Merge "Polish up metadata propagation for native window" into tm-dev
diff --git a/cmds/dumpstate/dumpstate.cpp b/cmds/dumpstate/dumpstate.cpp
index 24b201f..890c15f 100644
--- a/cmds/dumpstate/dumpstate.cpp
+++ b/cmds/dumpstate/dumpstate.cpp
@@ -2733,8 +2733,8 @@
                                         const android::base::unique_fd& screenshot_fd_in,
                                         bool is_screenshot_requested) {
     // Duplicate the fds because the passed in fds don't outlive the binder transaction.
-    bugreport_fd.reset(dup(bugreport_fd_in.get()));
-    screenshot_fd.reset(dup(screenshot_fd_in.get()));
+    bugreport_fd.reset(fcntl(bugreport_fd_in.get(), F_DUPFD_CLOEXEC, 0));
+    screenshot_fd.reset(fcntl(screenshot_fd_in.get(), F_DUPFD_CLOEXEC, 0));
 
     SetOptionsFromMode(bugreport_mode, this, is_screenshot_requested);
 }
diff --git a/cmds/installd/InstalldNativeService.cpp b/cmds/installd/InstalldNativeService.cpp
index c104fea..4e12579 100644
--- a/cmds/installd/InstalldNativeService.cpp
+++ b/cmds/installd/InstalldNativeService.cpp
@@ -1176,6 +1176,25 @@
     return res;
 }
 
+binder::Status InstalldNativeService::deleteReferenceProfile(const std::string& packageName,
+                                                             const std::string& profileName) {
+    ENFORCE_UID(AID_SYSTEM);
+    CHECK_ARGUMENT_PACKAGE_NAME(packageName);
+    LOCK_PACKAGE();
+
+    // This function only supports primary dex'es.
+    std::string path =
+            create_reference_profile_path(packageName, profileName, /*is_secondary_dex=*/false);
+    if (unlink(path.c_str()) != 0) {
+        if (errno == ENOENT) {
+            return ok();
+        } else {
+            return error("Failed to delete profile " + profileName + " for " + packageName);
+        }
+    }
+    return ok();
+}
+
 binder::Status InstalldNativeService::destroyAppData(const std::optional<std::string>& uuid,
         const std::string& packageName, int32_t userId, int32_t flags, int64_t ceDataInode) {
     ENFORCE_UID(AID_SYSTEM);
diff --git a/cmds/installd/InstalldNativeService.h b/cmds/installd/InstalldNativeService.h
index 87a9206..0432222 100644
--- a/cmds/installd/InstalldNativeService.h
+++ b/cmds/installd/InstalldNativeService.h
@@ -140,6 +140,8 @@
             bool* _aidl_return);
     binder::Status clearAppProfiles(const std::string& packageName, const std::string& profileName);
     binder::Status destroyAppProfiles(const std::string& packageName);
+    binder::Status deleteReferenceProfile(const std::string& packageName,
+                                          const std::string& profileName);
 
     binder::Status createProfileSnapshot(int32_t appId, const std::string& packageName,
             const std::string& profileName, const std::string& classpath, bool* _aidl_return);
diff --git a/cmds/installd/binder/android/os/IInstalld.aidl b/cmds/installd/binder/android/os/IInstalld.aidl
index 79c02e8..db03411 100644
--- a/cmds/installd/binder/android/os/IInstalld.aidl
+++ b/cmds/installd/binder/android/os/IInstalld.aidl
@@ -82,6 +82,7 @@
             @utf8InCpp String packageName, @utf8InCpp String profileName);
     void clearAppProfiles(@utf8InCpp String packageName, @utf8InCpp String profileName);
     void destroyAppProfiles(@utf8InCpp String packageName);
+    void deleteReferenceProfile(@utf8InCpp String packageName, @utf8InCpp String profileName);
 
     boolean createProfileSnapshot(int appId, @utf8InCpp String packageName,
             @utf8InCpp String profileName, @utf8InCpp String classpath);
diff --git a/cmds/installd/utils.cpp b/cmds/installd/utils.cpp
index 9801a9b..45aeab6 100644
--- a/cmds/installd/utils.cpp
+++ b/cmds/installd/utils.cpp
@@ -707,16 +707,16 @@
     auto temp_dir_path =
             base::StringPrintf("%s/%s", Dirname(pathname).c_str(), temp_dir_name.c_str());
 
-    if (::rename(pathname.c_str(), temp_dir_path.c_str())) {
+    auto dir_to_delete = temp_dir_path.c_str();
+    if (::rename(pathname.c_str(), dir_to_delete)) {
         if (ignore_if_missing && (errno == ENOENT)) {
             return 0;
         }
-        ALOGE("Couldn't rename %s -> %s: %s \n", pathname.c_str(), temp_dir_path.c_str(),
-              strerror(errno));
-        return -errno;
+        ALOGE("Couldn't rename %s -> %s: %s \n", pathname.c_str(), dir_to_delete, strerror(errno));
+        dir_to_delete = pathname.c_str();
     }
 
-    return delete_dir_contents(temp_dir_path.c_str(), 1, exclusion_predicate, ignore_if_missing);
+    return delete_dir_contents(dir_to_delete, 1, exclusion_predicate, ignore_if_missing);
 }
 
 bool is_renamed_deleted_dir(const std::string& path) {
diff --git a/include/android/multinetwork.h b/include/android/multinetwork.h
index 4c83a14..ee392fc 100644
--- a/include/android/multinetwork.h
+++ b/include/android/multinetwork.h
@@ -235,7 +235,7 @@
  *
  * Available since API level 33.
  */
-int android_tag_socket_with_uid(int sockfd, int tag, uid_t uid) __INTRODUCED_IN(33);
+int android_tag_socket_with_uid(int sockfd, uint32_t tag, uid_t uid) __INTRODUCED_IN(33);
 
 /*
  * Set the socket tag for traffic statistics on the specified socket.
@@ -245,14 +245,26 @@
  * opened by another UID or was previously tagged by another UID. Subsequent
  * calls always replace any existing parameters. The socket tag is kept when the
  * socket is sent to another process using binder IPCs or other mechanisms such
- * as UNIX socket fd passing.
+ * as UNIX socket fd passing. The tag is a value defined by the caller and used
+ * together with uid for data traffic accounting, so that the function callers
+ * can account different types of data usage for a uid.
  *
  * Returns 0 on success, or a negative POSIX error code (see errno.h) on
  * failure.
  *
+ * Some possible error codes:
+ * -EBADF           Bad socketfd.
+ * -EPERM           No permission.
+ * -EAFNOSUPPORT    Socket family is neither AF_INET nor AF_INET6.
+ * -EPROTONOSUPPORT Socket protocol is neither IPPROTO_UDP nor IPPROTO_TCP.
+ * -EMFILE          Too many stats entries.
+ * There are still other error codes that may provided by -errno of
+ * [getsockopt()](https://man7.org/linux/man-pages/man2/getsockopt.2.html) or by
+ * BPF maps read/write sys calls, which are set appropriately.
+ *
  * Available since API level 33.
  */
-int android_tag_socket(int sockfd, int tag) __INTRODUCED_IN(33);
+int android_tag_socket(int sockfd, uint32_t tag) __INTRODUCED_IN(33);
 
 /*
  * Untag a network socket.
@@ -267,6 +279,12 @@
  * Returns 0 on success, or a negative POSIX error code (see errno.h) on
  * failure.
  *
+ * One of possible error code:
+ * -EBADF           Bad socketfd.
+ * Other error codes are either provided by -errno of
+ * [getsockopt()](https://man7.org/linux/man-pages/man2/getsockopt.2.html) or by
+ * BPF map element deletion sys call, which are set appropriately.
+ *
  * Available since API level 33.
  */
 int android_untag_socket(int sockfd) __INTRODUCED_IN(33);
diff --git a/include/ftl/Flags.h b/include/ftl/Flags.h
index 708eaf5..db3d9ea 100644
--- a/include/ftl/Flags.h
+++ b/include/ftl/Flags.h
@@ -19,13 +19,12 @@
 #include <ftl/enum.h>
 #include <ftl/string.h>
 
+#include <bitset>
 #include <cstdint>
 #include <iterator>
 #include <string>
 #include <type_traits>
 
-#include "utils/BitSet.h"
-
 // TODO(b/185536303): Align with FTL style and namespace.
 
 namespace android {
@@ -56,21 +55,22 @@
           : mFlags(t) {}
 
     class Iterator {
-        // The type can't be larger than 64-bits otherwise it won't fit in BitSet64.
-        static_assert(sizeof(U) <= sizeof(uint64_t));
+        using Bits = std::uint64_t;
+        static_assert(sizeof(U) <= sizeof(Bits));
 
     public:
+        constexpr Iterator() = default;
         Iterator(Flags<F> flags) : mRemainingFlags(flags.mFlags) { (*this)++; }
-        Iterator() : mRemainingFlags(0), mCurrFlag(static_cast<F>(0)) {}
 
         // Pre-fix ++
         Iterator& operator++() {
-            if (mRemainingFlags.isEmpty()) {
-                mCurrFlag = static_cast<F>(0);
+            if (mRemainingFlags.none()) {
+                mCurrFlag = 0;
             } else {
-                uint64_t bit = mRemainingFlags.clearLastMarkedBit(); // counts from left
-                const U flag = 1 << (64 - bit - 1);
-                mCurrFlag = static_cast<F>(flag);
+                // TODO: Replace with std::countr_zero in C++20.
+                const Bits bit = static_cast<Bits>(__builtin_ctzll(mRemainingFlags.to_ullong()));
+                mRemainingFlags.reset(static_cast<std::size_t>(bit));
+                mCurrFlag = static_cast<U>(static_cast<Bits>(1) << bit);
             }
             return *this;
         }
@@ -88,7 +88,7 @@
 
         bool operator!=(Iterator other) const { return !(*this == other); }
 
-        F operator*() { return mCurrFlag; }
+        F operator*() const { return F{mCurrFlag}; }
 
         // iterator traits
 
@@ -107,8 +107,8 @@
         using pointer = void;
 
     private:
-        BitSet64 mRemainingFlags;
-        F mCurrFlag;
+        std::bitset<sizeof(Bits) * 8> mRemainingFlags;
+        U mCurrFlag = 0;
     };
 
     /*
diff --git a/include/ftl/enum.h b/include/ftl/enum.h
index 5234c05..82af1d6 100644
--- a/include/ftl/enum.h
+++ b/include/ftl/enum.h
@@ -261,10 +261,10 @@
   const auto value = to_underlying(v);
 
   // TODO: Replace with std::popcount and std::countr_zero in C++20.
-  if (__builtin_popcountl(value) != 1) return {};
+  if (__builtin_popcountll(value) != 1) return {};
 
   constexpr auto kRange = details::EnumRange<E, details::FlagName>{};
-  return kRange.values[__builtin_ctzl(value)];
+  return kRange.values[__builtin_ctzll(value)];
 }
 
 // Returns a stringified enumerator, or its integral value if not named.
diff --git a/include/ftl/fake_guard.h b/include/ftl/fake_guard.h
new file mode 100644
index 0000000..bacd1b2
--- /dev/null
+++ b/include/ftl/fake_guard.h
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#define FTL_ATTRIBUTE(a) __attribute__((a))
+
+namespace android::ftl {
+
+// Granular alternative to [[clang::no_thread_safety_analysis]]. Given a std::mutex-like object,
+// FakeGuard suppresses enforcement of thread-safe access to guarded variables within its scope.
+// While FakeGuard is scoped to a block, there are macro shorthands for a single expression, as
+// well as function/lambda scope (though calls must be indirect, e.g. virtual or std::function):
+//
+//   struct {
+//     std::mutex mutex;
+//     int x FTL_ATTRIBUTE(guarded_by(mutex)) = -1;
+//
+//     int f() {
+//       {
+//         ftl::FakeGuard guard(mutex);
+//         x = 0;
+//       }
+//
+//       return FTL_FAKE_GUARD(mutex, x + 1);
+//     }
+//
+//      std::function<int()> g() const {
+//        return [this]() FTL_FAKE_GUARD(mutex) { return x; };
+//      }
+//   } s;
+//
+//   assert(s.f() == 1);
+//   assert(s.g()() == 0);
+//
+// An example of a situation where FakeGuard helps is a mutex that guards writes on Thread 1, and
+// reads on Thread 2. Reads on Thread 1, which is the only writer, need not be under lock, so can
+// use FakeGuard to appease the thread safety analyzer. Another example is enforcing and documenting
+// exclusive access by a single thread. This is done by defining a global constant that represents a
+// thread context, and annotating guarded variables as if it were a mutex (though without any effect
+// at run time):
+//
+//   constexpr class [[clang::capability("mutex")]] {
+//   } kMainThreadContext;
+//
+template <typename Mutex>
+struct [[clang::scoped_lockable]] FakeGuard final {
+  explicit FakeGuard(const Mutex& mutex) FTL_ATTRIBUTE(acquire_capability(mutex)) {}
+  [[clang::release_capability()]] ~FakeGuard() {}
+
+  FakeGuard(const FakeGuard&) = delete;
+  FakeGuard& operator=(const FakeGuard&) = delete;
+};
+
+}  // namespace android::ftl
+
+// TODO: Enable in C++23 once standard attributes can be used on lambdas.
+#if 0
+#define FTL_FAKE_GUARD1(mutex) [[using clang: acquire_capability(mutex), release_capability(mutex)]]
+#else
+#define FTL_FAKE_GUARD1(mutex)             \
+  FTL_ATTRIBUTE(acquire_capability(mutex)) \
+  FTL_ATTRIBUTE(release_capability(mutex))
+#endif
+
+// The parentheses around `expr` are needed to deduce an lvalue or rvalue reference.
+#define FTL_FAKE_GUARD2(mutex, expr)            \
+  [&]() -> decltype(auto) {                     \
+    const android::ftl::FakeGuard guard(mutex); \
+    return (expr);                              \
+  }()
+
+#define FTL_MAKE_FAKE_GUARD(arg1, arg2, guard, ...) guard
+
+// The void argument suppresses a warning about zero variadic macro arguments.
+#define FTL_FAKE_GUARD(...) \
+  FTL_MAKE_FAKE_GUARD(__VA_ARGS__, FTL_FAKE_GUARD2, FTL_FAKE_GUARD1, void)(__VA_ARGS__)
diff --git a/include/input/PrintTools.h b/include/input/PrintTools.h
new file mode 100644
index 0000000..7c3b29b
--- /dev/null
+++ b/include/input/PrintTools.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <map>
+#include <set>
+#include <string>
+
+namespace android {
+
+template <typename T>
+std::string constToString(const T& v) {
+    return std::to_string(v);
+}
+
+/**
+ * Convert a set of integral types to string.
+ */
+template <typename T>
+std::string dumpSet(const std::set<T>& v, std::string (*toString)(const T&) = constToString) {
+    std::string out;
+    for (const T& entry : v) {
+        out += out.empty() ? "{" : ", ";
+        out += toString(entry);
+    }
+    return out.empty() ? "{}" : (out + "}");
+}
+
+/**
+ * Convert a map to string. Both keys and values of the map should be integral type.
+ */
+template <typename K, typename V>
+std::string dumpMap(const std::map<K, V>& map, std::string (*keyToString)(const K&) = constToString,
+                    std::string (*valueToString)(const V&) = constToString) {
+    std::string out;
+    for (const auto& [k, v] : map) {
+        if (!out.empty()) {
+            out += "\n";
+        }
+        out += keyToString(k) + ":" + valueToString(v);
+    }
+    return out;
+}
+
+const char* toString(bool value);
+
+} // namespace android
\ No newline at end of file
diff --git a/libs/binder/IUidObserver.cpp b/libs/binder/IUidObserver.cpp
index a1b08db..d952dc7 100644
--- a/libs/binder/IUidObserver.cpp
+++ b/libs/binder/IUidObserver.cpp
@@ -57,8 +57,7 @@
     }
 
     virtual void onUidStateChanged(uid_t uid, int32_t procState, int64_t procStateSeq,
-            int32_t capability)
-    {
+                                   int32_t capability) {
         Parcel data, reply;
         data.writeInterfaceToken(IUidObserver::getInterfaceDescriptor());
         data.writeInt32((int32_t) uid);
@@ -67,6 +66,12 @@
         data.writeInt32(capability);
         remote()->transact(ON_UID_STATE_CHANGED_TRANSACTION, data, &reply, IBinder::FLAG_ONEWAY);
     }
+
+    virtual void onUidProcAdjChanged(uid_t uid) {
+        Parcel data, reply;
+        data.writeInt32((int32_t)uid);
+        remote()->transact(ON_UID_PROC_ADJ_CHANGED_TRANSACTION, data, &reply, IBinder::FLAG_ONEWAY);
+    }
 };
 
 // ----------------------------------------------------------------------
@@ -102,6 +107,7 @@
             onUidIdle(uid, disabled);
             return NO_ERROR;
         } break;
+
         case ON_UID_STATE_CHANGED_TRANSACTION: {
             CHECK_INTERFACE(IUidObserver, data, reply);
             uid_t uid = data.readInt32();
@@ -111,6 +117,14 @@
             onUidStateChanged(uid, procState, procStateSeq, capability);
             return NO_ERROR;
         } break;
+
+        case ON_UID_PROC_ADJ_CHANGED_TRANSACTION: {
+            CHECK_INTERFACE(IUidObserver, data, reply);
+            uid_t uid = data.readInt32();
+            onUidProcAdjChanged(uid);
+            return NO_ERROR;
+        } break;
+
         default:
             return BBinder::onTransact(code, data, reply, flags);
     }
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index be50a75..58b0b35 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -1584,6 +1584,7 @@
 template<class T>
 status_t Parcel::readAligned(T *pArg) const {
     static_assert(PAD_SIZE_UNSAFE(sizeof(T)) == sizeof(T));
+    static_assert(std::is_trivially_copyable_v<T>);
 
     if ((mDataPos+sizeof(T)) <= mDataSize) {
         if (mObjectsSize > 0) {
@@ -1595,9 +1596,8 @@
             }
         }
 
-        const void* data = mData+mDataPos;
+        memcpy(pArg, mData + mDataPos, sizeof(T));
         mDataPos += sizeof(T);
-        *pArg =  *reinterpret_cast<const T*>(data);
         return NO_ERROR;
     } else {
         return NOT_ENOUGH_DATA;
@@ -1617,10 +1617,11 @@
 template<class T>
 status_t Parcel::writeAligned(T val) {
     static_assert(PAD_SIZE_UNSAFE(sizeof(T)) == sizeof(T));
+    static_assert(std::is_trivially_copyable_v<T>);
 
     if ((mDataPos+sizeof(val)) <= mDataCapacity) {
 restart_write:
-        *reinterpret_cast<T*>(mData+mDataPos) = val;
+        memcpy(mData + mDataPos, &val, sizeof(val));
         return finishWrite(sizeof(val));
     }
 
diff --git a/libs/binder/RpcState.cpp b/libs/binder/RpcState.cpp
index 2e7084e..6d89064 100644
--- a/libs/binder/RpcState.cpp
+++ b/libs/binder/RpcState.cpp
@@ -313,7 +313,8 @@
                            const sp<RpcSession>& session, const char* what, iovec* iovs, int niovs,
                            const std::function<status_t()>& altPoll) {
     for (int i = 0; i < niovs; i++) {
-        LOG_RPC_DETAIL("Sending %s on RpcTransport %p: %s", what, connection->rpcTransport.get(),
+        LOG_RPC_DETAIL("Sending %s (part %d of %d) on RpcTransport %p: %s",
+                       what, i + 1, niovs, connection->rpcTransport.get(),
                        android::base::HexString(iovs[i].iov_base, iovs[i].iov_len).c_str());
     }
 
@@ -343,7 +344,8 @@
     }
 
     for (int i = 0; i < niovs; i++) {
-        LOG_RPC_DETAIL("Received %s on RpcTransport %p: %s", what, connection->rpcTransport.get(),
+        LOG_RPC_DETAIL("Received %s (part %d of %d) on RpcTransport %p: %s",
+                       what, i + 1, niovs, connection->rpcTransport.get(),
                        android::base::HexString(iovs[i].iov_base, iovs[i].iov_len).c_str());
     }
     return OK;
@@ -660,8 +662,14 @@
 status_t RpcState::drainCommands(const sp<RpcSession::RpcConnection>& connection,
                                  const sp<RpcSession>& session, CommandType type) {
     uint8_t buf;
-    while (connection->rpcTransport->peek(&buf, sizeof(buf)).value_or(0) > 0) {
-        status_t status = getAndExecuteCommand(connection, session, type);
+    while (true) {
+        size_t num_bytes;
+        status_t status = connection->rpcTransport->peek(&buf, sizeof(buf), &num_bytes);
+        if (status == WOULD_BLOCK) break;
+        if (status != OK) return status;
+        if (!num_bytes) break;
+
+        status = getAndExecuteCommand(connection, session, type);
         if (status != OK) return status;
     }
     return OK;
diff --git a/libs/binder/RpcTransportRaw.cpp b/libs/binder/RpcTransportRaw.cpp
index 636e5d0..7cfc780 100644
--- a/libs/binder/RpcTransportRaw.cpp
+++ b/libs/binder/RpcTransportRaw.cpp
@@ -24,9 +24,6 @@
 #include "FdTrigger.h"
 #include "RpcState.h"
 
