diff --git a/cmds/bugreport/OWNERS b/cmds/bugreport/OWNERS
index 2a9b681..5f56531 100644
--- a/cmds/bugreport/OWNERS
+++ b/cmds/bugreport/OWNERS
@@ -1,4 +1,5 @@
 set noparent
 
+gavincorkery@google.com
 nandana@google.com
 jsharkey@android.com
diff --git a/cmds/bugreportz/OWNERS b/cmds/bugreportz/OWNERS
index 2a9b681..5f56531 100644
--- a/cmds/bugreportz/OWNERS
+++ b/cmds/bugreportz/OWNERS
@@ -1,4 +1,5 @@
 set noparent
 
+gavincorkery@google.com
 nandana@google.com
 jsharkey@android.com
diff --git a/cmds/dumpstate/OWNERS b/cmds/dumpstate/OWNERS
index 2a9b681..5f56531 100644
--- a/cmds/dumpstate/OWNERS
+++ b/cmds/dumpstate/OWNERS
@@ -1,4 +1,5 @@
 set noparent
 
+gavincorkery@google.com
 nandana@google.com
 jsharkey@android.com
diff --git a/cmds/dumpsys/OWNERS b/cmds/dumpsys/OWNERS
index 4f6a89e..97a63ca 100644
--- a/cmds/dumpsys/OWNERS
+++ b/cmds/dumpsys/OWNERS
@@ -1,5 +1,6 @@
 set noparent
 
+gavincorkery@google.com
 nandana@google.com
 jsharkey@android.com
 
diff --git a/cmds/installd/OWNERS b/cmds/installd/OWNERS
index fc745d0..d6807ff 100644
--- a/cmds/installd/OWNERS
+++ b/cmds/installd/OWNERS
@@ -9,3 +9,4 @@
 ngeoffray@google.com
 rpl@google.com
 toddke@google.com
+patb@google.com
diff --git a/include/android/surface_control.h b/include/android/surface_control.h
index 351e6fa..059bc41 100644
--- a/include/android/surface_control.h
+++ b/include/android/surface_control.h
@@ -133,6 +133,9 @@
  * ASurfaceTransaction_OnComplete callback can be used to be notified when a frame
  * including the updates in a transaction was presented.
  *
+ * Buffers which are replaced or removed from the scene in the transaction invoking
+ * this callback may be reused after this point.
+ *
  * \param context Optional context provided by the client that is passed into
  * the callback.
  *
@@ -153,6 +156,13 @@
  * are ready to be presented. This callback will be invoked before the
  * ASurfaceTransaction_OnComplete callback.
  *
+ * This callback does not mean buffers have been released! It simply means that any new
+ * transactions applied will not overwrite the transaction for which we are receiving
+ * a callback and instead will be included in the next frame. If you are trying to avoid
+ * dropping frames (overwriting transactions), and unable to use timestamps (Which provide
+ * a more efficient solution), then this method provides a method to pace your transaction
+ * application.
+ *
  * \param context Optional context provided by the client that is passed into the callback.
  *
  * \param stats Opaque handle that can be passed to ASurfaceTransactionStats functions to query
diff --git a/libs/binder/IPCThreadState.cpp b/libs/binder/IPCThreadState.cpp
index ef7fd44..18b77e6 100644
--- a/libs/binder/IPCThreadState.cpp
+++ b/libs/binder/IPCThreadState.cpp
@@ -366,19 +366,45 @@
 
 pid_t IPCThreadState::getCallingPid() const
 {
+    checkContextIsBinderForUse(__func__);
     return mCallingPid;
 }
 
 const char* IPCThreadState::getCallingSid() const
 {
+    checkContextIsBinderForUse(__func__);
     return mCallingSid;
 }
 
 uid_t IPCThreadState::getCallingUid() const
 {
+    checkContextIsBinderForUse(__func__);
     return mCallingUid;
 }
 
+IPCThreadState::SpGuard* IPCThreadState::pushGetCallingSpGuard(SpGuard* guard) {
+    SpGuard* orig = mServingStackPointerGuard;
+    mServingStackPointerGuard = guard;
+    return orig;
+}
+
+void IPCThreadState::restoreGetCallingSpGuard(SpGuard* guard) {
+    mServingStackPointerGuard = guard;
+}
+
+void IPCThreadState::checkContextIsBinderForUse(const char* use) const {
+    if (mServingStackPointerGuard == nullptr) return;
+
+    if (!mServingStackPointer || mServingStackPointerGuard < mServingStackPointer) {
+        LOG_ALWAYS_FATAL("In context %s, %s does not make sense.",
+                         mServingStackPointerGuard->context, use);
+    }
+
+    // in the case mServingStackPointer is deeper in the stack than the guard,
+    // we must be serving a binder transaction (maybe nested). This is a binder
+    // context, so we don't abort
+}
+
 int64_t IPCThreadState::clearCallingIdentity()
 {
     // ignore mCallingSid for legacy reasons
@@ -847,15 +873,15 @@
 }
 
 IPCThreadState::IPCThreadState()
-    : mProcess(ProcessState::self()),
-      mServingStackPointer(nullptr),
-      mWorkSource(kUnsetWorkSource),
-      mPropagateWorkSource(false),
-      mIsLooper(false),
-      mStrictModePolicy(0),
-      mLastTransactionBinderFlags(0),
-      mCallRestriction(mProcess->mCallRestriction)
-{
+      : mProcess(ProcessState::self()),
+        mServingStackPointer(nullptr),
+        mServingStackPointerGuard(nullptr),
+        mWorkSource(kUnsetWorkSource),
+        mPropagateWorkSource(false),
+        mIsLooper(false),
+        mStrictModePolicy(0),
+        mLastTransactionBinderFlags(0),
+        mCallRestriction(mProcess->mCallRestriction) {
     pthread_setspecific(gTLS, this);
     clearCaller();
     mIn.setDataCapacity(256);
diff --git a/libs/binder/RpcServer.cpp b/libs/binder/RpcServer.cpp
index c0cdcd6..9cc6e7f 100644
--- a/libs/binder/RpcServer.cpp
+++ b/libs/binder/RpcServer.cpp
@@ -22,6 +22,7 @@
 #include <thread>
 #include <vector>
 
+#include <android-base/scopeguard.h>
 #include <binder/Parcel.h>
 #include <binder/RpcServer.h>
 #include <log/log.h>
@@ -32,6 +33,7 @@
 
 namespace android {
 
+using base::ScopeGuard;
 using base::unique_fd;
 
 RpcServer::RpcServer() {}
@@ -107,65 +109,51 @@
 
 void RpcServer::setRootObject(const sp<IBinder>& binder) {
     std::lock_guard<std::mutex> _l(mLock);
-    mRootObject = binder;
+    mRootObjectWeak = mRootObject = binder;
+}
+
+void RpcServer::setRootObjectWeak(const wp<IBinder>& binder) {
+    std::lock_guard<std::mutex> _l(mLock);
+    mRootObject.clear();
+    mRootObjectWeak = binder;
 }
 
 sp<IBinder> RpcServer::getRootObject() {
     std::lock_guard<std::mutex> _l(mLock);
-    return mRootObject;
+    bool hasWeak = mRootObjectWeak.unsafe_get();
+    sp<IBinder> ret = mRootObjectWeak.promote();
+    ALOGW_IF(hasWeak && ret == nullptr, "RpcServer root object is freed, returning nullptr");
+    return ret;
 }
 
 void RpcServer::join() {
+    while (true) {
+        (void)acceptOne();
+    }
+}
+
+bool RpcServer::acceptOne() {
     LOG_ALWAYS_FATAL_IF(!mAgreedExperimental, "no!");
+    LOG_ALWAYS_FATAL_IF(!hasServer(), "RpcServer must be setup to join.");
+
+    unique_fd clientFd(
+            TEMP_FAILURE_RETRY(accept4(mServer.get(), nullptr, nullptr /*length*/, SOCK_CLOEXEC)));
+
+    if (clientFd < 0) {
+        ALOGE("Could not accept4 socket: %s", strerror(errno));
+        return false;
+    }
+    LOG_RPC_DETAIL("accept4 on fd %d yields fd %d", mServer.get(), clientFd.get());
+
     {
         std::lock_guard<std::mutex> _l(mLock);
-        LOG_ALWAYS_FATAL_IF(mServer.get() == -1, "RpcServer must be setup to join.");
+        std::thread thread =
+                std::thread(&RpcServer::establishConnection, this,
+                            std::move(sp<RpcServer>::fromExisting(this)), std::move(clientFd));
+        mConnectingThreads[thread.get_id()] = std::move(thread);
     }
 
-    while (true) {
-        unique_fd clientFd(TEMP_FAILURE_RETRY(
-                accept4(mServer.get(), nullptr, nullptr /*length*/, SOCK_CLOEXEC)));
-
-        if (clientFd < 0) {
-            ALOGE("Could not accept4 socket: %s", strerror(errno));
-            continue;
-        }
-        LOG_RPC_DETAIL("accept4 on fd %d yields fd %d", mServer.get(), clientFd.get());
-
-        // TODO(b/183988761): cannot trust this simple ID, should not block this
-        // thread
-        LOG_ALWAYS_FATAL_IF(!mAgreedExperimental, "no!");
-        int32_t id;
-        if (sizeof(id) != read(clientFd.get(), &id, sizeof(id))) {
-            ALOGE("Could not read ID from fd %d", clientFd.get());
-            continue;
-        }
-
-        {
-            std::lock_guard<std::mutex> _l(mLock);
-
-            sp<RpcSession> session;
-            if (id == RPC_SESSION_ID_NEW) {
-                // new client!
-                LOG_ALWAYS_FATAL_IF(mSessionIdCounter >= INT32_MAX, "Out of session IDs");
-                mSessionIdCounter++;
-
-                session = RpcSession::make();
-                session->setForServer(wp<RpcServer>::fromExisting(this), mSessionIdCounter);
-
-                mSessions[mSessionIdCounter] = session;
-            } else {
-                auto it = mSessions.find(id);
-                if (it == mSessions.end()) {
-                    ALOGE("Cannot add thread, no record of session with ID %d", id);
-                    continue;
-                }
-                session = it->second;
-            }
-
-            session->startThread(std::move(clientFd));
-        }
-    }
+    return true;
 }
 
 std::vector<sp<RpcSession>> RpcServer::listSessions() {
@@ -178,14 +166,74 @@
     return sessions;
 }
 
-bool RpcServer::setupSocketServer(const RpcSocketAddress& addr) {
-    LOG_RPC_DETAIL("Setting up socket server %s", addr.toString().c_str());
+size_t RpcServer::numUninitializedSessions() {
+    std::lock_guard<std::mutex> _l(mLock);
+    return mConnectingThreads.size();
+}
 
+void RpcServer::establishConnection(sp<RpcServer>&& server, base::unique_fd clientFd) {
+    LOG_ALWAYS_FATAL_IF(this != server.get(), "Must pass same ownership object");
+
+    // TODO(b/183988761): cannot trust this simple ID
+    LOG_ALWAYS_FATAL_IF(!mAgreedExperimental, "no!");
+    bool idValid = true;
+    int32_t id;
+    if (sizeof(id) != read(clientFd.get(), &id, sizeof(id))) {
+        ALOGE("Could not read ID from fd %d", clientFd.get());
+        idValid = false;
+    }
+
+    std::thread thisThread;
+    sp<RpcSession> session;
     {
         std::lock_guard<std::mutex> _l(mLock);
-        LOG_ALWAYS_FATAL_IF(mServer.get() != -1, "Each RpcServer can only have one server.");
+
+        auto threadId = mConnectingThreads.find(std::this_thread::get_id());
+        LOG_ALWAYS_FATAL_IF(threadId == mConnectingThreads.end(),
+                            "Must establish connection on owned thread");
+        thisThread = std::move(threadId->second);
+        ScopeGuard detachGuard = [&]() { thisThread.detach(); };
+        mConnectingThreads.erase(threadId);
+
+        if (!idValid) {
+            return;
+        }
+
+        if (id == RPC_SESSION_ID_NEW) {
+            LOG_ALWAYS_FATAL_IF(mSessionIdCounter >= INT32_MAX, "Out of session IDs");
+            mSessionIdCounter++;
+
+            session = RpcSession::make();
+            session->setForServer(wp<RpcServer>::fromExisting(this), mSessionIdCounter);
+
+            mSessions[mSessionIdCounter] = session;
+        } else {
+            auto it = mSessions.find(id);
+            if (it == mSessions.end()) {
+                ALOGE("Cannot add thread, no record of session with ID %d", id);
+                return;
+            }
+            session = it->second;
+        }
+
+        detachGuard.Disable();
+        session->preJoin(std::move(thisThread));
     }
 
