersNeedingFences().isEmpty()) {
-            sp<Fence> presentFence = getBE().mHwc->getPresentFence(displayId);
+            sp<Fence> presentFence =
+                    displayId ? getBE().mHwc->getPresentFence(*displayId) : Fence::NO_FENCE;
             for (auto& layer : display->getLayersNeedingFences()) {
                 layer->getBE().onLayerDisplayed(presentFence);
             }
         }
 
-        if (displayId >= 0) {
-            getBE().mHwc->clearReleaseFences(displayId);
+        if (displayId) {
+            getHwComposer().clearReleaseFences(*displayId);
         }
     }
 }
@@ -2247,72 +2264,36 @@
     // here the transaction has been committed
 }
 
-DisplayDevice::DisplayType SurfaceFlinger::determineDisplayType(hwc2_display_t hwcDisplayId,
-                                                                HWC2::Connection connection) const {
-    // Figure out whether the event is for the primary display or an
-    // external display by matching the Hwc display id against one for a
-    // connected display. If we did not find a match, we then check what
-    // displays are not already connected to determine the type. If we don't
-    // have a connected primary display, we assume the new display is meant to
-    // be the primary display, and then if we don't have an external display,
-    // we assume it is that.
-    const auto primaryHwcDisplayId = getBE().mHwc->getHwcDisplayId(DisplayDevice::DISPLAY_PRIMARY);
-    const auto externalHwcDisplayId =
-            getBE().mHwc->getHwcDisplayId(DisplayDevice::DISPLAY_EXTERNAL);
-    if (primaryHwcDisplayId && primaryHwcDisplayId == hwcDisplayId) {
-        return DisplayDevice::DISPLAY_PRIMARY;
-    } else if (externalHwcDisplayId && externalHwcDisplayId == hwcDisplayId) {
-        return DisplayDevice::DISPLAY_EXTERNAL;
-    } else if (connection == HWC2::Connection::Connected && !primaryHwcDisplayId) {
-        return DisplayDevice::DISPLAY_PRIMARY;
-    } else if (connection == HWC2::Connection::Connected && !externalHwcDisplayId) {
-        return DisplayDevice::DISPLAY_EXTERNAL;
-    }
-
-    return DisplayDevice::DISPLAY_ID_INVALID;
-}
-
 void SurfaceFlinger::processDisplayHotplugEventsLocked() {
     for (const auto& event : mPendingHotplugEvents) {
-        auto displayType = determineDisplayType(event.hwcDisplayId, event.connection);
-        if (displayType == DisplayDevice::DISPLAY_ID_INVALID) {
-            ALOGW("Unable to determine the display type for display %" PRIu64, event.hwcDisplayId);
-            continue;
-        }
+        const std::optional<DisplayIdentificationInfo> info =
+                getHwComposer().onHotplug(event.hwcDisplayId, event.connection);
 
-        if (getBE().mHwc->isUsingVrComposer() && displayType == DisplayDevice::DISPLAY_EXTERNAL) {
-            ALOGE("External displays are not supported by the vr hardware composer.");
+        if (!info) {
             continue;
         }
 
-        const auto displayId =
-                getBE().mHwc->onHotplug(event.hwcDisplayId, displayType, event.connection);
-        if (displayId) {
-            ALOGV("Display %" PRIu64 " has stable ID %" PRIu64, event.hwcDisplayId, *displayId);
-        }
-
         if (event.connection == HWC2::Connection::Connected) {
-            if (!mDisplayTokens[displayType].get()) {
-                ALOGV("Creating built in display %d", displayType);
-                mDisplayTokens[displayType] = new BBinder();
-                DisplayDeviceState info;
-                info.type = displayType;
-                info.displayName = displayType == DisplayDevice::DISPLAY_PRIMARY ?
-                        "Built-in Screen" : "External Screen";
-                info.isSecure = true; // All physical displays are currently considered secure.
-                mCurrentState.displays.add(mDisplayTokens[displayType], info);
-                mInterceptor->saveDisplayCreation(info);
+            if (!mPhysicalDisplayTokens.count(info->id)) {
+                ALOGV("Creating display %" PRIu64, info->id);
+                mPhysicalDisplayTokens[info->id] = new BBinder();
+                DisplayDeviceState state;
+                state.displayId = info->id;
+                state.isSecure = true; // All physical displays are currently considered secure.
+                state.displayName = info->name;
+                mCurrentState.displays.add(mPhysicalDisplayTokens[info->id], state);
+                mInterceptor->saveDisplayCreation(state);
             }
         } else {
-            ALOGV("Removing built in display %d", displayType);
+            ALOGV("Removing display %" PRIu64, info->id);
 
-            ssize_t idx = mCurrentState.displays.indexOfKey(mDisplayTokens[displayType]);
-            if (idx >= 0) {
-                const DisplayDeviceState& info(mCurrentState.displays.valueAt(idx));
-                mInterceptor->saveDisplayDeletion(info.sequenceId);
-                mCurrentState.displays.removeItemsAt(idx);
+            ssize_t index = mCurrentState.displays.indexOfKey(mPhysicalDisplayTokens[info->id]);
+            if (index >= 0) {
+                const DisplayDeviceState& state = mCurrentState.displays.valueAt(index);
+                mInterceptor->saveDisplayDeletion(state.sequenceId);
+                mCurrentState.displays.removeItemsAt(index);
             }
-            mDisplayTokens[displayType].clear();
+            mPhysicalDisplayTokens.erase(info->id);
         }
 
         processDisplayChangesLocked();
@@ -2322,31 +2303,36 @@
 }
 
 sp<DisplayDevice> SurfaceFlinger::setupNewDisplayDeviceInternal(
-        const wp<IBinder>& displayToken, int32_t displayId, const DisplayDeviceState& state,
-        const sp<DisplaySurface>& dispSurface, const sp<IGraphicBufferProducer>& producer) {
-    DisplayDeviceCreationArgs creationArgs(this, displayToken, state.type, displayId);
+        const wp<IBinder>& displayToken, const std::optional<DisplayId>& displayId,
+        const DisplayDeviceState& state, const sp<DisplaySurface>& dispSurface,
+        const sp<IGraphicBufferProducer>& producer) {
+    DisplayDeviceCreationArgs creationArgs(this, displayToken, displayId);
+    creationArgs.isVirtual = state.isVirtual();
     creationArgs.isSecure = state.isSecure;
     creationArgs.displaySurface = dispSurface;
     creationArgs.hasWideColorGamut = false;
     creationArgs.supportedPerFrameMetadata = 0;
 
-    if (useColorManagement && displayId >= 0) {
-        std::vector<ColorMode> modes = getHwComposer().getColorModes(displayId);
+    const bool isInternalDisplay = displayId && displayId == getInternalDisplayId();
+    creationArgs.isPrimary = isInternalDisplay;
+
+    if (useColorManagement && displayId) {
+        std::vector<ColorMode> modes = getHwComposer().getColorModes(*displayId);
         for (ColorMode colorMode : modes) {
             if (isWideColorMode(colorMode)) {
                 creationArgs.hasWideColorGamut = true;
             }
 
             std::vector<RenderIntent> renderIntents =
-                    getHwComposer().getRenderIntents(displayId, colorMode);
+                    getHwComposer().getRenderIntents(*displayId, colorMode);
             creationArgs.hwcColorModes.emplace(colorMode, renderIntents);
         }
     }
 
-    if (displayId >= 0) {
-        getHwComposer().getHdrCapabilities(displayId, &creationArgs.hdrCapabilities);
+    if (displayId) {
+        getHwComposer().getHdrCapabilities(*displayId, &creationArgs.hdrCapabilities);
         creationArgs.supportedPerFrameMetadata =
-                getHwComposer().getSupportedPerFrameMetadata(displayId);
+                getHwComposer().getSupportedPerFrameMetadata(*displayId);
     }
 
     auto nativeWindowSurface = getFactory().createNativeWindowSurface(producer);
@@ -2357,7 +2343,7 @@
      * Create our display's surface
      */
     std::unique_ptr<renderengine::Surface> renderSurface = getRenderEngine().createSurface();
-    renderSurface->setCritical(state.type == DisplayDevice::DISPLAY_PRIMARY);
+    renderSurface->setCritical(isInternalDisplay);
     renderSurface->setAsync(state.isVirtual());
     renderSurface->setNativeWindow(nativeWindow.get());
     creationArgs.displayWidth = renderSurface->getWidth();
@@ -2375,9 +2361,8 @@
         nativeWindow->setSwapInterval(nativeWindow.get(), 0);
     }
 
-    creationArgs.displayInstallOrientation = state.type == DisplayDevice::DISPLAY_PRIMARY
-            ? primaryDisplayOrientation
-            : DisplayState::eOrientationDefault;
+    creationArgs.displayInstallOrientation =
+            isInternalDisplay ? primaryDisplayOrientation : DisplayState::eOrientationDefault;
 
     // virtual displays are always considered enabled
     creationArgs.initialPowerMode = state.isVirtual() ? HWC_POWER_MODE_NORMAL : HWC_POWER_MODE_OFF;
@@ -2396,9 +2381,11 @@
     }
     setActiveColorModeInternal(display, defaultColorMode, defaultDataSpace,
                                RenderIntent::COLORIMETRIC);
-    if (state.type < DisplayDevice::DISPLAY_VIRTUAL) {
-        display->setActiveConfig(getHwComposer().getActiveConfigIndex(state.type));
+    if (!state.isVirtual()) {
+        LOG_ALWAYS_FATAL_IF(!displayId);
+        display->setActiveConfig(getHwComposer().getActiveConfigIndex(*displayId));
     }
+
     display->setLayerStack(state.layerStack);
     display->setProjection(state.orientation, state.viewport, state.frame);
     display->setDisplayName(state.displayName);
@@ -2424,6 +2411,10 @@
         for (size_t i = 0; i < dc;) {
             const ssize_t j = curr.indexOfKey(draw.keyAt(i));
             if (j < 0) {
+                // Save display IDs before disconnecting.
+                const auto internalDisplayId = getInternalDisplayId();
+                const auto externalDisplayId = getExternalDisplayId();
+
                 // in drawing state but not in current state
                 // Call makeCurrent() on the primary display so we can
                 // be sure that nothing associated with this display
@@ -2434,14 +2425,14 @@
                 if (const auto display = getDisplayDeviceLocked(draw.keyAt(i))) {
                     display->disconnect(getHwComposer());
                 }
-                if (draw[i].type == DisplayDevice::DISPLAY_PRIMARY) {
+                if (internalDisplayId && internalDisplayId == draw[i].displayId) {
                     if (mUseScheduler) {
                         mScheduler->hotplugReceived(mAppConnectionHandle,
                                                     EventThread::DisplayType::Primary, false);
                     } else {
                         mEventThread->onHotplugReceived(EventThread::DisplayType::Primary, false);
                     }
-                } else if (draw[i].type == DisplayDevice::DISPLAY_EXTERNAL) {
+                } else if (externalDisplayId && externalDisplayId == draw[i].displayId) {
                     if (mUseScheduler) {
                         mScheduler->hotplugReceived(mAppConnectionHandle,
                                                     EventThread::DisplayType::External, false);
@@ -2499,14 +2490,14 @@
                 sp<IGraphicBufferConsumer> bqConsumer;
                 getFactory().createBufferQueue(&bqProducer, &bqConsumer, false);
 
-                int32_t displayId = -1;
+                std::optional<DisplayId> displayId;
                 if (state.isVirtual()) {
                     // Virtual displays without a surface are dormant:
                     // they have external state (layer stack, projection,
                     // etc.) but no internal state (i.e. a DisplayDevice).
                     if (state.surface != nullptr) {
                         // Allow VR composer to use virtual displays.
-                        if (mUseHwcVirtualDisplays || getBE().mHwc->isUsingVrComposer()) {
+                        if (mUseHwcVirtualDisplays || getHwComposer().isUsingVrComposer()) {
                             int width = 0;
                             int status = state.surface->query(NATIVE_WINDOW_WIDTH, &width);
                             ALOGE_IF(status != NO_ERROR, "Unable to query width (%d)", status);
@@ -2518,14 +2509,14 @@
                             ALOGE_IF(status != NO_ERROR, "Unable to query format (%d)", status);
                             auto format = static_cast<ui::PixelFormat>(intFormat);
 
-                            getBE().mHwc->allocateVirtualDisplay(width, height, &format,
-                                                                 &displayId);
+                            displayId =
+                                    getHwComposer().allocateVirtualDisplay(width, height, &format);
                         }
 
                         // TODO: Plumb requested format back up to consumer
 
                         sp<VirtualDisplaySurface> vds =
-                                new VirtualDisplaySurface(*getBE().mHwc, displayId, state.surface,
+                                new VirtualDisplaySurface(getHwComposer(), displayId, state.surface,
                                                           bqProducer, bqConsumer,
                                                           state.displayName);
 
@@ -2538,8 +2529,9 @@
                              "surface is provided (%p), ignoring it",
                              state.surface.get());
 
-                    displayId = state.type;
-                    dispSurface = new FramebufferSurface(*getBE().mHwc, displayId, bqConsumer);
+                    displayId = state.displayId;
+                    LOG_ALWAYS_FATAL_IF(!displayId);
+                    dispSurface = new FramebufferSurface(getHwComposer(), *displayId, bqConsumer);
                     producer = bqProducer;
                 }
 
@@ -2549,7 +2541,9 @@
                                       setupNewDisplayDeviceInternal(displayToken, displayId, state,
                                                                     dispSurface, producer));
                     if (!state.isVirtual()) {
-                        if (state.type == DisplayDevice::DISPLAY_PRIMARY) {
+                        LOG_ALWAYS_FATAL_IF(!displayId);
+
+                        if (displayId == getInternalDisplayId()) {
                             if (mUseScheduler) {
                                 mScheduler->hotplugReceived(mAppConnectionHandle,
                                                             EventThread::DisplayType::Primary,
@@ -2558,7 +2552,7 @@
                                 mEventThread->onHotplugReceived(EventThread::DisplayType::Primary,
                                                                 true);
                             }
-                        } else if (state.type == DisplayDevice::DISPLAY_EXTERNAL) {
+                        } else if (displayId == getExternalDisplayId()) {
                             if (mUseScheduler) {
                                 mScheduler->hotplugReceived(mAppConnectionHandle,
                                                             EventThread::DisplayType::External,
@@ -2712,7 +2706,7 @@
 void SurfaceFlinger::updateCursorAsync()
 {
     for (const auto& [token, display] : mDisplays) {
-        if (display->getId() < 0) {
+        if (!display->getId()) {
             continue;
         }
 
@@ -3108,8 +3102,9 @@
                 case HWC2::Composition::Device:
                 case HWC2::Composition::Sideband:
                 case HWC2::Composition::SolidColor: {
+                    LOG_ALWAYS_FATAL_IF(!displayId);
                     const Layer::State& state(layer->getDrawingState());
-                    if (layer->getClearClientTarget(displayId) && !firstLayer &&
+                    if (layer->getClearClientTarget(*displayId) && !firstLayer &&
                         layer->isOpaque(state) && (layer->getAlpha() == 1.0f) &&
                         hasClientComposition) {
                         // never clear the very first layer since we're
@@ -3810,7 +3805,7 @@
 // ---------------------------------------------------------------------------
 
 void SurfaceFlinger::onInitializeDisplays() {
-    const auto displayToken = mDisplayTokens[DisplayDevice::DISPLAY_PRIMARY];
+    const auto displayToken = getInternalDisplayToken();
     if (!displayToken) return;
 
     // reset screen orientation and use primary layer stack
@@ -3834,7 +3829,7 @@
 
     setPowerModeInternal(display, HWC_POWER_MODE_NORMAL, /*stateLockHeld*/ false);
 
-    const auto activeConfig = getHwComposer().getActiveConfig(display->getId());
+    const auto activeConfig = getHwComposer().getActiveConfig(*display->getId());
     const nsecs_t period = activeConfig->getVsyncPeriod();
     mAnimFrameTracker.setDisplayRefreshPeriod(period);
 
@@ -3851,16 +3846,18 @@
 
 void SurfaceFlinger::setPowerModeInternal(const sp<DisplayDevice>& display, int mode,
                                           bool stateLockHeld) {
-    const int32_t displayId = display->getId();
-    ALOGD("Setting power mode %d on display %d", mode, displayId);
-
-    int currentMode = display->getPowerMode();
-    if (mode == currentMode) {
+    if (display->isVirtual()) {
+        ALOGE("%s: Invalid operation on virtual display", __FUNCTION__);
         return;
     }
 
-    if (display->isVirtual()) {
-        ALOGW("Trying to set power mode for virtual display");
+    const auto displayId = display->getId();
+    LOG_ALWAYS_FATAL_IF(!displayId);
+
+    ALOGD("Setting power mode %d on display %" PRIu64, mode, *displayId);
+
+    int currentMode = display->getPowerMode();
+    if (mode == currentMode) {
         return;
     }
 
@@ -3876,12 +3873,10 @@
         mInterceptor->savePowerModeUpdate(mCurrentState.displays.valueAt(idx).sequenceId, mode);
     }
 