-using android::base::ErrnoError;
-using android::base::Result;
-
 namespace android {
 
 namespace {
@@ -35,12 +32,20 @@
 class RpcTransportRaw : public RpcTransport {
 public:
     explicit RpcTransportRaw(android::base::unique_fd socket) : mSocket(std::move(socket)) {}
-    Result<size_t> peek(void *buf, size_t size) override {
+    status_t peek(void* buf, size_t size, size_t* out_size) override {
         ssize_t ret = TEMP_FAILURE_RETRY(::recv(mSocket.get(), buf, size, MSG_PEEK));
         if (ret < 0) {
-            return ErrnoError() << "recv(MSG_PEEK)";
+            int savedErrno = errno;
+            if (savedErrno == EAGAIN || savedErrno == EWOULDBLOCK) {
+                return WOULD_BLOCK;
+            }
+
+            LOG_RPC_DETAIL("RpcTransport peek(): %s", strerror(savedErrno));
+            return -savedErrno;
         }
-        return ret;
+
+        *out_size = static_cast<size_t>(ret);
+        return OK;
     }
 
     template <typename SendOrReceive>
diff --git a/libs/binder/RpcTransportTls.cpp b/libs/binder/RpcTransportTls.cpp
index 3936204..bc68c37 100644
--- a/libs/binder/RpcTransportTls.cpp
+++ b/libs/binder/RpcTransportTls.cpp
@@ -37,10 +37,6 @@
 #define LOG_TLS_DETAIL(...) ALOGV(__VA_ARGS__) // for type checking
 #endif
 
-using android::base::ErrnoError;
-using android::base::Error;
-using android::base::Result;
-
 namespace android {
 namespace {
 
@@ -165,17 +161,8 @@
         return ret;
     }
 
-    // |sslError| should be from Ssl::getError().
-    // If |sslError| is WANT_READ / WANT_WRITE, poll for POLLIN / POLLOUT respectively. Otherwise
-    // return error. Also return error if |fdTrigger| is triggered before or during poll().
-    status_t pollForSslError(android::base::borrowed_fd fd, int sslError, FdTrigger* fdTrigger,
-                             const char* fnString, int additionalEvent,
-                             const std::function<status_t()>& altPoll) {
+    status_t toStatus(int sslError, const char* fnString) {
         switch (sslError) {
-            case SSL_ERROR_WANT_READ:
-                return handlePoll(POLLIN | additionalEvent, fd, fdTrigger, fnString, altPoll);
-            case SSL_ERROR_WANT_WRITE:
-                return handlePoll(POLLOUT | additionalEvent, fd, fdTrigger, fnString, altPoll);
             case SSL_ERROR_SYSCALL: {
                 auto queue = toString();
                 LOG_TLS_DETAIL("%s(): %s. Treating as DEAD_OBJECT. Error queue: %s", fnString,
@@ -191,6 +178,22 @@
         }
     }
 
+    // |sslError| should be from Ssl::getError().
+    // If |sslError| is WANT_READ / WANT_WRITE, poll for POLLIN / POLLOUT respectively. Otherwise
+    // return error. Also return error if |fdTrigger| is triggered before or during poll().
+    status_t pollForSslError(android::base::borrowed_fd fd, int sslError, FdTrigger* fdTrigger,
+                             const char* fnString, int additionalEvent,
+                             const std::function<status_t()>& altPoll) {
+        switch (sslError) {
+            case SSL_ERROR_WANT_READ:
+                return handlePoll(POLLIN | additionalEvent, fd, fdTrigger, fnString, altPoll);
+            case SSL_ERROR_WANT_WRITE:
+                return handlePoll(POLLOUT | additionalEvent, fd, fdTrigger, fnString, altPoll);
+            default:
+                return toStatus(sslError, fnString);
+        }
+    }
+
 private:
     bool mHandled = false;
 
@@ -274,7 +277,7 @@
 public:
     RpcTransportTls(android::base::unique_fd socket, Ssl ssl)
           : mSocket(std::move(socket)), mSsl(std::move(ssl)) {}
-    Result<size_t> peek(void* buf, size_t size) override;
+    status_t peek(void* buf, size_t size, size_t* out_size) override;
     status_t interruptableWriteFully(FdTrigger* fdTrigger, iovec* iovs, int niovs,
                                      const std::function<status_t()>& altPoll) override;
     status_t interruptableReadFully(FdTrigger* fdTrigger, iovec* iovs, int niovs,
@@ -286,7 +289,7 @@
 };
 
 // Error code is errno.
-Result<size_t> RpcTransportTls::peek(void* buf, size_t size) {
+status_t RpcTransportTls::peek(void* buf, size_t size, size_t* out_size) {
     size_t todo = std::min<size_t>(size, std::numeric_limits<int>::max());
     auto [ret, errorQueue] = mSsl.call(SSL_peek, buf, static_cast<int>(todo));
     if (ret < 0) {
@@ -294,13 +297,15 @@
         if (err == SSL_ERROR_WANT_WRITE || err == SSL_ERROR_WANT_READ) {
             // Seen EAGAIN / EWOULDBLOCK on recv(2) / send(2).
             // Like RpcTransportRaw::peek(), don't handle it here.
-            return Error(EWOULDBLOCK) << "SSL_peek(): " << errorQueue.toString();
+            errorQueue.clear();
+            return WOULD_BLOCK;
         }
-        return Error() << "SSL_peek(): " << errorQueue.toString();
+        return errorQueue.toStatus(err, "SSL_peek");
     }
     errorQueue.clear();
     LOG_TLS_DETAIL("TLS: Peeked %d bytes!", ret);
-    return ret;
+    *out_size = static_cast<size_t>(ret);
+    return OK;
 }
 
 status_t RpcTransportTls::interruptableWriteFully(FdTrigger* fdTrigger, iovec* iovs, int niovs,
diff --git a/libs/binder/include/binder/RpcTransport.h b/libs/binder/include/binder/RpcTransport.h
index ade2d94..751c4f9 100644
--- a/libs/binder/include/binder/RpcTransport.h
+++ b/libs/binder/include/binder/RpcTransport.h
@@ -22,7 +22,6 @@
 #include <memory>
 #include <string>
 
-#include <android-base/result.h>
 #include <android-base/unique_fd.h>
 #include <utils/Errors.h>
 
@@ -41,7 +40,7 @@
     virtual ~RpcTransport() = default;
 
     // replacement of ::recv(MSG_PEEK). Error code may not be set if TLS is enabled.
-    [[nodiscard]] virtual android::base::Result<size_t> peek(void *buf, size_t size) = 0;
+    [[nodiscard]] virtual status_t peek(void *buf, size_t size, size_t *out_size) = 0;
 
     /**
      * Read (or write), but allow to be interrupted by a trigger.
diff --git a/libs/binder/include_activitymanager/binder/ActivityManager.h b/libs/binder/include_activitymanager/binder/ActivityManager.h
index abc7f1d..5dfbd44 100644
--- a/libs/binder/include_activitymanager/binder/ActivityManager.h
+++ b/libs/binder/include_activitymanager/binder/ActivityManager.h
@@ -31,20 +31,21 @@
 class ActivityManager
 {
 public:
-
     enum {
         // Flag for registerUidObserver: report uid state changed
-        UID_OBSERVER_PROCSTATE = 1<<0,
+        UID_OBSERVER_PROCSTATE = 1 << 0,
         // Flag for registerUidObserver: report uid gone
-        UID_OBSERVER_GONE = 1<<1,
+        UID_OBSERVER_GONE = 1 << 1,
         // Flag for registerUidObserver: report uid has become idle
-        UID_OBSERVER_IDLE = 1<<2,
+        UID_OBSERVER_IDLE = 1 << 2,
         // Flag for registerUidObserver: report uid has become active
-        UID_OBSERVER_ACTIVE = 1<<3,
+        UID_OBSERVER_ACTIVE = 1 << 3,
         // Flag for registerUidObserver: report uid cached state has changed
-        UID_OBSERVER_CACHED = 1<<4,
+        UID_OBSERVER_CACHED = 1 << 4,
         // Flag for registerUidObserver: report uid capability has changed
-        UID_OBSERVER_CAPABILITY = 1<<5,
+        UID_OBSERVER_CAPABILITY = 1 << 5,
+        // Flag for registerUidObserver: report pid oom adj has changed
+        UID_OBSERVER_PROC_OOM_ADJ = 1 << 6,
     };
 
     // PROCESS_STATE_* must come from frameworks/base/core/java/android/app/ProcessStateEnum.aidl.
diff --git a/libs/binder/include_activitymanager/binder/IUidObserver.h b/libs/binder/include_activitymanager/binder/IUidObserver.h
index 9291c0b..17f03a9 100644
--- a/libs/binder/include_activitymanager/binder/IUidObserver.h
+++ b/libs/binder/include_activitymanager/binder/IUidObserver.h
@@ -33,13 +33,15 @@
     virtual void onUidActive(uid_t uid) = 0;
     virtual void onUidIdle(uid_t uid, bool disabled) = 0;
     virtual void onUidStateChanged(uid_t uid, int32_t procState, int64_t procStateSeq,
-            int32_t capability) = 0;
+                                   int32_t capability) = 0;
+    virtual void onUidProcAdjChanged(uid_t uid) = 0;
 
     enum {
         ON_UID_GONE_TRANSACTION = IBinder::FIRST_CALL_TRANSACTION,
         ON_UID_ACTIVE_TRANSACTION,
         ON_UID_IDLE_TRANSACTION,
-        ON_UID_STATE_CHANGED_TRANSACTION
+        ON_UID_STATE_CHANGED_TRANSACTION,
+        ON_UID_PROC_ADJ_CHANGED_TRANSACTION
     };
 };
 
diff --git a/libs/binder/tests/include_tls_test_utils/binder/RpcTlsTestUtils.h b/libs/binder/tests/include_tls_test_utils/binder/RpcTlsTestUtils.h
index 094addd..50d12c4 100644
--- a/libs/binder/tests/include_tls_test_utils/binder/RpcTlsTestUtils.h
+++ b/libs/binder/tests/include_tls_test_utils/binder/RpcTlsTestUtils.h
@@ -18,6 +18,7 @@
 
 #include <memory>
 #include <mutex>
+#include <vector>
 
 #include <binder/RpcAuth.h>
 #include <binder/RpcCertificateFormat.h>
diff --git a/libs/ftl/Android.bp b/libs/ftl/Android.bp
index bc2eb23..ef20196 100644
--- a/libs/ftl/Android.bp
+++ b/libs/ftl/Android.bp
@@ -18,6 +18,7 @@
         "cast_test.cpp",
         "concat_test.cpp",
         "enum_test.cpp",
+        "fake_guard_test.cpp",
         "future_test.cpp",
         "small_map_test.cpp",
         "small_vector_test.cpp",
@@ -29,13 +30,6 @@
         "-Werror",
         "-Wextra",
         "-Wpedantic",
-    ],
-
-    header_libs: [
-        "libbase_headers",
-    ],
-
-    shared_libs: [
-        "libbase",
+        "-Wthread-safety",
     ],
 }
diff --git a/libs/ftl/enum_test.cpp b/libs/ftl/enum_test.cpp
index d8ce7a5..5592a01 100644
--- a/libs/ftl/enum_test.cpp
+++ b/libs/ftl/enum_test.cpp
@@ -143,6 +143,16 @@
     EXPECT_EQ(ftl::flag_string(Flags::kNone), "0b0");
     EXPECT_EQ(ftl::flag_string(Flags::kMask), "0b10010010");
     EXPECT_EQ(ftl::flag_string(Flags::kAll), "0b11111111");
+
+    enum class Flags64 : std::uint64_t {
+      kFlag0 = 0b1ull,
+      kFlag63 = 0x8000'0000'0000'0000ull,
+      kMask = kFlag0 | kFlag63
+    };
+
+    EXPECT_EQ(ftl::flag_string(Flags64::kFlag0), "kFlag0");
+    EXPECT_EQ(ftl::flag_string(Flags64::kFlag63), "kFlag63");
+    EXPECT_EQ(ftl::flag_string(Flags64::kMask), "0x8000000000000001");
   }
   {
     EXPECT_EQ(ftl::enum_string(Planet::kEarth), "kEarth");
diff --git a/libs/ftl/fake_guard_test.cpp b/libs/ftl/fake_guard_test.cpp
new file mode 100644
index 0000000..9d36e69
--- /dev/null
+++ b/libs/ftl/fake_guard_test.cpp
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2022 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 <ftl/fake_guard.h>
+#include <gtest/gtest.h>
+
+#include <functional>
+#include <mutex>
+
+namespace android::test {
+
+// Keep in sync with example usage in header file.
+TEST(FakeGuard, Example) {
+  struct {
+    std::mutex mutex;
+    int x FTL_ATTRIBUTE(guarded_by(mutex)) = -1;
+
+    int f() {
+      {
+        ftl::FakeGuard guard(mutex);
+        x = 0;
+      }
+
+      return FTL_FAKE_GUARD(mutex, x + 1);
+    }
+
+    std::function<int()> g() const {
+      return [this]() FTL_FAKE_GUARD(mutex) { return x; };
+    }
+  } s;
+
+  EXPECT_EQ(s.f(), 1);
+  EXPECT_EQ(s.g()(), 0);
+}
+
+}  // namespace android::test
diff --git a/libs/gui/LayerState.cpp b/libs/gui/LayerState.cpp
index 34db5b1..304fc17 100644
--- a/libs/gui/LayerState.cpp
+++ b/libs/gui/LayerState.cpp
@@ -134,6 +134,7 @@
     SAFE_PARCEL(output.writeByte, changeFrameRateStrategy);
     SAFE_PARCEL(output.writeUint32, fixedTransformHint);
     SAFE_PARCEL(output.writeBool, autoRefresh);
+    SAFE_PARCEL(output.writeBool, dimmingEnabled);
 
     SAFE_PARCEL(output.writeUint32, blurRegions.size());
     for (auto region : blurRegions) {
@@ -243,6 +244,7 @@
     SAFE_PARCEL(input.readUint32, &tmpUint32);
     fixedTransformHint = static_cast<ui::Transform::RotationFlags>(tmpUint32);
     SAFE_PARCEL(input.readBool, &autoRefresh);
+    SAFE_PARCEL(input.readBool, &dimmingEnabled);
 
     uint32_t numRegions = 0;
     SAFE_PARCEL(input.readUint32, &numRegions);
@@ -598,6 +600,10 @@
         what |= eColorSpaceAgnosticChanged;
         colorSpaceAgnostic = other.colorSpaceAgnostic;
     }
+    if (other.what & eDimmingEnabledChanged) {
+        what |= eDimmingEnabledChanged;
+        dimmingEnabled = other.dimmingEnabled;
+    }
     if ((other.what & what) != other.what) {
         ALOGE("Unmerged SurfaceComposer Transaction properties. LayerState::merge needs updating? "
               "other.what=0x%" PRIX64 " what=0x%" PRIX64 " unmerged flags=0x%" PRIX64,
diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index 52a22a7..6c197c4 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -1195,6 +1195,20 @@
     return *this;
 }
 
+SurfaceComposerClient::Transaction& SurfaceComposerClient::Transaction::setDimmingEnabled(
+        const sp<SurfaceControl>& sc, bool dimmingEnabled) {
+    layer_state_t* s = getLayerState(sc);
+    if (!s) {
+        mStatus = BAD_INDEX;
+        return *this;
+    }
+    s->what |= layer_state_t::eDimmingEnabledChanged;
+    s->dimmingEnabled = dimmingEnabled;
+
+    registerSurfaceControlForCallback(sc);
+    return *this;
+}
+
 SurfaceComposerClient::Transaction& SurfaceComposerClient::Transaction::setAlpha(
         const sp<SurfaceControl>& sc, float alpha) {
     layer_state_t* s = getLayerState(sc);
diff --git a/libs/gui/include/gui/LayerState.h b/libs/gui/include/gui/LayerState.h
index 0f37dab..4ca8d68 100644
--- a/libs/gui/include/gui/LayerState.h
+++ b/libs/gui/include/gui/LayerState.h
@@ -150,7 +150,7 @@
         eTransparentRegionChanged = 0x00000020,
         eFlagsChanged = 0x00000040,
         eLayerStackChanged = 0x00000080,
-        /* unused 0x00000400, */
+        eDimmingEnabledChanged = 0x00000400,
         eShadowRadiusChanged = 0x00000800,
         /* unused 0x00001000, */
         eBufferCropChanged = 0x00002000,
@@ -187,7 +187,7 @@
         eAutoRefreshChanged = 0x1000'00000000,
         eStretchChanged = 0x2000'00000000,
         eTrustedOverlayChanged = 0x4000'00000000,
-        eDropInputModeChanged = 0x8000'00000000,
+        eDropInputModeChanged = 0x8000'00000000
     };
 
     layer_state_t();
@@ -298,6 +298,8 @@
 
     // Force inputflinger to drop all input events for the layer and its children.
     gui::DropInputMode dropInputMode;
+
+    bool dimmingEnabled;
 };
 
 struct ComposerState {
diff --git a/libs/gui/include/gui/SurfaceComposerClient.h b/libs/gui/include/gui/SurfaceComposerClient.h
index 9d03f58..0cc43d8 100644
--- a/libs/gui/include/gui/SurfaceComposerClient.h
+++ b/libs/gui/include/gui/SurfaceComposerClient.h
@@ -491,6 +491,7 @@
                 uint32_t flags, uint32_t mask);
         Transaction& setTransparentRegionHint(const sp<SurfaceControl>& sc,
                 const Region& transparentRegion);
+        Transaction& setDimmingEnabled(const sp<SurfaceControl>& sc, bool dimmingEnabled);
         Transaction& setAlpha(const sp<SurfaceControl>& sc,
                 float alpha);
         Transaction& setMatrix(const sp<SurfaceControl>& sc,
diff --git a/libs/input/Android.bp b/libs/input/Android.bp
index 18fb7c1..1d4fc1f 100644
--- a/libs/input/Android.bp
+++ b/libs/input/Android.bp
@@ -50,6 +50,7 @@
         "Keyboard.cpp",
         "KeyCharacterMap.cpp",
         "KeyLayoutMap.cpp",
+        "PrintTools.cpp",
         "PropertyMap.cpp",
         "TouchVideoFrame.cpp",
         "VelocityControl.cpp",
@@ -102,6 +103,9 @@
 
             sanitize: {
                 misc_undefined: ["integer"],
+                diag: {
+                    misc_undefined: ["integer"],
+                },
             },
         },
         host: {
diff --git a/libs/input/PrintTools.cpp b/libs/input/PrintTools.cpp
new file mode 100644
index 0000000..5d6ae4e
--- /dev/null
+++ b/libs/input/PrintTools.cpp
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "PrintTools"
+
+#include <input/PrintTools.h>
+
+namespace android {
+
+const char* toString(bool value) {
+    return value ? "true" : "false";
+}
+
+} // namespace android
diff --git a/libs/input/VelocityTracker.cpp b/libs/input/VelocityTracker.cpp
index a6465ee..7f427f2 100644
--- a/libs/input/VelocityTracker.cpp
+++ b/libs/input/VelocityTracker.cpp
@@ -15,13 +15,6 @@
  */
 
 #define LOG_TAG "VelocityTracker"
-//#define LOG_NDEBUG 0
-
-// Log debug messages about velocity tracking.
-static constexpr bool DEBUG_VELOCITY = false;
-
-// Log debug messages about the progress of the algorithm itself.
-static constexpr bool DEBUG_STRATEGY = false;
 
 #include <array>
 #include <inttypes.h>
@@ -36,6 +29,27 @@
 
 namespace android {
 
+/**
+ * Log debug messages about velocity tracking.
+ * Enable this via "adb shell setprop log.tag.VelocityTrackerVelocity DEBUG" (requires restart)
+ */
+const bool DEBUG_VELOCITY =
+        __android_log_is_loggable(ANDROID_LOG_DEBUG, LOG_TAG "Velocity", ANDROID_LOG_INFO);
+
+/**
+ * Log debug messages about the progress of the algorithm itself.
+ * Enable this via "adb shell setprop log.tag.VelocityTrackerStrategy DEBUG" (requires restart)
+ */
+const bool DEBUG_STRATEGY =
+        __android_log_is_loggable(ANDROID_LOG_DEBUG, LOG_TAG "Strategy", ANDROID_LOG_INFO);
+
+/**
+ * Log debug messages about the 'impulse' strategy.
+ * Enable this via "adb shell setprop log.tag.VelocityTrackerImpulse DEBUG" (requires restart)
+ */
+const bool DEBUG_IMPULSE =
+        __android_log_is_loggable(ANDROID_LOG_DEBUG, LOG_TAG "Impulse", ANDROID_LOG_INFO);
+
 // Nanoseconds per milliseconds.
 static const nsecs_t NANOS_PER_MS = 1000000;
 