+    // avoid strong cycle
+    server = nullptr;
+    //
+    //
+    // DO NOT ACCESS MEMBER VARIABLES BELOW
+    //
+
+    session->join(std::move(clientFd));
+}
+
+bool RpcServer::setupSocketServer(const RpcSocketAddress& addr) {
+    LOG_RPC_DETAIL("Setting up socket server %s", addr.toString().c_str());
+    LOG_ALWAYS_FATAL_IF(hasServer(), "Each RpcServer can only have one server.");
+
     unique_fd serverFd(
             TEMP_FAILURE_RETRY(socket(addr.addr()->sa_family, SOCK_STREAM | SOCK_CLOEXEC, 0)));
     if (serverFd == -1) {
@@ -223,4 +271,27 @@
     (void)mSessions.erase(it);
 }
 
+bool RpcServer::hasServer() {
+    LOG_ALWAYS_FATAL_IF(!mAgreedExperimental, "no!");
+    std::lock_guard<std::mutex> _l(mLock);
+    return mServer.ok();
+}
+
+unique_fd RpcServer::releaseServer() {
+    LOG_ALWAYS_FATAL_IF(!mAgreedExperimental, "no!");
+    std::lock_guard<std::mutex> _l(mLock);
+    return std::move(mServer);
+}
+
+bool RpcServer::setupExternalServer(base::unique_fd serverFd) {
+    LOG_ALWAYS_FATAL_IF(!mAgreedExperimental, "no!");
+    std::lock_guard<std::mutex> _l(mLock);
+    if (mServer.ok()) {
+        ALOGE("Each RpcServer can only have one server.");
+        return false;
+    }
+    mServer = std::move(serverFd);
+    return true;
+}
+
 } // namespace android
diff --git a/libs/binder/RpcSession.cpp b/libs/binder/RpcSession.cpp
index f38135b..05fa49e 100644
--- a/libs/binder/RpcSession.cpp
+++ b/libs/binder/RpcSession.cpp
@@ -131,21 +131,13 @@
     return OK;
 }
 
-void RpcSession::startThread(unique_fd client) {
-    std::lock_guard<std::mutex> _l(mMutex);
-    sp<RpcSession> holdThis = sp<RpcSession>::fromExisting(this);
-    int fd = client.release();
-    auto thread = std::thread([=] {
-        holdThis->join(unique_fd(fd));
-        {
-            std::lock_guard<std::mutex> _l(holdThis->mMutex);
-            auto it = mThreads.find(std::this_thread::get_id());
-            LOG_ALWAYS_FATAL_IF(it == mThreads.end());
-            it->second.detach();
-            mThreads.erase(it);
-        }
-    });
-    mThreads[thread.get_id()] = std::move(thread);
+void RpcSession::preJoin(std::thread thread) {
+    LOG_ALWAYS_FATAL_IF(thread.get_id() != std::this_thread::get_id(), "Must own this thread");
+
+    {
+        std::lock_guard<std::mutex> _l(mMutex);
+        mThreads[thread.get_id()] = std::move(thread);
+    }
 }
 
 void RpcSession::join(unique_fd client) {
@@ -165,6 +157,14 @@
 
     LOG_ALWAYS_FATAL_IF(!removeServerConnection(connection),
                         "bad state: connection object guaranteed to be in list");
+
+    {
+        std::lock_guard<std::mutex> _l(mMutex);
+        auto it = mThreads.find(std::this_thread::get_id());
+        LOG_ALWAYS_FATAL_IF(it == mThreads.end());
+        it->second.detach();
+        mThreads.erase(it);
+    }
 }
 
 void RpcSession::terminateLocked() {
diff --git a/libs/binder/RpcState.cpp b/libs/binder/RpcState.cpp
index 20fdbfe..e5a6026 100644
--- a/libs/binder/RpcState.cpp
+++ b/libs/binder/RpcState.cpp
@@ -18,7 +18,9 @@
 
 #include "RpcState.h"
 
+#include <android-base/scopeguard.h>
 #include <binder/BpBinder.h>
+#include <binder/IPCThreadState.h>
 #include <binder/RpcServer.h>
 
 #include "Debug.h"
@@ -28,6 +30,8 @@
 
 namespace android {
 
+using base::ScopeGuard;
+
 RpcState::RpcState() {}
 RpcState::~RpcState() {}
 
@@ -182,6 +186,27 @@
     }
 }
 
+RpcState::CommandData::CommandData(size_t size) : mSize(size) {
+    // The maximum size for regular binder is 1MB for all concurrent
+    // transactions. A very small proportion of transactions are even
+    // larger than a page, but we need to avoid allocating too much
+    // data on behalf of an arbitrary client, or we could risk being in
+    // a position where a single additional allocation could run out of
+    // memory.
+    //
+    // Note, this limit may not reflect the total amount of data allocated for a
+    // transaction (in some cases, additional fixed size amounts are added),
+    // though for rough consistency, we should avoid cases where this data type
+    // is used for multiple dynamic allocations for a single transaction.
+    constexpr size_t kMaxTransactionAllocation = 100 * 1000;
+    if (size == 0) return;
+    if (size > kMaxTransactionAllocation) {
+        ALOGW("Transaction requested too much data allocation %zu", size);
+        return;
+    }
+    mData.reset(new (std::nothrow) uint8_t[size]);
+}
+
 bool RpcState::rpcSend(const base::unique_fd& fd, const char* what, const void* data, size_t size) {
     LOG_RPC_DETAIL("Sending %s on fd %d: %s", what, fd.get(), hexString(data, size).c_str());
 
@@ -326,7 +351,7 @@
             .asyncNumber = asyncNumber,
     };
 
-    ByteVec transactionData(sizeof(RpcWireTransaction) + data.dataSize());
+    CommandData transactionData(sizeof(RpcWireTransaction) + data.dataSize());
     if (!transactionData.valid()) {
         return NO_MEMORY;
     }
@@ -383,7 +408,7 @@
         if (status != OK) return status;
     }
 
-    ByteVec data(command.bodySize);
+    CommandData data(command.bodySize);
     if (!data.valid()) {
         return NO_MEMORY;
     }
@@ -449,6 +474,18 @@
 
 status_t RpcState::processServerCommand(const base::unique_fd& fd, const sp<RpcSession>& session,
                                         const RpcWireHeader& command) {
+    IPCThreadState* kernelBinderState = IPCThreadState::selfOrNull();
+    IPCThreadState::SpGuard spGuard{"processing binder RPC command"};
+    IPCThreadState::SpGuard* origGuard;
+    if (kernelBinderState != nullptr) {
+        origGuard = kernelBinderState->pushGetCallingSpGuard(&spGuard);
+    }
+    ScopeGuard guardUnguard = [&]() {
+        if (kernelBinderState != nullptr) {
+            kernelBinderState->restoreGetCallingSpGuard(origGuard);
+        }
+    };
+
     switch (command.command) {
         case RPC_COMMAND_TRANSACT:
             return processTransact(fd, session, command);
@@ -469,7 +506,7 @@
                                    const RpcWireHeader& command) {
     LOG_ALWAYS_FATAL_IF(command.command != RPC_COMMAND_TRANSACT, "command: %d", command.command);
 
-    ByteVec transactionData(command.bodySize);
+    CommandData transactionData(command.bodySize);
     if (!transactionData.valid()) {
         return NO_MEMORY;
     }
@@ -490,7 +527,7 @@
 }
 
 status_t RpcState::processTransactInternal(const base::unique_fd& fd, const sp<RpcSession>& session,
-                                           ByteVec transactionData) {
+                                           CommandData transactionData) {
     if (transactionData.size() < sizeof(RpcWireTransaction)) {
         ALOGE("Expecting %zu but got %zu bytes for RpcWireTransaction. Terminating!",
               sizeof(RpcWireTransaction), transactionData.size());
@@ -640,7 +677,7 @@
                 // justification for const_cast (consider avoiding priority_queue):
                 // - AsyncTodo operator< doesn't depend on 'data' object
                 // - gotta go fast
-                ByteVec data = std::move(
+                CommandData data = std::move(
                         const_cast<BinderNode::AsyncTodo&>(it->second.asyncTodo.top()).data);
                 it->second.asyncTodo.pop();
                 _l.unlock();
@@ -654,7 +691,7 @@
             .status = replyStatus,
     };
 
-    ByteVec replyData(sizeof(RpcWireReply) + reply.dataSize());
+    CommandData replyData(sizeof(RpcWireReply) + reply.dataSize());
     if (!replyData.valid()) {
         return NO_MEMORY;
     }
@@ -684,7 +721,7 @@
 status_t RpcState::processDecStrong(const base::unique_fd& fd, const RpcWireHeader& command) {
     LOG_ALWAYS_FATAL_IF(command.command != RPC_COMMAND_DEC_STRONG, "command: %d", command.command);
 
-    ByteVec commandData(command.bodySize);
+    CommandData commandData(command.bodySize);
     if (!commandData.valid()) {
         return NO_MEMORY;
     }
diff --git a/libs/binder/RpcState.h b/libs/binder/RpcState.h
index 83d0344..31f8a22 100644
--- a/libs/binder/RpcState.h
+++ b/libs/binder/RpcState.h
@@ -101,10 +101,10 @@
      */
     void terminate();
 
-    // alternative to std::vector<uint8_t> that doesn't abort on too big of allocations
-    struct ByteVec {
-        explicit ByteVec(size_t size)
-              : mData(size > 0 ? new (std::nothrow) uint8_t[size] : nullptr), mSize(size) {}
+    // Alternative to std::vector<uint8_t> that doesn't abort on allocation failure and caps
+    // large allocations to avoid being requested from allocating too much data.
+    struct CommandData {
+        explicit CommandData(size_t size);
         bool valid() { return mSize == 0 || mData != nullptr; }
         size_t size() { return mSize; }
         uint8_t* data() { return mData.get(); }
@@ -128,7 +128,7 @@
                                            const RpcWireHeader& command);
     [[nodiscard]] status_t processTransactInternal(const base::unique_fd& fd,
                                                    const sp<RpcSession>& session,
-                                                   ByteVec transactionData);
+                                                   CommandData transactionData);
     [[nodiscard]] status_t processDecStrong(const base::unique_fd& fd,
                                             const RpcWireHeader& command);
 
@@ -163,7 +163,7 @@
 
         // async transaction queue, _only_ for local binder
         struct AsyncTodo {
-            ByteVec data;
+            CommandData data;
             uint64_t asyncNumber = 0;
 
             bool operator<(const AsyncTodo& o) const {
diff --git a/libs/binder/include/binder/IPCThreadState.h b/libs/binder/include/binder/IPCThreadState.h
index 23a0cb0..5220b62 100644
--- a/libs/binder/include/binder/IPCThreadState.h
+++ b/libs/binder/include/binder/IPCThreadState.h
@@ -81,6 +81,32 @@
              */
             uid_t               getCallingUid() const;
 
+            /**
+             * Make it an abort to rely on getCalling* for a section of
+             * execution.
+             *
+             * Usage:
+             *     IPCThreadState::SpGuard guard { "..." };
+             *     auto* orig = pushGetCallingSpGuard(&guard);
+             *     {
+             *         // will abort if you call getCalling*, unless you are
+             *         // serving a nested binder transaction
+             *     }
+             *     restoreCallingSpGuard(orig);
+             */
+            struct SpGuard {
+                const char* context;
+            };
+            SpGuard* pushGetCallingSpGuard(SpGuard* guard);
+            void restoreGetCallingSpGuard(SpGuard* guard);
+            /**
+             * Used internally by getCalling*. Can also be used to assert that
+             * you are in a binder context (getCalling* is valid). This is
+             * intentionally not exposed as a boolean API since code should be
+             * written to know its environment.
+             */
+            void checkContextIsBinderForUse(const char* use) const;
+
             void                setStrictModePolicy(int32_t policy);
             int32_t             getStrictModePolicy() const;
 
@@ -203,6 +229,7 @@
             Parcel              mOut;
             status_t            mLastError;
             const void*         mServingStackPointer;
+            SpGuard* mServingStackPointerGuard;
             pid_t               mCallingPid;
             const char*         mCallingSid;
             uid_t               mCallingUid;
diff --git a/libs/binder/include/binder/LazyServiceRegistrar.h b/libs/binder/include/binder/LazyServiceRegistrar.h
index 9659732..f3ba830 100644
--- a/libs/binder/include/binder/LazyServiceRegistrar.h
+++ b/libs/binder/include/binder/LazyServiceRegistrar.h
@@ -50,8 +50,12 @@
                               int dumpFlags = IServiceManager::DUMP_FLAG_PRIORITY_DEFAULT);
      /**
       * Force the service to persist, even when it has 0 clients.
-      * If setting this flag from the server side, make sure to do so before calling registerService,
-      * or there may be a race with the default dynamic shutdown.
+      * If setting this flag from the server side, make sure to do so before calling
+      * registerService, or there may be a race with the default dynamic shutdown.
+      *
+      * This should only be used if it is every eventually set to false. If a
+      * service needs to persist but doesn't need to dynamically shut down,
+      * prefer to control it with another mechanism such as ctl.start.
       */
      void forcePersist(bool persist);
 
diff --git a/libs/binder/include/binder/RpcServer.h b/libs/binder/include/binder/RpcServer.h
index 3534d51..8f0c6fd 100644
--- a/libs/binder/include/binder/RpcServer.h
+++ b/libs/binder/include/binder/RpcServer.h
@@ -22,6 +22,7 @@
 #include <utils/RefBase.h>
 