-    int32_t type = display->getDisplayType();
     if (currentMode == HWC_POWER_MODE_OFF) {
         // Turn on the display
-        getHwComposer().setPowerMode(type, mode);
+        getHwComposer().setPowerMode(*displayId, mode);
         if (display->isPrimary() && mode != HWC_POWER_MODE_DOZE_SUSPEND) {
-            // FIXME: eventthread only knows about the main display right now
             if (mUseScheduler) {
                 mScheduler->onScreenAcquired(mAppConnectionHandle);
             } else {
@@ -3912,7 +3907,6 @@
             } else {
                 disableHardwareVsync(true); // also cancels any in-progress resync
             }
-            // FIXME: eventthread only knows about the main display right now
             if (mUseScheduler) {
                 mScheduler->onScreenReleased(mAppConnectionHandle);
             } else {
@@ -3920,15 +3914,14 @@
             }
         }
 
-        getHwComposer().setPowerMode(type, mode);
+        getHwComposer().setPowerMode(*displayId, mode);
         mVisibleRegionsDirty = true;
         // from this point on, SF will stop drawing on this display
     } else if (mode == HWC_POWER_MODE_DOZE ||
                mode == HWC_POWER_MODE_NORMAL) {
         // Update display while dozing
-        getHwComposer().setPowerMode(type, mode);
+        getHwComposer().setPowerMode(*displayId, mode);
         if (display->isPrimary() && currentMode == HWC_POWER_MODE_DOZE_SUSPEND) {
-            // FIXME: eventthread only knows about the main display right now
             if (mUseScheduler) {
                 mScheduler->onScreenAcquired(mAppConnectionHandle);
             } else {
@@ -3944,24 +3937,23 @@
             } else {
                 disableHardwareVsync(true); // also cancels any in-progress resync
             }
-            // FIXME: eventthread only knows about the main display right now
             if (mUseScheduler) {
                 mScheduler->onScreenReleased(mAppConnectionHandle);
             } else {
                 mEventThread->onScreenReleased();
             }
         }
-        getHwComposer().setPowerMode(type, mode);
+        getHwComposer().setPowerMode(*displayId, mode);
     } else {
         ALOGE("Attempting to set unknown power mode: %d\n", mode);
-        getHwComposer().setPowerMode(type, mode);
+        getHwComposer().setPowerMode(*displayId, mode);
     }
 
     if (display->isPrimary()) {
         mTimeStats.setPowerMode(mode);
     }
 
-    ALOGD("Finished setting power mode %d on display %d", mode, displayId);
+    ALOGD("Finished setting power mode %d on display %" PRIu64, mode, *displayId);
 }
 
 void SurfaceFlinger::setPowerMode(const sp<IBinder>& displayToken, int mode) {
@@ -4140,9 +4132,9 @@
         index++;
     }
 
-    if (const auto displayId = DisplayDevice::DISPLAY_PRIMARY;
-        getHwComposer().isConnected(displayId)) {
-        const auto activeConfig = getBE().mHwc->getActiveConfig(displayId);
+    if (const auto displayId = getInternalDisplayId();
+        displayId && getHwComposer().isConnected(*displayId)) {
+        const auto activeConfig = getHwComposer().getActiveConfig(*displayId);
         const nsecs_t period = activeConfig->getVsyncPeriod();
         result.appendFormat("%" PRId64 "\n", period);
     }
@@ -4283,13 +4275,17 @@
 
 void SurfaceFlinger::dumpDisplayIdentificationData(String8& result) const {
     for (const auto& [token, display] : mDisplays) {
-        const int32_t displayId = display->getId();
-        const auto hwcDisplayId = getHwComposer().getHwcDisplayId(displayId);
+        const auto displayId = display->getId();
+        if (!displayId) {
+            continue;
+        }
+        const auto hwcDisplayId = getHwComposer().fromPhysicalDisplayId(*displayId);
         if (!hwcDisplayId) {
             continue;
         }
 
-        result.appendFormat("Display %d (HWC display %" PRIu64 "): ", displayId, *hwcDisplayId);
+        result.appendFormat("Display %" PRIu64 " (HWC display %" PRIu64 "): ", *displayId,
+                            *hwcDisplayId);
         uint8_t port;
         DisplayIdentificationData data;
         if (!getHwComposer().getDisplayIdentificationData(*hwcDisplayId, &port, &data)) {
@@ -4320,7 +4316,6 @@
         result.append(edid->displayName.data(), edid->displayName.length());
         result.append("\"\n");
     }
-    result.append("\n");
 }
 
 void SurfaceFlinger::dumpWideColorInfo(String8& result) const {
@@ -4332,13 +4327,13 @@
     // TODO: print out if wide-color mode is active or not
 
     for (const auto& [token, display] : mDisplays) {
-        const int32_t displayId = display->getId();
-        if (displayId == DisplayDevice::DISPLAY_ID_INVALID) {
+        const auto displayId = display->getId();
+        if (!displayId) {
             continue;
         }
 
-        result.appendFormat("Display %d color modes:\n", displayId);
-        std::vector<ColorMode> modes = getHwComposer().getColorModes(displayId);
+        result.appendFormat("Display %" PRIu64 " color modes:\n", *displayId);
+        std::vector<ColorMode> modes = getHwComposer().getColorModes(*displayId);
         for (auto&& mode : modes) {
             result.appendFormat("    %s (%d)\n", decodeColorMode(mode).c_str(), mode);
         }
@@ -4394,11 +4389,12 @@
     layersProto.set_color_transform(decodeColorTransform(display.getColorTransform()));
     layersProto.set_global_transform(static_cast<int32_t>(display.getOrientationTransform()));
 
-    const int32_t displayId = display.getId();
+    const auto displayId = display.getId();
+    LOG_ALWAYS_FATAL_IF(!displayId);
     mDrawingState.traverseInZOrder([&](Layer* layer) {
-        if (!layer->visibleRegion.isEmpty() && layer->getBE().mHwcLayers.count(displayId)) {
+        if (!layer->visibleRegion.isEmpty() && layer->getBE().mHwcLayers.count(*displayId)) {
             LayerProto* layerProto = layersProto.add_layers();
-            layer->writeToProto(layerProto, displayId);
+            layer->writeToProto(layerProto, *displayId);
         }
     });
 
@@ -4452,25 +4448,19 @@
 
     const auto [sfEarlyOffset, appEarlyOffset] = mVsyncModulator.getEarlyOffsets();
     const auto [sfEarlyGlOffset, appEarlyGlOffset] = mVsyncModulator.getEarlyGlOffsets();
-    if (const auto displayId = DisplayDevice::DISPLAY_PRIMARY;
-        getHwComposer().isConnected(displayId)) {
-        const auto activeConfig = getHwComposer().getActiveConfig(displayId);
-        result.appendFormat("Display %d: "
-                "app phase %" PRId64 " ns, "
-                "sf phase %" PRId64 " ns, "
-                "early app phase %" PRId64 " ns, "
-                "early sf phase %" PRId64 " ns, "
-                "early app gl phase %" PRId64 " ns, "
-                "early sf gl phase %" PRId64 " ns, "
-                "present offset %" PRId64 " ns (refresh %" PRId64 " ns)",
-                displayId,
-                vsyncPhaseOffsetNs,
-                sfVsyncPhaseOffsetNs,
-                appEarlyOffset,
-                sfEarlyOffset,
-                appEarlyGlOffset,
-                sfEarlyGlOffset,
-                dispSyncPresentTimeOffset, activeConfig->getVsyncPeriod());
+    if (const auto displayId = getInternalDisplayId();
+        displayId && getHwComposer().isConnected(*displayId)) {
+        const auto activeConfig = getHwComposer().getActiveConfig(*displayId);
+        result.appendFormat("Display %" PRIu64 ": app phase %" PRId64 " ns, "
+                            "sf phase %" PRId64 " ns, "
+                            "early app phase %" PRId64 " ns, "
+                            "early sf phase %" PRId64 " ns, "
+                            "early app gl phase %" PRId64 " ns, "
+                            "early sf gl phase %" PRId64 " ns, "
+                            "present offset %" PRId64 " ns (refresh %" PRId64 " ns)",
+                            *displayId, vsyncPhaseOffsetNs, sfVsyncPhaseOffsetNs, appEarlyOffset,
+                            sfEarlyOffset, appEarlyGlOffset, sfEarlyGlOffset,
+                            dispSyncPresentTimeOffset, activeConfig->getVsyncPeriod());
     }
     result.append("\n");
 
@@ -4523,12 +4513,9 @@
     result.append("SurfaceFlinger global state:\n");
     colorizer.reset(result);
 
-    HWComposer& hwc(getHwComposer());
-    const auto display = getDefaultDisplayDeviceLocked();
-
     getBE().mRenderEngine->dump(result);
 
-    if (display) {
+    if (const auto display = getDefaultDisplayDeviceLocked()) {
         display->undefinedRegion.dump(result, "undefinedRegion");
         result.appendFormat("  orientation=%d, isPoweredOn=%d\n", display->getOrientation(),
                             display->isPoweredOn());
@@ -4537,8 +4524,9 @@
                         "  gpu_to_cpu_unsupported    : %d\n",
                         mTransactionFlags.load(), !mGpuToCpuSupported);
 
-    if (display) {
-        const auto activeConfig = getHwComposer().getActiveConfig(display->getId());
+    if (const auto displayId = getInternalDisplayId();
+        displayId && getHwComposer().isConnected(*displayId)) {
+        const auto activeConfig = getHwComposer().getActiveConfig(*displayId);
         result.appendFormat("  refresh-rate              : %f fps\n"
                             "  x-dpi                     : %f\n"
                             "  y-dpi                     : %f\n",
@@ -4570,14 +4558,14 @@
      * HWC layer minidump
      */
     for (const auto& [token, display] : mDisplays) {
-        const int32_t displayId = display->getId();
-        if (displayId == DisplayDevice::DISPLAY_ID_INVALID) {
+        const auto displayId = display->getId();
+        if (!displayId) {
             continue;
         }
 
-        result.appendFormat("Display %d HWC layers:\n", displayId);
+        result.appendFormat("Display %" PRIu64 " HWC layers:\n", *displayId);
         Layer::miniDumpHeader(result);
-        mCurrentState.traverseInZOrder([&](Layer* layer) { layer->miniDump(result, displayId); });
+        mCurrentState.traverseInZOrder([&](Layer* layer) { layer->miniDump(result, *displayId); });
         result.append("\n");
     }
 
@@ -4590,7 +4578,7 @@
     bool hwcDisabled = mDebugDisableHWC || mDebugRegion;
     result.appendFormat("  h/w composer %s\n",
             hwcDisabled ? "disabled" : "enabled");
-    hwc.dump(result);
+    getHwComposer().dump(result);
 
     /*
      * Dump gralloc state
@@ -4608,7 +4596,7 @@
     }
 }
 
-const Vector<sp<Layer>>& SurfaceFlinger::getLayerSortedByZForHwcDisplay(int32_t displayId) {
+const Vector<sp<Layer>>& SurfaceFlinger::getLayerSortedByZForHwcDisplay(DisplayId displayId) {
     // Note: mStateLock is held here
     for (const auto& [token, display] : mDisplays) {
         if (display->getId() == displayId) {
@@ -4616,7 +4604,7 @@
         }
     }
 
-    ALOGE("%s: Invalid display %d", __FUNCTION__, displayId);
+    ALOGE("%s: Invalid display %" PRIu64, __FUNCTION__, displayId);
     static const Vector<sp<Layer>> empty;
     return empty;
 }
@@ -4750,9 +4738,9 @@
         code == IBinder::SYSPROPS_TRANSACTION) {
         return OK;
     }
-    // Numbers from 1000 to 1030 are currently use for backdoors. The code
+    // Numbers from 1000 to 1031 are currently use for backdoors. The code
     // in onTransact verifies that the user is root, and has access to use SF.
-    if (code >= 1000 && code <= 1030) {
+    if (code >= 1000 && code <= 1031) {
         ALOGV("Accessing SurfaceFlinger through backdoor code: %u", code);
         return OK;
     }
@@ -5006,6 +4994,38 @@
                 reply->writeBool(useColorManagement);
                 return NO_ERROR;
             }
+            // Override default composition data space
+            // adb shell service call SurfaceFlinger 1031 i32 1 DATASPACE_NUMBER DATASPACE_NUMBER \
+            // && adb shell stop zygote && adb shell start zygote
+            // to restore: adb shell service call SurfaceFlinger 1031 i32 0 && \
+            // adb shell stop zygote && adb shell start zygote
+            case 1031: {
+                Mutex::Autolock _l(mStateLock);
+                n = data.readInt32();
+                if (n) {
+                    n = data.readInt32();
+                    if (n) {
+                        Dataspace dataspace = static_cast<Dataspace>(n);
+                        if (!validateCompositionDataspace(dataspace)) {
+                            return BAD_VALUE;
+                        }
+                        mDefaultCompositionDataspace = dataspace;
+                    }
+                    n = data.readInt32();
+                    if (n) {
+                        Dataspace dataspace = static_cast<Dataspace>(n);
+                        if (!validateCompositionDataspace(dataspace)) {
+                            return BAD_VALUE;
+                        }
+                        mWideColorGamutCompositionDataspace = dataspace;
+                    }
+                } else {
+                    // restore composition data space.
+                    mDefaultCompositionDataspace = defaultCompositionDataspace;
+                    mWideColorGamutCompositionDataspace = wideColorGamutCompositionDataspace;
+                }
+                return NO_ERROR;
+            }
         }
     }
     return err;
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 51168a6..e449e20 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -76,10 +76,11 @@
 #include <map>
 #include <mutex>
 #include <queue>
+#include <set>
 #include <string>
 #include <thread>
+#include <unordered_map>
 #include <utility>
-#include "RenderArea.h"
 
 #include <layerproto/LayerProtoHeader.h>
 
@@ -348,7 +349,7 @@
 
     // enable/disable h/w composer event
     // TODO: this should be made accessible only to EventThread
-    void setVsyncEnabled(int disp, int enabled);
+    void setVsyncEnabled(EventThread::DisplayType displayType, bool enabled);
 
     // called on the main thread by MessageQueue when an internal message
     // is received
@@ -357,7 +358,7 @@
 
     // for debugging only
     // TODO: this should be made accessible only to HWComposer
-    const Vector< sp<Layer> >& getLayerSortedByZForHwcDisplay(int id);
+    const Vector<sp<Layer>>& getLayerSortedByZForHwcDisplay(DisplayId displayId);
 
     renderengine::RenderEngine& getRenderEngine() const { return *getBE().mRenderEngine; }
 
@@ -659,7 +660,10 @@
     }
 
     sp<DisplayDevice> getDefaultDisplayDeviceLocked() {
-        return getDisplayDeviceLocked(mDisplayTokens[DisplayDevice::DISPLAY_PRIMARY]);
+        if (const auto token = getInternalDisplayToken()) {
+            return getDisplayDeviceLocked(token);
+        }
+        return nullptr;
     }
 
     // mark a region of a layer stack dirty. this updates the dirty
@@ -724,10 +728,8 @@
     /* ------------------------------------------------------------------------
      * Display management
      */
-    DisplayDevice::DisplayType determineDisplayType(hwc2_display_t hwcDisplayId,
-                                                    HWC2::Connection connection) const;
     sp<DisplayDevice> setupNewDisplayDeviceInternal(const wp<IBinder>& displayToken,
-                                                    int32_t displayId,
+                                                    const std::optional<DisplayId>& displayId,
                                                     const DisplayDeviceState& state,
                                                     const sp<DisplaySurface>& dispSurface,
                                                     const sp<IGraphicBufferProducer>& producer);
@@ -759,6 +761,37 @@
     }
 
 private:
+    sp<IBinder> getPhysicalDisplayToken(DisplayId displayId) const {
+        const auto it = mPhysicalDisplayTokens.find(displayId);
+        return it != mPhysicalDisplayTokens.end() ? it->second : nullptr;
+    }
+
+    std::optional<DisplayId> getPhysicalDisplayId(const sp<IBinder>& displayToken) const {
+        for (const auto& [id, token] : mPhysicalDisplayTokens) {
+            if (token == displayToken) {
+                return id;
+            }
+        }
+        return {};
+    }
+
+    // TODO(b/74619554): Remove special cases for primary display.
+    sp<IBinder> getInternalDisplayToken() const {
+        const auto displayId = getInternalDisplayId();
+        return displayId ? getPhysicalDisplayToken(*displayId) : nullptr;
+    }
+
+    std::optional<DisplayId> getInternalDisplayId() const {
+        const auto hwcDisplayId = getHwComposer().getInternalHwcDisplayId();
+        return hwcDisplayId ? getHwComposer().toPhysicalDisplayId(*hwcDisplayId) : std::nullopt;
+    }
+
+    // TODO(b/74619554): Remove special cases for external display.
+    std::optional<DisplayId> getExternalDisplayId() const {
+        const auto hwcDisplayId = getHwComposer().getExternalHwcDisplayId();
+        return hwcDisplayId ? getHwComposer().toPhysicalDisplayId(*hwcDisplayId) : std::nullopt;
+    }
+
     void listLayersLocked(const Vector<String16>& args, size_t& index, String8& result) const;
     void dumpStatsLocked(const Vector<String16>& args, size_t& index, String8& result) const;
     void clearStatsLocked(const Vector<String16>& args, size_t& index, String8& result);
@@ -836,7 +869,7 @@
     std::unique_ptr<VSyncSource> mSfEventThreadSource;
     std::unique_ptr<InjectVSyncSource> mVSyncInjector;
     std::unique_ptr<EventControlThread> mEventControlThread;
-    sp<IBinder> mDisplayTokens[DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES];
+    std::unordered_map<DisplayId, sp<IBinder>> mPhysicalDisplayTokens;
 
     VSyncModulator mVsyncModulator;
 