@@ -141,7 +155,7 @@
             return std::make_unique<LeastSquaresVelocityTrackerStrategy>(1);
 
         case VelocityTracker::Strategy::LSQ2:
-            if (DEBUG_STRATEGY) {
+            if (DEBUG_STRATEGY && !DEBUG_IMPULSE) {
                 ALOGI("Initializing lsq2 strategy");
             }
             return std::make_unique<LeastSquaresVelocityTrackerStrategy>(2);
@@ -1172,7 +1186,25 @@
     outEstimator->degree = 2; // similar results to 2nd degree fit
     outEstimator->confidence = 1;
     if (DEBUG_STRATEGY) {
-        ALOGD("velocity: (%f, %f)", outEstimator->xCoeff[1], outEstimator->yCoeff[1]);
+        ALOGD("velocity: (%.1f, %.1f)", outEstimator->xCoeff[1], outEstimator->yCoeff[1]);
+    }
+    if (DEBUG_IMPULSE) {
+        // TODO(b/134179997): delete this block once the switch to 'impulse' is complete.
+        // Calculate the lsq2 velocity for the same inputs to allow runtime comparisons
+        VelocityTracker lsq2(VelocityTracker::Strategy::LSQ2);
+        BitSet32 idBits;
+        const uint32_t pointerId = 0;
+        idBits.markBit(pointerId);
+        for (ssize_t i = m - 1; i >= 0; i--) {
+            lsq2.addMovement(time[i], idBits, {{x[i], y[i]}});
+        }
+        float outVx = 0, outVy = 0;
+        const bool computed = lsq2.getVelocity(pointerId, &outVx, &outVy);
+        if (computed) {
+            ALOGD("lsq2 velocity: (%.1f, %.1f)", outVx, outVy);
+        } else {
+            ALOGD("lsq2 velocity: could not compute velocity");
+        }
     }
     return true;
 }
diff --git a/libs/nativewindow/AHardwareBuffer.cpp b/libs/nativewindow/AHardwareBuffer.cpp
index 381900e..4a1784e 100644
--- a/libs/nativewindow/AHardwareBuffer.cpp
+++ b/libs/nativewindow/AHardwareBuffer.cpp
@@ -207,7 +207,11 @@
       if (result == 0) {
         outPlanes->planeCount = 3;
         outPlanes->planes[0].data = yuvData.y;
-        outPlanes->planes[0].pixelStride = 1;
+        if (format == AHARDWAREBUFFER_FORMAT_YCbCr_P010) {
+            outPlanes->planes[0].pixelStride = 2;
+        } else {
+            outPlanes->planes[0].pixelStride = 1;
+        }
         outPlanes->planes[0].rowStride = yuvData.ystride;
         outPlanes->planes[1].data = yuvData.cb;
         outPlanes->planes[1].pixelStride = yuvData.chroma_step;
diff --git a/libs/renderengine/skia/SkiaGLRenderEngine.cpp b/libs/renderengine/skia/SkiaGLRenderEngine.cpp
index 1665550..df9f8ab 100644
--- a/libs/renderengine/skia/SkiaGLRenderEngine.cpp
+++ b/libs/renderengine/skia/SkiaGLRenderEngine.cpp
@@ -39,6 +39,7 @@
 #include <gui/TraceUtils.h>
 #include <sync/sync.h>
 #include <ui/BlurRegion.h>
+#include <ui/DataspaceUtils.h>
 #include <ui/DebugUtils.h>
 #include <ui/GraphicBuffer.h>
 #include <utils/Trace.h>
@@ -1105,9 +1106,15 @@
                                                   .requiresLinearEffect = requiresLinearEffect,
                                                   .layerDimmingRatio = layerDimmingRatio}));
 
-            // Turn on dithering when dimming beyond this threshold.
+            // Turn on dithering when dimming beyond this (arbitrary) threshold...
             static constexpr float kDimmingThreshold = 0.2f;
-            if (layerDimmingRatio <= kDimmingThreshold) {
+            // ...or we're rendering an HDR layer down to an 8-bit target
+            // Most HDR standards require at least 10-bits of color depth for source content, so we
+            // can just extract the transfer function rather than dig into precise gralloc layout.
+            // Furthermore, we can assume that the only 8-bit target we support is RGBA8888.
+            const bool requiresDownsample = isHdrDataspace(layer.sourceDataspace) &&
+                    buffer->getPixelFormat() == PIXEL_FORMAT_RGBA_8888;
+            if (layerDimmingRatio <= kDimmingThreshold || requiresDownsample) {
                 paint.setDither(true);
             }
             paint.setAlphaf(layer.alpha);
diff --git a/libs/ui/Gralloc4.cpp b/libs/ui/Gralloc4.cpp
index 8de91da..1fce31d 100644
--- a/libs/ui/Gralloc4.cpp
+++ b/libs/ui/Gralloc4.cpp
@@ -359,20 +359,19 @@
             if (!gralloc4::isStandardPlaneLayoutComponentType(planeLayoutComponent.type)) {
                 continue;
             }
-            if (0 != planeLayoutComponent.offsetInBits % 8) {
-                unlock(bufferHandle);
-                return BAD_VALUE;
-            }
 
-            uint8_t* tmpData = static_cast<uint8_t*>(data) + planeLayout.offsetInBytes +
-                    (planeLayoutComponent.offsetInBits / 8);
+            uint8_t* tmpData = static_cast<uint8_t*>(data) + planeLayout.offsetInBytes;
+
+            // Note that `offsetInBits` may not be a multiple of 8 for packed formats (e.g. P010)
+            // but we still want to point to the start of the first byte.
+            tmpData += (planeLayoutComponent.offsetInBits / 8);
+
             uint64_t sampleIncrementInBytes;
 
             auto type = static_cast<PlaneLayoutComponentType>(planeLayoutComponent.type.value);
             switch (type) {
                 case PlaneLayoutComponentType::Y:
-                    if ((ycbcr.y != nullptr) || (planeLayoutComponent.sizeInBits != 8) ||
-                        (planeLayout.sampleIncrementInBits != 8)) {
+                    if ((ycbcr.y != nullptr) || (planeLayout.sampleIncrementInBits % 8 != 0)) {
                         unlock(bufferHandle);
                         return BAD_VALUE;
                     }
@@ -388,7 +387,8 @@
                     }
 
                     sampleIncrementInBytes = planeLayout.sampleIncrementInBits / 8;
-                    if ((sampleIncrementInBytes != 1) && (sampleIncrementInBytes != 2)) {
+                    if ((sampleIncrementInBytes != 1) && (sampleIncrementInBytes != 2) &&
+                        (sampleIncrementInBytes != 4)) {
                         unlock(bufferHandle);
                         return BAD_VALUE;
                     }
diff --git a/services/inputflinger/Android.bp b/services/inputflinger/Android.bp
index ed9bfd2..41878e3 100644
--- a/services/inputflinger/Android.bp
+++ b/services/inputflinger/Android.bp
@@ -58,6 +58,7 @@
     srcs: [
         "InputClassifier.cpp",
         "InputCommonConverter.cpp",
+        "PreferStylusOverTouchBlocker.cpp",
         "UnwantedInteractionBlocker.cpp",
         "InputManager.cpp",
     ],
diff --git a/services/inputflinger/InputListener.cpp b/services/inputflinger/InputListener.cpp
index 3a4b6c5..2a3924b 100644
--- a/services/inputflinger/InputListener.cpp
+++ b/services/inputflinger/InputListener.cpp
@@ -202,9 +202,11 @@
         coords += "}";
     }
     return StringPrintf("NotifyMotionArgs(id=%" PRId32 ", eventTime=%" PRId64 ", deviceId=%" PRId32
-                        ", source=%s, action=%s, pointerCount=%" PRIu32 " pointers=%s)",
+                        ", source=%s, action=%s, pointerCount=%" PRIu32
+                        " pointers=%s, flags=0x%08x)",
                         id, eventTime, deviceId, inputEventSourceToString(source).c_str(),
-                        MotionEvent::actionToString(action).c_str(), pointerCount, coords.c_str());
+                        MotionEvent::actionToString(action).c_str(), pointerCount, coords.c_str(),
+                        flags);
 }
 
 void NotifyMotionArgs::notify(InputListenerInterface& listener) const {
diff --git a/services/inputflinger/PreferStylusOverTouchBlocker.cpp b/services/inputflinger/PreferStylusOverTouchBlocker.cpp
new file mode 100644
index 0000000..beec2e1
--- /dev/null
+++ b/services/inputflinger/PreferStylusOverTouchBlocker.cpp
@@ -0,0 +1,216 @@
+/*
+ * Copyright (C) 2022 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 "PreferStylusOverTouchBlocker.h"
+#include <input/PrintTools.h>
+
+namespace android {
+
+static std::pair<bool, bool> checkToolType(const NotifyMotionArgs& args) {
+    bool hasStylus = false;
+    bool hasTouch = false;
+    for (size_t i = 0; i < args.pointerCount; i++) {
+        // Make sure we are canceling stylus pointers
+        const int32_t toolType = args.pointerProperties[i].toolType;
+        if (toolType == AMOTION_EVENT_TOOL_TYPE_STYLUS ||
+            toolType == AMOTION_EVENT_TOOL_TYPE_ERASER) {
+            hasStylus = true;
+        }
+        if (toolType == AMOTION_EVENT_TOOL_TYPE_FINGER) {
+            hasTouch = true;
+        }
+    }
+    return std::make_pair(hasTouch, hasStylus);
+}
+
+/**
+ * Intersect two sets in-place, storing the result in 'set1'.
+ * Find elements in set1 that are not present in set2 and delete them,
+ * relying on the fact that the two sets are ordered.
+ */
+template <typename T>
+static void intersectInPlace(std::set<T>& set1, const std::set<T>& set2) {
+    typename std::set<T>::iterator it1 = set1.begin();
+    typename std::set<T>::const_iterator it2 = set2.begin();
+    while (it1 != set1.end() && it2 != set2.end()) {
+        const T& element1 = *it1;
+        const T& element2 = *it2;
+        if (element1 < element2) {
+            // This element is not present in set2. Remove it from set1.
+            it1 = set1.erase(it1);
+            continue;
+        }
+        if (element2 < element1) {
+            it2++;
+        }
+        if (element1 == element2) {
+            it1++;
+            it2++;
+        }
+    }
+    // Remove the rest of the elements in set1 because set2 is already exhausted.
+    set1.erase(it1, set1.end());
+}
+
+/**
+ * Same as above, but prune a map
+ */
+template <typename K, class V>
+static void intersectInPlace(std::map<K, V>& map, const std::set<K>& set2) {
+    typename std::map<K, V>::iterator it1 = map.begin();
+    typename std::set<K>::const_iterator it2 = set2.begin();
+    while (it1 != map.end() && it2 != set2.end()) {
+        const auto& [key, _] = *it1;
+        const K& element2 = *it2;
+        if (key < element2) {
+            // This element is not present in set2. Remove it from map.
+            it1 = map.erase(it1);
+            continue;
+        }
+        if (element2 < key) {
+            it2++;
+        }
+        if (key == element2) {
+            it1++;
+            it2++;
+        }
+    }
+    // Remove the rest of the elements in map because set2 is already exhausted.
+    map.erase(it1, map.end());
+}
+
+// -------------------------------- PreferStylusOverTouchBlocker -----------------------------------
+
+std::vector<NotifyMotionArgs> PreferStylusOverTouchBlocker::processMotion(
+        const NotifyMotionArgs& args) {
+    const auto [hasTouch, hasStylus] = checkToolType(args);
+    const bool isUpOrCancel =
+            args.action == AMOTION_EVENT_ACTION_UP || args.action == AMOTION_EVENT_ACTION_CANCEL;
+
+    if (hasTouch && hasStylus) {
+        mDevicesWithMixedToolType.insert(args.deviceId);
+    }
+    // Handle the case where mixed touch and stylus pointers are reported. Add this device to the
+    // ignore list, since it clearly supports simultaneous touch and stylus.
+    if (mDevicesWithMixedToolType.find(args.deviceId) != mDevicesWithMixedToolType.end()) {
+        // This event comes from device with mixed stylus and touch event. Ignore this device.
+        if (mCanceledDevices.find(args.deviceId) != mCanceledDevices.end()) {
+            // If we started to cancel events from this device, continue to do so to keep
+            // the stream consistent. It should happen at most once per "mixed" device.
+            if (isUpOrCancel) {
+                mCanceledDevices.erase(args.deviceId);
+                mLastTouchEvents.erase(args.deviceId);
+            }
+            return {};
+        }
+        return {args};
+    }
+
+    const bool isStylusEvent = hasStylus;
+    const bool isDown = args.action == AMOTION_EVENT_ACTION_DOWN;
+
+    if (isStylusEvent) {
+        if (isDown) {
+            // Reject all touch while stylus is down
+            mActiveStyli.insert(args.deviceId);
+
+            // Cancel all current touch!
+            std::vector<NotifyMotionArgs> result;
+            for (auto& [deviceId, lastTouchEvent] : mLastTouchEvents) {
+                if (mCanceledDevices.find(deviceId) != mCanceledDevices.end()) {
+                    // Already canceled, go to next one.
+                    continue;
+                }
+                // Not yet canceled. Cancel it.
+                lastTouchEvent.action = AMOTION_EVENT_ACTION_CANCEL;
+                lastTouchEvent.flags |= AMOTION_EVENT_FLAG_CANCELED;
+                lastTouchEvent.eventTime = systemTime(SYSTEM_TIME_MONOTONIC);
+                result.push_back(lastTouchEvent);
+                mCanceledDevices.insert(deviceId);
+            }
+            result.push_back(args);
+            return result;
+        }
+        if (isUpOrCancel) {
+            mActiveStyli.erase(args.deviceId);
+        }
+        // Never drop stylus events
+        return {args};
+    }
+
+    const bool isTouchEvent = hasTouch;
+    if (isTouchEvent) {
+        // Suppress the current gesture if any stylus is still down
+        if (!mActiveStyli.empty()) {
+            mCanceledDevices.insert(args.deviceId);
+        }
+
+        const bool shouldDrop = mCanceledDevices.find(args.deviceId) != mCanceledDevices.end();
+        if (isUpOrCancel) {
+            mCanceledDevices.erase(args.deviceId);
+            mLastTouchEvents.erase(args.deviceId);
+        }
+
+        // If we already canceled the current gesture, then continue to drop events from it, even if
+        // the stylus has been lifted.
+        if (shouldDrop) {
+            return {};
+        }
+
+        if (!isUpOrCancel) {
+            mLastTouchEvents[args.deviceId] = args;
+        }
+        return {args};
+    }
+
+    // Not a touch or stylus event
+    return {args};
+}
+
+void PreferStylusOverTouchBlocker::notifyInputDevicesChanged(
+        const std::vector<InputDeviceInfo>& inputDevices) {
+    std::set<int32_t> presentDevices;
+    for (const InputDeviceInfo& device : inputDevices) {
+        presentDevices.insert(device.getId());
+    }
+    // Only keep the devices that are still present.
+    intersectInPlace(mDevicesWithMixedToolType, presentDevices);
+    intersectInPlace(mLastTouchEvents, presentDevices);
+    intersectInPlace(mCanceledDevices, presentDevices);
+    intersectInPlace(mActiveStyli, presentDevices);
+}
+
+void PreferStylusOverTouchBlocker::notifyDeviceReset(const NotifyDeviceResetArgs& args) {
+    mDevicesWithMixedToolType.erase(args.deviceId);
+    mLastTouchEvents.erase(args.deviceId);
+    mCanceledDevices.erase(args.deviceId);
+    mActiveStyli.erase(args.deviceId);
+}
+
+static std::string dumpArgs(const NotifyMotionArgs& args) {
+    return args.dump();
+}
+
+std::string PreferStylusOverTouchBlocker::dump() const {
+    std::string out;
+    out += "mActiveStyli: " + dumpSet(mActiveStyli) + "\n";
+    out += "mLastTouchEvents: " + dumpMap(mLastTouchEvents, constToString, dumpArgs) + "\n";
+    out += "mDevicesWithMixedToolType: " + dumpSet(mDevicesWithMixedToolType) + "\n";
+    out += "mCanceledDevices: " + dumpSet(mCanceledDevices) + "\n";
+    return out;
+}
+
+} // namespace android
diff --git a/services/inputflinger/PreferStylusOverTouchBlocker.h b/services/inputflinger/PreferStylusOverTouchBlocker.h
new file mode 100644
index 0000000..716dc4d
--- /dev/null
+++ b/services/inputflinger/PreferStylusOverTouchBlocker.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <optional>
+#include <set>
+#include "InputListener.h"
+
+namespace android {
+
+/**
+ * When stylus is down, all touch is ignored.
+ * TODO(b/210159205): delete this when simultaneous stylus and touch is supported
+ */
+class PreferStylusOverTouchBlocker {
+public:
+    /**
+     * Process the provided event and emit 0 or more events that should be used instead of it.
+     * In the majority of cases, the returned result will just be the provided args (array with
+     * only 1 element), unmodified.
+     *
+     * If the gesture should be blocked, the returned result may be:
+     *
+     * a) An empty array, if the current event should just be ignored completely
+     * b) An array of N elements, containing N-1 events with ACTION_CANCEL and the current event.
+     *
+     * The returned result is intended to be reinjected into the original event stream in
+     * replacement of the incoming event.
+     */
+    std::vector<NotifyMotionArgs> processMotion(const NotifyMotionArgs& args);
+    std::string dump() const;
+
+    void notifyInputDevicesChanged(const std::vector<InputDeviceInfo>& inputDevices);
+
+    void notifyDeviceReset(const NotifyDeviceResetArgs& args);
+
+private:
+    // Stores the device id's of styli that are currently down.
+    std::set<int32_t /*deviceId*/> mActiveStyli;
+    // For each device, store the last touch event as long as the touch is down. Upon liftoff,
+    // the entry is erased.
+    std::map<int32_t /*deviceId*/, NotifyMotionArgs> mLastTouchEvents;
+    // Device ids of devices for which the current touch gesture is canceled.
+    std::set<int32_t /*deviceId*/> mCanceledDevices;
+
+    // Device ids of input devices where we encountered simultaneous touch and stylus
+    // events. For these devices, we don't do any event processing (nothing is blocked or altered).
+    std::set<int32_t /*deviceId*/> mDevicesWithMixedToolType;
+};
+
+} // namespace android
\ No newline at end of file
diff --git a/services/inputflinger/UnwantedInteractionBlocker.cpp b/services/inputflinger/UnwantedInteractionBlocker.cpp
index 64dbb8c..b69e16a 100644
--- a/services/inputflinger/UnwantedInteractionBlocker.cpp
+++ b/services/inputflinger/UnwantedInteractionBlocker.cpp
@@ -44,7 +44,8 @@
 }
 
 static bool isFromTouchscreen(int32_t source) {
-    return isFromSource(source, AINPUT_SOURCE_TOUCHSCREEN);
+    return isFromSource(source, AINPUT_SOURCE_TOUCHSCREEN) &&
+            !isFromSource(source, AINPUT_SOURCE_STYLUS);
 }
 
 static ::base::TimeTicks toChromeTimestamp(nsecs_t eventTime) {
@@ -367,6 +368,14 @@
 }
 
 void UnwantedInteractionBlocker::notifyMotion(const NotifyMotionArgs* args) {
+    const std::vector<NotifyMotionArgs> processedArgs =
+            mPreferStylusOverTouchBlocker.processMotion(*args);
+    for (const NotifyMotionArgs& loopArgs : processedArgs) {
+        notifyMotionInner(&loopArgs);
+    }
+}
+
+void UnwantedInteractionBlocker::notifyMotionInner(const NotifyMotionArgs* args) {
     auto it = mPalmRejectors.find(args->deviceId);
     const bool sendToPalmRejector = it != mPalmRejectors.end() && isFromTouchscreen(args->source);
     if (!sendToPalmRejector) {
@@ -400,6 +409,7 @@
         mPalmRejectors.emplace(args->deviceId, info);
     }
     mListener.notifyDeviceReset(args);
+    mPreferStylusOverTouchBlocker.notifyDeviceReset(*args);
 }
 
 void UnwantedInteractionBlocker::notifyPointerCaptureChanged(
@@ -436,10 +446,13 @@
         auto const& [deviceId, _] = item;
         return devicesToKeep.find(deviceId) == devicesToKeep.end();
     });
+    mPreferStylusOverTouchBlocker.notifyInputDevicesChanged(inputDevices);
 }
 
 void UnwantedInteractionBlocker::dump(std::string& dump) {
     dump += "UnwantedInteractionBlocker:\n";
+    dump += "  mPreferStylusOverTouchBlocker:\n";
+    dump += addPrefix(mPreferStylusOverTouchBlocker.dump(), "    ");
     dump += StringPrintf("  mEnablePalmRejection: %s\n", toString(mEnablePalmRejection));
     dump += StringPrintf("  isPalmRejectionEnabled (flag value): %s\n",
                          toString(isPalmRejectionEnabled()));
diff --git a/services/inputflinger/UnwantedInteractionBlocker.h b/services/inputflinger/UnwantedInteractionBlocker.h
index 14068fd..8a1cd72 100644
--- a/services/inputflinger/UnwantedInteractionBlocker.h
+++ b/services/inputflinger/UnwantedInteractionBlocker.h
@@ -23,6 +23,8 @@
 #include "ui/events/ozone/evdev/touch_filter/neural_stylus_palm_detection_filter_util.h"
 #include "ui/events/ozone/evdev/touch_filter/palm_detection_filter.h"
 