 #include <mutex>
+#include <thread>
 
 // WARNING: This is a feature which is still in development, and it is subject
 // to radical change. Any production use of this may subject your code to any
@@ -73,6 +74,22 @@
      */
     [[nodiscard]] bool setupInetServer(unsigned int port, unsigned int* assignedPort);
 
+    /**
+     * If setup*Server has been successful, return true. Otherwise return false.
+     */
+    [[nodiscard]] bool hasServer();
+
+    /**
+     * If hasServer(), return the server FD. Otherwise return invalid FD.
+     */
+    [[nodiscard]] base::unique_fd releaseServer();
+
+    /**
+     * Set up server using an external FD previously set up by releaseServer().
+     * Return false if there's already a server.
+     */
+    bool setupExternalServer(base::unique_fd serverFd);
+
     void iUnderstandThisCodeIsExperimentalAndIWillNotUseItInProduction();
 
     /**
@@ -89,8 +106,14 @@
     /**
      * The root object can be retrieved by any client, without any
      * authentication. TODO(b/183988761)
+     *
+     * Holds a strong reference to the root object.
      */
     void setRootObject(const sp<IBinder>& binder);
+    /**
+     * Holds a weak reference to the root object.
+     */
+    void setRootObjectWeak(const wp<IBinder>& binder);
     sp<IBinder> getRootObject();
 
     /**
@@ -101,9 +124,16 @@
     void join();
 
     /**
+     * Accept one connection on this server. You must have at least one client
+     * session before calling this.
+     */
+    [[nodiscard]] bool acceptOne();
+
+    /**
      * For debugging!
      */
     std::vector<sp<RpcSession>> listSessions();
+    size_t numUninitializedSessions();
 
     ~RpcServer();
 
@@ -115,6 +145,7 @@
     friend sp<RpcServer>;
     RpcServer();
 
+    void establishConnection(sp<RpcServer>&& session, base::unique_fd clientFd);
     bool setupSocketServer(const RpcSocketAddress& address);
 
     bool mAgreedExperimental = false;
@@ -123,7 +154,9 @@
     base::unique_fd mServer; // socket we are accepting sessions on
 
     std::mutex mLock; // for below
+    std::map<std::thread::id, std::thread> mConnectingThreads;
     sp<IBinder> mRootObject;
+    wp<IBinder> mRootObjectWeak;
     std::map<int32_t, sp<RpcSession>> mSessions;
     int32_t mSessionIdCounter = 0;
 };
diff --git a/libs/binder/include/binder/RpcSession.h b/libs/binder/include/binder/RpcSession.h
index c8ab9e4..bcc213c 100644
--- a/libs/binder/include/binder/RpcSession.h
+++ b/libs/binder/include/binder/RpcSession.h
@@ -114,7 +114,9 @@
 
     status_t readId();
 
-    void startThread(base::unique_fd client);
+    // transfer ownership of thread
+    void preJoin(std::thread thread);
+    // join on thread passed to preJoin
     void join(base::unique_fd client);
     void terminateLocked();
 
diff --git a/libs/binder/ndk/include_platform/android/binder_manager.h b/libs/binder/ndk/include_platform/android/binder_manager.h
index a90b4aa..2a66941 100644
--- a/libs/binder/ndk/include_platform/android/binder_manager.h
+++ b/libs/binder/ndk/include_platform/android/binder_manager.h
@@ -35,7 +35,7 @@
  * \return EX_NONE on success.
  */
 __attribute__((warn_unused_result)) binder_exception_t AServiceManager_addService(
-        AIBinder* binder, const char* instance);
+        AIBinder* binder, const char* instance) __INTRODUCED_IN(29);
 
 /**
  * Gets a binder object with this specific instance name. Will return nullptr immediately if the
@@ -47,7 +47,8 @@
  *
  * \param instance identifier of the service used to lookup the service.
  */
-__attribute__((warn_unused_result)) AIBinder* AServiceManager_checkService(const char* instance);
+__attribute__((warn_unused_result)) AIBinder* AServiceManager_checkService(const char* instance)
+        __INTRODUCED_IN(29);
 
 /**
  * Gets a binder object with this specific instance name. Blocks for a couple of seconds waiting on
@@ -59,7 +60,8 @@
  *
  * \param instance identifier of the service used to lookup the service.
  */
-__attribute__((warn_unused_result)) AIBinder* AServiceManager_getService(const char* instance);
+__attribute__((warn_unused_result)) AIBinder* AServiceManager_getService(const char* instance)
+        __INTRODUCED_IN(29);
 
 /**
  * Registers a lazy service with the default service manager under the 'instance' name.
@@ -135,6 +137,10 @@
 /**
  * Prevent lazy services without client from shutting down their process
  *
+ * This should only be used if it is every eventually set to false. If a
+ * service needs to persist but doesn't need to dynamically shut down,
+ * prefer to control it with another mechanism.
+ *
  * \param persist 'true' if the process should not exit.
  */
 void AServiceManager_forceLazyServicesPersist(bool persist) __INTRODUCED_IN(31);
diff --git a/libs/binder/tests/IBinderRpcTest.aidl b/libs/binder/tests/IBinderRpcTest.aidl
index ef4198d..41daccc 100644
--- a/libs/binder/tests/IBinderRpcTest.aidl
+++ b/libs/binder/tests/IBinderRpcTest.aidl
@@ -55,4 +55,6 @@
     oneway void sleepMsAsync(int ms);
 
     void die(boolean cleanup);
+
+    void useKernelBinderCallingId();
 }
diff --git a/libs/binder/tests/binderLibTest.cpp b/libs/binder/tests/binderLibTest.cpp
index 0c3fbcd..45b2776 100644
--- a/libs/binder/tests/binderLibTest.cpp
+++ b/libs/binder/tests/binderLibTest.cpp
@@ -73,6 +73,7 @@
     BINDER_LIB_TEST_REGISTER_SERVER,
     BINDER_LIB_TEST_ADD_SERVER,
     BINDER_LIB_TEST_ADD_POLL_SERVER,
+    BINDER_LIB_TEST_USE_CALLING_GUARD_TRANSACTION,
     BINDER_LIB_TEST_CALL_BACK,
     BINDER_LIB_TEST_CALL_BACK_VERIFY_BUF,
     BINDER_LIB_TEST_DELAYED_CALL_BACK,
@@ -604,6 +605,24 @@
     EXPECT_THAT(callBack->getResult(), StatusEq(NO_ERROR));
 }
 
+TEST_F(BinderLibTest, NoBinderCallContextGuard) {
+    IPCThreadState::SpGuard spGuard{"NoBinderCallContext"};
+    IPCThreadState::SpGuard *origGuard = IPCThreadState::self()->pushGetCallingSpGuard(&spGuard);
+
+    // yes, this test uses threads, but it's careful and uses fork in addServer
+    EXPECT_DEATH({ IPCThreadState::self()->getCallingPid(); },
+                 "In context NoBinderCallContext, getCallingPid does not make sense.");
+
+    IPCThreadState::self()->restoreGetCallingSpGuard(origGuard);
+}
+
+TEST_F(BinderLibTest, BinderCallContextGuard) {
+    sp<IBinder> binder = addServer();
+    Parcel data, reply;
+    EXPECT_THAT(binder->transact(BINDER_LIB_TEST_USE_CALLING_GUARD_TRANSACTION, data, &reply),
+                StatusEq(DEAD_OBJECT));
+}
+
 TEST_F(BinderLibTest, AddServer)
 {
     sp<IBinder> server = addServer();
@@ -1262,6 +1281,18 @@
                 pthread_mutex_unlock(&m_serverWaitMutex);
                 return ret;
             }
+            case BINDER_LIB_TEST_USE_CALLING_GUARD_TRANSACTION: {
+                IPCThreadState::SpGuard spGuard{"GuardInBinderTransaction"};
+                IPCThreadState::SpGuard *origGuard =
+                        IPCThreadState::self()->pushGetCallingSpGuard(&spGuard);
+
+                // if the guard works, this should abort
+                (void)IPCThreadState::self()->getCallingPid();
+
+                IPCThreadState::self()->restoreGetCallingSpGuard(origGuard);
+                return NO_ERROR;
+            }
+
             case BINDER_LIB_TEST_GETPID:
                 reply->writeInt32(getpid());
                 return NO_ERROR;
@@ -1489,6 +1520,11 @@
 {
     binderLibTestServiceName += String16(binderserversuffix);
 
+    // Testing to make sure that calls that we are serving can use getCallin*
+    // even though we don't here.
+    IPCThreadState::SpGuard spGuard{"main server thread"};
+    (void)IPCThreadState::self()->pushGetCallingSpGuard(&spGuard);
+
     status_t ret;
     sp<IServiceManager> sm = defaultServiceManager();
     BinderLibTestService* testServicePtr;
diff --git a/libs/binder/tests/binderRpcTest.cpp b/libs/binder/tests/binderRpcTest.cpp
index b3ce744..3f94df2 100644
--- a/libs/binder/tests/binderRpcTest.cpp
+++ b/libs/binder/tests/binderRpcTest.cpp
@@ -23,6 +23,7 @@
 #include <android/binder_libbinder.h>
 #include <binder/Binder.h>
 #include <binder/BpBinder.h>
+#include <binder/IPCThreadState.h>
 #include <binder/IServiceManager.h>
 #include <binder/ProcessState.h>
 #include <binder/RpcServer.h>
@@ -49,6 +50,19 @@
     EXPECT_DEATH(p.markForBinder(sp<BBinder>::make()), "");
 }
 
+TEST(BinderRpc, SetExternalServer) {
+    base::unique_fd sink(TEMP_FAILURE_RETRY(open("/dev/null", O_RDWR)));
+    int sinkFd = sink.get();
+    auto server = RpcServer::make();
+    server->iUnderstandThisCodeIsExperimentalAndIWillNotUseItInProduction();
+    ASSERT_FALSE(server->hasServer());
+    ASSERT_TRUE(server->setupExternalServer(std::move(sink)));
+    ASSERT_TRUE(server->hasServer());
+    base::unique_fd retrieved = server->releaseServer();
+    ASSERT_FALSE(server->hasServer());
+    ASSERT_EQ(sinkFd, retrieved.get());
+}
+
 using android::binder::Status;
 
 #define EXPECT_OK(status)                 \
@@ -178,6 +192,13 @@
             _exit(1);
         }
     }
+    Status useKernelBinderCallingId() override {
+        // this is WRONG! It does not make sense when using RPC binder, and
+        // because it is SO wrong, and so much code calls this, it should abort!
+
+        (void)IPCThreadState::self()->getCallingPid();
+        return Status::ok();
+    }
 };
 sp<IBinder> MyBinderRpcTest::mHeldBinder;
 
@@ -874,6 +895,19 @@
     }
 }
 
+TEST_P(BinderRpc, UseKernelBinderCallingId) {
+    auto proc = createRpcTestSocketServerProcess(1);
+
+    // we can't allocate IPCThreadState so actually the first time should
+    // succeed :(
+    EXPECT_OK(proc.rootIface->useKernelBinderCallingId());
+
+    // second time! we catch the error :)
+    EXPECT_EQ(DEAD_OBJECT, proc.rootIface->useKernelBinderCallingId().transactionError());
+
+    proc.expectInvalid = true;
+}
+
 TEST_P(BinderRpc, WorksWithLibbinderNdkPing) {
     auto proc = createRpcTestSocketServerProcess(1);
 
@@ -929,6 +963,34 @@
                         }),
                         PrintSocketType);
 