@@ -937,6 +970,9 @@
     // Applied on Display P3 layers when the render intent is non-colorimetric.
     mat4 mEnhancedSaturationMatrix;
 
+    ui::Dataspace mDefaultCompositionDataspace;
+    ui::Dataspace mWideColorGamutCompositionDataspace;
+
     SurfaceFlingerBE mBE;
 
     bool mUseScheduler = false;
diff --git a/services/surfaceflinger/SurfaceInterceptor.cpp b/services/surfaceflinger/SurfaceInterceptor.cpp
index 57bda5a..7faaff6 100644
--- a/services/surfaceflinger/SurfaceInterceptor.cpp
+++ b/services/surfaceflinger/SurfaceInterceptor.cpp
@@ -495,8 +495,10 @@
     DisplayCreation* creation(increment->mutable_display_creation());
     creation->set_id(info.sequenceId);
     creation->set_name(info.displayName);
-    creation->set_type(info.type);
     creation->set_is_secure(info.isSecure);
+    if (info.displayId) {
+        creation->set_display_id(*info.displayId);
+    }
 }
 
 void SurfaceInterceptor::addDisplayDeletionLocked(Increment* increment, int32_t sequenceId) {
diff --git a/services/surfaceflinger/TimeStats/TimeStats.cpp b/services/surfaceflinger/TimeStats/TimeStats.cpp
index ace7c1b..9730e8c 100644
--- a/services/surfaceflinger/TimeStats/TimeStats.cpp
+++ b/services/surfaceflinger/TimeStats/TimeStats.cpp
@@ -173,8 +173,8 @@
         ALOGV("[%d]-[%" PRIu64 "]-presentFenceTime[%" PRId64 "]", layerID,
               timeRecords[0].frameTime.frameNumber, timeRecords[0].frameTime.presentTime);
 
+        const std::string& layerName = layerRecord.layerName;
         if (prevTimeRecord.ready) {
-            const std::string& layerName = layerRecord.layerName;
             if (!mTimeStats.stats.count(layerName)) {
                 mTimeStats.stats[layerName].layerName = layerName;
                 mTimeStats.stats[layerName].packageName = getPackageName(layerName);
@@ -220,6 +220,18 @@
                   timeRecords[0].frameTime.frameNumber, presentToPresentMs);
             timeStatsLayer.deltas["present2present"].insert(presentToPresentMs);
         }
+
+        // Output additional trace points to track frame time.
+        ATRACE_INT64(("TimeStats-Post - " + layerName).c_str(), timeRecords[0].frameTime.postTime);
+        ATRACE_INT64(("TimeStats-Acquire - " + layerName).c_str(),
+                     timeRecords[0].frameTime.acquireTime);
+        ATRACE_INT64(("TimeStats-Latch - " + layerName).c_str(),
+                     timeRecords[0].frameTime.latchTime);
+        ATRACE_INT64(("TimeStats-Desired - " + layerName).c_str(),
+                     timeRecords[0].frameTime.desiredTime);
+        ATRACE_INT64(("TimeStats-Present - " + layerName).c_str(),
+                     timeRecords[0].frameTime.presentTime);
+
         prevTimeRecord = timeRecords[0];
         timeRecords.pop_front();
         layerRecord.waitData--;
diff --git a/services/surfaceflinger/main_surfaceflinger.cpp b/services/surfaceflinger/main_surfaceflinger.cpp
index 9c2edca..92ae87b 100644
--- a/services/surfaceflinger/main_surfaceflinger.cpp
+++ b/services/surfaceflinger/main_surfaceflinger.cpp
@@ -28,7 +28,6 @@
 #include <cutils/sched_policy.h>
 #include <displayservice/DisplayService.h>
 #include <hidl/LegacySupport.h>
-#include "GpuService.h"
 #include "SurfaceFlinger.h"
 #include "SurfaceFlingerFactory.h"
 
@@ -104,10 +103,6 @@
     sm->addService(String16(SurfaceFlinger::getServiceName()), flinger, false,
                    IServiceManager::DUMP_FLAG_PRIORITY_CRITICAL | IServiceManager::DUMP_FLAG_PROTO);
 
-    // publish GpuService
-    sp<GpuService> gpuservice = new GpuService();
-    sm->addService(String16(GpuService::SERVICE_NAME), gpuservice, false);
-
     startDisplayService(); // dependency on SF getting registered above
 
     struct sched_param param = {0};
diff --git a/services/surfaceflinger/tests/unittests/CompositionTest.cpp b/services/surfaceflinger/tests/unittests/CompositionTest.cpp
index 1352df5..09bb8c5 100644
--- a/services/surfaceflinger/tests/unittests/CompositionTest.cpp
+++ b/services/surfaceflinger/tests/unittests/CompositionTest.cpp
@@ -65,6 +65,7 @@
 constexpr hwc2_layer_t HWC_LAYER = 5000;
 constexpr Transform DEFAULT_TRANSFORM = static_cast<Transform>(0);
 
+constexpr DisplayId DEFAULT_DISPLAY_ID = 42;
 constexpr int DEFAULT_DISPLAY_WIDTH = 1920;
 constexpr int DEFAULT_DISPLAY_HEIGHT = 1024;
 
@@ -226,12 +227,13 @@
     static constexpr int INIT_POWER_MODE = HWC_POWER_MODE_NORMAL;
 
     static void setupPreconditions(CompositionTest* test) {
-        FakeHwcDisplayInjector(DisplayDevice::DISPLAY_PRIMARY, HWC2::DisplayType::Physical)
+        FakeHwcDisplayInjector(DEFAULT_DISPLAY_ID, HWC2::DisplayType::Physical,
+                               true /* isPrimary */)
                 .setCapabilities(&test->mDefaultCapabilities)
                 .inject(&test->mFlinger, test->mComposer);
 
-        test->mDisplay = FakeDisplayDeviceInjector(test->mFlinger, DisplayDevice::DISPLAY_PRIMARY,
-                                                   DisplayDevice::DISPLAY_PRIMARY)
+        test->mDisplay = FakeDisplayDeviceInjector(test->mFlinger, DEFAULT_DISPLAY_ID,
+                                                   false /* isVirtual */, true /* isPrimary */)
                                  .setDisplaySize(DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_HEIGHT)
                                  .setDisplaySurface(test->mDisplaySurface)
                                  .setRenderSurface(std::unique_ptr<renderengine::Surface>(
@@ -553,10 +555,6 @@
                                   IComposerClient::Color({0xff, 0xff, 0xff, 0xff})))
                 .Times(1);
 
-        // TODO: ColorLayer::onPreComposition() always returns true, triggering an
-        // extra layer update in SurfaceFlinger::preComposition(). This seems
-        // wrong on the surface.
-        EXPECT_CALL(*test->mMessageQueue, invalidate()).Times(1);
     }
 
     static void setupHwcSetPerFrameBufferCallExpectations(CompositionTest* test) {
@@ -749,7 +747,9 @@
         EXPECT_CALL(*test->mComposer, createLayer(HWC_DISPLAY, _))
                 .WillOnce(DoAll(SetArgPointee<1>(HWC_LAYER), Return(Error::NONE)));
 
-        layer->createHwcLayer(test->mFlinger.mFlinger->getBE().mHwc.get(), test->mDisplay->getId());
+        const auto displayId = test->mDisplay->getId();
+        ASSERT_TRUE(displayId);
+        layer->createHwcLayer(test->mFlinger.mFlinger->getBE().mHwc.get(), *displayId);
 
         Mock::VerifyAndClear(test->mComposer);
 
@@ -762,8 +762,10 @@
     static void cleanupInjectedLayers(CompositionTest* test) {
         EXPECT_CALL(*test->mComposer, destroyLayer(HWC_DISPLAY, HWC_LAYER))
                 .WillOnce(Return(Error::NONE));
+        const auto displayId = test->mDisplay->getId();
+        ASSERT_TRUE(displayId);
         for (auto layer : test->mFlinger.mutableDrawingState().layersSortedByZ) {
-            layer->destroyHwcLayer(test->mDisplay->getId());
+            layer->destroyHwcLayer(*displayId);
         }
         test->mFlinger.mutableDrawingState().layersSortedByZ.clear();
     }
@@ -951,7 +953,7 @@
 
 struct ForcedClientCompositionResultVariant : public RECompositionResultVariant {
     static void setupLayerState(CompositionTest*, sp<Layer> layer) {
-        layer->forceClientComposition(DisplayDevice::DISPLAY_PRIMARY);
+        layer->forceClientComposition(DEFAULT_DISPLAY_ID);
     }
 
     template <typename Case>
diff --git a/services/surfaceflinger/tests/unittests/DisplayIdentificationTest.cpp b/services/surfaceflinger/tests/unittests/DisplayIdentificationTest.cpp
index 4f1c99e..55995d0 100644
--- a/services/surfaceflinger/tests/unittests/DisplayIdentificationTest.cpp
+++ b/services/surfaceflinger/tests/unittests/DisplayIdentificationTest.cpp
@@ -68,32 +68,44 @@
 
 } // namespace
 
+const DisplayIdentificationData& getInternalEdid() {
+    static const DisplayIdentificationData data = asDisplayIdentificationData(kInternalEdid);
+    return data;
+}
+
+const DisplayIdentificationData& getExternalEdid() {
+    static const DisplayIdentificationData data = asDisplayIdentificationData(kExternalEdid);
+    return data;
+}
+
+const DisplayIdentificationData& getExternalEedid() {
+    static const DisplayIdentificationData data = asDisplayIdentificationData(kExternalEedid);
+    return data;
+}
+
 TEST(DisplayIdentificationTest, isEdid) {
     EXPECT_FALSE(isEdid({}));
 
-    EXPECT_TRUE(isEdid(asDisplayIdentificationData(kInternalEdid)));
-    EXPECT_TRUE(isEdid(asDisplayIdentificationData(kExternalEdid)));
-    EXPECT_TRUE(isEdid(asDisplayIdentificationData(kExternalEedid)));
+    EXPECT_TRUE(isEdid(getInternalEdid()));
+    EXPECT_TRUE(isEdid(getExternalEdid()));
+    EXPECT_TRUE(isEdid(getExternalEedid()));
 }
 
 TEST(DisplayIdentificationTest, parseEdid) {
-    auto data = asDisplayIdentificationData(kInternalEdid);
-    auto edid = parseEdid(data);
+    auto edid = parseEdid(getInternalEdid());
     ASSERT_TRUE(edid);
     EXPECT_EQ(0x4ca3u, edid->manufacturerId);
     EXPECT_STREQ("SEC", edid->pnpId.data());
     // ASCII text should be used as fallback if display name and serial number are missing.
     EXPECT_EQ("121AT11-801", edid->displayName);
 
-    data = asDisplayIdentificationData(kExternalEdid);
-    edid = parseEdid(data);
+    edid = parseEdid(getExternalEdid());
     ASSERT_TRUE(edid);
     EXPECT_EQ(0x22f0u, edid->manufacturerId);
     EXPECT_STREQ("HWP", edid->pnpId.data());
     EXPECT_EQ("HP ZR30w", edid->displayName);
 
-    data = asDisplayIdentificationData(kExternalEedid);
-    edid = parseEdid(data);
+    edid = parseEdid(getExternalEedid());
     ASSERT_TRUE(edid);
     EXPECT_EQ(0x4c2du, edid->manufacturerId);
     EXPECT_STREQ("SAM", edid->pnpId.data());
@@ -105,7 +117,7 @@
     EXPECT_FALSE(parseEdid({}));
 
     // Display name must be printable.
-    auto data = asDisplayIdentificationData(kExternalEdid);
+    auto data = getExternalEdid();
     data[97] = '\x1b';
     auto edid = parseEdid(data);
     ASSERT_TRUE(edid);
@@ -128,20 +140,32 @@
     EXPECT_STREQ("SAM", getPnpId(0x4c2du).value_or(PnpId{}).data());
 }
 
-TEST(DisplayIdentificationTest, generateDisplayId) {
-    const auto primaryId = generateDisplayId(0, asDisplayIdentificationData(kInternalEdid));
-    ASSERT_TRUE(primaryId);
+TEST(DisplayIdentificationTest, parseDisplayIdentificationData) {
+    const auto primaryInfo = parseDisplayIdentificationData(0, getInternalEdid());
+    ASSERT_TRUE(primaryInfo);
 
-    const auto secondaryId = generateDisplayId(1, asDisplayIdentificationData(kExternalEdid));
-    ASSERT_TRUE(secondaryId);
+    const auto secondaryInfo = parseDisplayIdentificationData(1, getExternalEdid());
+    ASSERT_TRUE(secondaryInfo);
 
-    const auto tertiaryId = generateDisplayId(2, asDisplayIdentificationData(kExternalEedid));
-    ASSERT_TRUE(tertiaryId);
+    const auto tertiaryInfo = parseDisplayIdentificationData(2, getExternalEedid());
+    ASSERT_TRUE(tertiaryInfo);
 
     // Display IDs should be unique.
-    EXPECT_NE(primaryId, secondaryId);
-    EXPECT_NE(primaryId, tertiaryId);
-    EXPECT_NE(secondaryId, tertiaryId);
+    EXPECT_NE(primaryInfo->id, secondaryInfo->id);
+    EXPECT_NE(primaryInfo->id, tertiaryInfo->id);
+    EXPECT_NE(secondaryInfo->id, tertiaryInfo->id);
+}
+
+TEST(DisplayIdentificationTest, getFallbackDisplayId) {
+    // Manufacturer ID should be invalid.
+    ASSERT_FALSE(getPnpId(getFallbackDisplayId(0)));
+    ASSERT_FALSE(getPnpId(getFallbackDisplayId(0xffu)));
+}
+
+TEST(DisplayIdentificationTest, getVirtualDisplayId) {
+    // Manufacturer ID should be invalid.
+    ASSERT_FALSE(getPnpId(getVirtualDisplayId(0)));
+    ASSERT_FALSE(getPnpId(getVirtualDisplayId(0xffff'ffffu)));
 }
 
 } // namespace android
diff --git a/services/surfaceflinger/tests/unittests/DisplayIdentificationTest.h b/services/surfaceflinger/tests/unittests/DisplayIdentificationTest.h
new file mode 100644
index 0000000..1c8e5cc
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/DisplayIdentificationTest.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "DisplayHardware/DisplayIdentification.h"
+
+namespace android {
+
+const DisplayIdentificationData& getInternalEdid();
+const DisplayIdentificationData& getExternalEdid();
+const DisplayIdentificationData& getExternalEedid();
+
+} // namespace android
diff --git a/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp b/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
index d32627a..2e90a59 100644
--- a/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
+++ b/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
@@ -17,12 +17,16 @@
 #undef LOG_TAG
 #define LOG_TAG "LibSurfaceFlingerUnittests"
 
+#include <type_traits>
+
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
 #include <log/log.h>
 
 #include <ui/DebugUtils.h>
+
+#include "DisplayIdentificationTest.h"
 #include "TestableSurfaceFlinger.h"
 #include "mock/DisplayHardware/MockComposer.h"
 #include "mock/DisplayHardware/MockDisplaySurface.h"
@@ -75,9 +79,11 @@
 
 #define BOOL_SUBSTITUTE(TYPENAME) enum class TYPENAME : bool { FALSE = false, TRUE = true };
 
-BOOL_SUBSTITUTE(Critical);
 BOOL_SUBSTITUTE(Async);
+BOOL_SUBSTITUTE(Critical);
+BOOL_SUBSTITUTE(Primary);
 BOOL_SUBSTITUTE(Secure);
+BOOL_SUBSTITUTE(Virtual);
 
 /* ------------------------------------------------------------------------
  *
@@ -98,7 +104,7 @@
     // --------------------------------------------------------------------
     // Postcondition helpers
 
-    bool hasHwcDisplay(hwc2_display_t displayId);
+    bool hasPhysicalHwcDisplay(hwc2_display_t hwcDisplayId);
     bool hasTransactionFlagSet(int flag);
     bool hasDisplayDevice(sp<IBinder> displayToken);
     sp<DisplayDevice> getDisplayDevice(sp<IBinder> displayToken);
@@ -204,8 +210,8 @@
     });
 }
 
-bool DisplayTransactionTest::hasHwcDisplay(hwc2_display_t displayId) {
-    return mFlinger.mutableHwcDisplaySlots().count(displayId) == 1;
+bool DisplayTransactionTest::hasPhysicalHwcDisplay(hwc2_display_t hwcDisplayId) {
+    return mFlinger.mutableHwcPhysicalDisplayIdMap().count(hwcDisplayId) == 1;
 }
 
 bool DisplayTransactionTest::hasTransactionFlagSet(int flag) {
@@ -240,20 +246,67 @@
  *
  */
 