+#include "PreferStylusOverTouchBlocker.h"
+
 namespace android {
 
 // --- Functions for manipulation of event streams
@@ -88,9 +90,14 @@
     InputListenerInterface& mListener;
     const bool mEnablePalmRejection;
 
+    // When stylus is down, ignore touch
+    PreferStylusOverTouchBlocker mPreferStylusOverTouchBlocker;
+
     // Detect and reject unwanted palms on screen
     // Use a separate palm rejector for every touch device.
     std::map<int32_t /*deviceId*/, PalmRejector> mPalmRejectors;
+    // TODO(b/210159205): delete this when simultaneous stylus and touch is supported
+    void notifyMotionInner(const NotifyMotionArgs* args);
 };
 
 class SlotState {
diff --git a/services/inputflinger/benchmarks/InputDispatcher_benchmarks.cpp b/services/inputflinger/benchmarks/InputDispatcher_benchmarks.cpp
index 9691ad8..32eec29 100644
--- a/services/inputflinger/benchmarks/InputDispatcher_benchmarks.cpp
+++ b/services/inputflinger/benchmarks/InputDispatcher_benchmarks.cpp
@@ -263,15 +263,15 @@
 static void benchmarkNotifyMotion(benchmark::State& state) {
     // Create dispatcher
     sp<FakeInputDispatcherPolicy> fakePolicy = new FakeInputDispatcherPolicy();
-    std::unique_ptr<InputDispatcher> dispatcher = std::make_unique<InputDispatcher>(fakePolicy);
-    dispatcher->setInputDispatchMode(/*enabled*/ true, /*frozen*/ false);
-    dispatcher->start();
+    InputDispatcher dispatcher(fakePolicy);
+    dispatcher.setInputDispatchMode(/*enabled*/ true, /*frozen*/ false);
+    dispatcher.start();
 
     // Create a window that will receive motion events
     std::shared_ptr<FakeApplicationHandle> application = std::make_shared<FakeApplicationHandle>();
-    sp<FakeWindowHandle> window = new FakeWindowHandle(application, *dispatcher, "Fake Window");
+    sp<FakeWindowHandle> window = new FakeWindowHandle(application, dispatcher, "Fake Window");
 
-    dispatcher->setInputWindows({{ADISPLAY_ID_DEFAULT, {window}}});
+    dispatcher.setInputWindows({{ADISPLAY_ID_DEFAULT, {window}}});
 
     NotifyMotionArgs motionArgs = generateMotionArgs();
 
@@ -280,55 +280,79 @@
         motionArgs.action = AMOTION_EVENT_ACTION_DOWN;
         motionArgs.downTime = now();
         motionArgs.eventTime = motionArgs.downTime;
-        dispatcher->notifyMotion(&motionArgs);
+        dispatcher.notifyMotion(&motionArgs);
 
         // Send ACTION_UP
         motionArgs.action = AMOTION_EVENT_ACTION_UP;
         motionArgs.eventTime = now();
-        dispatcher->notifyMotion(&motionArgs);
+        dispatcher.notifyMotion(&motionArgs);
 
         window->consumeEvent();
         window->consumeEvent();
     }
 
-    dispatcher->stop();
+    dispatcher.stop();
 }
 
 static void benchmarkInjectMotion(benchmark::State& state) {
     // Create dispatcher
     sp<FakeInputDispatcherPolicy> fakePolicy = new FakeInputDispatcherPolicy();
-    std::unique_ptr<InputDispatcher> dispatcher = std::make_unique<InputDispatcher>(fakePolicy);
-    dispatcher->setInputDispatchMode(/*enabled*/ true, /*frozen*/ false);
-    dispatcher->start();
+    InputDispatcher dispatcher(fakePolicy);
+    dispatcher.setInputDispatchMode(/*enabled*/ true, /*frozen*/ false);
+    dispatcher.start();
 
     // Create a window that will receive motion events
     std::shared_ptr<FakeApplicationHandle> application = std::make_shared<FakeApplicationHandle>();
-    sp<FakeWindowHandle> window = new FakeWindowHandle(application, *dispatcher, "Fake Window");
+    sp<FakeWindowHandle> window = new FakeWindowHandle(application, dispatcher, "Fake Window");
 
-    dispatcher->setInputWindows({{ADISPLAY_ID_DEFAULT, {window}}});
+    dispatcher.setInputWindows({{ADISPLAY_ID_DEFAULT, {window}}});
 
     for (auto _ : state) {
         MotionEvent event = generateMotionEvent();
         // Send ACTION_DOWN
-        dispatcher->injectInputEvent(&event, INJECTOR_PID, INJECTOR_UID,
-                                     InputEventInjectionSync::NONE, INJECT_EVENT_TIMEOUT,
-                                     POLICY_FLAG_FILTERED | POLICY_FLAG_PASS_TO_USER);
+        dispatcher.injectInputEvent(&event, INJECTOR_PID, INJECTOR_UID,
+                                    InputEventInjectionSync::NONE, INJECT_EVENT_TIMEOUT,
+                                    POLICY_FLAG_FILTERED | POLICY_FLAG_PASS_TO_USER);
 
         // Send ACTION_UP
         event.setAction(AMOTION_EVENT_ACTION_UP);
-        dispatcher->injectInputEvent(&event, INJECTOR_PID, INJECTOR_UID,
-                                     InputEventInjectionSync::NONE, INJECT_EVENT_TIMEOUT,
-                                     POLICY_FLAG_FILTERED | POLICY_FLAG_PASS_TO_USER);
+        dispatcher.injectInputEvent(&event, INJECTOR_PID, INJECTOR_UID,
+                                    InputEventInjectionSync::NONE, INJECT_EVENT_TIMEOUT,
+                                    POLICY_FLAG_FILTERED | POLICY_FLAG_PASS_TO_USER);
 
         window->consumeEvent();
         window->consumeEvent();
     }
 
-    dispatcher->stop();
+    dispatcher.stop();
+}
+
+static void benchmarkOnWindowInfosChanged(benchmark::State& state) {
+    // Create dispatcher
+    sp<FakeInputDispatcherPolicy> fakePolicy = new FakeInputDispatcherPolicy();
+    InputDispatcher dispatcher(fakePolicy);
+    dispatcher.setInputDispatchMode(/*enabled*/ true, /*frozen*/ false);
+    dispatcher.start();
+
+    // Create a window
+    std::shared_ptr<FakeApplicationHandle> application = std::make_shared<FakeApplicationHandle>();
+    sp<FakeWindowHandle> window = new FakeWindowHandle(application, dispatcher, "Fake Window");
+
+    std::vector<gui::WindowInfo> windowInfos{*window->getInfo()};
+    gui::DisplayInfo info;
+    info.displayId = window->getInfo()->displayId;
+    std::vector<gui::DisplayInfo> displayInfos{info};
+
+    for (auto _ : state) {
+        dispatcher.onWindowInfosChanged(windowInfos, displayInfos);
+        dispatcher.onWindowInfosChanged({} /*windowInfos*/, {} /*displayInfos*/);
+    }
+    dispatcher.stop();
 }
 
 BENCHMARK(benchmarkNotifyMotion);
 BENCHMARK(benchmarkInjectMotion);
+BENCHMARK(benchmarkOnWindowInfosChanged);
 