+class BinderRpcServerRootObject : public ::testing::TestWithParam<std::tuple<bool, bool>> {};
+
+TEST_P(BinderRpcServerRootObject, WeakRootObject) {
+    using SetFn = std::function<void(RpcServer*, sp<IBinder>)>;
+    auto setRootObject = [](bool isStrong) -> SetFn {
+        return isStrong ? SetFn(&RpcServer::setRootObject) : SetFn(&RpcServer::setRootObjectWeak);
+    };
+
+    auto server = RpcServer::make();
+    auto [isStrong1, isStrong2] = GetParam();
+    auto binder1 = sp<BBinder>::make();
+    IBinder* binderRaw1 = binder1.get();
+    setRootObject(isStrong1)(server.get(), binder1);
+    EXPECT_EQ(binderRaw1, server->getRootObject());
+    binder1.clear();
+    EXPECT_EQ((isStrong1 ? binderRaw1 : nullptr), server->getRootObject());
+
+    auto binder2 = sp<BBinder>::make();
+    IBinder* binderRaw2 = binder2.get();
+    setRootObject(isStrong2)(server.get(), binder2);
+    EXPECT_EQ(binderRaw2, server->getRootObject());
+    binder2.clear();
+    EXPECT_EQ((isStrong2 ? binderRaw2 : nullptr), server->getRootObject());
+}
+
+INSTANTIATE_TEST_CASE_P(BinderRpc, BinderRpcServerRootObject,
+                        ::testing::Combine(::testing::Bool(), ::testing::Bool()));
+
 } // namespace android
 
 int main(int argc, char** argv) {
diff --git a/libs/binder/tests/rpc_fuzzer/Android.bp b/libs/binder/tests/rpc_fuzzer/Android.bp
new file mode 100644
index 0000000..1c75306
--- /dev/null
+++ b/libs/binder/tests/rpc_fuzzer/Android.bp
@@ -0,0 +1,40 @@
+package {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_native_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_native_license"],
+}
+
+cc_fuzz {
+    name: "binder_rpc_fuzzer",
+    host_supported: true,
+
+    fuzz_config: {
+        cc: ["smoreland@google.com"],
+    },
+
+    srcs: [
+        "main.cpp",
+    ],
+    static_libs: [
+        "libbase",
+        "libcutils",
+        "liblog",
+        "libutils",
+    ],
+
+    target: {
+        android: {
+            shared_libs: [
+                "libbinder",
+            ],
+        },
+        host: {
+            static_libs: [
+                "libbinder",
+            ],
+        },
+    },
+}
diff --git a/libs/binder/tests/rpc_fuzzer/main.cpp b/libs/binder/tests/rpc_fuzzer/main.cpp
new file mode 100644
index 0000000..3603ebe
--- /dev/null
+++ b/libs/binder/tests/rpc_fuzzer/main.cpp
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2021 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-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/unique_fd.h>
+#include <binder/Binder.h>
+#include <binder/Parcel.h>
+#include <binder/RpcServer.h>
+#include <binder/RpcSession.h>
+
+#include <sys/resource.h>
+#include <sys/un.h>
+
+namespace android {
+
+static const std::string kSock = std::string(getenv("TMPDIR") ?: "/tmp") +
+        "/binderRpcFuzzerSocket_" + std::to_string(getpid());
+
+size_t getHardMemoryLimit() {
+    struct rlimit limit;
+    CHECK(0 == getrlimit(RLIMIT_AS, &limit)) << errno;
+    return limit.rlim_max;
+}
+
+void setMemoryLimit(size_t cur, size_t max) {
+    const struct rlimit kLimit = {
+            .rlim_cur = cur,
+            .rlim_max = max,
+    };
+    CHECK(0 == setrlimit(RLIMIT_AS, &kLimit)) << errno;
+}
+
+class SomeBinder : public BBinder {
+    status_t onTransact(uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags = 0) {
+        (void)flags;
+
+        if ((code & 1) == 0) {
+            sp<IBinder> binder;
+            (void)data.readStrongBinder(&binder);
+            if (binder != nullptr) {
+                (void)binder->pingBinder();
+            }
+        }
+        if ((code & 2) == 0) {
+            (void)data.readInt32();
+        }
+        if ((code & 4) == 0) {
+            (void)reply->writeStrongBinder(sp<BBinder>::make());
+        }
+
+        return OK;
+    }
+};
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    if (size > 50000) return 0;
+
+    unlink(kSock.c_str());
+
+    sp<RpcServer> server = RpcServer::make();
+    server->setRootObject(sp<SomeBinder>::make());
+    server->iUnderstandThisCodeIsExperimentalAndIWillNotUseItInProduction();
+    CHECK(server->setupUnixDomainServer(kSock.c_str()));
+
+    static constexpr size_t kMemLimit = 1llu * 1024 * 1024 * 1024;
+    size_t hardLimit = getHardMemoryLimit();
+    setMemoryLimit(std::min(kMemLimit, hardLimit), hardLimit);
+
+    std::thread serverThread([=] { (void)server->acceptOne(); });
+
+    sockaddr_un addr{
+            .sun_family = AF_UNIX,
+    };
+    CHECK_LT(kSock.size(), sizeof(addr.sun_path));
+    memcpy(&addr.sun_path, kSock.c_str(), kSock.size());
+
+    base::unique_fd clientFd(TEMP_FAILURE_RETRY(socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)));
+    CHECK_NE(clientFd.get(), -1);
+    CHECK_EQ(0,
+             TEMP_FAILURE_RETRY(
+                     connect(clientFd.get(), reinterpret_cast<sockaddr*>(&addr), sizeof(addr))))
+            << strerror(errno);
+
+    serverThread.join();
+
+    // TODO(b/182938024): fuzz multiple sessions, instead of just one
+
+#if 0
+    // make fuzzer more productive locally by forcing it to create a new session
+    int32_t id = -1;
+    CHECK(base::WriteFully(clientFd, &id, sizeof(id)));
+#endif
+
+    CHECK(base::WriteFully(clientFd, data, size));
+
+    clientFd.reset();
+
+    // TODO(b/185167543): better way to force a server to shutdown
+    while (!server->listSessions().empty() && server->numUninitializedSessions()) {
+        usleep(1);
+    }
+
+    setMemoryLimit(hardLimit, hardLimit);
+
+    return 0;
+}
+
+} // namespace android
diff --git a/libs/sensor/Sensor.cpp b/libs/sensor/Sensor.cpp
index 240738d..0a49008 100644
--- a/libs/sensor/Sensor.cpp
+++ b/libs/sensor/Sensor.cpp
@@ -231,6 +231,10 @@
             mFlags |= SENSOR_FLAG_WAKE_UP;
         }
         break;
+    case SENSOR_TYPE_DEVICE_ORIENTATION:
+        mStringType = SENSOR_STRING_TYPE_DEVICE_ORIENTATION;
+        mFlags |= SENSOR_FLAG_ON_CHANGE_MODE;
+        break;
     case SENSOR_TYPE_DYNAMIC_SENSOR_META:
         mStringType = SENSOR_STRING_TYPE_DYNAMIC_SENSOR_META;
         mFlags |= SENSOR_FLAG_SPECIAL_REPORTING_MODE; // special trigger
diff --git a/services/inputflinger/dispatcher/InputDispatcher.cpp b/services/inputflinger/dispatcher/InputDispatcher.cpp
index 446c913..8bc877f 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.cpp
+++ b/services/inputflinger/dispatcher/InputDispatcher.cpp
@@ -4747,6 +4747,40 @@
     return true;
 }
 
+// Binder call
+bool InputDispatcher::transferTouch(const sp<IBinder>& destChannelToken) {
+    sp<IBinder> fromToken;
+    { // acquire lock
+        std::scoped_lock _l(mLock);
+
+        sp<InputWindowHandle> toWindowHandle = getWindowHandleLocked(destChannelToken);
+        if (toWindowHandle == nullptr) {
+            ALOGW("Could not find window associated with token=%p", destChannelToken.get());
+            return false;
+        }
+
+        const int32_t displayId = toWindowHandle->getInfo()->displayId;
+
+        auto touchStateIt = mTouchStatesByDisplay.find(displayId);
+        if (touchStateIt == mTouchStatesByDisplay.end()) {
+            ALOGD("Could not transfer touch because the display %" PRId32 " is not being touched",
+                  displayId);
+            return false;
+        }
+
+        TouchState& state = touchStateIt->second;
+        if (state.windows.size() != 1) {
+            ALOGW("Cannot transfer touch state because there are %zu windows being touched",
+                  state.windows.size());
+            return false;
+        }
+        const TouchedWindow& touchedWindow = state.windows[0];
+        fromToken = touchedWindow.windowHandle->getToken();
+    } // release lock
+
+    return transferTouchFocus(fromToken, destChannelToken);
+}
+
 void InputDispatcher::resetAndDropEverythingLocked(const char* reason) {
     if (DEBUG_FOCUS) {
         ALOGD("Resetting and dropping all events (%s).", reason);
diff --git a/services/inputflinger/dispatcher/InputDispatcher.h b/services/inputflinger/dispatcher/InputDispatcher.h
index 7ba03e8..6edc5f1 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.h
+++ b/services/inputflinger/dispatcher/InputDispatcher.h
@@ -81,60 +81,60 @@
  */
 class InputDispatcher : public android::InputDispatcherInterface {
 protected:
-    virtual ~InputDispatcher();
+    ~InputDispatcher() override;
 
 public:
     explicit InputDispatcher(const sp<InputDispatcherPolicyInterface>& policy);
 
-    virtual void dump(std::string& dump) override;
-    virtual void monitor() override;
-    virtual bool waitForIdle() override;
-    virtual status_t start() override;
-    virtual status_t stop() override;
+    void dump(std::string& dump) override;
+    void monitor() override;
+    bool waitForIdle() override;
+    status_t start() override;
+    status_t stop() override;
 
-    virtual void notifyConfigurationChanged(const NotifyConfigurationChangedArgs* args) override;
-    virtual void notifyKey(const NotifyKeyArgs* args) override;
-    virtual void notifyMotion(const NotifyMotionArgs* args) override;
-    virtual void notifySwitch(const NotifySwitchArgs* args) override;
-    virtual void notifySensor(const NotifySensorArgs* args) override;
-    virtual void notifyVibratorState(const NotifyVibratorStateArgs* args) override;
-    virtual void notifyDeviceReset(const NotifyDeviceResetArgs* args) override;
-    virtual void notifyPointerCaptureChanged(const NotifyPointerCaptureChangedArgs* args) override;
+    void notifyConfigurationChanged(const NotifyConfigurationChangedArgs* args) override;
+    void notifyKey(const NotifyKeyArgs* args) override;
+    void notifyMotion(const NotifyMotionArgs* args) override;
+    void notifySwitch(const NotifySwitchArgs* args) override;
+    void notifySensor(const NotifySensorArgs* args) override;
+    void notifyVibratorState(const NotifyVibratorStateArgs* args) override;
+    void notifyDeviceReset(const NotifyDeviceResetArgs* args) override;
+    void notifyPointerCaptureChanged(const NotifyPointerCaptureChangedArgs* args) override;
 
-    virtual android::os::InputEventInjectionResult injectInputEvent(
+    android::os::InputEventInjectionResult injectInputEvent(
             const InputEvent* event, int32_t injectorPid, int32_t injectorUid,
             android::os::InputEventInjectionSync syncMode, std::chrono::milliseconds timeout,
             uint32_t policyFlags) override;
 
-    virtual std::unique_ptr<VerifiedInputEvent> verifyInputEvent(const InputEvent& event) override;
+    std::unique_ptr<VerifiedInputEvent> verifyInputEvent(const InputEvent& event) override;
 
-    virtual void setInputWindows(
-            const std::unordered_map<int32_t, std::vector<sp<InputWindowHandle>>>&
-                    handlesPerDisplay) override;
-    virtual void setFocusedApplication(
+    void setInputWindows(const std::unordered_map<int32_t, std::vector<sp<InputWindowHandle>>>&
+                                 handlesPerDisplay) override;
+    void setFocusedApplication(
             int32_t displayId,
             const std::shared_ptr<InputApplicationHandle>& inputApplicationHandle) override;
-    virtual void setFocusedDisplay(int32_t displayId) override;
-    virtual void setInputDispatchMode(bool enabled, bool frozen) override;
-    virtual void setInputFilterEnabled(bool enabled) override;
-    virtual void setInTouchMode(bool inTouchMode) override;
-    virtual void setMaximumObscuringOpacityForTouch(float opacity) override;
-    virtual void setBlockUntrustedTouchesMode(android::os::BlockUntrustedTouchesMode mode) override;
+    void setFocusedDisplay(int32_t displayId) override;
+    void setInputDispatchMode(bool enabled, bool frozen) override;
+    void setInputFilterEnabled(bool enabled) override;
+    void setInTouchMode(bool inTouchMode) override;
+    void setMaximumObscuringOpacityForTouch(float opacity) override;
+    void setBlockUntrustedTouchesMode(android::os::BlockUntrustedTouchesMode mode) override;
 
-    virtual bool transferTouchFocus(const sp<IBinder>& fromToken, const sp<IBinder>& toToken,
-                                    bool isDragDrop = false) override;
+    bool transferTouchFocus(const sp<IBinder>& fromToken, const sp<IBinder>& toToken,
+                            bool isDragDrop = false) override;
+    bool transferTouch(const sp<IBinder>& destChannelToken) override;
 