-template <DisplayDevice::DisplayType type, DisplayDevice::DisplayType displayId, int width,
-          int height, Critical critical, Async async, Secure secure, int grallocUsage>
+template <typename PhysicalDisplay>
+struct PhysicalDisplayId {};
+
+template <DisplayId displayId>
+using VirtualDisplayId = std::integral_constant<DisplayId, displayId>;
+
+struct NoDisplayId {};
+
+template <typename>
+struct IsPhysicalDisplayId : std::bool_constant<false> {};
+
+template <typename PhysicalDisplay>
+struct IsPhysicalDisplayId<PhysicalDisplayId<PhysicalDisplay>> : std::bool_constant<true> {};
+
+template <typename>
+struct DisplayIdGetter;
+
+template <typename PhysicalDisplay>
+struct DisplayIdGetter<PhysicalDisplayId<PhysicalDisplay>> {
+    static std::optional<DisplayId> get() {
+        if (!PhysicalDisplay::HAS_IDENTIFICATION_DATA) {
+            return getFallbackDisplayId(static_cast<bool>(PhysicalDisplay::PRIMARY)
+                                                ? HWC_DISPLAY_PRIMARY
+                                                : HWC_DISPLAY_EXTERNAL);
+        }
+
+        const auto info =
+                parseDisplayIdentificationData(PhysicalDisplay::PORT,
+                                               PhysicalDisplay::GET_IDENTIFICATION_DATA());
+        return info ? std::make_optional(info->id) : std::nullopt;
+    }
+};
+
+template <DisplayId displayId>
+struct DisplayIdGetter<VirtualDisplayId<displayId>> {
+    static std::optional<DisplayId> get() { return displayId; }
+};
+
+template <>
+struct DisplayIdGetter<NoDisplayId> {
+    static std::optional<DisplayId> get() { return {}; }
+};
+
+// DisplayIdType can be:
+//     1) PhysicalDisplayId<...> for generated ID of physical display backed by HWC.
+//     2) VirtualDisplayId<...> for hard-coded ID of virtual display backed by HWC.
+//     3) NoDisplayId for virtual display without HWC backing.
+template <typename DisplayIdType, int width, int height, Critical critical, Async async,
+          Secure secure, Primary primary, int grallocUsage>
 struct DisplayVariant {
+    using DISPLAY_ID = DisplayIdGetter<DisplayIdType>;
+
     // The display width and height
     static constexpr int WIDTH = width;
     static constexpr int HEIGHT = height;
 
     static constexpr int GRALLOC_USAGE = grallocUsage;
 
-    // The type for this display
-    static constexpr DisplayDevice::DisplayType TYPE = type;
-    static_assert(TYPE != DisplayDevice::DISPLAY_ID_INVALID);
-
-    static constexpr DisplayDevice::DisplayType DISPLAY_ID = displayId;
+    // Whether the display is virtual or physical
+    static constexpr Virtual VIRTUAL =
+            IsPhysicalDisplayId<DisplayIdType>{} ? Virtual::FALSE : Virtual::TRUE;
 
     // When creating native window surfaces for the framebuffer, whether those should be critical
     static constexpr Critical CRITICAL = critical;
@@ -264,8 +317,14 @@
     // Whether the display should be treated as secure
     static constexpr Secure SECURE = secure;
 
+    // Whether the display is primary
+    static constexpr Primary PRIMARY = primary;
+
     static auto makeFakeExistingDisplayInjector(DisplayTransactionTest* test) {
-        auto injector = FakeDisplayDeviceInjector(test->mFlinger, TYPE, DISPLAY_ID);
+        auto injector =
+                FakeDisplayDeviceInjector(test->mFlinger, DISPLAY_ID::get(),
+                                          static_cast<bool>(VIRTUAL), static_cast<bool>(PRIMARY));
+
         injector.setSecure(static_cast<bool>(SECURE));
         return injector;
     }
@@ -306,7 +365,8 @@
     }
 };
 
-template <hwc2_display_t hwcDisplayId, HWC2::DisplayType hwcDisplayType, typename DisplayVariant>
+template <hwc2_display_t hwcDisplayId, HWC2::DisplayType hwcDisplayType, typename DisplayVariant,
+          typename PhysicalDisplay = void>
 struct HwcDisplayVariant {
     // The display id supplied by the HWC
     static constexpr hwc2_display_t HWC_DISPLAY_ID = hwcDisplayId;
@@ -325,7 +385,10 @@
 
     // Called by tests to inject a HWC display setup
     static void injectHwcDisplay(DisplayTransactionTest* test) {
-        FakeHwcDisplayInjector(DisplayVariant::TYPE, HWC_DISPLAY_TYPE)
+        const auto displayId = DisplayVariant::DISPLAY_ID::get();
+        ASSERT_TRUE(displayId);
+        FakeHwcDisplayInjector(*displayId, HWC_DISPLAY_TYPE,
+                               static_cast<bool>(DisplayVariant::PRIMARY))
                 .setHwcDisplayId(HWC_DISPLAY_ID)
                 .setWidth(DisplayVariant::WIDTH)
                 .setHeight(DisplayVariant::HEIGHT)
@@ -362,8 +425,16 @@
                     getDisplayAttribute(HWC_DISPLAY_ID, HWC_ACTIVE_CONFIG_ID,
                                         IComposerClient::Attribute::DPI_Y, _))
                 .WillOnce(DoAll(SetArgPointee<3>(DEFAULT_DPI), Return(Error::NONE)));
-        EXPECT_CALL(*test->mComposer, getDisplayIdentificationData(HWC_DISPLAY_ID, _, _))
-                .WillRepeatedly(Return(Error::UNSUPPORTED));
+
+        if (PhysicalDisplay::HAS_IDENTIFICATION_DATA) {
+            EXPECT_CALL(*test->mComposer, getDisplayIdentificationData(HWC_DISPLAY_ID, _, _))
+                    .WillOnce(DoAll(SetArgPointee<1>(PhysicalDisplay::PORT),
+                                    SetArgPointee<2>(PhysicalDisplay::GET_IDENTIFICATION_DATA()),
+                                    Return(Error::NONE)));
+        } else {
+            EXPECT_CALL(*test->mComposer, getDisplayIdentificationData(HWC_DISPLAY_ID, _, _))
+                    .WillOnce(Return(Error::UNSUPPORTED));
+        }
     }
 
     // Called by tests to set up HWC call expectations
@@ -373,50 +444,67 @@
     }
 };
 
-struct NonHwcDisplayVariant {
-    static void injectHwcDisplay(DisplayTransactionTest*) {}
-
-    static void setupHwcGetActiveConfigCallExpectations(DisplayTransactionTest* test) {
-        EXPECT_CALL(*test->mComposer, getActiveConfig(_, _)).Times(0);
-    }
-};
-
 // Physical displays are expected to be synchronous, secure, and have a HWC display for output.
 constexpr uint32_t GRALLOC_USAGE_PHYSICAL_DISPLAY =
         GRALLOC_USAGE_HW_RENDER | GRALLOC_USAGE_HW_COMPOSER | GRALLOC_USAGE_HW_FB;
 
-template <hwc2_display_t hwcDisplayId, DisplayDevice::DisplayType type, int width, int height,
+template <hwc2_display_t hwcDisplayId, typename PhysicalDisplay, int width, int height,
           Critical critical>
 struct PhysicalDisplayVariant
-      : public DisplayVariant<type, type, width, height, critical, Async::FALSE, Secure::TRUE,
-                              GRALLOC_USAGE_PHYSICAL_DISPLAY>,
-        public HwcDisplayVariant<hwcDisplayId, HWC2::DisplayType::Physical,
-                                 DisplayVariant<type, type, width, height, critical, Async::FALSE,
-                                                Secure::TRUE, GRALLOC_USAGE_PHYSICAL_DISPLAY>> {};
+      : DisplayVariant<PhysicalDisplayId<PhysicalDisplay>, width, height, critical, Async::FALSE,
+                       Secure::TRUE, PhysicalDisplay::PRIMARY, GRALLOC_USAGE_PHYSICAL_DISPLAY>,
+        HwcDisplayVariant<hwcDisplayId, HWC2::DisplayType::Physical,
+                          DisplayVariant<PhysicalDisplayId<PhysicalDisplay>, width, height,
+                                         critical, Async::FALSE, Secure::TRUE,
+                                         PhysicalDisplay::PRIMARY, GRALLOC_USAGE_PHYSICAL_DISPLAY>,
+                          PhysicalDisplay> {};
+
+template <bool hasIdentificationData>
+struct PrimaryDisplay {
+    static constexpr Primary PRIMARY = Primary::TRUE;
+    static constexpr uint8_t PORT = 255;
+    static constexpr bool HAS_IDENTIFICATION_DATA = hasIdentificationData;
+    static constexpr auto GET_IDENTIFICATION_DATA = getInternalEdid;
+};
+
+template <bool hasIdentificationData>
+struct ExternalDisplay {
+    static constexpr Primary PRIMARY = Primary::FALSE;
+    static constexpr uint8_t PORT = 254;
+    static constexpr bool HAS_IDENTIFICATION_DATA = hasIdentificationData;
+    static constexpr auto GET_IDENTIFICATION_DATA = getExternalEdid;
+};
+
+struct TertiaryDisplay {
+    static constexpr Primary PRIMARY = Primary::FALSE;
+};
 
 // A primary display is a physical display that is critical
 using PrimaryDisplayVariant =
-        PhysicalDisplayVariant<1001, DisplayDevice::DISPLAY_PRIMARY, 3840, 2160, Critical::TRUE>;
+        PhysicalDisplayVariant<1001, PrimaryDisplay<false>, 3840, 2160, Critical::TRUE>;
 
 // An external display is physical display that is not critical.
 using ExternalDisplayVariant =
-        PhysicalDisplayVariant<1002, DisplayDevice::DISPLAY_EXTERNAL, 1920, 1280, Critical::FALSE>;
+        PhysicalDisplayVariant<1002, ExternalDisplay<false>, 1920, 1280, Critical::FALSE>;
 
 using TertiaryDisplayVariant =
-        PhysicalDisplayVariant<1003, DisplayDevice::DISPLAY_EXTERNAL, 1600, 1200, Critical::FALSE>;
+        PhysicalDisplayVariant<1003, TertiaryDisplay, 1600, 1200, Critical::FALSE>;
 
 // A virtual display not supported by the HWC.
 constexpr uint32_t GRALLOC_USAGE_NONHWC_VIRTUAL_DISPLAY = 0;
 
 template <int width, int height, Secure secure>
 struct NonHwcVirtualDisplayVariant
-      : public DisplayVariant<DisplayDevice::DISPLAY_VIRTUAL, DisplayDevice::DISPLAY_ID_INVALID,
-                              width, height, Critical::FALSE, Async::TRUE, secure,
-                              GRALLOC_USAGE_NONHWC_VIRTUAL_DISPLAY>,
-        public NonHwcDisplayVariant {
-    using Base = DisplayVariant<DisplayDevice::DISPLAY_VIRTUAL, DisplayDevice::DISPLAY_ID_INVALID,
-                                width, height, Critical::FALSE, Async::TRUE, secure,
-                                GRALLOC_USAGE_NONHWC_VIRTUAL_DISPLAY>;
+      : DisplayVariant<NoDisplayId, width, height, Critical::FALSE, Async::TRUE, secure,
+                       Primary::FALSE, GRALLOC_USAGE_NONHWC_VIRTUAL_DISPLAY> {
+    using Base = DisplayVariant<NoDisplayId, width, height, Critical::FALSE, Async::TRUE, secure,
+                                Primary::FALSE, GRALLOC_USAGE_NONHWC_VIRTUAL_DISPLAY>;
+
+    static void injectHwcDisplay(DisplayTransactionTest*) {}
+
+    static void setupHwcGetActiveConfigCallExpectations(DisplayTransactionTest* test) {
+        EXPECT_CALL(*test->mComposer, getActiveConfig(_, _)).Times(0);
+    }
 
     static void setupNativeWindowSurfaceCreationCallExpectations(DisplayTransactionTest* test) {
         Base::setupNativeWindowSurfaceCreationCallExpectations(test);
@@ -429,14 +517,14 @@
 
 template <int width, int height, Secure secure>
 struct HwcVirtualDisplayVariant
-      : public DisplayVariant<DisplayDevice::DISPLAY_VIRTUAL, DisplayDevice::DISPLAY_VIRTUAL, width,
-                              height, Critical::FALSE, Async::TRUE, secure,
-                              GRALLOC_USAGE_HWC_VIRTUAL_DISPLAY>,
-        public HwcDisplayVariant<1010, HWC2::DisplayType::Virtual,
-                                 NonHwcVirtualDisplayVariant<width, height, secure>> {
-    using Base =
-            DisplayVariant<DisplayDevice::DISPLAY_VIRTUAL, DisplayDevice::DISPLAY_VIRTUAL, width,
-                           height, Critical::FALSE, Async::TRUE, secure, GRALLOC_USAGE_HW_COMPOSER>;
+      : DisplayVariant<VirtualDisplayId<42>, width, height, Critical::FALSE, Async::TRUE, secure,
+                       Primary::FALSE, GRALLOC_USAGE_HWC_VIRTUAL_DISPLAY>,
+        HwcDisplayVariant<
+                1010, HWC2::DisplayType::Virtual,
+                DisplayVariant<VirtualDisplayId<42>, width, height, Critical::FALSE, Async::TRUE,
+                               secure, Primary::FALSE, GRALLOC_USAGE_HWC_VIRTUAL_DISPLAY>> {
+    using Base = DisplayVariant<VirtualDisplayId<42>, width, height, Critical::FALSE, Async::TRUE,
+                                secure, Primary::FALSE, GRALLOC_USAGE_HW_COMPOSER>;
     using Self = HwcVirtualDisplayVariant<width, height, secure>;
 
     static void setupNativeWindowSurfaceCreationCallExpectations(DisplayTransactionTest* test) {
@@ -850,8 +938,8 @@
     // The display should have been added to the current state
     ASSERT_TRUE(hasCurrentDisplayState(displayToken));
     const auto& display = getCurrentDisplayState(displayToken);
-    EXPECT_EQ(DisplayDevice::DISPLAY_VIRTUAL, display.type);
-    EXPECT_EQ(false, display.isSecure);
+    EXPECT_TRUE(display.isVirtual());
+    EXPECT_FALSE(display.isSecure);
     EXPECT_EQ(name.string(), display.displayName);
 
     // --------------------------------------------------------------------
@@ -881,8 +969,8 @@
     // The display should have been added to the current state
     ASSERT_TRUE(hasCurrentDisplayState(displayToken));
     const auto& display = getCurrentDisplayState(displayToken);
-    EXPECT_EQ(DisplayDevice::DISPLAY_VIRTUAL, display.type);
-    EXPECT_EQ(true, display.isSecure);
+    EXPECT_TRUE(display.isVirtual());
+    EXPECT_TRUE(display.isSecure);
     EXPECT_EQ(name.string(), display.displayName);
 
     // --------------------------------------------------------------------
@@ -1002,9 +1090,12 @@
  */
 class GetBestColorModeTest : public DisplayTransactionTest {
 public:
+    static constexpr DisplayId DEFAULT_DISPLAY_ID = 777;
+
     GetBestColorModeTest()
           : DisplayTransactionTest(),
-            mInjector(FakeDisplayDeviceInjector(mFlinger, DisplayDevice::DISPLAY_PRIMARY, 0)) {}
+            mInjector(FakeDisplayDeviceInjector(mFlinger, DEFAULT_DISPLAY_ID, false /* isVirtual */,
+                                                true /* isPrimary */)) {}
 
     void setHasWideColorGamut(bool hasWideColorGamut) { mHasWideColorGamut = hasWideColorGamut; }
 
@@ -1127,18 +1218,22 @@
     // Invocation
 
     DisplayDeviceState state;
-    state.type = Case::Display::TYPE;
+    state.displayId = static_cast<bool>(Case::Display::VIRTUAL) ? std::nullopt
+                                                                : Case::Display::DISPLAY_ID::get();
     state.isSecure = static_cast<bool>(Case::Display::SECURE);
 
-    auto device = mFlinger.setupNewDisplayDeviceInternal(displayToken, Case::Display::TYPE, state,
-                                                         displaySurface, producer);
+    auto device =
+            mFlinger.setupNewDisplayDeviceInternal(displayToken, Case::Display::DISPLAY_ID::get(),
+                                                   state, displaySurface, producer);
 
     // --------------------------------------------------------------------
     // Postconditions
 
     ASSERT_TRUE(device != nullptr);
-    EXPECT_EQ(Case::Display::TYPE, device->getDisplayType());
+    EXPECT_EQ(Case::Display::DISPLAY_ID::get(), device->getId());
+    EXPECT_EQ(static_cast<bool>(Case::Display::VIRTUAL), device->isVirtual());
     EXPECT_EQ(static_cast<bool>(Case::Display::SECURE), device->isSecure());
+    EXPECT_EQ(static_cast<bool>(Case::Display::PRIMARY), device->isPrimary());
     EXPECT_EQ(Case::Display::WIDTH, device->getWidth());
     EXPECT_EQ(Case::Display::HEIGHT, device->getHeight());
     EXPECT_EQ(Case::WideColorSupport::WIDE_COLOR_SUPPORTED, device->hasWideColorGamut());
@@ -1166,11 +1261,14 @@
 }
 
 TEST_F(SetupNewDisplayDeviceInternalTest, createHwcVirtualDisplay) {
-    // We need to resize this so that the HWC thinks the virtual display
-    // is something it created.
-    mFlinger.mutableHwcDisplayData().resize(3);
+    using Case = HwcVirtualDisplayCase;
 
-    setupNewDisplayDeviceInternalTest<HwcVirtualDisplayCase>();
+    // Insert display data so that the HWC thinks it created the virtual display.
+    const auto displayId = Case::Display::DISPLAY_ID::get();
+    ASSERT_TRUE(displayId);
+    mFlinger.mutableHwcDisplayData()[*displayId] = {};
+
+    setupNewDisplayDeviceInternalTest<Case>();
 }
 
 TEST_F(SetupNewDisplayDeviceInternalTest, createWideColorP3Display) {
@@ -1258,7 +1356,7 @@
 