 } // namespace android::inputdispatcher
 
diff --git a/services/inputflinger/dispatcher/InputDispatcher.cpp b/services/inputflinger/dispatcher/InputDispatcher.cpp
index c8a3ccf..6bab349 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.cpp
+++ b/services/inputflinger/dispatcher/InputDispatcher.cpp
@@ -2350,8 +2350,8 @@
                                         *touchedWindow.windowHandle->getInfo()) ||
                                  (touchedWindow.targetFlags & InputTarget::FLAG_FOREGROUND) != 0;
                      })) {
-        ALOGI("Dropping event because there is no touched window on display %d to receive it.",
-              displayId);
+        ALOGI("Dropping event because there is no touched window on display %d to receive it: %s",
+              displayId, entry.getDescription().c_str());
         injectionResult = InputEventInjectionResult::FAILED;
         goto Failed;
     }
diff --git a/services/inputflinger/tests/Android.bp b/services/inputflinger/tests/Android.bp
index 9d200bd..76a7c19 100644
--- a/services/inputflinger/tests/Android.bp
+++ b/services/inputflinger/tests/Android.bp
@@ -47,6 +47,7 @@
         "InputReader_test.cpp",
         "InputFlingerService_test.cpp",
         "LatencyTracker_test.cpp",
+        "PreferStylusOverTouch_test.cpp",
         "TestInputListener.cpp",
         "UinputDevice.cpp",
         "UnwantedInteractionBlocker_test.cpp",
diff --git a/services/inputflinger/tests/PreferStylusOverTouch_test.cpp b/services/inputflinger/tests/PreferStylusOverTouch_test.cpp
new file mode 100644
index 0000000..8e2ab88
--- /dev/null
+++ b/services/inputflinger/tests/PreferStylusOverTouch_test.cpp
@@ -0,0 +1,502 @@
+/*
+ * Copyright (C) 2022 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 <gtest/gtest.h>
+#include "../PreferStylusOverTouchBlocker.h"
+
+namespace android {
+
+constexpr int32_t TOUCH_DEVICE_ID = 3;
+constexpr int32_t SECOND_TOUCH_DEVICE_ID = 4;
+constexpr int32_t STYLUS_DEVICE_ID = 5;
+constexpr int32_t SECOND_STYLUS_DEVICE_ID = 6;
+
+constexpr int DOWN = AMOTION_EVENT_ACTION_DOWN;
+constexpr int MOVE = AMOTION_EVENT_ACTION_MOVE;
+constexpr int UP = AMOTION_EVENT_ACTION_UP;
+constexpr int CANCEL = AMOTION_EVENT_ACTION_CANCEL;
+static constexpr int32_t POINTER_1_DOWN =
+        AMOTION_EVENT_ACTION_POINTER_DOWN | (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT);
+constexpr int32_t TOUCHSCREEN = AINPUT_SOURCE_TOUCHSCREEN;
+constexpr int32_t STYLUS = AINPUT_SOURCE_STYLUS;
+
+struct PointerData {
+    float x;
+    float y;
+};
+
+static NotifyMotionArgs generateMotionArgs(nsecs_t downTime, nsecs_t eventTime, int32_t action,
+                                           const std::vector<PointerData>& points,
+                                           uint32_t source) {
+    size_t pointerCount = points.size();
+    if (action == DOWN || action == UP) {
+        EXPECT_EQ(1U, pointerCount) << "Actions DOWN and UP can only contain a single pointer";
+    }
+
+    PointerProperties pointerProperties[pointerCount];
+    PointerCoords pointerCoords[pointerCount];
+
+    const int32_t deviceId = isFromSource(source, TOUCHSCREEN) ? TOUCH_DEVICE_ID : STYLUS_DEVICE_ID;
+    const int32_t toolType = isFromSource(source, TOUCHSCREEN) ? AMOTION_EVENT_TOOL_TYPE_FINGER
+                                                               : AMOTION_EVENT_TOOL_TYPE_STYLUS;
+    for (size_t i = 0; i < pointerCount; i++) {
+        pointerProperties[i].clear();
+        pointerProperties[i].id = i;
+        pointerProperties[i].toolType = toolType;
+
+        pointerCoords[i].clear();
+        pointerCoords[i].setAxisValue(AMOTION_EVENT_AXIS_X, points[i].x);
+        pointerCoords[i].setAxisValue(AMOTION_EVENT_AXIS_Y, points[i].y);
+    }
+
+    // Currently, can't have STYLUS source without it also being a TOUCH source. Update the source
+    // accordingly.
+    if (isFromSource(source, STYLUS)) {
+        source |= TOUCHSCREEN;
+    }
+
+    // Define a valid motion event.
+    NotifyMotionArgs args(/* id */ 0, eventTime, 0 /*readTime*/, deviceId, source, 0 /*displayId*/,
+                          POLICY_FLAG_PASS_TO_USER, action, /* actionButton */ 0,
+                          /* flags */ 0, AMETA_NONE, /* buttonState */ 0,
+                          MotionClassification::NONE, AMOTION_EVENT_EDGE_FLAG_NONE, pointerCount,
+                          pointerProperties, pointerCoords, /* xPrecision */ 0, /* yPrecision */ 0,
+                          AMOTION_EVENT_INVALID_CURSOR_POSITION,
+                          AMOTION_EVENT_INVALID_CURSOR_POSITION, downTime, /* videoFrames */ {});
+
+    return args;
+}
+
+class PreferStylusOverTouchTest : public testing::Test {
+protected:
+    void assertNotBlocked(const NotifyMotionArgs& args) { assertResponse(args, {args}); }
+
+    void assertDropped(const NotifyMotionArgs& args) { assertResponse(args, {}); }
+
+    void assertResponse(const NotifyMotionArgs& args,
+                        const std::vector<NotifyMotionArgs>& expected) {
+        std::vector<NotifyMotionArgs> receivedArgs = mBlocker.processMotion(args);
+        ASSERT_EQ(expected.size(), receivedArgs.size());
+        for (size_t i = 0; i < expected.size(); i++) {
+            // The 'eventTime' of CANCEL events is dynamically generated. Don't check this field.
+            if (expected[i].action == CANCEL && receivedArgs[i].action == CANCEL) {
+                receivedArgs[i].eventTime = expected[i].eventTime;
+            }
+
+            ASSERT_EQ(expected[i], receivedArgs[i])
+                    << expected[i].dump() << " vs " << receivedArgs[i].dump();
+        }
+    }
+
+    void notifyInputDevicesChanged(const std::vector<InputDeviceInfo>& devices) {
+        mBlocker.notifyInputDevicesChanged(devices);
+    }
+
+    void dump() const { ALOGI("Blocker: \n%s\n", mBlocker.dump().c_str()); }
+
+private:
+    PreferStylusOverTouchBlocker mBlocker;
+};
+
+TEST_F(PreferStylusOverTouchTest, TouchGestureIsNotBlocked) {
+    NotifyMotionArgs args;
+
+    args = generateMotionArgs(0 /*downTime*/, 0 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(0 /*downTime*/, 1 /*eventTime*/, MOVE, {{1, 3}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(0 /*downTime*/, 2 /*eventTime*/, UP, {{1, 3}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+}
+
+TEST_F(PreferStylusOverTouchTest, StylusGestureIsNotBlocked) {
+    NotifyMotionArgs args;
+
+    args = generateMotionArgs(0 /*downTime*/, 0 /*eventTime*/, DOWN, {{1, 2}}, STYLUS);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(0 /*downTime*/, 1 /*eventTime*/, MOVE, {{1, 3}}, STYLUS);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(0 /*downTime*/, 2 /*eventTime*/, UP, {{1, 3}}, STYLUS);
+    assertNotBlocked(args);
+}
+
+/**
+ * Existing touch gesture should be canceled when stylus goes down. There should be an ACTION_CANCEL
+ * event generated.
+ */
+TEST_F(PreferStylusOverTouchTest, TouchIsCanceledWhenStylusGoesDown) {
+    NotifyMotionArgs args;
+
+    args = generateMotionArgs(0 /*downTime*/, 0 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(0 /*downTime*/, 1 /*eventTime*/, MOVE, {{1, 3}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(3 /*downTime*/, 3 /*eventTime*/, DOWN, {{10, 30}}, STYLUS);
+    NotifyMotionArgs cancelArgs =
+            generateMotionArgs(0 /*downTime*/, 1 /*eventTime*/, CANCEL, {{1, 3}}, TOUCHSCREEN);
+    cancelArgs.flags |= AMOTION_EVENT_FLAG_CANCELED;
+    assertResponse(args, {cancelArgs, args});
+
+    // Both stylus and touch events continue. Stylus should be not blocked, and touch should be
+    // blocked
+    args = generateMotionArgs(3 /*downTime*/, 4 /*eventTime*/, MOVE, {{10, 31}}, STYLUS);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(0 /*downTime*/, 5 /*eventTime*/, MOVE, {{1, 4}}, TOUCHSCREEN);
+    assertDropped(args);
+}
+
+/**
+ * Stylus goes down after touch gesture.
+ */
+TEST_F(PreferStylusOverTouchTest, StylusDownAfterTouch) {
+    NotifyMotionArgs args;
+
+    args = generateMotionArgs(0 /*downTime*/, 0 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(0 /*downTime*/, 1 /*eventTime*/, MOVE, {{1, 3}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(0 /*downTime*/, 2 /*eventTime*/, UP, {{1, 3}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+
+    // Stylus goes down
+    args = generateMotionArgs(3 /*downTime*/, 3 /*eventTime*/, DOWN, {{10, 30}}, STYLUS);
+    assertNotBlocked(args);
+}
+
+/**
+ * New touch events should be simply blocked (dropped) when stylus is down. No CANCEL event should
+ * be generated.
+ */
+TEST_F(PreferStylusOverTouchTest, NewTouchIsBlockedWhenStylusIsDown) {
+    NotifyMotionArgs args;
+    constexpr nsecs_t stylusDownTime = 0;
+    constexpr nsecs_t touchDownTime = 1;
+
+    args = generateMotionArgs(stylusDownTime, 0 /*eventTime*/, DOWN, {{10, 30}}, STYLUS);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(touchDownTime, 1 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertDropped(args);
+
+    // Stylus should continue to work
+    args = generateMotionArgs(stylusDownTime, 2 /*eventTime*/, MOVE, {{10, 31}}, STYLUS);
+    assertNotBlocked(args);
+
+    // Touch should continue to be blocked
+    args = generateMotionArgs(touchDownTime, 1 /*eventTime*/, MOVE, {{1, 3}}, TOUCHSCREEN);
+    assertDropped(args);
+
+    args = generateMotionArgs(0 /*downTime*/, 5 /*eventTime*/, MOVE, {{1, 4}}, TOUCHSCREEN);
+    assertDropped(args);
+}
+
+/**
+ * New touch events should be simply blocked (dropped) when stylus is down. No CANCEL event should
+ * be generated.
+ */
+TEST_F(PreferStylusOverTouchTest, NewTouchWorksAfterStylusIsLifted) {
+    NotifyMotionArgs args;
+    constexpr nsecs_t stylusDownTime = 0;
+    constexpr nsecs_t touchDownTime = 4;
+
+    // Stylus goes down and up
+    args = generateMotionArgs(stylusDownTime, 0 /*eventTime*/, DOWN, {{10, 30}}, STYLUS);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(stylusDownTime, 2 /*eventTime*/, MOVE, {{10, 31}}, STYLUS);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(stylusDownTime, 3 /*eventTime*/, UP, {{10, 31}}, STYLUS);
+    assertNotBlocked(args);
+
+    // New touch goes down. It should not be blocked
+    args = generateMotionArgs(touchDownTime, touchDownTime, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(touchDownTime, 5 /*eventTime*/, MOVE, {{1, 3}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+
+    args = generateMotionArgs(touchDownTime, 6 /*eventTime*/, UP, {{1, 3}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+}
+
+/**
+ * Once a touch gesture is canceled, it should continue to be canceled, even if the stylus has been
+ * lifted.
+ */
+TEST_F(PreferStylusOverTouchTest, AfterStylusIsLiftedCurrentTouchIsBlocked) {
+    NotifyMotionArgs args;
+    constexpr nsecs_t stylusDownTime = 0;
+    constexpr nsecs_t touchDownTime = 1;
+
+    assertNotBlocked(generateMotionArgs(stylusDownTime, 0 /*eventTime*/, DOWN, {{10, 30}}, STYLUS));
+
+    args = generateMotionArgs(touchDownTime, 1 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertDropped(args);
+
+    // Lift the stylus
+    args = generateMotionArgs(stylusDownTime, 2 /*eventTime*/, UP, {{10, 30}}, STYLUS);
+    assertNotBlocked(args);
+
+    // Touch should continue to be blocked
+    args = generateMotionArgs(touchDownTime, 3 /*eventTime*/, MOVE, {{1, 3}}, TOUCHSCREEN);
+    assertDropped(args);
+
+    args = generateMotionArgs(touchDownTime, 4 /*eventTime*/, UP, {{1, 3}}, TOUCHSCREEN);
+    assertDropped(args);
+
+    // New touch should go through, though.
+    constexpr nsecs_t newTouchDownTime = 5;
+    args = generateMotionArgs(newTouchDownTime, 5 /*eventTime*/, DOWN, {{10, 20}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+}
+
+/**
+ * If an event with mixed stylus and touch pointers is encountered, it should be ignored. Touches
+ * from such should pass, even if stylus from the same device goes down.
+ */
+TEST_F(PreferStylusOverTouchTest, MixedStylusAndTouchPointersAreIgnored) {
+    NotifyMotionArgs args;
+
+    // Event from a stylus device, but with finger tool type
+    args = generateMotionArgs(1 /*downTime*/, 1 /*eventTime*/, DOWN, {{1, 2}}, STYLUS);
+    // Keep source stylus, but make the tool type touch
+    args.pointerProperties[0].toolType = AMOTION_EVENT_TOOL_TYPE_FINGER;
+    assertNotBlocked(args);
+
+    // Second pointer (stylus pointer) goes down, from the same device
+    args = generateMotionArgs(1 /*downTime*/, 2 /*eventTime*/, POINTER_1_DOWN, {{1, 2}, {10, 20}},
+                              STYLUS);
+    // Keep source stylus, but make the tool type touch
+    args.pointerProperties[0].toolType = AMOTION_EVENT_TOOL_TYPE_STYLUS;
+    assertNotBlocked(args);
+
+    // Second pointer (stylus pointer) goes down, from the same device
+    args = generateMotionArgs(1 /*downTime*/, 3 /*eventTime*/, MOVE, {{2, 3}, {11, 21}}, STYLUS);
+    // Keep source stylus, but make the tool type touch
+    args.pointerProperties[0].toolType = AMOTION_EVENT_TOOL_TYPE_FINGER;
+    assertNotBlocked(args);
+}
+
+/**
+ * When there are two touch devices, stylus down should cancel all current touch streams.
+ */
+TEST_F(PreferStylusOverTouchTest, TouchFromTwoDevicesAndStylus) {
+    NotifyMotionArgs touch1Down =
+            generateMotionArgs(1 /*downTime*/, 1 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertNotBlocked(touch1Down);
+
+    NotifyMotionArgs touch2Down =
+            generateMotionArgs(2 /*downTime*/, 2 /*eventTime*/, DOWN, {{3, 4}}, TOUCHSCREEN);
+    touch2Down.deviceId = SECOND_TOUCH_DEVICE_ID;
+    assertNotBlocked(touch2Down);
+
+    NotifyMotionArgs stylusDown =
+            generateMotionArgs(3 /*downTime*/, 3 /*eventTime*/, DOWN, {{10, 30}}, STYLUS);
+    NotifyMotionArgs cancelArgs1 = touch1Down;
+    cancelArgs1.action = CANCEL;
+    cancelArgs1.flags |= AMOTION_EVENT_FLAG_CANCELED;
+    NotifyMotionArgs cancelArgs2 = touch2Down;
+    cancelArgs2.action = CANCEL;
+    cancelArgs2.flags |= AMOTION_EVENT_FLAG_CANCELED;
+    assertResponse(stylusDown, {cancelArgs1, cancelArgs2, stylusDown});
+}
+
+/**
+ * Touch should be canceled when stylus goes down. After the stylus lifts up, the touch from that
+ * device should continue to be canceled.
+ * If one of the devices is already canceled, it should remain canceled, but new touches from a
+ * different device should go through.
+ */
+TEST_F(PreferStylusOverTouchTest, AllTouchMustLiftAfterCanceledByStylus) {
+    // First device touches down
+    NotifyMotionArgs touch1Down =
+            generateMotionArgs(1 /*downTime*/, 1 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertNotBlocked(touch1Down);
+
+    // Stylus goes down - touch should be canceled
+    NotifyMotionArgs stylusDown =
+            generateMotionArgs(2 /*downTime*/, 2 /*eventTime*/, DOWN, {{10, 30}}, STYLUS);
+    NotifyMotionArgs cancelArgs1 = touch1Down;
+    cancelArgs1.action = CANCEL;
+    cancelArgs1.flags |= AMOTION_EVENT_FLAG_CANCELED;
+    assertResponse(stylusDown, {cancelArgs1, stylusDown});
+
+    // Stylus goes up
+    NotifyMotionArgs stylusUp =
+            generateMotionArgs(2 /*downTime*/, 3 /*eventTime*/, UP, {{10, 30}}, STYLUS);
+    assertNotBlocked(stylusUp);
+
+    // Touch from the first device remains blocked
+    NotifyMotionArgs touch1Move =
+            generateMotionArgs(1 /*downTime*/, 4 /*eventTime*/, MOVE, {{2, 3}}, TOUCHSCREEN);
+    assertDropped(touch1Move);
+
+    // Second touch goes down. It should not be blocked because stylus has already lifted.
+    NotifyMotionArgs touch2Down =
+            generateMotionArgs(5 /*downTime*/, 5 /*eventTime*/, DOWN, {{31, 32}}, TOUCHSCREEN);
+    touch2Down.deviceId = SECOND_TOUCH_DEVICE_ID;
+    assertNotBlocked(touch2Down);
+
+    // First device is lifted up. It's already been canceled, so the UP event should be dropped.
+    NotifyMotionArgs touch1Up =
+            generateMotionArgs(1 /*downTime*/, 6 /*eventTime*/, UP, {{2, 3}}, TOUCHSCREEN);
+    assertDropped(touch1Up);
+
+    // Touch from second device touch should continue to work
+    NotifyMotionArgs touch2Move =
+            generateMotionArgs(5 /*downTime*/, 7 /*eventTime*/, MOVE, {{32, 33}}, TOUCHSCREEN);
+    touch2Move.deviceId = SECOND_TOUCH_DEVICE_ID;
+    assertNotBlocked(touch2Move);
+
+    // Second touch lifts up
+    NotifyMotionArgs touch2Up =
+            generateMotionArgs(5 /*downTime*/, 8 /*eventTime*/, UP, {{32, 33}}, TOUCHSCREEN);
+    touch2Up.deviceId = SECOND_TOUCH_DEVICE_ID;
+    assertNotBlocked(touch2Up);
+
+    // Now that all touch has been lifted, new touch from either first or second device should work
+    NotifyMotionArgs touch3Down =
+            generateMotionArgs(9 /*downTime*/, 9 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertNotBlocked(touch3Down);
+
+    NotifyMotionArgs touch4Down =
+            generateMotionArgs(10 /*downTime*/, 10 /*eventTime*/, DOWN, {{100, 200}}, TOUCHSCREEN);
+    touch4Down.deviceId = SECOND_TOUCH_DEVICE_ID;
+    assertNotBlocked(touch4Down);
+}
+
+/**
+ * When we don't know that a specific device does both stylus and touch, and we only see touch
+ * pointers from it, we should treat it as a touch device. That means, the device events should be
+ * canceled when stylus from another device goes down. When we detect simultaneous touch and stylus
+ * from this device though, we should just pass this device through without canceling anything.
+ *
+ * In this test:
+ * 1. Start by touching down with device 1
+ * 2. Device 2 has stylus going down
+ * 3. Device 1 should be canceled.
+ * 4. When we add stylus pointers to the device 1, they should continue to be canceled.
+ * 5. Device 1 lifts up.
+ * 6. Subsequent events from device 1 should not be canceled even if stylus is down.
+ * 7. If a reset happens, and such device is no longer there, then we should
+ * Therefore, the device 1 is "ignored" and does not participate into "prefer stylus over touch"
+ * behaviour.
+ */
+TEST_F(PreferStylusOverTouchTest, MixedStylusAndTouchDeviceIsCanceledAtFirst) {
+    // Touch from device 1 goes down
+    NotifyMotionArgs touchDown =
+            generateMotionArgs(1 /*downTime*/, 1 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    touchDown.source = STYLUS;
+    assertNotBlocked(touchDown);
+
+    // Stylus from device 2 goes down. Touch should be canceled.
+    NotifyMotionArgs args =
+            generateMotionArgs(2 /*downTime*/, 2 /*eventTime*/, DOWN, {{10, 20}}, STYLUS);
+    NotifyMotionArgs cancelTouchArgs = touchDown;
+    cancelTouchArgs.action = CANCEL;
+    cancelTouchArgs.flags |= AMOTION_EVENT_FLAG_CANCELED;
+    assertResponse(args, {cancelTouchArgs, args});
+
+    // Introduce a stylus pointer into the device 1 stream. It should be ignored.
+    args = generateMotionArgs(1 /*downTime*/, 3 /*eventTime*/, POINTER_1_DOWN, {{1, 2}, {3, 4}},
+                              TOUCHSCREEN);
+    args.pointerProperties[1].toolType = AMOTION_EVENT_TOOL_TYPE_STYLUS;
+    args.source = STYLUS;
+    assertDropped(args);
+
+    // Lift up touch from the mixed touch/stylus device
+    args = generateMotionArgs(1 /*downTime*/, 4 /*eventTime*/, CANCEL, {{1, 2}, {3, 4}},
+                              TOUCHSCREEN);
+    args.pointerProperties[1].toolType = AMOTION_EVENT_TOOL_TYPE_STYLUS;
+    args.source = STYLUS;
+    assertDropped(args);
+
+    // Stylus from device 2 is still down. Since the device 1 is now identified as a mixed
+    // touch/stylus device, its events should go through, even if they are touch.
+    args = generateMotionArgs(5 /*downTime*/, 5 /*eventTime*/, DOWN, {{21, 22}}, TOUCHSCREEN);
+    touchDown.source = STYLUS;
+    assertResponse(args, {args});
+
+    // Reconfigure such that only the stylus device remains
+    InputDeviceInfo stylusDevice;
+    stylusDevice.initialize(STYLUS_DEVICE_ID, 1 /*generation*/, 1 /*controllerNumber*/,
+                            {} /*identifier*/, "stylus device", false /*external*/,
+                            false /*hasMic*/);
+    notifyInputDevicesChanged({stylusDevice});
+    // The touchscreen device was removed, so we no longer remember anything about it. We should
+    // again start blocking touch events from it.
+    args = generateMotionArgs(6 /*downTime*/, 6 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    args.source = STYLUS;
+    assertDropped(args);
+}
+
+/**
+ * If two styli are active at the same time, touch should be blocked until both of them are lifted.
+ * If one of them lifts, touch should continue to be blocked.
+ */
+TEST_F(PreferStylusOverTouchTest, TouchIsBlockedWhenTwoStyliAreUsed) {
+    NotifyMotionArgs args;
+
+    // First stylus is down
+    assertNotBlocked(generateMotionArgs(0 /*downTime*/, 0 /*eventTime*/, DOWN, {{10, 30}}, STYLUS));
+
+    // Second stylus is down
+    args = generateMotionArgs(1 /*downTime*/, 1 /*eventTime*/, DOWN, {{20, 40}}, STYLUS);
+    args.deviceId = SECOND_STYLUS_DEVICE_ID;
+    assertNotBlocked(args);
+
+    // Touch goes down. It should be ignored.
+    args = generateMotionArgs(2 /*downTime*/, 2 /*eventTime*/, DOWN, {{1, 2}}, TOUCHSCREEN);
+    assertDropped(args);
+
+    // Lift the first stylus
+    args = generateMotionArgs(0 /*downTime*/, 3 /*eventTime*/, UP, {{10, 30}}, STYLUS);
+    assertNotBlocked(args);
+
+    // Touch should continue to be blocked
+    args = generateMotionArgs(2 /*downTime*/, 4 /*eventTime*/, UP, {{1, 2}}, TOUCHSCREEN);
+    assertDropped(args);
+
+    // New touch should be blocked because second stylus is still down
+    args = generateMotionArgs(5 /*downTime*/, 5 /*eventTime*/, DOWN, {{5, 6}}, TOUCHSCREEN);
+    assertDropped(args);
+
+    // Second stylus goes up
+    args = generateMotionArgs(1 /*downTime*/, 6 /*eventTime*/, UP, {{20, 40}}, STYLUS);
+    args.deviceId = SECOND_STYLUS_DEVICE_ID;
+    assertNotBlocked(args);
+
+    // Current touch gesture should continue to be blocked
+    // Touch should continue to be blocked
+    args = generateMotionArgs(5 /*downTime*/, 7 /*eventTime*/, UP, {{5, 6}}, TOUCHSCREEN);
+    assertDropped(args);
+
+    // Now that all styli were lifted, new touch should go through
+    args = generateMotionArgs(8 /*downTime*/, 8 /*eventTime*/, DOWN, {{7, 8}}, TOUCHSCREEN);
+    assertNotBlocked(args);
+}
+
+} // namespace android
diff --git a/services/inputflinger/tests/UnwantedInteractionBlocker_test.cpp b/services/inputflinger/tests/UnwantedInteractionBlocker_test.cpp
index a3220cc..e378096 100644
--- a/services/inputflinger/tests/UnwantedInteractionBlocker_test.cpp
+++ b/services/inputflinger/tests/UnwantedInteractionBlocker_test.cpp
@@ -490,6 +490,14 @@
             &(args = generateMotionArgs(0 /*downTime*/, 4 /*eventTime*/, DOWN, {{7, 8, 9}})));
 }
 
+TEST_F(UnwantedInteractionBlockerTest, NoCrashWhenStylusSourceWithFingerToolIsReceived) {
+    mBlocker->notifyInputDevicesChanged({generateTestDeviceInfo()});
+    NotifyMotionArgs args = generateMotionArgs(0 /*downTime*/, 1 /*eventTime*/, DOWN, {{1, 2, 3}});
+    args.pointerProperties[0].toolType = AMOTION_EVENT_TOOL_TYPE_FINGER;
+    args.source = AINPUT_SOURCE_STYLUS;
+    mBlocker->notifyMotion(&args);
+}
+
 /**
  * If input devices have changed, but the important device info that's used by the
  * UnwantedInteractionBlocker has not changed, there should not be a reset.
@@ -511,6 +519,34 @@
             &(args = generateMotionArgs(0 /*downTime*/, 4 /*eventTime*/, MOVE, {{7, 8, 9}})));
 }
 
+/**
+ * Send a touch event, and then a stylus event. Make sure that both work.
+ */
+TEST_F(UnwantedInteractionBlockerTest, StylusAfterTouchWorks) {
+    NotifyMotionArgs args;
+    mBlocker->notifyInputDevicesChanged({generateTestDeviceInfo()});
+    args = generateMotionArgs(0 /*downTime*/, 0 /*eventTime*/, DOWN, {{1, 2, 3}});
+    mBlocker->notifyMotion(&args);
+    args = generateMotionArgs(0 /*downTime*/, 1 /*eventTime*/, MOVE, {{4, 5, 6}});
+    mBlocker->notifyMotion(&args);
+    args = generateMotionArgs(0 /*downTime*/, 2 /*eventTime*/, UP, {{4, 5, 6}});
+    mBlocker->notifyMotion(&args);
+
+    // Now touch down stylus
+    args = generateMotionArgs(3 /*downTime*/, 3 /*eventTime*/, DOWN, {{10, 20, 30}});
+    args.pointerProperties[0].toolType = AMOTION_EVENT_TOOL_TYPE_STYLUS;
+    args.source |= AINPUT_SOURCE_STYLUS;
+    mBlocker->notifyMotion(&args);
+    args = generateMotionArgs(3 /*downTime*/, 4 /*eventTime*/, MOVE, {{40, 50, 60}});
+    args.pointerProperties[0].toolType = AMOTION_EVENT_TOOL_TYPE_STYLUS;
+    args.source |= AINPUT_SOURCE_STYLUS;
+    mBlocker->notifyMotion(&args);
+    args = generateMotionArgs(3 /*downTime*/, 5 /*eventTime*/, UP, {{40, 50, 60}});
+    args.pointerProperties[0].toolType = AMOTION_EVENT_TOOL_TYPE_STYLUS;
+    args.source |= AINPUT_SOURCE_STYLUS;
+    mBlocker->notifyMotion(&args);
+}
+
 using UnwantedInteractionBlockerTestDeathTest = UnwantedInteractionBlockerTest;
 
 /**
diff --git a/services/sensorservice/SensorService.h b/services/sensorservice/SensorService.h
index 7194db3..b18d204 100644
--- a/services/sensorservice/SensorService.h
+++ b/services/sensorservice/SensorService.h
@@ -257,11 +257,13 @@
 
             bool isUidActive(uid_t uid);
 
-            void onUidGone(uid_t uid, bool disabled);
-            void onUidActive(uid_t uid);
-            void onUidIdle(uid_t uid, bool disabled);
+            void onUidGone(uid_t uid, bool disabled) override;
+            void onUidActive(uid_t uid) override;
+            void onUidIdle(uid_t uid, bool disabled) override;
             void onUidStateChanged(uid_t uid __unused, int32_t procState __unused,
-                                   int64_t procStateSeq __unused, int32_t capability __unused) {}
+                                   int64_t procStateSeq __unused,
+                                   int32_t capability __unused) override {}
+            void onUidProcAdjChanged(uid_t uid __unused) override {}
 
             void addOverrideUid(uid_t uid, bool active);
             void removeOverrideUid(uid_t uid);
diff --git a/services/sensorservice/SensorServiceUtils.cpp b/services/sensorservice/SensorServiceUtils.cpp
index 7dd2331..6bad962 100644
--- a/services/sensorservice/SensorServiceUtils.cpp
+++ b/services/sensorservice/SensorServiceUtils.cpp
@@ -39,6 +39,7 @@
             return 5;
 
         case SENSOR_TYPE_MAGNETIC_FIELD_UNCALIBRATED:
+        case SENSOR_TYPE_ACCELEROMETER_UNCALIBRATED:
         case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
         case SENSOR_TYPE_ACCELEROMETER_LIMITED_AXES:
         case SENSOR_TYPE_GYROSCOPE_LIMITED_AXES:
diff --git a/services/surfaceflinger/BufferStateLayer.cpp b/services/surfaceflinger/BufferStateLayer.cpp
index bcae8d9..c5d7a60 100644
--- a/services/surfaceflinger/BufferStateLayer.cpp
+++ b/services/surfaceflinger/BufferStateLayer.cpp
@@ -1098,6 +1098,13 @@
         }
     }
 
+    if (s.what & layer_state_t::eDimmingEnabledChanged) {
+        if (mDrawingState.dimmingEnabled != s.dimmingEnabled) {
+            ALOGV("%s: false [eDimmingEnabledChanged changed]", __func__);
+            return false;
+        }
+    }
+
     ALOGV("%s: true", __func__);
     return true;
 }
diff --git a/services/surfaceflinger/CompositionEngine/Android.bp b/services/surfaceflinger/CompositionEngine/Android.bp
index aefc014..516c3ef 100644
--- a/services/surfaceflinger/CompositionEngine/Android.bp
+++ b/services/surfaceflinger/CompositionEngine/Android.bp
@@ -23,6 +23,7 @@
         "android.hardware.graphics.composer3-V1-ndk",
         "android.hardware.power@1.0",
         "android.hardware.power@1.3",
+        "android.hardware.power-V2-cpp",
         "libbase",
         "libcutils",
         "libgui",
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFECompositionState.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFECompositionState.h
index 283fe86..974f7c6 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFECompositionState.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFECompositionState.h
@@ -207,6 +207,9 @@
     // framerate of the layer as measured by LayerHistory
     float fps;
 
+    // The dimming flag
+    bool dimmingEnabled{true};
+
     virtual ~LayerFECompositionState();
 
     // Debugging
diff --git a/services/surfaceflinger/CompositionEngine/src/LayerFECompositionState.cpp b/services/surfaceflinger/CompositionEngine/src/LayerFECompositionState.cpp
index ff7d430..6631a27 100644
--- a/services/surfaceflinger/CompositionEngine/src/LayerFECompositionState.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/LayerFECompositionState.cpp
@@ -121,6 +121,7 @@
     dumpVal(out, "isColorspaceAgnostic", isColorspaceAgnostic);
     dumpVal(out, "dataspace", toString(dataspace), dataspace);
     dumpVal(out, "hdr metadata types", hdrMetadata.validTypes);
+    dumpVal(out, "dimming enabled", dimmingEnabled);
     dumpVal(out, "colorTransform", colorTransform);
 
     out.append("\n");
diff --git a/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp b/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
index 723593d..3289d55 100644
--- a/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
@@ -324,9 +324,10 @@
 