-    virtual base::Result<std::unique_ptr<InputChannel>> createInputChannel(
+    base::Result<std::unique_ptr<InputChannel>> createInputChannel(
             const std::string& name) override;
-    virtual void setFocusedWindow(const FocusRequest&) override;
-    virtual base::Result<std::unique_ptr<InputChannel>> createInputMonitor(int32_t displayId,
-                                                                           bool isGestureMonitor,
-                                                                           const std::string& name,
-                                                                           int32_t pid) override;
-    virtual status_t removeInputChannel(const sp<IBinder>& connectionToken) override;
-    virtual status_t pilferPointers(const sp<IBinder>& token) override;
-    virtual void requestPointerCapture(const sp<IBinder>& windowToken, bool enabled) override;
-    virtual bool flushSensor(int deviceId, InputDeviceSensorType sensorType) override;
+    void setFocusedWindow(const FocusRequest&) override;
+    base::Result<std::unique_ptr<InputChannel>> createInputMonitor(int32_t displayId,
+                                                                   bool isGestureMonitor,
+                                                                   const std::string& name,
+                                                                   int32_t pid) override;
+    status_t removeInputChannel(const sp<IBinder>& connectionToken) override;
+    status_t pilferPointers(const sp<IBinder>& token) override;
+    void requestPointerCapture(const sp<IBinder>& windowToken, bool enabled) override;
+    bool flushSensor(int deviceId, InputDeviceSensorType sensorType) override;
 
     std::array<uint8_t, 32> sign(const VerifiedInputEvent& event) const;
 
diff --git a/services/inputflinger/dispatcher/include/InputDispatcherInterface.h b/services/inputflinger/dispatcher/include/InputDispatcherInterface.h
index b601dfc..7f85e53 100644
--- a/services/inputflinger/dispatcher/include/InputDispatcherInterface.h
+++ b/services/inputflinger/dispatcher/include/InputDispatcherInterface.h
@@ -151,6 +151,14 @@
      */
     virtual bool transferTouchFocus(const sp<IBinder>& fromToken, const sp<IBinder>& toToken,
                                     bool isDragDrop) = 0;
+
+    /**
+     * Transfer touch focus to the provided channel, no matter where the current touch is.
+     *
+     * Return true on success, false if there was no on-going touch.
+     */
+    virtual bool transferTouch(const sp<IBinder>& destChannelToken) = 0;
+
     /**
      * Sets focus on the specified window.
      */
diff --git a/services/inputflinger/tests/InputDispatcher_test.cpp b/services/inputflinger/tests/InputDispatcher_test.cpp
index bbf51f6..855453e 100644
--- a/services/inputflinger/tests/InputDispatcher_test.cpp
+++ b/services/inputflinger/tests/InputDispatcher_test.cpp
@@ -1714,7 +1714,13 @@
                          0 /*expectedFlags*/);
 }
 
-TEST_F(InputDispatcherTest, TransferTouchFocus_OnePointer) {
+using TransferFunction =
+        std::function<bool(sp<InputDispatcher> dispatcher, sp<IBinder>, sp<IBinder>)>;
+
+class TransferTouchFixture : public InputDispatcherTest,
+                             public ::testing::WithParamInterface<TransferFunction> {};
+
+TEST_P(TransferTouchFixture, TransferTouch_OnePointer) {
     std::shared_ptr<FakeApplicationHandle> application = std::make_shared<FakeApplicationHandle>();
 
     // Create a couple of windows
@@ -1735,8 +1741,10 @@
     firstWindow->consumeMotionDown();
     secondWindow->assertNoEvents();
 
-    // Transfer touch focus to the second window
-    mDispatcher->transferTouchFocus(firstWindow->getToken(), secondWindow->getToken());
+    // Transfer touch to the second window
+    TransferFunction f = GetParam();
+    const bool success = f(mDispatcher, firstWindow->getToken(), secondWindow->getToken());
+    ASSERT_TRUE(success);
     // The first window gets cancel and the second gets down
     firstWindow->consumeMotionCancel();
     secondWindow->consumeMotionDown();
@@ -1751,7 +1759,7 @@
     secondWindow->consumeMotionUp();
 }
 
-TEST_F(InputDispatcherTest, TransferTouchFocus_TwoPointerNoSplitTouch) {
+TEST_P(TransferTouchFixture, TransferTouch_TwoPointersNonSplitTouch) {
     std::shared_ptr<FakeApplicationHandle> application = std::make_shared<FakeApplicationHandle>();
 
     PointF touchPoint = {10, 10};
@@ -1786,7 +1794,9 @@
     secondWindow->assertNoEvents();
 
     // Transfer touch focus to the second window
-    mDispatcher->transferTouchFocus(firstWindow->getToken(), secondWindow->getToken());
+    TransferFunction f = GetParam();
+    bool success = f(mDispatcher, firstWindow->getToken(), secondWindow->getToken());
+    ASSERT_TRUE(success);
     // The first window gets cancel and the second gets down and pointer down
     firstWindow->consumeMotionCancel();
     secondWindow->consumeMotionDown();
@@ -1813,6 +1823,21 @@
     secondWindow->consumeMotionUp();
 }
 
+// For the cases of single pointer touch and two pointers non-split touch, the api's
+// 'transferTouch' and 'transferTouchFocus' are equivalent in behaviour. They only differ
+// for the case where there are multiple pointers split across several windows.
+INSTANTIATE_TEST_SUITE_P(TransferFunctionTests, TransferTouchFixture,
+                         ::testing::Values(
+                                 [&](sp<InputDispatcher> dispatcher, sp<IBinder> /*ignored*/,
+                                     sp<IBinder> destChannelToken) {
+                                     return dispatcher->transferTouch(destChannelToken);
+                                 },
+                                 [&](sp<InputDispatcher> dispatcher, sp<IBinder> from,
+                                     sp<IBinder> to) {
+                                     return dispatcher->transferTouchFocus(from, to,
+                                                                           false /*isDragAndDrop*/);
+                                 }));
+
 TEST_F(InputDispatcherTest, TransferTouchFocus_TwoPointersSplitTouch) {
     std::shared_ptr<FakeApplicationHandle> application = std::make_shared<FakeApplicationHandle>();
 
@@ -1883,6 +1908,82 @@
     secondWindow->consumeMotionUp();
 }
 
+// Same as TransferTouchFocus_TwoPointersSplitTouch, but using 'transferTouch' api.
+// Unlike 'transferTouchFocus', calling 'transferTouch' when there are two windows receiving
+// touch is not supported, so the touch should continue on those windows and the transferred-to
+// window should get nothing.
+TEST_F(InputDispatcherTest, TransferTouch_TwoPointersSplitTouch) {
+    std::shared_ptr<FakeApplicationHandle> application = std::make_shared<FakeApplicationHandle>();
+
+    // Create a non touch modal window that supports split touch
+    sp<FakeWindowHandle> firstWindow =
+            new FakeWindowHandle(application, mDispatcher, "First Window", ADISPLAY_ID_DEFAULT);
+    firstWindow->setFrame(Rect(0, 0, 600, 400));
+    firstWindow->setFlags(InputWindowInfo::Flag::NOT_TOUCH_MODAL |
+                          InputWindowInfo::Flag::SPLIT_TOUCH);
+
+    // Create a non touch modal window that supports split touch
+    sp<FakeWindowHandle> secondWindow =
+            new FakeWindowHandle(application, mDispatcher, "Second Window", ADISPLAY_ID_DEFAULT);
+    secondWindow->setFrame(Rect(0, 400, 600, 800));
+    secondWindow->setFlags(InputWindowInfo::Flag::NOT_TOUCH_MODAL |
+                           InputWindowInfo::Flag::SPLIT_TOUCH);
+
+    // Add the windows to the dispatcher
+    mDispatcher->setInputWindows({{ADISPLAY_ID_DEFAULT, {firstWindow, secondWindow}}});
+
+    PointF pointInFirst = {300, 200};
+    PointF pointInSecond = {300, 600};
+
+    // Send down to the first window
+    NotifyMotionArgs firstDownMotionArgs =
+            generateMotionArgs(AMOTION_EVENT_ACTION_DOWN, AINPUT_SOURCE_TOUCHSCREEN,
+                               ADISPLAY_ID_DEFAULT, {pointInFirst});
+    mDispatcher->notifyMotion(&firstDownMotionArgs);
+    // Only the first window should get the down event
+    firstWindow->consumeMotionDown();
+    secondWindow->assertNoEvents();
+
+    // Send down to the second window
+    NotifyMotionArgs secondDownMotionArgs =
+            generateMotionArgs(AMOTION_EVENT_ACTION_POINTER_DOWN |
+                                       (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
+                               AINPUT_SOURCE_TOUCHSCREEN, ADISPLAY_ID_DEFAULT,
+                               {pointInFirst, pointInSecond});
+    mDispatcher->notifyMotion(&secondDownMotionArgs);
+    // The first window gets a move and the second a down
+    firstWindow->consumeMotionMove();
+    secondWindow->consumeMotionDown();
+
+    // Transfer touch focus to the second window
+    const bool transferred = mDispatcher->transferTouch(secondWindow->getToken());
+    // The 'transferTouch' call should not succeed, because there are 2 touched windows
+    ASSERT_FALSE(transferred);
+    firstWindow->assertNoEvents();
+    secondWindow->assertNoEvents();
+
+    // The rest of the dispatch should proceed as normal
+    // Send pointer up to the second window
+    NotifyMotionArgs pointerUpMotionArgs =
+            generateMotionArgs(AMOTION_EVENT_ACTION_POINTER_UP |
+                                       (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
+                               AINPUT_SOURCE_TOUCHSCREEN, ADISPLAY_ID_DEFAULT,
+                               {pointInFirst, pointInSecond});
+    mDispatcher->notifyMotion(&pointerUpMotionArgs);
+    // The first window gets MOVE and the second gets pointer up
+    firstWindow->consumeMotionMove();
+    secondWindow->consumeMotionUp();
+
+    // Send up event to the first window
+    NotifyMotionArgs upMotionArgs =
+            generateMotionArgs(AMOTION_EVENT_ACTION_UP, AINPUT_SOURCE_TOUCHSCREEN,
+                               ADISPLAY_ID_DEFAULT);
+    mDispatcher->notifyMotion(&upMotionArgs);
+    // The first window gets nothing and the second gets up
+    firstWindow->consumeMotionUp();
+    secondWindow->assertNoEvents();
+}
+
 TEST_F(InputDispatcherTest, FocusedWindow_ReceivesFocusEventAndKeyEvent) {
     std::shared_ptr<FakeApplicationHandle> application = std::make_shared<FakeApplicationHandle>();
     sp<FakeWindowHandle> window =
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h
index 4976213..9fba7aa 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h
@@ -163,6 +163,9 @@
     // Enables (or disables) composition on this output
     virtual void setCompositionEnabled(bool) = 0;
 
+    // Enables (or disables) layer caching on this output
+    virtual void setLayerCachingEnabled(bool) = 0;
+
     // Sets the projection state to use
     virtual void setProjection(ui::Rotation orientation, const Rect& layerStackSpaceRect,
                                const Rect& orientedDisplaySpaceRect) = 0;
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h
index eeb20fc..2893c3f 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h
@@ -20,6 +20,7 @@
 #include <compositionengine/Output.h>
 #include <compositionengine/impl/ClientCompositionRequestCache.h>
 #include <compositionengine/impl/OutputCompositionState.h>
+#include <compositionengine/impl/planner/Planner.h>
 #include <renderengine/DisplaySettings.h>
 #include <renderengine/LayerSettings.h>
 #include <memory>
@@ -28,21 +29,18 @@
 
 namespace android::compositionengine::impl {
 
-namespace planner {
-class Planner;
-} // namespace planner
-
 // The implementation class contains the common implementation, but does not
 // actually contain the final output state.
 class Output : public virtual compositionengine::Output {
 public:
-    Output();
+    Output() = default;
     ~Output() override;
 
     // compositionengine::Output overrides
     bool isValid() const override;
     std::optional<DisplayId> getDisplayId() const override;
     void setCompositionEnabled(bool) override;
+    void setLayerCachingEnabled(bool) override;
     void setProjection(ui::Rotation orientation, const Rect& layerStackSpaceRect,
                        const Rect& orientedDisplaySpaceRect) override;
     void setDisplaySize(const ui::Size&) override;
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayer.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayer.h
index 2488c66..2ffd472 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayer.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayer.h
@@ -78,9 +78,10 @@
     void writeSidebandStateToHWC(HWC2::Layer*, const LayerFECompositionState&);
     void writeBufferStateToHWC(HWC2::Layer*, const LayerFECompositionState&);
     void writeCompositionTypeToHWC(HWC2::Layer*, Hwc2::IComposerClient::Composition,
-                                   bool isPeekingThrough);
+                                   bool isPeekingThrough, bool skipLayer);
     void detectDisallowedCompositionTypeChange(Hwc2::IComposerClient::Composition from,
                                                Hwc2::IComposerClient::Composition to) const;
+    bool isClientCompositionForced(bool isPeekingThrough) const;
 };
 
 // This template factory function standardizes the implementation details of the
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayerCompositionState.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayerCompositionState.h
index b98043b..3f670a1 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayerCompositionState.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayerCompositionState.h
@@ -125,6 +125,9 @@
 
         // Set to true when overridden info has been sent to HW composer
         bool stateOverridden = false;
+
+        // True when this layer was skipped as part of SF-side layer caching.
+        bool layerSkipped = false;
     };
 