     EXPECT_CALL(*mSurfaceInterceptor, saveDisplayCreation(_)).Times(1);
     EXPECT_CALL(*mEventThread,
-                onHotplugReceived(Case::Display::TYPE == DisplayDevice::DISPLAY_PRIMARY
+                onHotplugReceived(static_cast<bool>(Case::Display::PRIMARY)
                                           ? EventThread::DisplayType::Primary
                                           : EventThread::DisplayType::External,
                                   true))
@@ -1269,7 +1367,7 @@
 void HandleTransactionLockedTest::setupCommonCallExpectationsForDisconnectProcessing() {
     EXPECT_CALL(*mSurfaceInterceptor, saveDisplayDeletion(_)).Times(1);
     EXPECT_CALL(*mEventThread,
-                onHotplugReceived(Case::Display::TYPE == DisplayDevice::DISPLAY_PRIMARY
+                onHotplugReceived(static_cast<bool>(Case::Display::PRIMARY)
                                           ? EventThread::DisplayType::Primary
                                           : EventThread::DisplayType::External,
                                   false))
@@ -1282,30 +1380,35 @@
     ASSERT_TRUE(hasDisplayDevice(displayToken));
     const auto& device = getDisplayDevice(displayToken);
     EXPECT_EQ(static_cast<bool>(Case::Display::SECURE), device->isSecure());
-    EXPECT_EQ(Case::Display::TYPE == DisplayDevice::DISPLAY_PRIMARY, device->isPrimary());
+    EXPECT_EQ(static_cast<bool>(Case::Display::PRIMARY), device->isPrimary());
 
     // The display should have been set up in the current display state
     ASSERT_TRUE(hasCurrentDisplayState(displayToken));
     const auto& current = getCurrentDisplayState(displayToken);
-    EXPECT_EQ(Case::Display::TYPE, current.type);
+    EXPECT_EQ(static_cast<bool>(Case::Display::VIRTUAL), current.isVirtual());
+    EXPECT_EQ(static_cast<bool>(Case::Display::VIRTUAL) ? std::nullopt
+                                                        : Case::Display::DISPLAY_ID::get(),
+              current.displayId);
 
     // The display should have been set up in the drawing display state
     ASSERT_TRUE(hasDrawingDisplayState(displayToken));
     const auto& draw = getDrawingDisplayState(displayToken);
-    EXPECT_EQ(Case::Display::TYPE, draw.type);
+    EXPECT_EQ(static_cast<bool>(Case::Display::VIRTUAL), draw.isVirtual());
+    EXPECT_EQ(static_cast<bool>(Case::Display::VIRTUAL) ? std::nullopt
+                                                        : Case::Display::DISPLAY_ID::get(),
+              draw.displayId);
 }
 
 template <typename Case>
 void HandleTransactionLockedTest::verifyPhysicalDisplayIsConnected() {
     // HWComposer should have an entry for the display
-    EXPECT_TRUE(hasHwcDisplay(Case::Display::HWC_DISPLAY_ID));
+    EXPECT_TRUE(hasPhysicalHwcDisplay(Case::Display::HWC_DISPLAY_ID));
 
-    // The display should be set up as a built-in display.
-    static_assert(0 <= Case::Display::TYPE &&
-                          Case::Display::TYPE < DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES,
-                  "Must use a valid physical display type index for the fixed-size array");
-    auto& displayToken = mFlinger.mutableDisplayTokens()[Case::Display::TYPE];
-    ASSERT_TRUE(displayToken != nullptr);
+    // SF should have a display token.
+    const auto displayId = Case::Display::DISPLAY_ID::get();
+    ASSERT_TRUE(displayId);
+    ASSERT_TRUE(mFlinger.mutablePhysicalDisplayTokens().count(*displayId) == 1);
+    auto& displayToken = mFlinger.mutablePhysicalDisplayTokens()[*displayId];
 
     verifyDisplayIsConnected<Case>(displayToken);
 }
@@ -1371,7 +1474,7 @@
     // Postconditions
 
     // HWComposer should not have an entry for the display
-    EXPECT_FALSE(hasHwcDisplay(Case::Display::HWC_DISPLAY_ID));
+    EXPECT_FALSE(hasPhysicalHwcDisplay(Case::Display::HWC_DISPLAY_ID));
 }
 
 template <typename Case>
@@ -1407,13 +1510,12 @@
     // Postconditions
 
     // HWComposer should not have an entry for the display
-    EXPECT_FALSE(hasHwcDisplay(Case::Display::HWC_DISPLAY_ID));
+    EXPECT_FALSE(hasPhysicalHwcDisplay(Case::Display::HWC_DISPLAY_ID));
 
-    // The display should not be set up as a built-in display.
-    ASSERT_TRUE(0 <= Case::Display::TYPE &&
-                Case::Display::TYPE < DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES);
-    auto displayToken = mFlinger.mutableDisplayTokens()[Case::Display::TYPE];
-    EXPECT_TRUE(displayToken == nullptr);
+    // SF should not have a display token.
+    const auto displayId = Case::Display::DISPLAY_ID::get();
+    ASSERT_TRUE(displayId);
+    ASSERT_TRUE(mFlinger.mutablePhysicalDisplayTokens().count(*displayId) == 0);
 
     // The existing token should have been removed
     verifyDisplayIsNotConnected(existing.token());
@@ -1500,13 +1602,12 @@
     // Postconditions
 
     // HWComposer should not have an entry for the display
-    EXPECT_FALSE(hasHwcDisplay(Case::Display::HWC_DISPLAY_ID));
+    EXPECT_FALSE(hasPhysicalHwcDisplay(Case::Display::HWC_DISPLAY_ID));
 
-    // The display should not be set up as a primary built-in display.
-    ASSERT_TRUE(0 <= Case::Display::TYPE &&
-                Case::Display::TYPE < DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES);
-    auto displayToken = mFlinger.mutableDisplayTokens()[Case::Display::TYPE];
-    EXPECT_TRUE(displayToken == nullptr);
+    // SF should not have a display token.
+    const auto displayId = Case::Display::DISPLAY_ID::get();
+    ASSERT_TRUE(displayId);
+    ASSERT_TRUE(mFlinger.mutablePhysicalDisplayTokens().count(*displayId) == 0);
 }
 
 TEST_F(HandleTransactionLockedTest, processesHotplugDisconnectThenConnectPrimary) {
@@ -1545,10 +1646,10 @@
 
     // The existing token should have been removed
     verifyDisplayIsNotConnected(existing.token());
-    static_assert(0 <= Case::Display::TYPE &&
-                          Case::Display::TYPE < DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES,
-                  "Display type must be a built-in display");
-    EXPECT_NE(existing.token(), mFlinger.mutableDisplayTokens()[Case::Display::TYPE]);
+    const auto displayId = Case::Display::DISPLAY_ID::get();
+    ASSERT_TRUE(displayId);
+    ASSERT_TRUE(mFlinger.mutablePhysicalDisplayTokens().count(*displayId) == 1);
+    EXPECT_NE(existing.token(), mFlinger.mutablePhysicalDisplayTokens()[*displayId]);
 
     // A new display should be connected in its place
 
@@ -1578,13 +1679,12 @@
     // surface(producer)
     sp<BBinder> displayToken = new BBinder();
 
-    DisplayDeviceState info;
-    info.type = Case::Display::TYPE;
-    info.isSecure = static_cast<bool>(Case::Display::SECURE);
+    DisplayDeviceState state;
+    state.isSecure = static_cast<bool>(Case::Display::SECURE);
 
     sp<mock::GraphicBufferProducer> surface{new mock::GraphicBufferProducer()};
-    info.surface = surface;
-    mFlinger.mutableCurrentState().displays.add(displayToken, info);
+    state.surface = surface;
+    mFlinger.mutableCurrentState().displays.add(displayToken, state);
 
     // --------------------------------------------------------------------
     // Call Expectations
@@ -1646,11 +1746,10 @@
     // surface.
     sp<BBinder> displayToken = new BBinder();
 
-    DisplayDeviceState info;
-    info.type = Case::Display::TYPE;
-    info.isSecure = static_cast<bool>(Case::Display::SECURE);
+    DisplayDeviceState state;
+    state.isSecure = static_cast<bool>(Case::Display::SECURE);
 
-    mFlinger.mutableCurrentState().displays.add(displayToken, info);
+    mFlinger.mutableCurrentState().displays.add(displayToken, state);
 
     // --------------------------------------------------------------------
     // Call Expectations
@@ -1669,7 +1768,7 @@
     // The drawing display state will be set from the current display state.
     ASSERT_TRUE(hasDrawingDisplayState(displayToken));
     const auto& draw = getDrawingDisplayState(displayToken);
-    EXPECT_EQ(Case::Display::TYPE, draw.type);
+    EXPECT_EQ(static_cast<bool>(Case::Display::VIRTUAL), draw.isVirtual());
 }
 
 TEST_F(HandleTransactionLockedTest, processesVirtualDisplayRemoval) {
@@ -1679,7 +1778,9 @@
     // Preconditions
 
     // A virtual display is set up but is removed from the current state.
-    mFlinger.mutableHwcDisplayData().resize(3);
+    const auto displayId = Case::Display::DISPLAY_ID::get();
+    ASSERT_TRUE(displayId);
+    mFlinger.mutableHwcDisplayData()[*displayId] = {};
     Case::Display::injectHwcDisplay(this);
     auto existing = Case::Display::makeFakeExistingDisplayInjector(this);
     existing.inject();
@@ -2799,9 +2900,10 @@
     // --------------------------------------------------------------------
     // Preconditions
 
-    // We need to resize this so that the HWC thinks the virtual display
-    // is something it created.
-    mFlinger.mutableHwcDisplayData().resize(3);
+    // Insert display data so that the HWC thinks it created the virtual display.
+    const auto displayId = Case::Display::DISPLAY_ID::get();
+    ASSERT_TRUE(displayId);
+    mFlinger.mutableHwcDisplayData()[*displayId] = {};
 
     // A virtual display device is set up
     Case::Display::injectHwcDisplay(this);
diff --git a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
index c3534e8..b046e4a 100644
--- a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
+++ b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
@@ -178,10 +178,6 @@
         layer->getBE().compositionInfo.hwc.sidebandStream = sidebandStream;
     }
 
-    void setLayerCompositionType(sp<Layer> layer, HWC2::Composition type) {
-        layer->getBE().mHwcLayers[DisplayDevice::DISPLAY_PRIMARY].compositionType = type;
-    };
-
     void setLayerPotentialCursor(sp<Layer> layer, bool potentialCursor) {
         layer->mPotentialCursor = potentialCursor;
     }
@@ -200,7 +196,8 @@
 
     auto resetDisplayState() { return mFlinger->resetDisplayState(); }
 
-    auto setupNewDisplayDeviceInternal(const wp<IBinder>& displayToken, int32_t displayId,
+    auto setupNewDisplayDeviceInternal(const wp<IBinder>& displayToken,
+                                       const std::optional<DisplayId>& displayId,
                                        const DisplayDeviceState& state,
                                        const sp<DisplaySurface>& dispSurface,
                                        const sp<IGraphicBufferProducer>& producer) {
@@ -263,7 +260,6 @@
     auto& mutableCurrentState() { return mFlinger->mCurrentState; }
     auto& mutableDisplayColorSetting() { return mFlinger->mDisplayColorSetting; }
     auto& mutableDisplays() { return mFlinger->mDisplays; }
-    auto& mutableDisplayTokens() { return mFlinger->mDisplayTokens; }
     auto& mutableDrawingState() { return mFlinger->mDrawingState; }
     auto& mutableEventControlThread() { return mFlinger->mEventControlThread; }
     auto& mutableEventQueue() { return mFlinger->mEventQueue; }
@@ -273,6 +269,7 @@
     auto& mutableInterceptor() { return mFlinger->mInterceptor; }
     auto& mutableMainThreadId() { return mFlinger->mMainThreadId; }
     auto& mutablePendingHotplugEvents() { return mFlinger->mPendingHotplugEvents; }
+    auto& mutablePhysicalDisplayTokens() { return mFlinger->mPhysicalDisplayTokens; }
     auto& mutablePrimaryDispSync() { return mFlinger->mPrimaryDispSync; }
     auto& mutablePrimaryHWVsyncEnabled() { return mFlinger->mPrimaryHWVsyncEnabled; }
     auto& mutableTexturePool() { return mFlinger->mTexturePool; }
@@ -280,8 +277,13 @@
     auto& mutableUseHwcVirtualDisplays() { return mFlinger->mUseHwcVirtualDisplays; }
 
     auto& mutableComposerSequenceId() { return mFlinger->getBE().mComposerSequenceId; }
-    auto& mutableHwcDisplayData() { return mFlinger->getBE().mHwc->mDisplayData; }
-    auto& mutableHwcDisplaySlots() { return mFlinger->getBE().mHwc->mHwcDisplaySlots; }
+    auto& mutableHwcDisplayData() { return mFlinger->getHwComposer().mDisplayData; }
+    auto& mutableHwcPhysicalDisplayIdMap() {
+        return mFlinger->getHwComposer().mPhysicalDisplayIdMap;
+    }
+
+    auto& mutableInternalHwcDisplayId() { return mFlinger->getHwComposer().mInternalHwcDisplayId; }
+    auto& mutableExternalHwcDisplayId() { return mFlinger->getHwComposer().mExternalHwcDisplayId; }
 
     ~TestableSurfaceFlinger() {
         // All these pointer and container clears help ensure that GMock does
@@ -333,8 +335,9 @@
         static constexpr int32_t DEFAULT_DPI = 320;
         static constexpr int32_t DEFAULT_ACTIVE_CONFIG = 0;
 
-        FakeHwcDisplayInjector(DisplayDevice::DisplayType type, HWC2::DisplayType hwcDisplayType)
-              : mType(type), mHwcDisplayType(hwcDisplayType) {}
+        FakeHwcDisplayInjector(DisplayId displayId, HWC2::DisplayType hwcDisplayType,
+                               bool isPrimary)
+              : mDisplayId(displayId), mHwcDisplayType(hwcDisplayType), mIsPrimary(isPrimary) {}
 
         auto& setHwcDisplayId(hwc2_display_t displayId) {
             mHwcDisplayId = displayId;
@@ -403,17 +406,22 @@
             display->mutableConfigs().emplace(mActiveConfig, config.build());
             display->mutableIsConnected() = true;
 
-            ASSERT_TRUE(flinger->mutableHwcDisplayData().size() > static_cast<size_t>(mType));
-            flinger->mutableHwcDisplayData()[mType] = HWComposer::DisplayData();
-            flinger->mutableHwcDisplayData()[mType].hwcDisplay = display.get();
-            flinger->mutableHwcDisplaySlots().emplace(mHwcDisplayId, mType);
+            flinger->mutableHwcDisplayData()[mDisplayId].hwcDisplay = display.get();
+
+            if (mHwcDisplayType == HWC2::DisplayType::Physical) {
+                flinger->mutableHwcPhysicalDisplayIdMap().emplace(mHwcDisplayId, mDisplayId);
+                (mIsPrimary ? flinger->mutableInternalHwcDisplayId()
+                            : flinger->mutableExternalHwcDisplayId()) = mHwcDisplayId;
+            }
 
             flinger->mFakeHwcDisplays.push_back(std::move(display));
         }
 
     private:
-        DisplayDevice::DisplayType mType;
-        HWC2::DisplayType mHwcDisplayType;
+        const DisplayId mDisplayId;
+        const HWC2::DisplayType mHwcDisplayType;
+        const bool mIsPrimary;
+
         hwc2_display_t mHwcDisplayId = DEFAULT_HWC_DISPLAY_ID;
         int32_t mWidth = DEFAULT_WIDTH;
         int32_t mHeight = DEFAULT_HEIGHT;
@@ -427,10 +435,13 @@
 
     class FakeDisplayDeviceInjector {
     public:
-        FakeDisplayDeviceInjector(TestableSurfaceFlinger& flinger, DisplayDevice::DisplayType type,
-                                  int32_t displayId)
-              : mFlinger(flinger),
-                mCreationArgs(flinger.mFlinger.get(), mDisplayToken, type, displayId) {}
+        FakeDisplayDeviceInjector(TestableSurfaceFlinger& flinger,
+                                  const std::optional<DisplayId>& displayId, bool isVirtual,
+                                  bool isPrimary)
+              : mFlinger(flinger), mCreationArgs(flinger.mFlinger.get(), mDisplayToken, displayId) {
+            mCreationArgs.isVirtual = isVirtual;
+            mCreationArgs.isPrimary = isPrimary;
+        }
 
         sp<IBinder> token() const { return mDisplayToken; }
 
@@ -497,7 +508,7 @@
 
         sp<DisplayDevice> inject() {
             DisplayDeviceState state;
-            state.type = mCreationArgs.type;
+            state.displayId = mCreationArgs.isVirtual ? std::nullopt : mCreationArgs.displayId;
             state.isSecure = mCreationArgs.isSecure;
 
             sp<DisplayDevice> device = new DisplayDevice(std::move(mCreationArgs));
@@ -505,9 +516,9 @@
             mFlinger.mutableCurrentState().displays.add(mDisplayToken, state);
             mFlinger.mutableDrawingState().displays.add(mDisplayToken, state);
 