     // For hdr content, treat the white point as the display brightness - HDR content should not be
     // boosted or dimmed.
+    // If the layer explicitly requests to disable dimming, then don't dim either.
     if (isHdrDataspace(state.dataspace) ||
         getOutput().getState().displayBrightnessNits == getOutput().getState().sdrWhitePointNits ||
-        getOutput().getState().displayBrightnessNits == 0.f) {
+        getOutput().getState().displayBrightnessNits == 0.f || !layerFEState->dimmingEnabled) {
         state.dimmingRatio = 1.f;
         state.whitePointNits = getOutput().getState().displayBrightnessNits;
     } else {
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
index 8eb1946..ceee48c 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
@@ -668,6 +668,13 @@
     EXPECT_EQ(mOutputState.sdrWhitePointNits / mOutputState.displayBrightnessNits,
               mOutputLayer.getState().dimmingRatio);
 
+    mLayerFEState.dimmingEnabled = false;
+    mOutputLayer.updateCompositionState(false, false, ui::Transform::RotationFlags::ROT_0);
+    EXPECT_EQ(mOutputState.displayBrightnessNits, mOutputLayer.getState().whitePointNits);
+    EXPECT_EQ(1.f, mOutputLayer.getState().dimmingRatio);
+
+    // change dimmingEnabled back to true.
+    mLayerFEState.dimmingEnabled = true;
     mLayerFEState.dataspace = ui::Dataspace::BT2020_ITU_PQ;
     mLayerFEState.isColorspaceAgnostic = false;
     mOutputLayer.updateCompositionState(false, false, ui::Transform::RotationFlags::ROT_0);
diff --git a/services/surfaceflinger/DisplayDevice.h b/services/surfaceflinger/DisplayDevice.h
index 2c4a300..d5d87b4 100644
--- a/services/surfaceflinger/DisplayDevice.h
+++ b/services/surfaceflinger/DisplayDevice.h
@@ -21,6 +21,7 @@
 #include <string>
 #include <unordered_map>
 
+#include <android-base/thread_annotations.h>
 #include <android/native_window.h>
 #include <binder/IBinder.h>
 #include <gui/LayerState.h>
@@ -28,6 +29,7 @@
 #include <renderengine/RenderEngine.h>
 #include <system/window.h>
 #include <ui/DisplayId.h>
+#include <ui/DisplayIdentification.h>
 #include <ui/DisplayState.h>
 #include <ui/GraphicTypes.h>
 #include <ui/HdrCapabilities.h>
@@ -39,15 +41,11 @@
 #include <utils/RefBase.h>
 #include <utils/Timers.h>
 
-#include "MainThreadGuard.h"
-
-#include <ui/DisplayIdentification.h>
 #include "DisplayHardware/DisplayMode.h"
 #include "DisplayHardware/Hal.h"
 #include "DisplayHardware/PowerAdvisor.h"
-
 #include "Scheduler/RefreshRateConfigs.h"
-
+#include "ThreadContext.h"
 #include "TracedOrdinal.h"
 
 namespace android {
@@ -99,9 +97,9 @@
     void setLayerStack(ui::LayerStack);
     void setDisplaySize(int width, int height);
     void setProjection(ui::Rotation orientation, Rect viewport, Rect frame);
-    void stageBrightness(float brightness) REQUIRES(SF_MAIN_THREAD);
-    void persistBrightness(bool needsComposite) REQUIRES(SF_MAIN_THREAD);
-    bool isBrightnessStale() const REQUIRES(SF_MAIN_THREAD);
+    void stageBrightness(float brightness) REQUIRES(kMainThreadContext);
+    void persistBrightness(bool needsComposite) REQUIRES(kMainThreadContext);
+    bool isBrightnessStale() const REQUIRES(kMainThreadContext);
     void setFlags(uint32_t flags);
 
     ui::Rotation getPhysicalOrientation() const { return mPhysicalOrientation; }
@@ -109,7 +107,7 @@
 
     static ui::Transform::RotationFlags getPrimaryDisplayRotationFlags();
 
-    std::optional<float> getStagedBrightness() const REQUIRES(SF_MAIN_THREAD);
+    std::optional<float> getStagedBrightness() const REQUIRES(kMainThreadContext);
     ui::Transform::RotationFlags getTransformHint() const;
     const ui::Transform& getTransform() const;
     const Rect& getLayerStackSpaceRect() const;
@@ -209,15 +207,15 @@
     bool setDesiredActiveMode(const ActiveModeInfo&) EXCLUDES(mActiveModeLock);
     std::optional<ActiveModeInfo> getDesiredActiveMode() const EXCLUDES(mActiveModeLock);
     void clearDesiredActiveModeState() EXCLUDES(mActiveModeLock);
-    ActiveModeInfo getUpcomingActiveMode() const REQUIRES(SF_MAIN_THREAD) {
+    ActiveModeInfo getUpcomingActiveMode() const REQUIRES(kMainThreadContext) {
         return mUpcomingActiveMode;
     }
 
-    void setActiveMode(DisplayModeId) REQUIRES(SF_MAIN_THREAD);
+    void setActiveMode(DisplayModeId) REQUIRES(kMainThreadContext);
     status_t initiateModeChange(const ActiveModeInfo&,
                                 const hal::VsyncPeriodChangeConstraints& constraints,
                                 hal::VsyncPeriodChangeTimeline* outTimeline)
-            REQUIRES(SF_MAIN_THREAD);
+            REQUIRES(kMainThreadContext);
 
     // Return the immutable list of supported display modes. The HWC may report different modes
     // after a hotplug reconnect event, in which case the DisplayDevice object will be recreated.
@@ -304,7 +302,7 @@
     ActiveModeInfo mDesiredActiveMode GUARDED_BY(mActiveModeLock);
     TracedOrdinal<bool> mDesiredActiveModeChanged
             GUARDED_BY(mActiveModeLock) = {"DesiredActiveModeChanged", false};
-    ActiveModeInfo mUpcomingActiveMode GUARDED_BY(SF_MAIN_THREAD);
+    ActiveModeInfo mUpcomingActiveMode GUARDED_BY(kMainThreadContext);
 };
 
 struct DisplayDeviceState {
diff --git a/services/surfaceflinger/DisplayHardware/PowerAdvisor.cpp b/services/surfaceflinger/DisplayHardware/PowerAdvisor.cpp
index 44c086d..05f488b 100644
--- a/services/surfaceflinger/DisplayHardware/PowerAdvisor.cpp
+++ b/services/surfaceflinger/DisplayHardware/PowerAdvisor.cpp
@@ -32,7 +32,6 @@
 #include <utils/Trace.h>
 
 #include <android/hardware/power/1.3/IPower.h>
-#include <android/hardware/power/IPower.h>
 #include <android/hardware/power/IPowerHintSession.h>
 #include <android/hardware/power/WorkDuration.h>
 
@@ -62,8 +61,6 @@
 
 using scheduler::OneShotTimer;
 
-class AidlPowerHalWrapper;
-
 PowerAdvisor::~PowerAdvisor() = default;
 
 namespace {
@@ -294,259 +291,232 @@
     const sp<V1_3::IPower> mPowerHal = nullptr;
 };
 
-class AidlPowerHalWrapper : public PowerAdvisor::HalWrapper {
-public:
-    AidlPowerHalWrapper(sp<IPower> powerHal) : mPowerHal(std::move(powerHal)) {
-        auto ret = mPowerHal->isModeSupported(Mode::EXPENSIVE_RENDERING, &mHasExpensiveRendering);
-        if (!ret.isOk()) {
-            mHasExpensiveRendering = false;
-        }
-
-        ret = mPowerHal->isBoostSupported(Boost::DISPLAY_UPDATE_IMMINENT,
-                                          &mHasDisplayUpdateImminent);
-        if (!ret.isOk()) {
-            mHasDisplayUpdateImminent = false;
-        }
-
-        mSupportsPowerHint = checkPowerHintSessionSupported();
+AidlPowerHalWrapper::AidlPowerHalWrapper(sp<IPower> powerHal) : mPowerHal(std::move(powerHal)) {
+    auto ret = mPowerHal->isModeSupported(Mode::EXPENSIVE_RENDERING, &mHasExpensiveRendering);
+    if (!ret.isOk()) {
+        mHasExpensiveRendering = false;
     }
 
-    ~AidlPowerHalWrapper() override {
-        if (mPowerHintSession != nullptr) {
-            mPowerHintSession->close();
-            mPowerHintSession = nullptr;
-        }
-    };
-
-    static std::unique_ptr<HalWrapper> connect() {
-        // This only waits if the service is actually declared
-        sp<IPower> powerHal = waitForVintfService<IPower>();
-        if (powerHal == nullptr) {
-            return nullptr;
-        }
-        ALOGI("Loaded AIDL Power HAL service");
-
-        return std::make_unique<AidlPowerHalWrapper>(std::move(powerHal));
+    ret = mPowerHal->isBoostSupported(Boost::DISPLAY_UPDATE_IMMINENT, &mHasDisplayUpdateImminent);
+    if (!ret.isOk()) {
+        mHasDisplayUpdateImminent = false;
     }
 
-    bool setExpensiveRendering(bool enabled) override {
-        ALOGV("AIDL setExpensiveRendering %s", enabled ? "T" : "F");
-        if (!mHasExpensiveRendering) {
-            ALOGV("Skipped sending EXPENSIVE_RENDERING because HAL doesn't support it");
-            return true;
-        }
+    mSupportsPowerHint = checkPowerHintSessionSupported();
+}
 
-        auto ret = mPowerHal->setMode(Mode::EXPENSIVE_RENDERING, enabled);
-        if (ret.isOk()) {
-            traceExpensiveRendering(enabled);
-        }
-        return ret.isOk();
+AidlPowerHalWrapper::~AidlPowerHalWrapper() {
+    if (mPowerHintSession != nullptr) {
+        mPowerHintSession->close();
+        mPowerHintSession = nullptr;
     }
-
-    bool notifyDisplayUpdateImminent() override {
-        ALOGV("AIDL notifyDisplayUpdateImminent");
-        if (!mHasDisplayUpdateImminent) {
-            ALOGV("Skipped sending DISPLAY_UPDATE_IMMINENT because HAL doesn't support it");
-            return true;
-        }
-
-        auto ret = mPowerHal->setBoost(Boost::DISPLAY_UPDATE_IMMINENT, 0);
-        return ret.isOk();
-    }
-
-    // only version 2+ of the aidl supports power hint sessions, hidl has no support
-    bool supportsPowerHintSession() override { return mSupportsPowerHint; }
-
-    bool checkPowerHintSessionSupported() {
-        int64_t unused;
-        // Try to get preferred rate to determine if hint sessions are supported
-        // We check for isOk not EX_UNSUPPORTED_OPERATION to lump other errors
-        return mPowerHal->getHintSessionPreferredRate(&unused).isOk();
-    }
-
-    bool isPowerHintSessionRunning() override { return mPowerHintSession != nullptr; }
-
-    void closePowerHintSession() {
-        if (mPowerHintSession != nullptr) {
-            mPowerHintSession->close();
-            mPowerHintSession = nullptr;
-        }
-    }
-
-    void restartPowerHintSession() {
-        closePowerHintSession();
-        startPowerHintSession();
-    }
-
-    void setPowerHintSessionThreadIds(const std::vector<int32_t>& threadIds) override {
-        if (threadIds != mPowerHintThreadIds) {
-            mPowerHintThreadIds = threadIds;
-            if (isPowerHintSessionRunning()) {
-                restartPowerHintSession();
-            }
-        }
-    }
-
-    bool startPowerHintSession() override {
-        if (mPowerHintSession != nullptr || mPowerHintThreadIds.empty()) {
-            ALOGV("Cannot start power hint session, skipping");
-            return false;
-        }
-        auto ret = mPowerHal->createHintSession(getpid(), static_cast<int32_t>(getuid()),
-                                                mPowerHintThreadIds, mTargetDuration,
-                                                &mPowerHintSession);
-        if (!ret.isOk()) {
-            ALOGW("Failed to start power hint session with error: %s",
-                  ret.exceptionToString(ret.exceptionCode()).c_str());
-        } else {
-            mLastTargetDurationSent = mTargetDuration;
-        }
-        return isPowerHintSessionRunning();
-    }
-
-    bool shouldSetTargetDuration(int64_t targetDurationNanos) {
-        // report if the change in target from our last submission to now exceeds the threshold
-        return abs(1.0 -
-                   static_cast<double>(mLastTargetDurationSent) /
-                           static_cast<double>(targetDurationNanos)) >=
-                kAllowedTargetDeviationPercent;
-    }
-
-    void setTargetWorkDuration(int64_t targetDurationNanos) override {
-        ATRACE_CALL();
-        mTargetDuration = targetDurationNanos;
-        if (sTraceHintSessionData) ATRACE_INT64("Time target", targetDurationNanos);
-        if (!sNormalizeTarget && shouldSetTargetDuration(targetDurationNanos) &&
-            isPowerHintSessionRunning()) {
-            if (mLastActualDurationSent.has_value()) {
-                // update the error term here since we are actually sending an update to powerhal
-                if (sTraceHintSessionData)
-                    ATRACE_INT64("Target error term",
-                                 targetDurationNanos - *mLastActualDurationSent);
-            }
-            ALOGV("Sending target time: %lld ns", static_cast<long long>(targetDurationNanos));
-            mLastTargetDurationSent = targetDurationNanos;
-            auto ret = mPowerHintSession->updateTargetWorkDuration(targetDurationNanos);
-            if (!ret.isOk()) {
-                ALOGW("Failed to set power hint target work duration with error: %s",
-                      ret.exceptionMessage().c_str());
-                mShouldReconnectHal = true;
-            }
-        }
-    }
-
-    bool shouldReportActualDurationsNow() {
-        // report if we have never reported before or are approaching a stale session
-        if (!mLastActualDurationSent.has_value() ||
-            (systemTime() - mLastActualReportTimestamp) > kStaleTimeout.count()) {
-            return true;
-        }
-
-        if (!mActualDuration.has_value()) {
-            return false;
-        }
-
-        // duration of most recent timing
-        const double mostRecentActualDuration = static_cast<double>(*mActualDuration);
-        // duration of the last timing actually reported to the powerhal
-        const double lastReportedActualDuration = static_cast<double>(*mLastActualDurationSent);
-
-        // report if the change in duration from then to now exceeds the threshold
-        return abs(1.0 - mostRecentActualDuration / lastReportedActualDuration) >=
-                kAllowedActualDeviationPercent;
-    }
-
-    void sendActualWorkDuration(int64_t actualDurationNanos, nsecs_t timeStampNanos) override {
-        ATRACE_CALL();
-
-        if (actualDurationNanos < 0 || !isPowerHintSessionRunning()) {
-            ALOGV("Failed to send actual work duration, skipping");
-            return;
-        }
-
-        WorkDuration duration;
-        duration.durationNanos = actualDurationNanos;
-        mActualDuration = actualDurationNanos;
-
-        // normalize the sent values to a pre-set target
-        if (sNormalizeTarget) {
-            duration.durationNanos += mLastTargetDurationSent - mTargetDuration;
-        }
-        duration.timeStampNanos = timeStampNanos;
-        mPowerHintQueue.push_back(duration);
-
-        long long targetNsec = mTargetDuration;
-        long long durationNsec = actualDurationNanos;
-
-        if (sTraceHintSessionData) {
-            ATRACE_INT64("Measured duration", durationNsec);
-            ATRACE_INT64("Target error term", targetNsec - durationNsec);
-        }
-
-        ALOGV("Sending actual work duration of: %lld on target: %lld with error: %lld",
-              durationNsec, targetNsec, targetNsec - durationNsec);
-
-        // This rate limiter queues similar duration reports to the powerhal into
-        // batches to avoid excessive binder calls. The criteria to send a given batch
-        // are outlined in shouldReportActualDurationsNow()
-        if (shouldReportActualDurationsNow()) {
-            ALOGV("Sending hint update batch");
-            mLastActualReportTimestamp = systemTime();
-            auto ret = mPowerHintSession->reportActualWorkDuration(mPowerHintQueue);
-            if (!ret.isOk()) {
-                ALOGW("Failed to report actual work durations with error: %s",
-                      ret.exceptionMessage().c_str());
-                mShouldReconnectHal = true;
-            }
-            mPowerHintQueue.clear();
-            // we save the non-normalized value here to detect % changes
-            mLastActualDurationSent = actualDurationNanos;
-        }
-    }
-
-    bool shouldReconnectHAL() override { return mShouldReconnectHal; }
-
-    std::vector<int32_t> getPowerHintSessionThreadIds() override { return mPowerHintThreadIds; }
-
-    std::optional<int64_t> getTargetWorkDuration() override { return mTargetDuration; }
-
-private:
-    const sp<IPower> mPowerHal = nullptr;
-    bool mHasExpensiveRendering = false;
-    bool mHasDisplayUpdateImminent = false;
-    // Used to indicate an error state and need for reconstruction
-    bool mShouldReconnectHal = false;
-    // This is not thread safe, but is currently protected by mPowerHalMutex so it needs no lock
-    sp<IPowerHintSession> mPowerHintSession = nullptr;
-    // Queue of actual durations saved to report
-    std::vector<WorkDuration> mPowerHintQueue;
-    // The latest un-normalized values we have received for target and actual
-    int64_t mTargetDuration = kDefaultTarget.count();
-    std::optional<int64_t> mActualDuration;
-    // The list of thread ids, stored so we can restart the session from this class if needed
-    std::vector<int32_t> mPowerHintThreadIds;
-    bool mSupportsPowerHint;
-    // Keep track of the last messages sent for rate limiter change detection
-    std::optional<int64_t> mLastActualDurationSent;
-    // timestamp of the last report we sent, used to avoid stale sessions
-    int64_t mLastActualReportTimestamp = 0;
-    int64_t mLastTargetDurationSent = kDefaultTarget.count();
-    // Whether to normalize all the actual values as error terms relative to a constant target
-    // This saves a binder call by not setting the target, and should not affect the pid values
-    static const bool sNormalizeTarget;
-    // Whether we should emit ATRACE_INT data for hint sessions
-    static const bool sTraceHintSessionData;
-    // Max percent the actual duration can vary without causing a report (eg: 0.1 = 10%)
-    static constexpr double kAllowedActualDeviationPercent = 0.1;
-    // Max percent the target duration can vary without causing a report (eg: 0.05 = 5%)
-    static constexpr double kAllowedTargetDeviationPercent = 0.05;
-    // Target used for init and normalization, the actual value does not really matter
-    static constexpr const std::chrono::nanoseconds kDefaultTarget = 50ms;
-    // Amount of time after the last message was sent before the session goes stale
-    // actually 100ms but we use 80 here to ideally avoid going stale
-    static constexpr const std::chrono::nanoseconds kStaleTimeout = 80ms;
 };
 