     // The HWC state is optional, and is only set up if there is any potential
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Flattener.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Flattener.h
index b09f1d1..864251f 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Flattener.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Flattener.h
@@ -36,8 +36,7 @@
 
 class Flattener {
 public:
-    Flattener(Predictor& predictor, bool enableHolePunch = false)
-          : mEnableHolePunch(enableHolePunch), mPredictor(predictor) {}
+    Flattener(bool enableHolePunch = false) : mEnableHolePunch(enableHolePunch) {}
 
     void setDisplaySize(ui::Size size) { mDisplaySize = size; }
 
@@ -64,7 +63,6 @@
     void buildCachedSets(std::chrono::steady_clock::time_point now);
 
     const bool mEnableHolePunch;
-    Predictor& mPredictor;
 
     ui::Size mDisplaySize;
 
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Planner.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Planner.h
index c2037a8..4365b93 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Planner.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Planner.h
@@ -76,6 +76,8 @@
 
     std::optional<Predictor::PredictedPlan> mPredictedPlan;
     NonBufferHash mFlattenedHash = 0;
+
+    bool mPredictorEnabled = false;
 };
 
 } // namespace compositionengine::impl::planner
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h
index 5aa53e5..749675d 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h
@@ -36,6 +36,7 @@
     MOCK_CONST_METHOD0(getDisplayId, std::optional<DisplayId>());
 
     MOCK_METHOD1(setCompositionEnabled, void(bool));
+    MOCK_METHOD1(setLayerCachingEnabled, void(bool));
     MOCK_METHOD3(setProjection, void(ui::Rotation, const Rect&, const Rect&));
     MOCK_METHOD1(setDisplaySize, void(const ui::Size&));
     MOCK_METHOD2(setLayerStackFilter, void(uint32_t, bool));
diff --git a/services/surfaceflinger/CompositionEngine/src/Output.cpp b/services/surfaceflinger/CompositionEngine/src/Output.cpp
index 297e687..796fe7d 100644
--- a/services/surfaceflinger/CompositionEngine/src/Output.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/Output.cpp
@@ -55,18 +55,6 @@
 
 namespace impl {
 
-Output::Output() {
-    const bool enableLayerCaching = [] {
-        const bool enable =
-                android::sysprop::SurfaceFlingerProperties::enable_layer_caching().value_or(false);
-        return base::GetBoolProperty(std::string("debug.sf.enable_layer_caching"), enable);
-    }();
-
-    if (enableLayerCaching) {
-        mPlanner = std::make_unique<planner::Planner>();
-    }
-}
-
 namespace {
 
 template <typename T>
@@ -135,6 +123,21 @@
     dirtyEntireOutput();
 }
 
+void Output::setLayerCachingEnabled(bool enabled) {
+    if (enabled == (mPlanner != nullptr)) {
+        return;
+    }
+
+    if (enabled) {
+        mPlanner = std::make_unique<planner::Planner>();
+        if (mRenderSurface) {
+            mPlanner->setDisplaySize(mRenderSurface->getSize());
+        }
+    } else {
+        mPlanner.reset();
+    }
+}
+
 void Output::setProjection(ui::Rotation orientation, const Rect& layerStackSpaceRect,
                            const Rect& orientedDisplaySpaceRect) {
     auto& outputState = editState();
diff --git a/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp b/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
index 01da070..cd14327 100644
--- a/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <DisplayHardware/Hal.h>
 #include <android-base/stringprintf.h>
 #include <compositionengine/DisplayColorProfile.h>
 #include <compositionengine/LayerFECompositionState.h>
@@ -350,12 +351,14 @@
     writeOutputDependentPerFrameStateToHWC(hwcLayer.get());
     writeOutputIndependentPerFrameStateToHWC(hwcLayer.get(), *outputIndependentState);
 
-    writeCompositionTypeToHWC(hwcLayer.get(), requestedCompositionType, isPeekingThrough);
+    writeCompositionTypeToHWC(hwcLayer.get(), requestedCompositionType, isPeekingThrough,
+                              skipLayer);
 
     // Always set the layer color after setting the composition type.
     writeSolidColorStateToHWC(hwcLayer.get(), *outputIndependentState);
 
     editState().hwc->stateOverridden = isOverridden;
+    editState().hwc->layerSkipped = skipLayer;
 }
 
 void OutputLayer::writeOutputDependentGeometryStateToHWC(HWC2::Layer* hwcLayer,
@@ -482,7 +485,8 @@
 
     const Region& surfaceDamage = getState().overrideInfo.buffer
             ? getState().overrideInfo.damageRegion
-            : outputIndependentState.surfaceDamage;
+            : (getState().hwc->stateOverridden ? Region::INVALID_REGION
+                                               : outputIndependentState.surfaceDamage);
 
     if (auto error = hwcLayer->setSurfaceDamage(surfaceDamage); error != hal::Error::NONE) {
         ALOGE("[%s] Failed to set surface damage: %s (%d)", getLayerFE().getDebugName(),
@@ -573,17 +577,19 @@
 
 void OutputLayer::writeCompositionTypeToHWC(HWC2::Layer* hwcLayer,
                                             hal::Composition requestedCompositionType,
-                                            bool isPeekingThrough) {
+                                            bool isPeekingThrough, bool skipLayer) {
     auto& outputDependentState = editState();
 
-    // If we are forcing client composition, we need to tell the HWC
-    if (outputDependentState.forceClientComposition ||
-        (!isPeekingThrough && getLayerFE().hasRoundedCorners())) {
+    if (isClientCompositionForced(isPeekingThrough)) {
+        // If we are forcing client composition, we need to tell the HWC
         requestedCompositionType = hal::Composition::CLIENT;
     }
 
     // Set the requested composition type with the HWC whenever it changes
-    if (outputDependentState.hwc->hwcCompositionType != requestedCompositionType) {
+    // We also resend the composition type when this layer was previously skipped, to ensure that
+    // the composition type is up-to-date.
+    if (outputDependentState.hwc->hwcCompositionType != requestedCompositionType ||
+        (outputDependentState.hwc->layerSkipped && !skipLayer)) {
         outputDependentState.hwc->hwcCompositionType = requestedCompositionType;
 
         if (auto error = hwcLayer->setCompositionType(requestedCompositionType);
@@ -663,12 +669,22 @@
     }
 }
 
+bool OutputLayer::isClientCompositionForced(bool isPeekingThrough) const {
+    return getState().forceClientComposition ||
+            (!isPeekingThrough && getLayerFE().hasRoundedCorners());
+}
+
 void OutputLayer::applyDeviceCompositionTypeChange(hal::Composition compositionType) {
     auto& state = editState();
     LOG_FATAL_IF(!state.hwc);
     auto& hwcState = *state.hwc;
 
-    detectDisallowedCompositionTypeChange(hwcState.hwcCompositionType, compositionType);
+    // Only detected disallowed changes if this was not a skip layer, because the
+    // validated composition type may be arbitrary (usually DEVICE, to reflect that there were
+    // fewer GPU layers)
+    if (!hwcState.layerSkipped) {
+        detectDisallowedCompositionTypeChange(hwcState.hwcCompositionType, compositionType);
+    }
 
     hwcState.hwcCompositionType = compositionType;
 }
diff --git a/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp b/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp
index a63f21f..4453a99 100644
--- a/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp
@@ -20,7 +20,6 @@
 
 #include <compositionengine/impl/planner/Flattener.h>
 #include <compositionengine/impl/planner/LayerState.h>
-#include <compositionengine/impl/planner/Predictor.h>
 
 using time_point = std::chrono::steady_clock::time_point;
 using namespace std::chrono_literals;
@@ -126,9 +125,11 @@
         return left.first < right.first;
     };
 
-    const size_t maxLayerCount = std::max_element(mInitialLayerCounts.cbegin(),
-                                                  mInitialLayerCounts.cend(), compareLayerCounts)
-                                         ->first;
+    const size_t maxLayerCount = mInitialLayerCounts.empty()
+            ? 0u
+            : std::max_element(mInitialLayerCounts.cbegin(), mInitialLayerCounts.cend(),
+                               compareLayerCounts)
+                      ->first;
 
     result.append("\n    Initial counts:\n");
     for (size_t count = 1; count < maxLayerCount; ++count) {
@@ -408,7 +409,7 @@
     }
 
     // TODO(b/181192467): Actually compute new LayerState vector and corresponding hash for each run
-    mPredictor.getPredictedPlan({}, 0);
+    // and feedback into the predictor
 
     ++mCachedSetCreationCount;
     mCachedSetCreationCost += mNewCachedSet->getCreationCost();
diff --git a/services/surfaceflinger/CompositionEngine/src/planner/Planner.cpp b/services/surfaceflinger/CompositionEngine/src/planner/Planner.cpp
index 7e85dca..c26eb1e 100644
--- a/services/surfaceflinger/CompositionEngine/src/planner/Planner.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/planner/Planner.cpp
@@ -27,8 +27,13 @@
 namespace android::compositionengine::impl::planner {
 
 Planner::Planner()
-      : mFlattener(mPredictor,
-                   base::GetBoolProperty(std::string("debug.sf.enable_hole_punch_pip"), false)) {}
+      : mFlattener(base::GetBoolProperty(std::string("debug.sf.enable_hole_punch_pip"), false)) {
+    // Implicitly, layer caching must also be enabled.
+    // E.g., setprop debug.sf.enable_layer_caching 1, or
+    // adb shell service call SurfaceFlinger 1040 i32 1 [i64 <display ID>]
+    mPredictorEnabled =
+            base::GetBoolProperty(std::string("debug.sf.enable_planner_prediction"), false);
+}
 
 void Planner::setDisplaySize(ui::Size size) {
     mFlattener.setDisplaySize(size);
@@ -99,19 +104,25 @@
     const bool layersWereFlattened = hash != mFlattenedHash;
     ALOGV("[%s] Initial hash %zx flattened hash %zx", __func__, hash, mFlattenedHash);
 
-    mPredictedPlan =
-            mPredictor.getPredictedPlan(layersWereFlattened ? std::vector<const LayerState*>()
-                                                            : mCurrentLayers,
-                                        mFlattenedHash);
-    if (mPredictedPlan) {
-        ALOGV("[%s] Predicting plan %s", __func__, to_string(mPredictedPlan->plan).c_str());
-    } else {
-        ALOGV("[%s] No prediction found\n", __func__);
+    if (mPredictorEnabled) {
+        mPredictedPlan =
+                mPredictor.getPredictedPlan(layersWereFlattened ? std::vector<const LayerState*>()
+                                                                : mCurrentLayers,
+                                            mFlattenedHash);
+        if (mPredictedPlan) {
+            ALOGV("[%s] Predicting plan %s", __func__, to_string(mPredictedPlan->plan).c_str());
+        } else {
+            ALOGV("[%s] No prediction found\n", __func__);
+        }
     }
 }
 
 void Planner::reportFinalPlan(
         compositionengine::Output::OutputLayersEnumerator<compositionengine::Output>&& layers) {
+    if (!mPredictorEnabled) {
+        return;
+    }
+
     Plan finalPlan;
     const GraphicBuffer* currentOverrideBuffer = nullptr;
     bool hasSkippedLayers = false;
@@ -185,7 +196,9 @@
                 return;
             }
 
-            mPredictor.compareLayerStacks(leftHash, rightHash, result);
+            if (mPredictorEnabled) {
+                mPredictor.compareLayerStacks(leftHash, rightHash, result);
+            }
         } else if (command == "--describe" || command == "-d") {
             if (args.size() < 3) {
                 base::StringAppendF(&result,
@@ -209,7 +222,9 @@
                 return;
             }
 
-            mPredictor.describeLayerStack(hash, result);
+            if (mPredictorEnabled) {
+                mPredictor.describeLayerStack(hash, result);
+            }
         } else if (command == "--help" || command == "-h") {
             dumpUsage(result);
         } else if (command == "--similar" || command == "-s") {
@@ -232,7 +247,9 @@
                 return;
             }
 
-            mPredictor.listSimilarStacks(*plan, result);
+            if (mPredictorEnabled) {
+                mPredictor.listSimilarStacks(*plan, result);
+            }
         } else if (command == "--layers" || command == "-l") {
             mFlattener.dumpLayers(result);
         } else {
@@ -247,7 +264,9 @@
     mFlattener.dump(result);
     result.append("\n");
 