-            if (state.type >= DisplayDevice::DISPLAY_PRIMARY &&
-                state.type < DisplayDevice::DISPLAY_VIRTUAL) {
-                mFlinger.mutableDisplayTokens()[state.type] = mDisplayToken;
+            if (!mCreationArgs.isVirtual) {
+                LOG_ALWAYS_FATAL_IF(!state.displayId);
+                mFlinger.mutablePhysicalDisplayTokens()[*state.displayId] = mDisplayToken;
             }
 
             return device;
diff --git a/services/thermalservice/Android.bp b/services/thermalservice/Android.bp
deleted file mode 100644
index 2812c13..0000000
--- a/services/thermalservice/Android.bp
+++ /dev/null
@@ -1,63 +0,0 @@
-subdirs = [
-    "libthermalcallback"
-]
-
-cc_library {
-    name: "libthermalservice",
-
-    srcs: [
-        "aidl/android/os/IThermalEventListener.aidl",
-        "aidl/android/os/IThermalService.aidl",
-        "aidl/android/os/Temperature.cpp",
-    ],
-    aidl: {
-      include_dirs: ["frameworks/native/services/thermalservice/aidl"],
-      export_aidl_headers: true,
-    },
-    export_include_dirs: ["aidl"],
-
-    shared_libs: [
-        "libbinder",
-        "libutils",
-    ],
-
-    cflags: [
-        "-Wall",
-        "-Werror",
-        "-Wunused",
-        "-Wunreachable-code",
-    ],
-}
-
-cc_binary {
-    name: "thermalserviced",
-
-    srcs: [
-        "ThermalService.cpp",
-        "thermalserviced.cpp",
-    ],
-
-    include_dirs: ["frameworks/native"],
-
-    shared_libs: [
-        "libbase",
-        "libthermalservice",
-        "libbinder",
-        "libutils",
-        "libthermalcallback",
-        "android.hardware.thermal@1.1",
-        "android.hardware.thermal@2.0",
-        "libhidlbase",
-        "libhidltransport",
-        "liblog",
-    ],
-
-    cflags: [
-        "-Wall",
-        "-Werror",
-        "-Wunused",
-        "-Wunreachable-code",
-    ],
-
-    init_rc: ["thermalservice.rc"],
-}
diff --git a/services/thermalservice/ThermalService.cpp b/services/thermalservice/ThermalService.cpp
deleted file mode 100644
index b1a80de..0000000
--- a/services/thermalservice/ThermalService.cpp
+++ /dev/null
@@ -1,162 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "ThermalService.h"
-#include <android-base/file.h>
-#include <android-base/stringprintf.h>
-#include <android/os/IThermalEventListener.h>
-#include <android/os/IThermalService.h>
-#include <android/os/Temperature.h>
-#include <binder/IPCThreadState.h>
-#include <binder/IServiceManager.h>
-#include <binder/PermissionCache.h>
-#include <log/log.h>
-#include <private/android_filesystem_config.h>
-#include <utils/Errors.h>
-#include <utils/Mutex.h>
-#include <utils/String16.h>
-
-namespace android {
-namespace os {
-
-/**
- * Dump thermal service
- * @param fd file descriptor for dumping
- * @param args not used
- */
-status_t ThermalService::dump(int fd, const Vector<String16>& /* args */) {
-    status_t ret = OK;
-    std::string result;
-    const IPCThreadState* ipc = IPCThreadState::self();
-    const int pid = ipc->getCallingPid();
-    const int uid = ipc->getCallingUid();
-    if ((uid != AID_SHELL) &&
-        !PermissionCache::checkPermission(String16("android.permission.DUMP"), pid, uid)) {
-        result = android::base::
-                StringPrintf("Permission Denial: can't dump ThermalService from pid=%d, uid=%d\n",
-                             pid, uid);
-        ret = PERMISSION_DENIED;
-    } else {
-        Mutex::Autolock _l(mListenersLock);
-        result = android::base::StringPrintf("ThermalEventListener registered: %d\n",
-                                             (int)mListeners.size());
-    }
-    if (!android::base::WriteStringToFd(result, fd)) {
-        SLOGE("Failed to dump fd: %d", fd);
-        ret = FDS_NOT_ALLOWED;
-    }
-    return ret;
-}
-
-/**
- * Notify registered listeners of a thermal throttling start/stop event.
- * @param temperature the temperature at which the event was generated
- */
-binder::Status ThermalService::notifyThrottling(
-    const bool isThrottling, const Temperature& temperature) {
-    Mutex::Autolock _l(mListenersLock);
-
-    mThrottled = isThrottling;
-    mThrottleTemperature = temperature;
-
-    for (size_t i = 0; i < mListeners.size(); i++) {
-      mListeners[i]->notifyThrottling(isThrottling, temperature);
-    }
-    return binder::Status::ok();
-}
-
-/**
- * Query whether the system is currently thermal throttling.
- * @return true if currently thermal throttling, else false
- */
-binder::Status ThermalService::isThrottling(bool* _aidl_return) {
-    Mutex::Autolock _l(mListenersLock);
-    *_aidl_return = mThrottled;
-    return binder::Status::ok();
-}
-
-/**
- * Register a new thermal event listener.
- * @param listener the client's IThermalEventListener instance to which
- *                 notifications are to be sent
- */
-binder::Status ThermalService::registerThermalEventListener(
-    const sp<IThermalEventListener>& listener) {
-    {
-        if (listener == NULL) {
-            return binder::Status::ok();
-        }
-        Mutex::Autolock _l(mListenersLock);
-        // check whether this is a duplicate
-        for (size_t i = 0; i < mListeners.size(); i++) {
-            if (IInterface::asBinder(mListeners[i]) ==
-                IInterface::asBinder(listener)) {
-                return binder::Status::ok();
-            }
-        }
-
-        mListeners.add(listener);
-        IInterface::asBinder(listener)->linkToDeath(this);
-    }
-
-    return binder::Status::ok();
-}
-
-/**
- * Unregister a previously-registered thermal event listener.
- * @param listener the client's IThermalEventListener instance to which
- *                 notifications are to no longer be sent
- */
-binder::Status ThermalService::unregisterThermalEventListener(
-    const sp<IThermalEventListener>& listener) {
-    if (listener == NULL) {
-        return binder::Status::ok();
-    }
-    Mutex::Autolock _l(mListenersLock);
-    for (size_t i = 0; i < mListeners.size(); i++) {
-        if (IInterface::asBinder(mListeners[i]) ==
-            IInterface::asBinder(listener)) {
-            IInterface::asBinder(mListeners[i])->unlinkToDeath(this);
-            mListeners.removeAt(i);
-            break;
-        }
-    }
-
-    return binder::Status::ok();
-}
-
-void ThermalService::binderDied(const wp<IBinder>& who) {
-    Mutex::Autolock _l(mListenersLock);
-
-    for (size_t i = 0; i < mListeners.size(); i++) {
-        if (IInterface::asBinder(mListeners[i]) == who) {
-            mListeners.removeAt(i);
-            break;
-        }
-    }
-}
-
-/**
- * Publish the supplied ThermalService to servicemanager.
- */
-void ThermalService::publish(
-    const sp<ThermalService>& service) {
-    defaultServiceManager()->addService(String16("thermalservice"),
-                                        service);
-}
-
-}  // namespace os
-}  // namespace android
diff --git a/services/thermalservice/ThermalService.h b/services/thermalservice/ThermalService.h
deleted file mode 100644
index d3da900..0000000
--- a/services/thermalservice/ThermalService.h
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef ANDROID_THERMALSERVICE_THERMALSERVICE_H
-#define ANDROID_THERMALSERVICE_THERMALSERVICE_H
-
-#include <android/os/BnThermalService.h>
-#include <android/os/IThermalEventListener.h>
-#include <android/os/Temperature.h>
-#include <utils/Mutex.h>
-#include <utils/String16.h>
-#include <utils/Vector.h>
-
-namespace android {
-namespace os {
-
-class ThermalService : public BnThermalService,
-                       public IBinder::DeathRecipient {
-public:
-  ThermalService() : mThrottled(false) {};
-    void publish(const sp<ThermalService>& service);
-    binder::Status notifyThrottling(
-        const bool isThrottling, const Temperature& temperature);
-    status_t dump(int fd, const Vector<String16>& args) override;
-
-private:
-    Mutex mListenersLock;
-    Vector<sp<IThermalEventListener> > mListeners;
-    bool mThrottled;
-    Temperature mThrottleTemperature;
-
-    binder::Status registerThermalEventListener(
-        const sp<IThermalEventListener>& listener);
-    binder::Status unregisterThermalEventListener(
-        const sp<IThermalEventListener>& listener);
-    binder::Status isThrottling(bool* _aidl_return);
-    void binderDied(const wp<IBinder>& who);
-};
-
-};  // namespace os
-};  // namespace android
-
-#endif // ANDROID_THERMALSERVICE_THERMALSERVICE_H
diff --git a/services/thermalservice/aidl/android/os/IThermalEventListener.aidl b/services/thermalservice/aidl/android/os/IThermalEventListener.aidl
deleted file mode 100644
index 050325e..0000000
--- a/services/thermalservice/aidl/android/os/IThermalEventListener.aidl
+++ /dev/null
@@ -1,32 +0,0 @@
-/**
- * Copyright (c) 2017, The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.os;
-
-import android.os.Temperature;
-
-/**
-  * Listener for thermal events.
-  * {@hide}
-  */
-oneway interface IThermalEventListener {
-    /**
-     * Called when a thermal throttling start/stop event is received.
-     * @param temperature the temperature at which the event was generated.
-     */
-    void notifyThrottling(
-        in boolean isThrottling, in Temperature temperature);
-}
diff --git a/services/thermalservice/aidl/android/os/IThermalService.aidl b/services/thermalservice/aidl/android/os/IThermalService.aidl
deleted file mode 100644
index e699202..0000000
--- a/services/thermalservice/aidl/android/os/IThermalService.aidl
+++ /dev/null
@@ -1,48 +0,0 @@
-/**
- * Copyright (c) 2017, The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.os;
-
-import android.os.IThermalEventListener;
-import android.os.Temperature;
-
-/** {@hide} */
-interface IThermalService {
-    /**
-      * Register a listener for thermal events.
-      * @param listener the IThermalEventListener to be notified.
-      * {@hide}
-      */
-    void registerThermalEventListener(in IThermalEventListener listener);
-    /**
-      * Unregister a previously-registered listener for thermal events.
-      * @param listener the IThermalEventListener to no longer be notified.
-      * {@hide}
-      */
-    void unregisterThermalEventListener(in IThermalEventListener listener);
-    /**
-      * Send a thermal throttling start/stop notification to all listeners.
-      * @param temperature the temperature at which the event was generated.
-      * {@hide}
-      */
-    oneway void notifyThrottling(
-        in boolean isThrottling, in Temperature temperature);
-    /**
-      * Return whether system performance is currently thermal throttling.
-      * {@hide}
-      */
-    boolean isThrottling();
-}
diff --git a/services/thermalservice/aidl/android/os/Temperature.aidl b/services/thermalservice/aidl/android/os/Temperature.aidl
deleted file mode 100644
index 0293c39..0000000
--- a/services/thermalservice/aidl/android/os/Temperature.aidl
+++ /dev/null
@@ -1,5 +0,0 @@
-package android.os;
-
-/* Encodes a temperature used by ThermalService. */
-
-parcelable Temperature cpp_header "android/os/Temperature.h";
diff --git a/services/thermalservice/aidl/android/os/Temperature.cpp b/services/thermalservice/aidl/android/os/Temperature.cpp
deleted file mode 100644
index df207b7..0000000
--- a/services/thermalservice/aidl/android/os/Temperature.cpp
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "android/os/Temperature.h"
-
-#include <math.h>
-#include <stdint.h>
-#include <binder/Parcel.h>
-#include <hardware/thermal.h>
-#include <sys/types.h>
-#include <utils/Errors.h>
-
-namespace android {
-namespace os {
-
-Temperature::Temperature() : value_(NAN), type_(DEVICE_TEMPERATURE_UNKNOWN) {}
-
-Temperature::Temperature(const float value, const int type) :
-    value_(value), type_(type)  {}
-
-Temperature::~Temperature() {}
-
-/*
- * Parcel read/write code must be kept in sync with
- * frameworks/base/core/java/android/os/Temperature.java
- */
-
-status_t Temperature::readFromParcel(const Parcel* p) {
-    value_ = p->readFloat();
-    type_ = p->readInt32();
-    return OK;
-}
-
-status_t Temperature::writeToParcel(Parcel* p) const {
-    p->writeFloat(value_);
-    p->writeInt32(type_);
-    return OK;
-}
-
-}  // namespace os
-}  // namespace android
diff --git a/services/thermalservice/aidl/android/os/Temperature.h b/services/thermalservice/aidl/android/os/Temperature.h
deleted file mode 100644
index bbc5607..0000000
--- a/services/thermalservice/aidl/android/os/Temperature.h
+++ /dev/null
@@ -1,33 +0,0 @@
-#ifndef ANDROID_THERMALSERVICE_AIDL_ANDROID_OS_TEMPERATURE_H
-#define ANDROID_THERMALSERVICE_AIDL_ANDROID_OS_TEMPERATURE_H
-
-#include <binder/Parcelable.h>
-
-namespace android {
-namespace os {
-
-class Temperature : public Parcelable {
- public:
-
-  Temperature();
-  Temperature(const float value, const int type);
-  ~Temperature() override;
-
-  float getValue() const {return value_;};
-  float getType() const {return type_;};
-
-  status_t writeToParcel(Parcel* parcel) const override;
-  status_t readFromParcel(const Parcel* parcel) override;
-
- private:
-  // The value of the temperature as a float, or NAN if unknown.
-  float value_;
-  // The type of the temperature, an enum temperature_type from
-  // hardware/thermal.h
-  int type_;
-};
-
-}  // namespace os
-}  // namespace android
-
-#endif   // ANDROID_THERMALSERVICE_AIDL_ANDROID_OS_TEMPERATURE_H
diff --git a/services/thermalservice/libthermalcallback/Android.bp b/services/thermalservice/libthermalcallback/Android.bp
deleted file mode 100644
index 312579c..0000000
--- a/services/thermalservice/libthermalcallback/Android.bp
+++ /dev/null
@@ -1,21 +0,0 @@
-cc_library_shared {
-    name: "libthermalcallback",
-    srcs: [
-        "ThermalCallback.cpp",
-        "ThermalChangedCallback.cpp",
-    ],
-    cflags: [
-        "-Wall",
-        "-Werror",
-    ],
-    include_dirs: ["frameworks/native"],
-    shared_libs: [
-        "android.hardware.thermal@1.1",
-        "android.hardware.thermal@2.0",
-        "libhidlbase",
-        "libhidltransport",
-        "liblog",
-        "libthermalservice",
-        "libutils",
-    ],
-}
diff --git a/services/thermalservice/libthermalcallback/ThermalCallback.cpp b/services/thermalservice/libthermalcallback/ThermalCallback.cpp
deleted file mode 100644
index 0f3132c..0000000
--- a/services/thermalservice/libthermalcallback/ThermalCallback.cpp
+++ /dev/null
@@ -1,69 +0,0 @@
-#define LOG_TAG "android.hardware.thermal.thermalcallback@1.1-impl"
-#include <log/log.h>
-
-#include <android/os/Temperature.h>
-#include <hardware/thermal.h>
-#include <cmath>
-#include "ThermalCallback.h"
-#include "services/thermalservice/ThermalService.h"
-
-namespace android {
-namespace hardware {
-namespace thermal {
-namespace V1_1 {
-namespace implementation {
-
-using ::android::os::ThermalService;
-using ::android::hardware::thermal::V1_0::TemperatureType;
-
-// Register a binder ThermalService object for sending events
-void ThermalCallback::registerThermalService(sp<ThermalService> thermalService)
-{
-    mThermalService = thermalService;
-}
-
-// Methods from IThermalCallback::V1_1 follow.
-Return<void> ThermalCallback::notifyThrottling(
-      bool isThrottling,
-      const android::hardware::thermal::V1_0::Temperature& temperature) {
-
-    // Convert HIDL IThermal Temperature to binder IThermalService Temperature.
-    if (mThermalService != nullptr) {
-        float value = NAN;
-        int type = DEVICE_TEMPERATURE_UNKNOWN;
-
-        switch(temperature.type) {
-          case TemperatureType::CPU:
-            type = DEVICE_TEMPERATURE_CPU;
-            break;
-          case TemperatureType::GPU:
-            type = DEVICE_TEMPERATURE_GPU;
-            break;
-          case TemperatureType::BATTERY:
-            type = DEVICE_TEMPERATURE_BATTERY;
-            break;
-          case TemperatureType::SKIN:
-            type = DEVICE_TEMPERATURE_SKIN;
-            break;
-          case TemperatureType::UNKNOWN:
-          default:
-            type = DEVICE_TEMPERATURE_UNKNOWN;
-            break;
-        }
-
-        value = temperature.currentValue == UNKNOWN_TEMPERATURE ? NAN :
-            temperature.currentValue;
-
-        android::os::Temperature thermal_svc_temp(value, type);
-        mThermalService->notifyThrottling(isThrottling, thermal_svc_temp);
-    } else {
-        SLOGE("IThermalService binder service not created, drop throttling event");
-    }
-    return Void();
-}
-
-}  // namespace implementation
-}  // namespace V1_1
-}  // namespace thermal
-}  // namespace hardware
-}  // namespace android
diff --git a/services/thermalservice/libthermalcallback/ThermalCallback.h b/services/thermalservice/libthermalcallback/ThermalCallback.h
deleted file mode 100644
index 3d72c68..0000000
--- a/services/thermalservice/libthermalcallback/ThermalCallback.h
+++ /dev/null
@@ -1,43 +0,0 @@
-#ifndef ANDROID_HARDWARE_THERMAL_V1_1_THERMALCALLBACK_H
-#define ANDROID_HARDWARE_THERMAL_V1_1_THERMALCALLBACK_H
-
-#include <android/hardware/thermal/1.1/IThermalCallback.h>
-#include <android/hardware/thermal/1.0/types.h>
-#include <android/os/Temperature.h>
-#include <hidl/MQDescriptor.h>
-#include <hidl/Status.h>
-#include "services/thermalservice/ThermalService.h"
-
-namespace android {
-namespace hardware {
-namespace thermal {
-namespace V1_1 {
-namespace implementation {
-
-using ::android::hardware::Return;
-using ::android::hardware::Void;
-using ::android::os::ThermalService;
-
-class ThermalCallback : public IThermalCallback {
- public:
-    // Register a binder ThermalService object for sending events
-    void registerThermalService(sp<ThermalService> thermalService);
-
-    // Methods from IThermalCallback::V1_1 follow.
-    Return<void> notifyThrottling(
-        bool isThrottling,
-        const android::hardware::thermal::V1_0::Temperature& temperature)
-        override;
-
- private:
-    // Our registered binder ThermalService object to use for sending events
-    sp<android::os::ThermalService> mThermalService;
-};
-
-}  // namespace implementation
-}  // namespace V1_1
-}  // namespace thermal
-}  // namespace hardware
-}  // namespace android
-
-#endif  // ANDROID_HARDWARE_THERMAL_V1_1_THERMALCALLBACK_H
diff --git a/services/thermalservice/libthermalcallback/ThermalChangedCallback.cpp b/services/thermalservice/libthermalcallback/ThermalChangedCallback.cpp
deleted file mode 100644
index bb48387..0000000
--- a/services/thermalservice/libthermalcallback/ThermalChangedCallback.cpp
+++ /dev/null
@@ -1,85 +0,0 @@
-/*
- * Copyright (C) 2018 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#define LOG_TAG "android.hardware.thermal.thermalchangedcallback@2.0-impl"
-#include <log/log.h>
-
-#include <android/os/Temperature.h>
-#include <hardware/thermal.h>
-#include <cmath>
-#include "ThermalChangedCallback.h"
-#include "services/thermalservice/ThermalService.h"
-
-namespace android {
-namespace hardware {
-namespace thermal {
-namespace V2_0 {
-namespace implementation {
-
-using ::android::hardware::thermal::V2_0::TemperatureType;
-using ::android::hardware::thermal::V2_0::ThrottlingSeverity;
-using ::android::os::ThermalService;
-
-// Register a binder ThermalService object for sending events
-void ThermalChangedCallback::registerThermalService(sp<ThermalService> thermalService) {
-    mThermalService = thermalService;
-}
-
-// Methods from IThermalChangedCallback::V2_0 follow.
-Return<void> ThermalChangedCallback::notifyThrottling(
-        const android::hardware::thermal::V2_0::Temperature& temperature) {
-    // Convert HIDL IThermal Temperature to binder IThermalService Temperature.
-    if (mThermalService != nullptr) {
-        float value = NAN;
-        int type = DEVICE_TEMPERATURE_UNKNOWN;
-
-        switch (temperature.type) {
-            case TemperatureType::CPU:
-                type = DEVICE_TEMPERATURE_CPU;
-                break;
-            case TemperatureType::GPU:
-                type = DEVICE_TEMPERATURE_GPU;
-                break;
-            case TemperatureType::BATTERY:
-                type = DEVICE_TEMPERATURE_BATTERY;
-                break;
-            case TemperatureType::SKIN:
-                type = DEVICE_TEMPERATURE_SKIN;
-                break;
-            case TemperatureType::UNKNOWN:
-            default:
-                type = DEVICE_TEMPERATURE_UNKNOWN;
-                break;
-        }
-        bool isThrottling = (static_cast<size_t>(temperature.throttlingStatus) >=
-                             static_cast<size_t>(ThrottlingSeverity::SEVERE))
-                ? true
-                : false;
-        value = temperature.value == UNKNOWN_TEMPERATURE ? NAN :
-                temperature.value;
-        android::os::Temperature thermal_svc_temp(value, type);
-        mThermalService->notifyThrottling(isThrottling, thermal_svc_temp);
-    } else {
-        SLOGE("IThermalService binder service not created, drop throttling event");
-    }
-    return Void();
-}
-
-} // namespace implementation
-} // namespace V2_0
-} // namespace thermal
-} // namespace hardware
-} // namespace android
diff --git a/services/thermalservice/libthermalcallback/ThermalChangedCallback.h b/services/thermalservice/libthermalcallback/ThermalChangedCallback.h
deleted file mode 100644
index 03de049..0000000
--- a/services/thermalservice/libthermalcallback/ThermalChangedCallback.h
+++ /dev/null
@@ -1,57 +0,0 @@
-/*
- * Copyright (C) 2018 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef ANDROID_HARDWARE_THERMAL_V1_1_THERMALCHANGEDCALLBACK_H
-#define ANDROID_HARDWARE_THERMAL_V1_1_THERMALCHANGEDCALLBACK_H
-
-#include <android/hardware/thermal/2.0/IThermalChangedCallback.h>
-#include <android/hardware/thermal/2.0/types.h>
-#include <android/os/Temperature.h>
-#include <hidl/MQDescriptor.h>
-#include <hidl/Status.h>
-#include "services/thermalservice/ThermalService.h"
-
-namespace android {
-namespace hardware {
-namespace thermal {
-namespace V2_0 {
-namespace implementation {
-
-using ::android::hardware::Return;
-using ::android::hardware::Void;
-using ::android::os::ThermalService;
-
-class ThermalChangedCallback : public IThermalChangedCallback {
-public:
-    // Register a binder ThermalService object for sending events
-    void registerThermalService(sp<ThermalService> thermalService);
-
-    // Methods from I ThermalChangedCallback::V2_0 follow.
-    Return<void> notifyThrottling(
-            const android::hardware::thermal::V2_0::Temperature& temperature) override;
-
-private:
-    // Our registered binder ThermalService object to use for sending events
-    sp<android::os::ThermalService> mThermalService;
-};
-
-} // namespace implementation
-} // namespace V2_0
-} // namespace thermal
-} // namespace hardware
-} // namespace android
-
-#endif // ANDROID_HARDWARE_THERMAL_V1_1_THERMALCHANGEDCALLBACK_H
diff --git a/services/thermalservice/thermalservice.rc b/services/thermalservice/thermalservice.rc
deleted file mode 100644
index 5e20170..0000000
--- a/services/thermalservice/thermalservice.rc
+++ /dev/null
@@ -1,6 +0,0 @@
-service thermalservice /system/bin/thermalserviced
-    class core
-    user system
-    group system
-    onrestart restart zygote
-    writepid /dev/cpuset/foreground/tasks
diff --git a/services/thermalservice/thermalserviced.cpp b/services/thermalservice/thermalserviced.cpp
deleted file mode 100644
index 0bfaaff..0000000
--- a/services/thermalservice/thermalserviced.cpp
+++ /dev/null
@@ -1,177 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#define LOG_TAG "thermalserviced"
-#include <log/log.h>
-
-#include "ThermalService.h"
-#include "libthermalcallback/ThermalCallback.h"
-#include "libthermalcallback/ThermalChangedCallback.h"
-#include "thermalserviced.h"
-
-#include <android/hardware/thermal/1.1/IThermal.h>
-#include <android/hardware/thermal/2.0/IThermal.h>
-#include <android/hardware/thermal/2.0/types.h>
-
-#include <binder/IPCThreadState.h>
-#include <binder/IServiceManager.h>
-#include <hidl/HidlTransportSupport.h>
-
-using namespace android;
-using IThermal1_1 = ::android::hardware::thermal::V1_1::IThermal;
-using IThermal2_0 = ::android::hardware::thermal::V2_0::IThermal;
-using ::android::hardware::configureRpcThreadpool;
-using ::android::hardware::hidl_death_recipient;
-using ::android::hardware::Return;
-using ::android::hardware::thermal::V1_0::ThermalStatus;
-using ::android::hardware::thermal::V1_0::ThermalStatusCode;
-using ::android::hardware::thermal::V1_1::IThermalCallback;
-using ::android::hardware::thermal::V1_1::implementation::ThermalCallback;
-using ::android::hardware::thermal::V2_0::IThermalChangedCallback;
-using ::android::hardware::thermal::V2_0::TemperatureType;
-using ::android::hidl::base::V1_0::IBase;
-using ::android::os::ThermalService;
-
-namespace {
-
-// Our thermalserviced main object
-ThermalServiceDaemon* gThermalServiceDaemon;
-
-// Thermal HAL 1.1 client
-sp<IThermal1_1> gThermalHal1_1 = nullptr;
-// Thermal HAL 2.0 client
-sp<IThermal2_0> gThermalHal2_0 = nullptr;
-
-// Binder death notifier informing of Thermal HAL death.
-struct ThermalServiceDeathRecipient : hidl_death_recipient {
-    virtual void serviceDied(
-        uint64_t cookie __unused, const wp<IBase>& who __unused) {
-        SLOGE("IThermal HAL died");
-        gThermalHal1_1 = nullptr;
-        gThermalHal2_0 = nullptr;
-        gThermalServiceDaemon->getThermalHal();
-    }
-};
-
-}  // anonymous namespace
-
-void ThermalServiceDaemon::thermalServiceStartup() {
-    // Binder IThermal1_1Service startup
-    mThermalService = new android::os::ThermalService;
-    mThermalService->publish(mThermalService);
-    // Register IThermalService object to ThermalHAL callback
-    if (mThermalCallback_2_0 != nullptr) {
-        mThermalCallback_2_0->registerThermalService(mThermalService);
-    } else if (mThermalCallback_1_1 != nullptr) {
-        mThermalCallback_1_1->registerThermalService(mThermalService);
-    }
-    IPCThreadState::self()->joinThreadPool();
-}
-
-// Lookup Thermal HAL, register death notifier, register our
-// ThermalCallback with the Thermal HAL.
-void ThermalServiceDaemon::getThermalHal() {
-    static sp<ThermalServiceDeathRecipient> gThermalHalDied = nullptr;
-    // Binder death notifier for Thermal HAL
-    if (gThermalHalDied == nullptr) {
-        gThermalHalDied = new ThermalServiceDeathRecipient();
-    }
-
-    gThermalHal2_0 = IThermal2_0::getService();
-    if (gThermalHal2_0 == nullptr) {
-        SLOGW("Unable to get Thermal HAL V2.0, fallback to 1.1");
-        gThermalHal1_1 = IThermal1_1::getService();
-        if (gThermalHal1_1 == nullptr) {
-            SLOGW("Unable to get Thermal HAL V1.1, vendor thermal event "
-                  "notification not available");
-            return;
-        }
-        if (gThermalHalDied != nullptr) {
-            gThermalHal1_1->linkToDeath(gThermalHalDied, 0x451F /* cookie */);
-        }
-
-        if (mThermalCallback_1_1 != nullptr) {
-            Return<void> ret = gThermalHal1_1->registerThermalCallback(mThermalCallback_1_1);
-            if (!ret.isOk()) {
-                SLOGE("registerThermalCallback failed, status: %s", ret.description().c_str());
-            }
-        }
-    } else {
-        if (gThermalHalDied != nullptr) {
-            gThermalHal2_0->linkToDeath(gThermalHalDied, 0x451F /* cookie */);
-        }
-
-        if (mThermalCallback_2_0 != nullptr) {
-            Return<void> ret =
-                    gThermalHal2_0
-                            ->registerThermalChangedCallback(mThermalCallback_2_0, false,
-                                                             TemperatureType::SKIN, // not used
-                                                             [](ThermalStatus status) {
-                                                                 if (ThermalStatusCode::SUCCESS !=
-                                                                     status.code) {
-                                                                     SLOGE("registerThermalChangedC"
-                                                                           "allback failed, "
-                                                                           "status: %s",
-                                                                           status.debugMessage
-                                                                                   .c_str());
-                                                                 }
-                                                             });
-            if (!ret.isOk()) {
-                SLOGE("registerThermalChangedCallback failed, status: %s",
-                      ret.description().c_str());
-            }
-        }
-    }
-}
-
-ThermalServiceDaemon::~ThermalServiceDaemon() {
-    if (mThermalCallback_2_0 != nullptr && gThermalHal2_0 != nullptr) {
-        Return<void> ret =
-                gThermalHal2_0
-                        ->unregisterThermalChangedCallback(
-                            mThermalCallback_2_0,
-                            [](ThermalStatus status) {
-                                if (ThermalStatusCode::SUCCESS !=
-                                    status.code) {
-                                    SLOGE("unregisterThermalChangedCallback failed, status: %s",
-                                          status.debugMessage
-                                          .c_str());
-                                }
-                            });
-        if (!ret.isOk()) {
-            SLOGE("unregisterThermalChangedCallback failed, status: %s", ret.description().c_str());
-        }
-    }
-}
-
-void ThermalServiceDaemon::thermalCallbackStartup() {
-    // HIDL IThermal Callback startup
-    // Need at least 2 threads in thread pool since we wait for dead HAL
-    // to come back on the binder death notification thread and we need
-    // another thread for the incoming service now available call.
-    configureRpcThreadpool(2, false /* callerWillJoin */);
-    mThermalCallback_1_1 = new ThermalCallback();
-    mThermalCallback_2_0 = new ThermalChangedCallback();
-    // Lookup Thermal HAL 1.1 and 2.0 to register our Callback.
-    getThermalHal();
-}
-
-int main(int /*argc*/, char** /*argv*/) {
-    gThermalServiceDaemon = new ThermalServiceDaemon();
-    gThermalServiceDaemon->thermalCallbackStartup();
-    gThermalServiceDaemon->thermalServiceStartup();
-    /* NOTREACHED */
-}
diff --git a/services/thermalservice/thermalserviced.h b/services/thermalservice/thermalserviced.h
deleted file mode 100644
index ff7a483..0000000
--- a/services/thermalservice/thermalserviced.h
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef ANDROID_THERMALSERVICE_THERMALSERVICED_H
-#define ANDROID_THERMALSERVICE_THERMALSERVICED_H
-
-#include "ThermalService.h"
-#include "libthermalcallback/ThermalCallback.h"
-#include "libthermalcallback/ThermalChangedCallback.h"
-
-using namespace android;
-using ::android::hardware::thermal::V1_0::Temperature;
-using ::android::hardware::thermal::V1_1::implementation::ThermalCallback;
-using ::android::hardware::thermal::V2_0::implementation::ThermalChangedCallback;
-using ::android::os::ThermalService;
-
-class ThermalServiceDaemon {
- public:
-    ~ThermalServiceDaemon();
-    void thermalServiceStartup();
-    void thermalCallbackStartup();
-    void getThermalHal();
-    ThermalServiceDaemon(){};
-
- private:
-    sp<ThermalService> mThermalService;
-    sp<ThermalCallback> mThermalCallback_1_1;
-    sp<ThermalChangedCallback> mThermalCallback_2_0;
-};
-
-#endif  // ANDROID_THERMALSERVICE_THERMALSERVICED_H
diff --git a/services/vr/bufferhubd/consumer_queue_channel.cpp b/services/vr/bufferhubd/consumer_queue_channel.cpp
index 74b549d..5d7d4e9 100644
--- a/services/vr/bufferhubd/consumer_queue_channel.cpp
+++ b/services/vr/bufferhubd/consumer_queue_channel.cpp
@@ -80,27 +80,35 @@
 }
 