+std::unique_ptr<PowerAdvisor::HalWrapper> AidlPowerHalWrapper::connect() {
+    // This only waits if the service is actually declared
+    sp<IPower> powerHal = waitForVintfService<IPower>();
+    if (powerHal == nullptr) {
+        return nullptr;
+    }
+    ALOGI("Loaded AIDL Power HAL service");
+
+    return std::make_unique<AidlPowerHalWrapper>(std::move(powerHal));
+}
+
+bool AidlPowerHalWrapper::setExpensiveRendering(bool enabled) {
+    ALOGV("AIDL setExpensiveRendering %s", enabled ? "T" : "F");
+    if (!mHasExpensiveRendering) {
+        ALOGV("Skipped sending EXPENSIVE_RENDERING because HAL doesn't support it");
+        return true;
+    }
+
+    auto ret = mPowerHal->setMode(Mode::EXPENSIVE_RENDERING, enabled);
+    if (ret.isOk()) {
+        traceExpensiveRendering(enabled);
+    }
+    return ret.isOk();
+}
+
+bool AidlPowerHalWrapper::notifyDisplayUpdateImminent() {
+    ALOGV("AIDL notifyDisplayUpdateImminent");
+    if (!mHasDisplayUpdateImminent) {
+        ALOGV("Skipped sending DISPLAY_UPDATE_IMMINENT because HAL doesn't support it");
+        return true;
+    }
+
+    auto ret = mPowerHal->setBoost(Boost::DISPLAY_UPDATE_IMMINENT, 0);
+    return ret.isOk();
+}
+
+// only version 2+ of the aidl supports power hint sessions, hidl has no support
+bool AidlPowerHalWrapper::supportsPowerHintSession() {
+    return mSupportsPowerHint;
+}
+
+bool AidlPowerHalWrapper::checkPowerHintSessionSupported() {
+    int64_t unused;
+    // Try to get preferred rate to determine if hint sessions are supported
+    // We check for isOk not EX_UNSUPPORTED_OPERATION to lump together errors
+    return mPowerHal->getHintSessionPreferredRate(&unused).isOk();
+}
+
+bool AidlPowerHalWrapper::isPowerHintSessionRunning() {
+    return mPowerHintSession != nullptr;
+}
+
+void AidlPowerHalWrapper::closePowerHintSession() {
+    if (mPowerHintSession != nullptr) {
+        mPowerHintSession->close();
+        mPowerHintSession = nullptr;
+    }
+}
+
+void AidlPowerHalWrapper::restartPowerHintSession() {
+    closePowerHintSession();
+    startPowerHintSession();
+}
+
+void AidlPowerHalWrapper::setPowerHintSessionThreadIds(const std::vector<int32_t>& threadIds) {
+    if (threadIds != mPowerHintThreadIds) {
+        mPowerHintThreadIds = threadIds;
+        if (isPowerHintSessionRunning()) {
+            restartPowerHintSession();
+        }
+    }
+}
+
+bool AidlPowerHalWrapper::startPowerHintSession() {
+    if (mPowerHintSession != nullptr || mPowerHintThreadIds.empty()) {
+        ALOGV("Cannot start power hint session, skipping");
+        return false;
+    }
+    auto ret =
+            mPowerHal->createHintSession(getpid(), static_cast<int32_t>(getuid()),
+                                         mPowerHintThreadIds, mTargetDuration, &mPowerHintSession);
+    if (!ret.isOk()) {
+        ALOGW("Failed to start power hint session with error: %s",
+              ret.exceptionToString(ret.exceptionCode()).c_str());
+    } else {
+        mLastTargetDurationSent = mTargetDuration;
+    }
+    return isPowerHintSessionRunning();
+}
+
+bool AidlPowerHalWrapper::shouldSetTargetDuration(int64_t targetDurationNanos) {
+    if (targetDurationNanos <= 0) {
+        return false;
+    }
+    // report if the change in target from our last submission to now exceeds the threshold
+    return abs(1.0 -
+               static_cast<double>(mLastTargetDurationSent) /
+                       static_cast<double>(targetDurationNanos)) >= kAllowedTargetDeviationPercent;
+}
+
+void AidlPowerHalWrapper::setTargetWorkDuration(int64_t targetDurationNanos) {
+    ATRACE_CALL();
+    mTargetDuration = targetDurationNanos;
+    if (sTraceHintSessionData) ATRACE_INT64("Time target", targetDurationNanos);
+    if (!sNormalizeTarget && isPowerHintSessionRunning() &&
+        shouldSetTargetDuration(targetDurationNanos)) {
+        if (mLastActualDurationSent.has_value()) {
+            // update the error term here since we are actually sending an update to powerhal
+            if (sTraceHintSessionData)
+                ATRACE_INT64("Target error term", targetDurationNanos - *mLastActualDurationSent);
+        }
+        ALOGV("Sending target time: %" PRId64 "ns", targetDurationNanos);
+        mLastTargetDurationSent = targetDurationNanos;
+        auto ret = mPowerHintSession->updateTargetWorkDuration(targetDurationNanos);
+        if (!ret.isOk()) {
+            ALOGW("Failed to set power hint target work duration with error: %s",
+                  ret.exceptionMessage().c_str());
+            mShouldReconnectHal = true;
+        }
+    }
+}
+
+bool AidlPowerHalWrapper::shouldReportActualDurationsNow() {
+    // report if we have never reported before or are approaching a stale session
+    if (!mLastActualDurationSent.has_value() ||
+        (systemTime() - mLastActualReportTimestamp) > kStaleTimeout.count()) {
+        return true;
+    }
+
+    if (!mActualDuration.has_value()) {
+        return false;
+    }
+
+    // duration of most recent timing
+    const double mostRecentActualDuration = static_cast<double>(*mActualDuration);
+    // duration of the last timing actually reported to the powerhal
+    const double lastReportedActualDuration = static_cast<double>(*mLastActualDurationSent);
+
+    // report if the change in duration from then to now exceeds the threshold
+    return abs(1.0 - mostRecentActualDuration / lastReportedActualDuration) >=
+            kAllowedActualDeviationPercent;
+}
+
+void AidlPowerHalWrapper::sendActualWorkDuration(int64_t actualDurationNanos,
+                                                 nsecs_t timeStampNanos) {
+    ATRACE_CALL();
+
+    if (actualDurationNanos < 0 || !isPowerHintSessionRunning()) {
+        ALOGV("Failed to send actual work duration, skipping");
+        return;
+    }
+
+    WorkDuration duration;
+    duration.durationNanos = actualDurationNanos;
+    mActualDuration = actualDurationNanos;
+
+    // normalize the sent values to a pre-set target
+    if (sNormalizeTarget) {
+        duration.durationNanos += mLastTargetDurationSent - mTargetDuration;
+    }
+    duration.timeStampNanos = timeStampNanos;
+    mPowerHintQueue.push_back(duration);
+
+    nsecs_t targetNsec = mTargetDuration;
+    nsecs_t durationNsec = actualDurationNanos;
+
+    if (sTraceHintSessionData) {
+        ATRACE_INT64("Measured duration", durationNsec);
+        ATRACE_INT64("Target error term", targetNsec - durationNsec);
+    }
+
+    ALOGV("Sending actual work duration of: %" PRId64 " on target: %" PRId64
+          " with error: %" PRId64,
+          durationNsec, targetNsec, targetNsec - durationNsec);
+
+    // This rate limiter queues similar duration reports to the powerhal into
+    // batches to avoid excessive binder calls. The criteria to send a given batch
+    // are outlined in shouldReportActualDurationsNow()
+    if (shouldReportActualDurationsNow()) {
+        ALOGV("Sending hint update batch");
+        mLastActualReportTimestamp = systemTime();
+        auto ret = mPowerHintSession->reportActualWorkDuration(mPowerHintQueue);
+        if (!ret.isOk()) {
+            ALOGW("Failed to report actual work durations with error: %s",
+                  ret.exceptionMessage().c_str());
+            mShouldReconnectHal = true;
+        }
+        mPowerHintQueue.clear();
+        // we save the non-normalized value here to detect % changes
+        mLastActualDurationSent = actualDurationNanos;
+    }
+}
+
+bool AidlPowerHalWrapper::shouldReconnectHAL() {
+    return mShouldReconnectHal;
+}
+
+std::vector<int32_t> AidlPowerHalWrapper::getPowerHintSessionThreadIds() {
+    return mPowerHintThreadIds;
+}
+
+std::optional<int64_t> AidlPowerHalWrapper::getTargetWorkDuration() {
+    return mTargetDuration;
+}
+
 const bool AidlPowerHalWrapper::sTraceHintSessionData =
         base::GetBoolProperty(std::string("debug.sf.trace_hint_sessions"), false);
 
diff --git a/services/surfaceflinger/DisplayHardware/PowerAdvisor.h b/services/surfaceflinger/DisplayHardware/PowerAdvisor.h
index 0db56aa..3f47ffd 100644
--- a/services/surfaceflinger/DisplayHardware/PowerAdvisor.h
+++ b/services/surfaceflinger/DisplayHardware/PowerAdvisor.h
@@ -22,6 +22,7 @@
 
 #include <utils/Mutex.h>
 
+#include <android/hardware/power/IPower.h>
 #include <ui/DisplayIdentification.h>
 #include "../Scheduler/OneShotTimer.h"
 
@@ -118,6 +119,69 @@
     scheduler::OneShotTimer mScreenUpdateTimer;
 };
 
+class AidlPowerHalWrapper : public PowerAdvisor::HalWrapper {
+public:
+    explicit AidlPowerHalWrapper(sp<hardware::power::IPower> powerHal);
+    ~AidlPowerHalWrapper() override;
+
+    static std::unique_ptr<HalWrapper> connect();
+
+    bool setExpensiveRendering(bool enabled) override;
+    bool notifyDisplayUpdateImminent() override;
+    bool supportsPowerHintSession() override;
+    bool isPowerHintSessionRunning() override;
+    void restartPowerHintSession() override;
+    void setPowerHintSessionThreadIds(const std::vector<int32_t>& threadIds) override;
+    bool startPowerHintSession() override;
+    void setTargetWorkDuration(int64_t targetDurationNanos) override;
+    void sendActualWorkDuration(int64_t actualDurationNanos, nsecs_t timeStampNanos) override;
+    bool shouldReconnectHAL() override;
+    std::vector<int32_t> getPowerHintSessionThreadIds() override;
+    std::optional<int64_t> getTargetWorkDuration() override;
+
+private:
+    bool checkPowerHintSessionSupported();
+    void closePowerHintSession();
+    bool shouldReportActualDurationsNow();
+    bool shouldSetTargetDuration(int64_t targetDurationNanos);
+
+    const sp<hardware::power::IPower> mPowerHal = nullptr;
+    bool mHasExpensiveRendering = false;
+    bool mHasDisplayUpdateImminent = false;
+    // Used to indicate an error state and need for reconstruction
+    bool mShouldReconnectHal = false;
+    // This is not thread safe, but is currently protected by mPowerHalMutex so it needs no lock
+    sp<hardware::power::IPowerHintSession> mPowerHintSession = nullptr;
+    // Queue of actual durations saved to report
+    std::vector<hardware::power::WorkDuration> mPowerHintQueue;
+    // The latest un-normalized values we have received for target and actual
+    int64_t mTargetDuration = kDefaultTarget.count();
+    std::optional<int64_t> mActualDuration;
+    // The list of thread ids, stored so we can restart the session from this class if needed
+    std::vector<int32_t> mPowerHintThreadIds;
+    bool mSupportsPowerHint;
+    // Keep track of the last messages sent for rate limiter change detection
+    std::optional<int64_t> mLastActualDurationSent;
+    // timestamp of the last report we sent, used to avoid stale sessions
+    int64_t mLastActualReportTimestamp = 0;
+    int64_t mLastTargetDurationSent = kDefaultTarget.count();
+    // Whether to normalize all the actual values as error terms relative to a constant target
+    // This saves a binder call by not setting the target, and should not affect the pid values
+    static const bool sNormalizeTarget;
+    // Whether we should emit ATRACE_INT data for hint sessions
+    static const bool sTraceHintSessionData;
+
+    // Max percent the actual duration can vary without causing a report (eg: 0.1 = 10%)
+    static constexpr double kAllowedActualDeviationPercent = 0.1;
+    // Max percent the target duration can vary without causing a report (eg: 0.05 = 5%)
+    static constexpr double kAllowedTargetDeviationPercent = 0.05;
+    // Target used for init and normalization, the actual value does not really matter
+    static constexpr const std::chrono::nanoseconds kDefaultTarget = 50ms;
+    // Amount of time after the last message was sent before the session goes stale
+    // actually 100ms but we use 80 here to ideally avoid going stale
+    static constexpr const std::chrono::nanoseconds kStaleTimeout = 80ms;
+};
+
 } // namespace impl
 } // namespace Hwc2
 } // namespace android
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index fa5a1c8..3d00b90 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -37,6 +37,7 @@
 #include <cutils/native_handle.h>
 #include <cutils/properties.h>
 #include <ftl/enum.h>
+#include <ftl/fake_guard.h>
 #include <gui/BufferItem.h>
 #include <gui/LayerDebugInfo.h>
 #include <gui/Surface.h>
@@ -139,6 +140,7 @@
     mDrawingState.destinationFrame.makeInvalid();
     mDrawingState.isTrustedOverlay = false;
     mDrawingState.dropInputMode = gui::DropInputMode::NONE;
+    mDrawingState.dimmingEnabled = true;
 
     if (args.flags & ISurfaceComposerClient::eNoColorFill) {
         // Set an invalid color so there is no color fill.
@@ -477,6 +479,7 @@
     compositionState->colorTransformIsIdentity = !hasColorTransform();
     compositionState->surfaceDamage = surfaceDamageRegion;
     compositionState->hasProtectedContent = isProtected();
+    compositionState->dimmingEnabled = isDimmingEnabled();
 
     const bool usesRoundedCorners = getRoundedCornerState().radius != 0.f;
 
@@ -1038,6 +1041,16 @@
     return true;
 }
 
+bool Layer::setDimmingEnabled(const bool dimmingEnabled) {
+    if (mDrawingState.dimmingEnabled == dimmingEnabled) return false;
+
+    mDrawingState.sequence++;
+    mDrawingState.dimmingEnabled = dimmingEnabled;
+    mDrawingState.modified = true;
+    setTransactionFlags(eTransactionNeeded);
+    return true;
+}
+
 bool Layer::setFrameRateSelectionPriority(int32_t priority) {
     if (mDrawingState.frameRateSelectionPriority == priority) return false;
     mDrawingState.frameRateSelectionPriority = priority;
@@ -2045,10 +2058,10 @@
     writeToProtoCommonState(layerProto, LayerVector::StateSet::Drawing, traceFlags);
 
     if (traceFlags & LayerTracing::TRACE_COMPOSITION) {
+        ftl::FakeGuard guard(mFlinger->mStateLock); // Called from the main thread.
+
         // Only populate for the primary display.
-        UnnecessaryLock assumeLocked(mFlinger->mStateLock); // called from the main thread.
-        const auto display = mFlinger->getDefaultDisplayDeviceLocked();
-        if (display) {
+        if (const auto display = mFlinger->getDefaultDisplayDeviceLocked()) {
             const auto compositionType = getCompositionType(*display);
             layerProto->set_hwc_composition_type(static_cast<HwcCompositionType>(compositionType));
             LayerProtoHelper::writeToProto(getVisibleRegion(display.get()),
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 846460d..565a6ff 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -281,6 +281,8 @@
         gui::DropInputMode dropInputMode;
 
         bool autoRefresh = false;
+
+        bool dimmingEnabled = true;
     };
 
     /*
@@ -411,6 +413,7 @@
     virtual mat4 getColorTransform() const;
     virtual bool hasColorTransform() const;
     virtual bool isColorSpaceAgnostic() const { return mDrawingState.colorSpaceAgnostic; }
+    virtual bool isDimmingEnabled() const { return getDrawingState().dimmingEnabled; };
 
     // Used only to set BufferStateLayer state
     virtual bool setTransform(uint32_t /*transform*/) { return false; };
@@ -437,6 +440,7 @@
     }
     virtual bool setBackgroundColor(const half3& color, float alpha, ui::Dataspace dataspace);
     virtual bool setColorSpaceAgnostic(const bool agnostic);
+    virtual bool setDimmingEnabled(const bool dimmingEnabled);
     virtual bool setFrameRateSelectionPriority(int32_t priority);
     virtual bool setFixedTransformHint(ui::Transform::RotationFlags fixedTransformHint);
     virtual void setAutoRefresh(bool /* autoRefresh */) {}
diff --git a/services/surfaceflinger/MainThreadGuard.h b/services/surfaceflinger/MainThreadGuard.h
deleted file mode 100644
index c1aa118..0000000
--- a/services/surfaceflinger/MainThreadGuard.h
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright 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.
- */
-
-#pragma once
-
-#include <utils/Mutex.h>
-
-namespace android {
-namespace {
-
-// Helps to ensure that some functions runs on SF's main thread by using the
-// clang thread safety annotations.
-class CAPABILITY("mutex") MainThreadGuard {
-} SF_MAIN_THREAD;
-
-struct SCOPED_CAPABILITY MainThreadScopedGuard {
-public:
-    explicit MainThreadScopedGuard(MainThreadGuard& mutex) ACQUIRE(mutex) {}
-    ~MainThreadScopedGuard() RELEASE() {}
-};
-} // namespace
-} // namespace android
diff --git a/services/surfaceflinger/MutexUtils.h b/services/surfaceflinger/MutexUtils.h
new file mode 100644
index 0000000..f8be6f3
--- /dev/null
+++ b/services/surfaceflinger/MutexUtils.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <log/log.h>
+#include <utils/Mutex.h>
+
+namespace android {
+
+struct SCOPED_CAPABILITY ConditionalLock {
+    ConditionalLock(Mutex& mutex, bool lock) ACQUIRE(mutex) : mutex(mutex), lock(lock) {
+        if (lock) mutex.lock();
+    }
+
+    ~ConditionalLock() RELEASE() {
+        if (lock) mutex.unlock();
+    }
+
+    Mutex& mutex;
+    const bool lock;
+};
+
+struct SCOPED_CAPABILITY TimedLock {
+    TimedLock(Mutex& mutex, nsecs_t timeout, const char* whence) ACQUIRE(mutex)
+          : mutex(mutex), status(mutex.timedLock(timeout)) {
+        ALOGE_IF(!locked(), "%s timed out locking: %s (%d)", whence, strerror(-status), status);
+    }
+
+    ~TimedLock() RELEASE() {
+        if (locked()) mutex.unlock();
+    }
+
+    bool locked() const { return status == NO_ERROR; }
+
+    Mutex& mutex;
+    const status_t status;
+};
+
+} // namespace android
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 9f5a7df..5adc177 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -24,7 +24,10 @@
 
 #include "SurfaceFlinger.h"
 
+#include <android-base/parseint.h>
 #include <android-base/properties.h>
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
 #include <android/configuration.h>
 #include <android/gui/IDisplayEventConnection.h>
 #include <android/hardware/configstore/1.0/ISurfaceFlingerConfigs.h>
@@ -49,6 +52,7 @@
 #include <configstore/Utils.h>
 #include <cutils/compiler.h>
 #include <cutils/properties.h>
+#include <ftl/fake_guard.h>
 #include <ftl/future.h>
 #include <ftl/small_map.h>
 #include <gui/BufferQueue.h>
@@ -123,6 +127,7 @@
 #include "LayerRenderArea.h"
 #include "LayerVector.h"
 #include "MonitoredProducer.h"
+#include "MutexUtils.h"
 #include "NativeWindowSurface.h"
 #include "RefreshRateOverlay.h"
 #include "RegionSamplingThread.h"
@@ -138,49 +143,26 @@
 #include "TimeStats/TimeStats.h"
 #include "TunnelModeEnabledReporter.h"
 #include "WindowInfosListenerInvoker.h"
-#include "android-base/parseint.h"
-#include "android-base/stringprintf.h"
-#include "android-base/strings.h"
 
 #include <aidl/android/hardware/graphics/common/DisplayDecorationSupport.h>
 #include <aidl/android/hardware/graphics/composer3/DisplayCapability.h>
 
-#define MAIN_THREAD ACQUIRE(mStateLock) RELEASE(mStateLock)
-
-// Note: The parentheses around `expr` are needed to deduce an lvalue or rvalue reference.
-#define ON_MAIN_THREAD(expr)                                       \
-    [&]() -> decltype(auto) {                                      \
-        LOG_FATAL_IF(std::this_thread::get_id() != mMainThreadId); \
-        UnnecessaryLock lock(mStateLock);                          \
-        return (expr);                                             \
-    }()
-
-#define MAIN_THREAD_GUARD(expr)                                    \
-    [&]() -> decltype(auto) {                                      \
-        LOG_FATAL_IF(std::this_thread::get_id() != mMainThreadId); \
-        MainThreadScopedGuard lock(SF_MAIN_THREAD);                \
-        return (expr);                                             \
-    }()
-
 #undef NO_THREAD_SAFETY_ANALYSIS
 #define NO_THREAD_SAFETY_ANALYSIS \
-    _Pragma("GCC error \"Prefer MAIN_THREAD macros or {Conditional,Timed,Unnecessary}Lock.\"")
-
-using aidl::android::hardware::graphics::common::DisplayDecorationSupport;
-using aidl::android::hardware::graphics::composer3::Capability;
-using aidl::android::hardware::graphics::composer3::DisplayCapability;
-using KernelIdleTimerController =
-        ::android::scheduler::RefreshRateConfigs::KernelIdleTimerController;
+    _Pragma("GCC error \"Prefer <ftl/fake_guard.h> or MutexUtils.h helpers.\"")
 
 namespace android {
 
 using namespace std::string_literals;
 
-using namespace android::hardware::configstore;
-using namespace android::hardware::configstore::V1_0;
-using namespace android::sysprop;
+using namespace hardware::configstore;
+using namespace hardware::configstore::V1_0;
+using namespace sysprop;
 
-using android::hardware::power::Boost;
+using aidl::android::hardware::graphics::common::DisplayDecorationSupport;
+using aidl::android::hardware::graphics::composer3::Capability;
+using aidl::android::hardware::graphics::composer3::DisplayCapability;
+
 using base::StringAppendF;
 using gui::DisplayInfo;
 using gui::IDisplayEventConnection;
@@ -191,6 +173,8 @@
 using ui::DisplayPrimaries;
 using ui::RenderIntent;
 