-    mPredictor.dump(result);
+    if (mPredictorEnabled) {
+        mPredictor.dump(result);
+    }
 }
 
 void Planner::dumpUsage(std::string& result) const {
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
index 3adfe40..5bd1216 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
@@ -1065,12 +1065,62 @@
                               kOverrideSurfaceDamage);
     expectSetHdrMetadataAndBufferCalls(kOverrideHwcSlot, kOverrideBuffer, kOverrideFence);
     expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::DEVICE);
+    EXPECT_CALL(*mLayerFE, hasRoundedCorners()).WillRepeatedly(Return(false));
+
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false, 0,
+                                 /*zIsOverridden*/ false, /*isPeekingThrough*/ false);
+}
+
+TEST_F(OutputLayerWriteStateToHWCTest, previousOverriddenLayerSendsSurfaceDamage) {
+    mLayerFEState.compositionType = Hwc2::IComposerClient::Composition::DEVICE;
+    mOutputLayer.editState().hwc->stateOverridden = true;
+
+    expectGeometryCommonCalls();
+    expectPerFrameCommonCalls(SimulateUnsupported::None, kDataspace, kOutputSpaceVisibleRegion,
+                              Region::INVALID_REGION);
+    expectSetHdrMetadataAndBufferCalls();
+    expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::DEVICE);
+    EXPECT_CALL(*mLayerFE, hasRoundedCorners()).WillRepeatedly(Return(false));
+
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false, 0,
+                                 /*zIsOverridden*/ false, /*isPeekingThrough*/ false);
+}
+
+TEST_F(OutputLayerWriteStateToHWCTest, previousSkipLayerSendsUpdatedDeviceCompositionInfo) {
+    mLayerFEState.compositionType = Hwc2::IComposerClient::Composition::DEVICE;
+    mOutputLayer.editState().hwc->stateOverridden = true;
+    mOutputLayer.editState().hwc->layerSkipped = true;
+    mOutputLayer.editState().hwc->hwcCompositionType = Hwc2::IComposerClient::Composition::DEVICE;
+
+    expectGeometryCommonCalls();
+    expectPerFrameCommonCalls(SimulateUnsupported::None, kDataspace, kOutputSpaceVisibleRegion,
+                              Region::INVALID_REGION);
+    expectSetHdrMetadataAndBufferCalls();
+    expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::DEVICE);
     EXPECT_CALL(*mLayerFE, hasRoundedCorners()).WillOnce(Return(false));
 
     mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false, 0,
                                  /*zIsOverridden*/ false, /*isPeekingThrough*/ false);
 }
 
+TEST_F(OutputLayerWriteStateToHWCTest, previousSkipLayerSendsUpdatedClientCompositionInfo) {
+    mLayerFEState.compositionType = Hwc2::IComposerClient::Composition::DEVICE;
+    mOutputLayer.editState().forceClientComposition = true;
+    mOutputLayer.editState().hwc->stateOverridden = true;
+    mOutputLayer.editState().hwc->layerSkipped = true;
+    mOutputLayer.editState().hwc->hwcCompositionType = Hwc2::IComposerClient::Composition::CLIENT;
+
+    expectGeometryCommonCalls();
+    expectPerFrameCommonCalls(SimulateUnsupported::None, kDataspace, kOutputSpaceVisibleRegion,
+                              Region::INVALID_REGION);
+    expectSetHdrMetadataAndBufferCalls();
+    expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::CLIENT);
+    EXPECT_CALL(*mLayerFE, hasRoundedCorners()).WillRepeatedly(Return(false));
+
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false, 0,
+                                 /*zIsOverridden*/ false, /*isPeekingThrough*/ false);
+}
+
 TEST_F(OutputLayerWriteStateToHWCTest, peekThroughChangesBlendMode) {
     auto peekThroughLayerFE = sp<compositionengine::mock::LayerFE>::make();
     OutputLayer peekThroughLayer{mOutput, peekThroughLayerFE};
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
index 27980a0..11736d1 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
@@ -238,6 +238,28 @@
 }
 
 /*
+ * Output::setLayerCachingEnabled()
+ */
+
+TEST_F(OutputTest, setLayerCachingEnabled_enablesCaching) {
+    const auto kSize = ui::Size(1, 1);
+    EXPECT_CALL(*mRenderSurface, getSize()).WillRepeatedly(ReturnRef(kSize));
+    mOutput->setLayerCachingEnabled(false);
+    mOutput->setLayerCachingEnabled(true);
+
+    EXPECT_TRUE(mOutput->plannerEnabled());
+}
+
+TEST_F(OutputTest, setLayerCachingEnabled_disablesCaching) {
+    const auto kSize = ui::Size(1, 1);
+    EXPECT_CALL(*mRenderSurface, getSize()).WillRepeatedly(ReturnRef(kSize));
+    mOutput->setLayerCachingEnabled(true);
+    mOutput->setLayerCachingEnabled(false);
+
+    EXPECT_FALSE(mOutput->plannerEnabled());
+}
+
+/*
  * Output::setProjection()
  */
 
@@ -972,9 +994,7 @@
     mOutput.editState().usesDeviceComposition = true;
 
     EXPECT_CALL(mOutput, chooseCompositionStrategy()).Times(1);
-    if (mOutput.plannerEnabled()) {
-        EXPECT_CALL(mOutput, getOutputLayerCount()).WillOnce(Return(0u));
-    }
+    EXPECT_CALL(mOutput, getOutputLayerCount()).WillRepeatedly(Return(0u));
     EXPECT_CALL(*mRenderSurface, prepareFrame(false, true));
 
     mOutput.prepareFrame();
diff --git a/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp b/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp
index 71757f6..25fab49 100644
--- a/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp
@@ -18,7 +18,6 @@
 #include <compositionengine/impl/planner/CachedSet.h>
 #include <compositionengine/impl/planner/Flattener.h>
 #include <compositionengine/impl/planner/LayerState.h>
-#include <compositionengine/impl/planner/Predictor.h>
 #include <compositionengine/mock/LayerFE.h>
 #include <compositionengine/mock/OutputLayer.h>
 #include <gtest/gtest.h>
@@ -31,7 +30,6 @@
 using impl::planner::Flattener;
 using impl::planner::LayerState;
 using impl::planner::NonBufferHash;
-using impl::planner::Predictor;
 
 using testing::_;
 using testing::ByMove;
@@ -47,7 +45,7 @@
 
 class FlattenerTest : public testing::Test {
 public:
-    FlattenerTest() : mFlattener(std::make_unique<Flattener>(mPredictor, true)) {}
+    FlattenerTest() : mFlattener(std::make_unique<Flattener>(true)) {}
     void SetUp() override;
 
 protected:
@@ -55,10 +53,6 @@
     void initializeFlattener(const std::vector<const LayerState*>& layers);
     void expectAllLayersFlattened(const std::vector<const LayerState*>& layers);
 
-    // TODO(b/181192467): Once Flattener starts to do something useful with Predictor,
-    // mPredictor should be mocked and checked for expectations.
-    Predictor mPredictor;
-
     // mRenderEngine may be held as a pointer to mFlattener, so mFlattener must be destroyed first.
     renderengine::mock::RenderEngine mRenderEngine;
     std::unique_ptr<Flattener> mFlattener;
diff --git a/services/surfaceflinger/DisplayDevice.cpp b/services/surfaceflinger/DisplayDevice.cpp
index da8c080..0f18235 100644
--- a/services/surfaceflinger/DisplayDevice.cpp
+++ b/services/surfaceflinger/DisplayDevice.cpp
@@ -138,6 +138,10 @@
     getCompositionDisplay()->setCompositionEnabled(mPowerMode != hal::PowerMode::OFF);
 }
 
+void DisplayDevice::enableLayerCaching(bool enable) {
+    getCompositionDisplay()->setLayerCachingEnabled(enable);
+}
+
 hal::PowerMode DisplayDevice::getPowerMode() const {
     return mPowerMode;
 }
diff --git a/services/surfaceflinger/DisplayDevice.h b/services/surfaceflinger/DisplayDevice.h
index 68846d3..bf249cd 100644
--- a/services/surfaceflinger/DisplayDevice.h
+++ b/services/surfaceflinger/DisplayDevice.h
@@ -157,6 +157,9 @@
     void setPowerMode(hardware::graphics::composer::hal::PowerMode mode);
     bool isPoweredOn() const;
 
+    // Enables layer caching on this DisplayDevice
+    void enableLayerCaching(bool enable);
+
     ui::Dataspace getCompositionDataSpace() const;
 
     /* ------------------------------------------------------------------------
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index def2711..4fee723 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -129,7 +129,6 @@
     mCurrentState.frameRateSelectionPriority = PRIORITY_UNSET;
     mCurrentState.metadata = args.metadata;
     mCurrentState.shadowRadius = 0.f;
-    mCurrentState.treeHasFrameRateVote = false;
     mCurrentState.fixedTransformHint = ui::Transform::ROT_INVALID;
     mCurrentState.frameTimelineInfo = {};
     mCurrentState.postTime = -1;
@@ -861,8 +860,15 @@
         // list.
         addSurfaceFrameDroppedForBuffer(bufferSurfaceFrame);
     }
+    const bool frameRateVoteChanged =
+            mDrawingState.frameRateForLayerTree != stateToCommit.frameRateForLayerTree;
     mDrawingState = stateToCommit;
 
+    if (frameRateVoteChanged) {
+        mFlinger->mScheduler->recordLayerHistory(this, systemTime(),
+                                                 LayerHistory::LayerUpdateType::SetFrameRate);
+    }
+
     // Set the present state for all bufferlessSurfaceFramesTX to Presented. The
     // bufferSurfaceFrameTX will be presented in latchBuffer.
     for (auto& [token, surfaceFrame] : mDrawingState.bufferlessSurfaceFramesTX) {
@@ -1265,8 +1271,7 @@
     };
 
     // update parents and children about the vote
-    // First traverse the tree and count how many layers has votes. In addition
-    // activate the layers in Scheduler's LayerHistory for it to check for changes
+    // First traverse the tree and count how many layers has votes.
     int layersWithVote = 0;
     traverseTree([&layersWithVote](Layer* layer) {
         const auto layerVotedWithDefaultCompatibility =
@@ -1286,20 +1291,11 @@
         }
     });
 
-    // Now update the other layers
+    // Now we can update the tree frame rate vote for each layer in the tree
+    const bool treeHasFrameRateVote = layersWithVote > 0;
     bool transactionNeeded = false;
-    traverseTree([layersWithVote, &transactionNeeded, this](Layer* layer) {
-        const bool treeHasFrameRateVote = layersWithVote > 0;
-        if (layer->mCurrentState.treeHasFrameRateVote != treeHasFrameRateVote) {
-            layer->mCurrentState.sequence++;
-            layer->mCurrentState.treeHasFrameRateVote = treeHasFrameRateVote;
-            layer->mCurrentState.modified = true;
-            layer->setTransactionFlags(eTransactionNeeded);
-            transactionNeeded = true;
-
-            mFlinger->mScheduler->recordLayerHistory(layer, systemTime(),
-                                                     LayerHistory::LayerUpdateType::SetFrameRate);
-        }
+    traverseTree([treeHasFrameRateVote, &transactionNeeded](Layer* layer) {
+        transactionNeeded = layer->updateFrameRateForLayerTree(treeHasFrameRateVote);
     });
 
     if (transactionNeeded) {
@@ -1428,32 +1424,42 @@
     return surfaceFrame;
 }
 
-Layer::FrameRate Layer::getFrameRateForLayerTree() const {
-    const auto frameRate = getDrawingState().frameRate;
+bool Layer::updateFrameRateForLayerTree(bool treeHasFrameRateVote) {
+    const auto updateCurrentState = [&](FrameRate frameRate) {
+        if (mCurrentState.frameRateForLayerTree == frameRate) {
+            return false;
+        }
+        mCurrentState.frameRateForLayerTree = frameRate;
+        mCurrentState.sequence++;
+        mCurrentState.modified = true;
+        setTransactionFlags(eTransactionNeeded);
+        return true;
+    };
+
+    const auto frameRate = mCurrentState.frameRate;
     if (frameRate.rate.isValid() || frameRate.type == FrameRateCompatibility::NoVote) {
-        return frameRate;
+        return updateCurrentState(frameRate);
     }
 
     // This layer doesn't have a frame rate. Check if its ancestors have a vote
-    if (sp<Layer> parent = getParent(); parent) {
-        if (const auto parentFrameRate = parent->getFrameRateForLayerTree();
-            parentFrameRate.rate.isValid()) {
-            return parentFrameRate;
+    for (sp<Layer> parent = getParent(); parent; parent = parent->getParent()) {
+        if (parent->mCurrentState.frameRate.rate.isValid()) {
+            return updateCurrentState(parent->mCurrentState.frameRate);
         }
     }
 
     // This layer and its ancestors don't have a frame rate. If one of successors
     // has a vote, return a NoVote for successors to set the vote
-    if (getDrawingState().treeHasFrameRateVote) {
-        return {Fps(0.0f), FrameRateCompatibility::NoVote};
+    if (treeHasFrameRateVote) {
+        return updateCurrentState(FrameRate(Fps(0.0f), FrameRateCompatibility::NoVote));
     }
 