 void ConsumerQueueChannel::RegisterNewBuffer(
-    const std::shared_ptr<ProducerChannel>& producer_channel, size_t slot) {
-  ALOGD_IF(TRACE,
-           "ConsumerQueueChannel::RegisterNewBuffer: queue_id=%d buffer_id=%d "
-           "slot=%zu silent=%d",
-           buffer_id(), producer_channel->buffer_id(), slot, silent_);
+    const std::shared_ptr<ProducerChannel>& producer_channel,
+    size_t producer_slot) {
+  ALOGD_IF(TRACE, "%s: queue_id=%d buffer_id=%d slot=%zu silent=%d",
+           __FUNCTION__, buffer_id(), producer_channel->buffer_id(),
+           producer_slot, silent_);
   // Only register buffers if the queue is not silent.
-  if (!silent_) {
-    pending_buffer_slots_.emplace(producer_channel, slot);
-
-    // Signal the client that there is new buffer available.
-    SignalAvailable();
+  if (silent_) {
+    return;
   }
+
+  auto status = producer_channel->CreateConsumerStateMask();
+  if (!status.ok()) {
+    ALOGE("%s: Failed to create consumer state mask: %s", __FUNCTION__,
+          status.GetErrorMessage().c_str());
+    return;
+  }
+  uint64_t consumer_state_mask = status.get();
+
+  pending_buffer_slots_.emplace(producer_channel, producer_slot,
+                                consumer_state_mask);
+  // Signal the client that there is new buffer available.
+  SignalAvailable();
 }
 
 Status<std::vector<std::pair<RemoteChannelHandle, size_t>>>
 ConsumerQueueChannel::OnConsumerQueueImportBuffers(Message& message) {
   std::vector<std::pair<RemoteChannelHandle, size_t>> buffer_handles;
-  ATRACE_NAME("ConsumerQueueChannel::OnConsumerQueueImportBuffers");
-  ALOGD_IF(TRACE,
-           "ConsumerQueueChannel::OnConsumerQueueImportBuffers: "
-           "pending_buffer_slots=%zu",
+  ATRACE_NAME(__FUNCTION__);
+  ALOGD_IF(TRACE, "%s: pending_buffer_slots=%zu", __FUNCTION__,
            pending_buffer_slots_.size());
 