-    return frameRate;
+    return updateCurrentState(frameRate);
 }
 
-// ----------------------------------------------------------------------------
-// pageflip handling...
-// ----------------------------------------------------------------------------
+Layer::FrameRate Layer::getFrameRateForLayerTree() const {
+    return getDrawingState().frameRateForLayerTree;
+}
 
 bool Layer::isHiddenByPolicy() const {
     const State& s(mDrawingState);
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index ad4166b..8139d8a 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -239,8 +239,8 @@
 
         FrameRate frameRate;
 
-        // Indicates whether parents / children of this layer had set FrameRate
-        bool treeHasFrameRateVote;
+        // The combined frame rate of parents / children of this layer
+        FrameRate frameRateForLayerTree;
 
         // Set by window manager indicating the layer and all its children are
         // in a different orientation than the display. The hint suggests that
@@ -1057,6 +1057,8 @@
     // Fills in the frame and transform info for the InputWindowInfo
     void fillInputFrameInfo(InputWindowInfo& info, const ui::Transform& toPhysicalDisplay);
 
+    bool updateFrameRateForLayerTree(bool treeHasFrameRateVote);
+
     // Cached properties computed from drawing state
     // Effective transform taking into account parent transforms and any parent scaling, which is
     // a transform from the current layer coordinate space to display(screen) coordinate space.
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index a033bee..682eff8 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -287,6 +287,8 @@
 const String16 sReadFramebuffer("android.permission.READ_FRAME_BUFFER");
 const String16 sControlDisplayBrightness("android.permission.CONTROL_DISPLAY_BRIGHTNESS");
 const String16 sDump("android.permission.DUMP");
+const String16 sCaptureBlackoutContent("android.permission.CAPTURE_BLACKOUT_CONTENT");
+
 const char* KERNEL_IDLE_TIMER_PROP = "graphics.display.kernel_idle_timer.enabled";
 
 // ---------------------------------------------------------------------------
@@ -381,6 +383,12 @@
     mColorSpaceAgnosticDataspace =
             static_cast<ui::Dataspace>(color_space_agnostic_dataspace(Dataspace::UNKNOWN));
 
+    mLayerCachingEnabled = [] {
+        const bool enable =
+                android::sysprop::SurfaceFlingerProperties::enable_layer_caching().value_or(false);
+        return base::GetBoolProperty(std::string("debug.sf.enable_layer_caching"), enable);
+    }();
+
     useContextPriority = use_context_priority(true);
 
     using Values = SurfaceFlingerProperties::primary_display_orientation_values;
@@ -2632,6 +2640,7 @@
     builder.setGpuVirtualDisplayIdGenerator(mGpuVirtualDisplayIdGenerator);
     builder.setName(state.displayName);
     const auto compositionDisplay = getCompositionEngine().createDisplay(builder.build());
+    compositionDisplay->setLayerCachingEnabled(mLayerCachingEnabled);
 
     sp<compositionengine::DisplaySurface> displaySurface;
     sp<IGraphicBufferProducer> producer;
@@ -5177,9 +5186,9 @@
         code == IBinder::SYSPROPS_TRANSACTION) {
         return OK;
     }
-    // Numbers from 1000 to 1038 are currently used for backdoors. The code
+    // Numbers from 1000 to 1040 are currently used for backdoors. The code
     // in onTransact verifies that the user is root, and has access to use SF.
-    if (code >= 1000 && code <= 1039) {
+    if (code >= 1000 && code <= 1040) {
         ALOGV("Accessing SurfaceFlinger through backdoor code: %u", code);
         return OK;
     }
@@ -5576,6 +5585,36 @@
                 mScheduler->onFrameRateOverridesChanged(mAppConnectionHandle, displayId);
                 return NO_ERROR;
             }
+            // Toggle caching feature
+            // First argument is an int32 - nonzero enables caching and zero disables caching
+            // Second argument is an optional uint64 - if present, then limits enabling/disabling
+            // caching to a particular physical display
+            case 1040: {
+                n = data.readInt32();
+                std::optional<PhysicalDisplayId> inputId = std::nullopt;
+                if (uint64_t inputDisplayId; data.readUint64(&inputDisplayId) == NO_ERROR) {
+                    const auto token =
+                            getPhysicalDisplayToken(static_cast<PhysicalDisplayId>(inputDisplayId));
+                    if (!token) {
+                        ALOGE("No display with id: %" PRIu64, inputDisplayId);
+                        return NAME_NOT_FOUND;
+                    }
+
+                    inputId = std::make_optional<PhysicalDisplayId>(inputDisplayId);
+                }
+                {
+                    Mutex::Autolock lock(mStateLock);
+                    mLayerCachingEnabled = n != 0;
+                    for (const auto& [_, display] : mDisplays) {
+                        if (!inputId || *inputId == display->getPhysicalId()) {
+                            display->enableLayerCaching(mLayerCachingEnabled);
+                        }
+                    }
+                }
+                invalidateHwcGeometry();
+                repaintEverything();
+                return NO_ERROR;
+            }
         }
     }
     return err;
@@ -5671,6 +5710,14 @@
     }
 }
 
+static bool hasCaptureBlackoutContentPermission() {
+    IPCThreadState* ipc = IPCThreadState::self();
+    const int pid = ipc->getCallingPid();
+    const int uid = ipc->getCallingUid();
+    return uid == AID_GRAPHICS || uid == AID_SYSTEM ||
+            PermissionCache::checkPermission(sCaptureBlackoutContent, pid, uid);
+}
+
 static status_t validateScreenshotPermissions(const CaptureArgs& captureArgs) {
     IPCThreadState* ipc = IPCThreadState::self();
     const int pid = ipc->getCallingPid();
@@ -5841,6 +5888,10 @@
     Rect layerStackSpaceRect;
     ui::Dataspace dataspace;
     bool captureSecureLayers;
+
+    // Call this before holding mStateLock to avoid any deadlocking.
+    bool canCaptureBlackoutContent = hasCaptureBlackoutContentPermission();
+
     {
         Mutex::Autolock lock(mStateLock);
 
@@ -5850,9 +5901,8 @@
             return NAME_NOT_FOUND;
         }
 
-        const int uid = IPCThreadState::self()->getCallingUid();
-        const bool forSystem = uid == AID_GRAPHICS || uid == AID_SYSTEM;
-        if (!forSystem && parent->getCurrentState().flags & layer_state_t::eLayerSecure) {
+        if (!canCaptureBlackoutContent &&
+            parent->getCurrentState().flags & layer_state_t::eLayerSecure) {
             ALOGW("Attempting to capture secure layer: PERMISSION_DENIED");
             return PERMISSION_DENIED;
         }
@@ -6002,8 +6052,7 @@
         return BAD_VALUE;
     }
 
-    const int uid = IPCThreadState::self()->getCallingUid();
-    const bool forSystem = uid == AID_GRAPHICS || uid == AID_SYSTEM;
+    bool canCaptureBlackoutContent = hasCaptureBlackoutContentPermission();
 
     static_cast<void>(schedule([=, renderAreaFuture = std::move(renderAreaFuture)]() mutable {
         if (mRefreshPending) {
@@ -6023,8 +6072,9 @@
 
         status_t result = NO_ERROR;
         renderArea->render([&] {
-            result = renderScreenImplLocked(*renderArea, traverseLayers, buffer, forSystem,
-                                            regionSampling, grayscale, captureResults);
+            result = renderScreenImplLocked(*renderArea, traverseLayers, buffer,
+                                            canCaptureBlackoutContent, regionSampling, grayscale,
+                                            captureResults);
         });
 
         captureResults.result = result;
@@ -6036,8 +6086,9 @@
 
 status_t SurfaceFlinger::renderScreenImplLocked(
         const RenderArea& renderArea, TraverseLayersFunction traverseLayers,
-        const std::shared_ptr<renderengine::ExternalTexture>& buffer, bool forSystem,
-        bool regionSampling, bool grayscale, ScreenCaptureResults& captureResults) {
+        const std::shared_ptr<renderengine::ExternalTexture>& buffer,
+        bool canCaptureBlackoutContent, bool regionSampling, bool grayscale,
+        ScreenCaptureResults& captureResults) {
     ATRACE_CALL();
 
     traverseLayers([&](Layer* layer) {
@@ -6050,7 +6101,7 @@
     // We allow the system server to take screenshots of secure layers for
     // use in situations like the Screen-rotation animation and place
     // the impetus on WindowManager to not persist them.
-    if (captureResults.capturedSecureLayers && !forSystem) {
+    if (captureResults.capturedSecureLayers && !canCaptureBlackoutContent) {
         ALOGW("FB is protected: PERMISSION_DENIED");
         return PERMISSION_DENIED;
     }
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 4bbdd48..15b77f1 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -911,8 +911,8 @@
                                  const sp<IScreenCaptureListener>&);
     status_t renderScreenImplLocked(const RenderArea&, TraverseLayersFunction,
                                     const std::shared_ptr<renderengine::ExternalTexture>&,
-                                    bool forSystem, bool regionSampling, bool grayscale,
-                                    ScreenCaptureResults&);
+                                    bool canCaptureBlackoutContent, bool regionSampling,
+                                    bool grayscale, ScreenCaptureResults&);
 
     sp<DisplayDevice> getDisplayByIdOrLayerStack(uint64_t displayOrLayerStack) REQUIRES(mStateLock);
     sp<DisplayDevice> getDisplayById(DisplayId displayId) const REQUIRES(mStateLock);
@@ -1236,6 +1236,7 @@
     int mDebugRegion = 0;
     bool mDebugDisableHWC = false;
     bool mDebugDisableTransformHint = false;
+    bool mLayerCachingEnabled = false;
     volatile nsecs_t mDebugInTransaction = 0;
     bool mForceFullDamage = false;
     bool mPropagateBackpressureClientComposition = false;
diff --git a/services/surfaceflinger/tests/LayerTypeTransaction_test.cpp b/services/surfaceflinger/tests/LayerTypeTransaction_test.cpp
index 4753362..34c9182 100644
--- a/services/surfaceflinger/tests/LayerTypeTransaction_test.cpp
+++ b/services/surfaceflinger/tests/LayerTypeTransaction_test.cpp
@@ -19,6 +19,7 @@
 #pragma clang diagnostic ignored "-Wconversion"
 
 #include <gui/BufferItemConsumer.h>
+#include <private/android_filesystem_config.h>
 #include "TransactionTestHarnesses.h"
 
 namespace android {
@@ -170,7 +171,11 @@
     args.displayToken = mDisplay;
 
     ScreenCaptureResults captureResults;
-    ASSERT_EQ(PERMISSION_DENIED, ScreenCapture::captureDisplay(args, captureResults));
+    {
+        // Ensure the UID is not root because root has all permissions
+        UIDFaker f(AID_APP_START);
+        ASSERT_EQ(PERMISSION_DENIED, ScreenCapture::captureDisplay(args, captureResults));
+    }
 
     Transaction().setFlags(layer, 0, layer_state_t::eLayerSecure).apply(true);
     ASSERT_EQ(NO_ERROR, ScreenCapture::captureDisplay(args, captureResults));
diff --git a/services/surfaceflinger/tests/ScreenCapture_test.cpp b/services/surfaceflinger/tests/ScreenCapture_test.cpp
index 2e9c10c..6912fcf 100644
--- a/services/surfaceflinger/tests/ScreenCapture_test.cpp
+++ b/services/surfaceflinger/tests/ScreenCapture_test.cpp
@@ -84,7 +84,11 @@
 
     Transaction().show(layer).setLayer(layer, INT32_MAX).apply(true);
 
-    ASSERT_EQ(PERMISSION_DENIED, ScreenCapture::captureDisplay(mCaptureArgs, mCaptureResults));
+    {
+        // Ensure the UID is not root because root has all permissions
+        UIDFaker f(AID_APP_START);
+        ASSERT_EQ(PERMISSION_DENIED, ScreenCapture::captureDisplay(mCaptureArgs, mCaptureResults));
+    }
 
     UIDFaker f(AID_SYSTEM);
 
@@ -528,7 +532,7 @@
     ASSERT_EQ(NAME_NOT_FOUND, ScreenCapture::captureLayers(args, captureResults));
 }
 
-TEST_F(ScreenCaptureTest, CaputureSecureLayer) {
+TEST_F(ScreenCaptureTest, CaptureSecureLayer) {
     sp<SurfaceControl> redLayer = createLayer(String8("Red surface"), 60, 60,
                                               ISurfaceComposerClient::eFXSurfaceBufferState);
     sp<SurfaceControl> secureLayer =
@@ -552,8 +556,12 @@
     args.childrenOnly = false;
     ScreenCaptureResults captureResults;
 
-    // Call from outside system with secure layers will result in permission denied
-    ASSERT_EQ(PERMISSION_DENIED, ScreenCapture::captureLayers(args, captureResults));
+    {
+        // Ensure the UID is not root because root has all permissions
+        UIDFaker f(AID_APP_START);
+        // Call from outside system with secure layers will result in permission denied
+        ASSERT_EQ(PERMISSION_DENIED, ScreenCapture::captureLayers(args, captureResults));
+    }
 
     UIDFaker f(AID_SYSTEM);