   // Indicate this is a silent queue that will not import buffers.
@@ -108,30 +116,30 @@
     return ErrorStatus(EBADR);
 
   while (!pending_buffer_slots_.empty()) {
-    auto producer_channel = pending_buffer_slots_.front().first.lock();
-    size_t producer_slot = pending_buffer_slots_.front().second;
+    auto producer_channel =
+        pending_buffer_slots_.front().producer_channel.lock();
+    size_t producer_slot = pending_buffer_slots_.front().producer_slot;
+    uint64_t consumer_state_mask =
+        pending_buffer_slots_.front().consumer_state_mask;
     pending_buffer_slots_.pop();
 
     // It's possible that the producer channel has expired. When this occurs,
     // ignore the producer channel.
     if (producer_channel == nullptr) {
-      ALOGW(
-          "ConsumerQueueChannel::OnConsumerQueueImportBuffers: producer "
-          "channel has already been expired.");
+      ALOGW("%s: producer channel has already been expired.", __FUNCTION__);
       continue;
     }
 
-    auto status = producer_channel->CreateConsumer(message);
+    auto status =
+        producer_channel->CreateConsumer(message, consumer_state_mask);
 
     // If no buffers are imported successfully, clear available and return an
     // error. Otherwise, return all consumer handles already imported
     // successfully, but keep available bits on, so that the client can retry
     // importing remaining consumer buffers.
     if (!status) {
-      ALOGE(
-          "ConsumerQueueChannel::OnConsumerQueueImportBuffers: Failed create "
-          "consumer: %s",
-          status.GetErrorMessage().c_str());
+      ALOGE("%s: Failed create consumer: %s", __FUNCTION__,
+            status.GetErrorMessage().c_str());
       if (buffer_handles.empty()) {
         ClearAvailable();
         return status.error_status();
diff --git a/services/vr/bufferhubd/include/private/dvr/consumer_queue_channel.h b/services/vr/bufferhubd/include/private/dvr/consumer_queue_channel.h
index 8f35437..3a81b03 100644
--- a/services/vr/bufferhubd/include/private/dvr/consumer_queue_channel.h
+++ b/services/vr/bufferhubd/include/private/dvr/consumer_queue_channel.h
@@ -3,8 +3,8 @@
 
 #include <queue>
 
-#include <private/dvr/bufferhub_rpc.h>
 #include <private/dvr/buffer_hub.h>
+#include <private/dvr/bufferhub_rpc.h>
 #include <private/dvr/consumer_channel.h>
 #include <private/dvr/producer_queue_channel.h>
 
@@ -28,7 +28,8 @@
   // Called by ProdcuerQueueChannel to notify consumer queue that a new
   // buffer has been allocated.
   void RegisterNewBuffer(
-      const std::shared_ptr<ProducerChannel>& producer_channel, size_t slot);
+      const std::shared_ptr<ProducerChannel>& producer_channel,
+      size_t producer_slot);
 
   // Called after clients been signaled by service that new buffer has been
   // allocated. Clients uses kOpConsumerQueueImportBuffers to import new
@@ -40,14 +41,29 @@
   void OnProducerClosed();
 
  private:
+  // Data structure to store relavant info of a newly allocated producer buffer
+  // so that consumer channel and buffer can be created later.
+  struct PendingBuffer {
+    PendingBuffer(std::shared_ptr<ProducerChannel> channel, size_t slot,
+                  uint64_t mask) {
+      producer_channel = channel;
+      producer_slot = slot;
+      consumer_state_mask = mask;
+    }
+    PendingBuffer() = delete;
+
+    std::weak_ptr<ProducerChannel> producer_channel;
+    size_t producer_slot;
+    uint64_t consumer_state_mask;
+  };
+
   std::shared_ptr<ProducerQueueChannel> GetProducer() const;
 
   // Pointer to the producer channel.
   std::weak_ptr<Channel> producer_;
 
   // Tracks newly allocated buffer producers along with it's slot number.
-  std::queue<std::pair<std::weak_ptr<ProducerChannel>, size_t>>
-      pending_buffer_slots_;
+  std::queue<PendingBuffer> pending_buffer_slots_;
 
   // Tracks how many buffers have this queue imported.
   size_t capacity_;
diff --git a/services/vr/bufferhubd/include/private/dvr/producer_channel.h b/services/vr/bufferhubd/include/private/dvr/producer_channel.h
index 5868b09..3ad9c70 100644
--- a/services/vr/bufferhubd/include/private/dvr/producer_channel.h
+++ b/services/vr/bufferhubd/include/private/dvr/producer_channel.h
@@ -53,7 +53,9 @@
 
   BufferDescription<BorrowedHandle> GetBuffer(uint64_t client_state_mask);
 
-  pdx::Status<RemoteChannelHandle> CreateConsumer(Message& message);
+  pdx::Status<RemoteChannelHandle> CreateConsumer(Message& message,
+                                                  uint64_t consumer_state_mask);
+  pdx::Status<uint64_t> CreateConsumerStateMask();
   pdx::Status<RemoteChannelHandle> OnNewConsumer(Message& message);
 
   pdx::Status<LocalFence> OnConsumerAcquire(Message& message);
@@ -93,7 +95,7 @@
   LocalFence post_fence_;
   LocalFence returned_fence_;
   size_t user_metadata_size_;  // size of user requested buffer buffer size.
-  size_t metadata_buf_size_;  // size of the ion buffer that holds metadata.
+  size_t metadata_buf_size_;   // size of the ion buffer that holds metadata.
 
   pdx::LocalHandle acquire_fence_fd_;
   pdx::LocalHandle release_fence_fd_;
@@ -111,6 +113,10 @@
   pdx::Status<void> OnProducerPost(Message& message, LocalFence acquire_fence);
   pdx::Status<LocalFence> OnProducerGain(Message& message);
 
+  // Remove consumer from atomics in shared memory based on consumer_state_mask.
+  // This function is used for clean up for failures in CreateConsumer method.
+  void RemoveConsumerClientMask(uint64_t consumer_state_mask);
+
   ProducerChannel(const ProducerChannel&) = delete;
   void operator=(const ProducerChannel&) = delete;
 };
diff --git a/services/vr/bufferhubd/producer_channel.cpp b/services/vr/bufferhubd/producer_channel.cpp
index 397c0ae..c6e8ea9 100644
--- a/services/vr/bufferhubd/producer_channel.cpp
+++ b/services/vr/bufferhubd/producer_channel.cpp
@@ -248,21 +248,7 @@
   return {GetBuffer(BufferHubDefs::kFirstClientBitMask)};
 }
 
-Status<RemoteChannelHandle> ProducerChannel::CreateConsumer(Message& message) {
-  ATRACE_NAME("ProducerChannel::CreateConsumer");
-  ALOGD_IF(TRACE,
-           "ProducerChannel::CreateConsumer: buffer_id=%d, producer_owns=%d",
-           buffer_id(), producer_owns_);
-
-  int channel_id;
-  auto status = message.PushChannel(0, nullptr, &channel_id);
-  if (!status) {
-    ALOGE(
-        "ProducerChannel::CreateConsumer: Failed to push consumer channel: %s",
-        status.GetErrorMessage().c_str());
-    return ErrorStatus(ENOMEM);
-  }
-
+Status<uint64_t> ProducerChannel::CreateConsumerStateMask() {
   // Try find the next consumer state bit which has not been claimed by any
   // consumer yet.
   // memory_order_acquire is chosen here because all writes in other threads
@@ -277,7 +263,6 @@
         "consumers per producer: 63.");
     return ErrorStatus(E2BIG);
   }
-
   uint64_t updated_active_clients_bit_mask =
       current_active_clients_bit_mask | client_state_mask;
   // Set the updated value only if the current value stays the same as what was
@@ -286,28 +271,71 @@
   // thread, and the modification will be visible in other threads that acquire
   // active_clients_bit_mask_. If the comparison fails, load the result of
   // all writes from all threads to updated_active_clients_bit_mask.
-  if (!active_clients_bit_mask_->compare_exchange_weak(
-          current_active_clients_bit_mask, updated_active_clients_bit_mask,
-          std::memory_order_acq_rel, std::memory_order_acquire)) {
+  // Keep on finding the next available slient state mask until succeed or out
+  // of memory.
+  while (!active_clients_bit_mask_->compare_exchange_weak(
+      current_active_clients_bit_mask, updated_active_clients_bit_mask,
+      std::memory_order_acq_rel, std::memory_order_acquire)) {
     ALOGE("Current active clients bit mask is changed to %" PRIx64
-          ", which was expected to be %" PRIx64 ".",
+          ", which was expected to be %" PRIx64
+          ". Trying to generate a new client state mask to resolve race "
+          "condition.",
           updated_active_clients_bit_mask, current_active_clients_bit_mask);
-    return ErrorStatus(EBUSY);
+    client_state_mask = BufferHubDefs::FindNextAvailableClientStateMask(
+        current_active_clients_bit_mask | orphaned_consumer_bit_mask_);
+    if (client_state_mask == 0ULL) {
+      ALOGE(
+          "ProducerChannel::CreateConsumer: reached the maximum mumber of "
+          "consumers per producer: 63.");
+      return ErrorStatus(E2BIG);
+    }
+    updated_active_clients_bit_mask =
+        current_active_clients_bit_mask | client_state_mask;
   }
 
-  auto consumer =
-      std::make_shared<ConsumerChannel>(service(), buffer_id(), channel_id,
-                                        client_state_mask, shared_from_this());
+  return {client_state_mask};
+}
+
+void ProducerChannel::RemoveConsumerClientMask(uint64_t consumer_state_mask) {
+  // Clear up the buffer state and fence state in case there is already
+  // something there due to possible race condition between producer post and
+  // consumer failed to create channel.
+  buffer_state_->fetch_and(~consumer_state_mask, std::memory_order_release);
+  fence_state_->fetch_and(~consumer_state_mask, std::memory_order_release);
+
+  // Restore the consumer state bit and make it visible in other threads that
+  // acquire the active_clients_bit_mask_.
+  active_clients_bit_mask_->fetch_and(~consumer_state_mask,
+                                      std::memory_order_release);
+}
+
+Status<RemoteChannelHandle> ProducerChannel::CreateConsumer(
+    Message& message, uint64_t consumer_state_mask) {
+  ATRACE_NAME("ProducerChannel::CreateConsumer");
+  ALOGD_IF(TRACE,
+           "ProducerChannel::CreateConsumer: buffer_id=%d, producer_owns=%d",
+           buffer_id(), producer_owns_);
+
+  int channel_id;
+  auto status = message.PushChannel(0, nullptr, &channel_id);
+  if (!status) {
+    ALOGE(
+        "ProducerChannel::CreateConsumer: Failed to push consumer channel: %s",
+        status.GetErrorMessage().c_str());
+    RemoveConsumerClientMask(consumer_state_mask);
+    return ErrorStatus(ENOMEM);
+  }
+
+  auto consumer = std::make_shared<ConsumerChannel>(
+      service(), buffer_id(), channel_id, consumer_state_mask,
+      shared_from_this());
   const auto channel_status = service()->SetChannel(channel_id, consumer);
   if (!channel_status) {
     ALOGE(
         "ProducerChannel::CreateConsumer: failed to set new consumer channel: "
         "%s",
         channel_status.GetErrorMessage().c_str());
-    // Restore the consumer state bit and make it visible in other threads that
-    // acquire the active_clients_bit_mask_.
-    active_clients_bit_mask_->fetch_and(~client_state_mask,
-                                        std::memory_order_release);
+    RemoveConsumerClientMask(consumer_state_mask);
     return ErrorStatus(ENOMEM);
   }
 
@@ -327,7 +355,11 @@
 Status<RemoteChannelHandle> ProducerChannel::OnNewConsumer(Message& message) {
   ATRACE_NAME("ProducerChannel::OnNewConsumer");
   ALOGD_IF(TRACE, "ProducerChannel::OnNewConsumer: buffer_id=%d", buffer_id());
-  return CreateConsumer(message);
+  auto status = CreateConsumerStateMask();
+  if (!status.ok()) {
+    return status.error_status();
+  }
+  return CreateConsumer(message, /*consumer_state_mask=*/status.get());
 }
 
 Status<void> ProducerChannel::OnProducerPost(Message&,
diff --git a/services/vr/hardware_composer/impl/vr_composer_client.cpp b/services/vr/hardware_composer/impl/vr_composer_client.cpp
index 4b90031..d775711 100644
--- a/services/vr/hardware_composer/impl/vr_composer_client.cpp
+++ b/services/vr/hardware_composer/impl/vr_composer_client.cpp
@@ -19,6 +19,8 @@
 #include <hardware/gralloc1.h>
 #include <log/log.h>
 
+#include <memory>
+
 #include "impl/vr_hwc.h"
 #include "impl/vr_composer_client.h"
 
@@ -39,7 +41,7 @@
 
 std::unique_ptr<ComposerCommandEngine>
 VrComposerClient::createCommandEngine() {
-  return std::unique_ptr<VrCommandEngine>(new VrCommandEngine(*this));
+  return std::make_unique<VrCommandEngine>(*this);
 }
 
 VrComposerClient::VrCommandEngine::VrCommandEngine(VrComposerClient& client)
diff --git a/services/vr/performanced/performance_service_tests.cpp b/services/vr/performanced/performance_service_tests.cpp
index 4065785..a24c889 100644
--- a/services/vr/performanced/performance_service_tests.cpp
+++ b/services/vr/performanced/performance_service_tests.cpp
@@ -12,16 +12,16 @@
 #include <thread>
 #include <utility>
 
+#include <android-base/strings.h>
 #include <android-base/unique_fd.h>
 #include <dvr/performance_client_api.h>
 #include <gtest/gtest.h>
 #include <private/android_filesystem_config.h>
 
 #include "stdio_filebuf.h"
-#include "string_trim.h"
 #include "unique_file.h"
 
-using android::dvr::Trim;
+using android::base::Trim;
 using android::dvr::UniqueFile;
 using android::dvr::stdio_filebuf;
 
diff --git a/services/vr/performanced/string_trim.h b/services/vr/performanced/string_trim.h
deleted file mode 100644
index 7094e9f..0000000
--- a/services/vr/performanced/string_trim.h
+++ /dev/null
@@ -1,46 +0,0 @@
-#ifndef ANDROID_DVR_PERFORMANCED_STRING_TRIM_H_
-#define ANDROID_DVR_PERFORMANCED_STRING_TRIM_H_
-
-#include <functional>
-#include <locale>
-#include <string>
-
-namespace android {
-namespace dvr {
-
-// Trims whitespace from the left side of |subject| and returns the result as a
-// new string.
-inline std::string LeftTrim(std::string subject) {
-  subject.erase(subject.begin(),
-                std::find_if(subject.begin(), subject.end(),
-                             std::not1(std::ptr_fun<int, int>(std::isspace))));
-  return subject;
-}
-
-// Trims whitespace from the right side of |subject| and returns the result as a
-// new string.
-inline std::string RightTrim(std::string subject) {
-  subject.erase(std::find_if(subject.rbegin(), subject.rend(),
-                             std::not1(std::ptr_fun<int, int>(std::isspace)))
-                    .base(),
-                subject.end());
-  return subject;
-}
-
-// Trims whitespace from the both sides of |subject| and returns the result as a
-// new string.
-inline std::string Trim(std::string subject) {
-  subject.erase(subject.begin(),
-                std::find_if(subject.begin(), subject.end(),
-                             std::not1(std::ptr_fun<int, int>(std::isspace))));
-  subject.erase(std::find_if(subject.rbegin(), subject.rend(),
-                             std::not1(std::ptr_fun<int, int>(std::isspace)))
-                    .base(),
-                subject.end());
-  return subject;
-}
-
-}  // namespace dvr
-}  // namespace android
-
-#endif  // ANDROID_DVR_PERFORMANCED_STRING_TRIM_H_
diff --git a/services/vr/performanced/task.cpp b/services/vr/performanced/task.cpp
index bda1682..2fc96bf 100644
--- a/services/vr/performanced/task.cpp
+++ b/services/vr/performanced/task.cpp
@@ -10,10 +10,10 @@
 #include <memory>
 #include <sstream>
 
+#include <android-base/strings.h>
 #include <android-base/unique_fd.h>
 
 #include "stdio_filebuf.h"
-#include "string_trim.h"
 
 namespace {
 
@@ -102,7 +102,7 @@
 
       // The status file has lines with the format <field>:<value>. Extract the
       // value after the colon.
-      return Trim(line.substr(offset + field.size() + 1));
+      return android::base::Trim(line.substr(offset + field.size() + 1));
     }
   }
 
@@ -123,7 +123,7 @@
       }
 
       std::string key = line.substr(0, offset);
-      std::string value = Trim(line.substr(offset + 1));
+      std::string value = android::base::Trim(line.substr(offset + 1));
 
       ALOGD_IF(TRACE, "Task::ReadStatusFields: key=\"%s\" value=\"%s\"",
                key.c_str(), value.c_str());
@@ -156,7 +156,7 @@
     std::string line = "";
     std::getline(file_stream, line);
 
-    return Trim(line);
+    return android::base::Trim(line);
   } else {
     return "";
   }