+using KernelIdleTimerController = scheduler::RefreshRateConfigs::KernelIdleTimerController;
+
 namespace hal = android::hardware::graphics::composer::hal;
 
 namespace {
@@ -222,38 +206,6 @@
 
 #pragma clang diagnostic pop
 
-template <typename Mutex>
-struct SCOPED_CAPABILITY ConditionalLockGuard {
-    ConditionalLockGuard(Mutex& mutex, bool lock) ACQUIRE(mutex) : mutex(mutex), lock(lock) {
-        if (lock) mutex.lock();
-    }
-
-    ~ConditionalLockGuard() RELEASE() {
-        if (lock) mutex.unlock();
-    }
-
-    Mutex& mutex;
-    const bool lock;
-};
-
-using ConditionalLock = ConditionalLockGuard<Mutex>;
-
-struct SCOPED_CAPABILITY TimedLock {
-    TimedLock(Mutex& mutex, nsecs_t timeout, const char* whence) ACQUIRE(mutex)
-          : mutex(mutex), status(mutex.timedLock(timeout)) {
-        ALOGE_IF(!locked(), "%s timed out locking: %s (%d)", whence, strerror(-status), status);
-    }
-
-    ~TimedLock() RELEASE() {
-        if (locked()) mutex.unlock();
-    }
-
-    bool locked() const { return status == NO_ERROR; }
-
-    Mutex& mutex;
-    const status_t status;
-};
-
 // TODO(b/141333600): Consolidate with DisplayMode::Builder::getDefaultDensity.
 constexpr float FALLBACK_DENSITY = ACONFIGURATION_DENSITY_TV;
 
@@ -729,13 +681,15 @@
             if (renderEngineTid.has_value()) {
                 tidList.emplace_back(*renderEngineTid);
             }
-            mPowerAdvisor.startPowerHintSession(tidList);
+            if (!mPowerAdvisor.startPowerHintSession(tidList)) {
+                ALOGW("Cannot start power hint session");
+            }
         }
 
         mBootStage = BootStage::FINISHED;
 
         if (property_get_bool("sf.debug.show_refresh_rate_overlay", false)) {
-            ON_MAIN_THREAD(enableRefreshRateOverlay(true));
+            FTL_FAKE_GUARD(mStateLock, enableRefreshRateOverlay(true));
         }
     }));
 }
@@ -936,8 +890,9 @@
         FrameEvent::DEQUEUE_READY,
         FrameEvent::RELEASE,
     };
-    ConditionalLock _l(mStateLock,
-            std::this_thread::get_id() != mMainThreadId);
+
+    ConditionalLock lock(mStateLock, std::this_thread::get_id() != mMainThreadId);
+
     if (!getHwComposer().hasCapability(Capability::PRESENT_FENCE_IS_NOT_RELIABLE)) {
         outSupported->push_back(FrameEvent::DISPLAY_PRESENT);
     }
@@ -1040,13 +995,8 @@
 
         outMode.resolution = ui::Size(width, height);
 
-        if (mEmulatedDisplayDensity) {
-            outMode.xDpi = mEmulatedDisplayDensity;
-            outMode.yDpi = mEmulatedDisplayDensity;
-        } else {
-            outMode.xDpi = xDpi;
-            outMode.yDpi = yDpi;
-        }
+        outMode.xDpi = xDpi;
+        outMode.yDpi = yDpi;
 
         const nsecs_t period = mode->getVsyncPeriod();
         outMode.refreshRate = Fps::fromPeriodNsecs(period).getValue();
@@ -1142,7 +1092,7 @@
     }
 
     auto future = mScheduler->schedule([=]() -> status_t {
-        const auto display = ON_MAIN_THREAD(getDisplayDeviceLocked(displayToken));
+        const auto display = FTL_FAKE_GUARD(mStateLock, getDisplayDeviceLocked(displayToken));
         if (!display) {
             ALOGE("Attempt to set allowed display modes for invalid display token %p",
                   displayToken.get());
@@ -1183,7 +1133,9 @@
         return;
     }
 
-    const auto upcomingModeInfo = MAIN_THREAD_GUARD(display->getUpcomingActiveMode());
+    const auto upcomingModeInfo =
+            FTL_FAKE_GUARD(kMainThreadContext, display->getUpcomingActiveMode());
+
     if (!upcomingModeInfo.mode) {
         // There is no pending mode change. This can happen if the active
         // display changed and the mode change happened on a different display.
@@ -1202,9 +1154,8 @@
         return;
     }
 
-    // We just created this display so we can call even if we are not on
-    // the main thread
-    MainThreadScopedGuard fakeMainThreadGuard(SF_MAIN_THREAD);
+    // We just created this display so we can call even if we are not on the main thread.
+    ftl::FakeGuard guard(kMainThreadContext);
     display->setActiveMode(upcomingModeInfo.mode->getId());
 
     const Fps refreshRate = upcomingModeInfo.mode->getFps();
@@ -1289,8 +1240,10 @@
         constraints.seamlessRequired = false;
         hal::VsyncPeriodChangeTimeline outTimeline;
 
-        const auto status = MAIN_THREAD_GUARD(
-                display->initiateModeChange(*desiredActiveMode, constraints, &outTimeline));
+        const auto status = FTL_FAKE_GUARD(kMainThreadContext,
+                                           display->initiateModeChange(*desiredActiveMode,
+                                                                       constraints, &outTimeline));
+
         if (status != NO_ERROR) {
             // initiateModeChange may fail if a hotplug event is just about
             // to be sent. We just log the error in this case.
@@ -1323,7 +1276,7 @@
 }
 
 void SurfaceFlinger::disableExpensiveRendering() {
-    auto future = mScheduler->schedule([=]() MAIN_THREAD {
+    auto future = mScheduler->schedule([=]() FTL_FAKE_GUARD(mStateLock) {
         ATRACE_CALL();
         if (mPowerAdvisor.isUsingExpensiveRendering()) {
             for (const auto& [_, display] : mDisplays) {
@@ -1372,7 +1325,7 @@
         return BAD_VALUE;
     }
 
-    auto future = mScheduler->schedule([=]() MAIN_THREAD -> status_t {
+    auto future = mScheduler->schedule([=]() FTL_FAKE_GUARD(mStateLock) -> status_t {
         const auto display = getDisplayDeviceLocked(displayToken);
         if (!display) {
             ALOGE("Attempt to set active color mode %s (%d) for invalid display token %p",
@@ -1407,17 +1360,17 @@
 }
 
 status_t SurfaceFlinger::getBootDisplayModeSupport(bool* outSupport) const {
-    auto future = mScheduler->schedule([=]() MAIN_THREAD mutable -> status_t {
-        *outSupport = getHwComposer().hasCapability(Capability::BOOT_DISPLAY_CONFIG);
-        return NO_ERROR;
-    });
-    return future.get();
+    auto future = mScheduler->schedule(
+            [this] { return getHwComposer().hasCapability(Capability::BOOT_DISPLAY_CONFIG); });
+
+    *outSupport = future.get();
+    return NO_ERROR;
 }
 
 status_t SurfaceFlinger::setBootDisplayMode(const sp<IBinder>& displayToken,
                                             ui::DisplayModeId modeId) {
     const char* const whence = __func__;
-    auto future = mScheduler->schedule([=]() MAIN_THREAD -> status_t {
+    auto future = mScheduler->schedule([=]() FTL_FAKE_GUARD(mStateLock) -> status_t {
         const auto display = getDisplayDeviceLocked(displayToken);
         if (!display) {
             ALOGE("%s: Invalid display token %p", whence, displayToken.get());
@@ -1444,7 +1397,7 @@
 
 status_t SurfaceFlinger::clearBootDisplayMode(const sp<IBinder>& displayToken) {
     const char* const whence = __func__;
-    auto future = mScheduler->schedule([=]() MAIN_THREAD -> status_t {
+    auto future = mScheduler->schedule([=]() FTL_FAKE_GUARD(mStateLock) -> status_t {
         if (const auto displayId = getPhysicalDisplayIdLocked(displayToken)) {
             return getHwComposer().clearBootDisplayMode(*displayId);
         } else {
@@ -1457,7 +1410,7 @@
 
 void SurfaceFlinger::setAutoLowLatencyMode(const sp<IBinder>& displayToken, bool on) {
     const char* const whence = __func__;
-    static_cast<void>(mScheduler->schedule([=]() MAIN_THREAD {
+    static_cast<void>(mScheduler->schedule([=]() FTL_FAKE_GUARD(mStateLock) {
         if (const auto displayId = getPhysicalDisplayIdLocked(displayToken)) {
             getHwComposer().setAutoLowLatencyMode(*displayId, on);
         } else {
@@ -1468,7 +1421,7 @@
 
 void SurfaceFlinger::setGameContentType(const sp<IBinder>& displayToken, bool on) {
     const char* const whence = __func__;
-    static_cast<void>(mScheduler->schedule([=]() MAIN_THREAD {
+    static_cast<void>(mScheduler->schedule([=]() FTL_FAKE_GUARD(mStateLock) {
         if (const auto displayId = getPhysicalDisplayIdLocked(displayToken)) {
             const auto type = on ? hal::ContentType::GAME : hal::ContentType::NONE;
             getHwComposer().setContentType(*displayId, type);
@@ -1533,7 +1486,7 @@
                                                           bool enable, uint8_t componentMask,
                                                           uint64_t maxFrames) {
     const char* const whence = __func__;
-    auto future = mScheduler->schedule([=]() MAIN_THREAD -> status_t {
+    auto future = mScheduler->schedule([=]() FTL_FAKE_GUARD(mStateLock) -> status_t {
         if (const auto displayId = getPhysicalDisplayIdLocked(displayToken)) {
             return getHwComposer().setDisplayContentSamplingEnabled(*displayId, enable,
                                                                     componentMask, maxFrames);
@@ -1610,7 +1563,7 @@
 status_t SurfaceFlinger::getLayerDebugInfo(std::vector<LayerDebugInfo>* outLayers) {
     outLayers->clear();
     auto future = mScheduler->schedule([=] {
-        const auto display = ON_MAIN_THREAD(getDefaultDisplayDeviceLocked());
+        const auto display = FTL_FAKE_GUARD(mStateLock, getDefaultDisplayDeviceLocked());
         mDrawingState.traverseInZOrder([&](Layer* layer) {
             outLayers->push_back(layer->getLayerDebugInfo(display.get()));
         });
@@ -1722,7 +1675,7 @@
     }
 
     const char* const whence = __func__;
-    return ftl::chain(mScheduler->schedule([=]() MAIN_THREAD {
+    return ftl::chain(mScheduler->schedule([=]() FTL_FAKE_GUARD(mStateLock) {
                if (const auto display = getDisplayDeviceLocked(displayToken)) {
                    const bool supportsDisplayBrightnessCommand =
                            getHwComposer().getComposer()->isSupported(
@@ -1736,7 +1689,9 @@
                                compositionDisplay->editState().displayBrightnessNits;
                        compositionDisplay->setDisplayBrightness(brightness.sdrWhitePointNits,
                                                                 brightness.displayBrightnessNits);
-                       MAIN_THREAD_GUARD(display->stageBrightness(brightness.displayBrightness));
+                       FTL_FAKE_GUARD(kMainThreadContext,
+                                      display->stageBrightness(brightness.displayBrightness));
+
                        if (brightness.sdrWhitePointNits / brightness.displayBrightnessNits !=
                            currentDimmingRatio) {
                            scheduleComposite(FrameHint::kNone);
@@ -1806,6 +1761,7 @@
 }
 
 status_t SurfaceFlinger::notifyPowerBoost(int32_t boostId) {
+    using hardware::power::Boost;
     Boost powerBoost = static_cast<Boost>(boostId);
 
     if (powerBoost == Boost::INTERACTION) {
@@ -1966,7 +1922,7 @@
     ATRACE_CALL();
 
     // On main thread to avoid race conditions with display power state.
-    static_cast<void>(mScheduler->schedule([=]() MAIN_THREAD {
+    static_cast<void>(mScheduler->schedule([=]() FTL_FAKE_GUARD(mStateLock) {
         mHWCVsyncPendingState = enabled ? hal::Vsync::ENABLE : hal::Vsync::DISABLE;
 
         if (const auto display = getDefaultDisplayDeviceLocked();
@@ -2014,8 +1970,8 @@
                                                           : stats.vsyncTime + stats.vsyncPeriod;
 }
 
-bool SurfaceFlinger::commit(nsecs_t frameTime, int64_t vsyncId, nsecs_t expectedVsyncTime) {
-    MainThreadScopedGuard mainThreadGuard(SF_MAIN_THREAD);
+bool SurfaceFlinger::commit(nsecs_t frameTime, int64_t vsyncId, nsecs_t expectedVsyncTime)
+        FTL_FAKE_GUARD(kMainThreadContext) {
     // we set this once at the beginning of commit to ensure consistency throughout the whole frame
     mPowerHintSessionData.sessionEnabled = mPowerAdvisor.usePowerHintSession();
     if (mPowerHintSessionData.sessionEnabled) {
@@ -2181,20 +2137,21 @@
         mLayerTracing.notify(mVisibleRegionsDirty, frameTime);
     }
 
-    MAIN_THREAD_GUARD(persistDisplayBrightness(mustComposite));
+    persistDisplayBrightness(mustComposite);
 
     return mustComposite && CC_LIKELY(mBootStage != BootStage::BOOTLOADER);
 }
 
-void SurfaceFlinger::composite(nsecs_t frameTime, int64_t vsyncId) {
+void SurfaceFlinger::composite(nsecs_t frameTime, int64_t vsyncId)
+        FTL_FAKE_GUARD(kMainThreadContext) {
     ATRACE_FORMAT("%s %" PRId64, __func__, vsyncId);
-    MainThreadScopedGuard mainThreadGuard(SF_MAIN_THREAD);
+
     if (mPowerHintSessionData.sessionEnabled) {
         mPowerHintSessionData.compositeStart = systemTime();
     }
 
     compositionengine::CompositionRefreshArgs refreshArgs;
-    const auto& displays = ON_MAIN_THREAD(mDisplays);
+    const auto& displays = FTL_FAKE_GUARD(mStateLock, mDisplays);
     refreshArgs.outputs.reserve(displays.size());
     for (const auto& [_, display] : displays) {
         refreshArgs.outputs.push_back(display->getCompositionDisplay());
@@ -2432,7 +2389,7 @@
     ATRACE_CALL();
     ALOGV("postComposition");
 
-    const auto* display = ON_MAIN_THREAD(getDefaultDisplayDeviceLocked()).get();
+    const auto* display = FTL_FAKE_GUARD(mStateLock, getDefaultDisplayDeviceLocked()).get();
 
     getBE().mGlCompositionDoneTimeline.updateSignalTimes();
     std::shared_ptr<FenceTime> glCompositionDoneFenceTime;
@@ -2632,44 +2589,37 @@
 }
 
 FloatRect SurfaceFlinger::getMaxDisplayBounds() {
-    // Find the largest width and height among all the displays.
-    int32_t maxDisplayWidth = 0;
-    int32_t maxDisplayHeight = 0;
+    const ui::Size maxSize = [this] {
+        ftl::FakeGuard guard(mStateLock);
 
-    // If there are no displays, set a valid display bounds so we can still compute a valid layer
-    // bounds.
-    if (ON_MAIN_THREAD(mDisplays.size()) == 0) {
-        maxDisplayWidth = maxDisplayHeight = 5000;
-    }
+        // The LayerTraceGenerator tool runs without displays.
+        if (mDisplays.empty()) return ui::Size{5000, 5000};
 
-    for (const auto& pair : ON_MAIN_THREAD(mDisplays)) {
-        const auto& displayDevice = pair.second;
-        int32_t width = displayDevice->getWidth();
-        int32_t height = displayDevice->getHeight();
-        if (width > maxDisplayWidth) {
-            maxDisplayWidth = width;
-        }
-        if (height > maxDisplayHeight) {
-            maxDisplayHeight = height;
-        }
-    }
+        return std::accumulate(mDisplays.begin(), mDisplays.end(), ui::kEmptySize,
+                               [](ui::Size size, const auto& pair) -> ui::Size {
+                                   const auto& display = pair.second;
+                                   return {std::max(size.getWidth(), display->getWidth()),
+                                           std::max(size.getHeight(), display->getHeight())};
+                               });
+    }();
 
     // Ignore display bounds for now since they will be computed later. Use a large Rect bound
     // to ensure it's bigger than an actual display will be.
-    FloatRect maxBounds = FloatRect(-maxDisplayWidth * 10, -maxDisplayHeight * 10,
-                                    maxDisplayWidth * 10, maxDisplayHeight * 10);
-    return maxBounds;
+    const float xMax = maxSize.getWidth() * 10.f;
+    const float yMax = maxSize.getHeight() * 10.f;
+
+    return {-xMax, -yMax, xMax, yMax};
 }
 
 void SurfaceFlinger::computeLayerBounds() {
-    FloatRect maxBounds = getMaxDisplayBounds();
+    const FloatRect maxBounds = getMaxDisplayBounds();
     for (const auto& layer : mDrawingState.layersSortedByZ) {
         layer->computeBounds(maxBounds, ui::Transform(), 0.f /* shadowRadius */);
     }
 }
 
 void SurfaceFlinger::postFrame() {
-    const auto display = ON_MAIN_THREAD(getDefaultDisplayDeviceLocked());
+    const auto display = FTL_FAKE_GUARD(mStateLock, getDefaultDisplayDeviceLocked());
     if (display && getHwComposer().isConnected(display->getPhysicalId())) {
         uint32_t flipCount = display->getPageFlipCount();
         if (flipCount % LOG_FRAME_STATS_PERIOD == 0) {
@@ -2923,7 +2873,8 @@
                                                     RenderIntent::COLORIMETRIC,
                                                     Dataspace::UNKNOWN});
     if (!state.isVirtual()) {
-        MAIN_THREAD_GUARD(display->setActiveMode(state.physical->activeMode->getId()));
+        FTL_FAKE_GUARD(kMainThreadContext,
+                       display->setActiveMode(state.physical->activeMode->getId()));
         display->setDeviceProductInfo(state.physical->deviceProductInfo);
     }
 
@@ -3293,7 +3244,7 @@
         return;
     }
 
-    for (const auto& [_, display] : ON_MAIN_THREAD(mDisplays)) {
+    for (const auto& [_, display] : FTL_FAKE_GUARD(mStateLock, mDisplays)) {
         if (const auto brightness = display->getStagedBrightness(); brightness) {
             if (!needsComposite) {
                 const status_t error =
@@ -3316,7 +3267,7 @@
                                       std::vector<DisplayInfo>& outDisplayInfos) {
     ftl::SmallMap<ui::LayerStack, DisplayDevice::InputInfo, 4> displayInputInfos;
 
-    for (const auto& [_, display] : ON_MAIN_THREAD(mDisplays)) {
+    for (const auto& [_, display] : FTL_FAKE_GUARD(mStateLock, mDisplays)) {
         const auto layerStack = display->getLayerStack();
         const auto info = display->getInputInfo();
 
@@ -3361,7 +3312,7 @@
 
 void SurfaceFlinger::updateCursorAsync() {
     compositionengine::CompositionRefreshArgs refreshArgs;
-    for (const auto& [_, display] : ON_MAIN_THREAD(mDisplays)) {
+    for (const auto& [_, display] : FTL_FAKE_GUARD(mStateLock, mDisplays)) {
         if (HalDisplayId::tryCast(display->getId())) {
             refreshArgs.outputs.push_back(display->getCompositionDisplay());
         }
@@ -3546,7 +3497,7 @@
 }
 
 void SurfaceFlinger::invalidateLayerStack(const sp<const Layer>& layer, const Region& dirty) {
-    for (const auto& [token, displayDevice] : ON_MAIN_THREAD(mDisplays)) {
+    for (const auto& [token, displayDevice] : FTL_FAKE_GUARD(mStateLock, mDisplays)) {
         auto display = displayDevice->getCompositionDisplay();
         if (display->includesLayer(layer->getOutputFilter())) {
             display->editState().dirtyRegion.orSelf(dirty);
@@ -4534,6 +4485,9 @@
     if (what & layer_state_t::eAutoRefreshChanged) {
         layer->setAutoRefresh(s.autoRefresh);
     }
+    if (what & layer_state_t::eDimmingEnabledChanged) {
+        if (layer->setDimmingEnabled(s.dimmingEnabled)) flags |= eTraversalNeeded;
+    }
     if (what & layer_state_t::eTrustedOverlayChanged) {
         if (layer->setTrustedOverlay(s.isTrustedOverlay)) {
             flags |= eTraversalNeeded;
@@ -4832,7 +4786,8 @@
 
 void SurfaceFlinger::initializeDisplays() {
     // Async since we may be called from the main thread.
-    static_cast<void>(mScheduler->schedule([this]() MAIN_THREAD { onInitializeDisplays(); }));
+    static_cast<void>(
+            mScheduler->schedule([this]() FTL_FAKE_GUARD(mStateLock) { onInitializeDisplays(); }));
 }
 
 void SurfaceFlinger::setPowerModeInternal(const sp<DisplayDevice>& display, hal::PowerMode mode) {
@@ -4932,7 +4887,7 @@
 }
 
 void SurfaceFlinger::setPowerMode(const sp<IBinder>& displayToken, int mode) {
-    auto future = mScheduler->schedule([=]() MAIN_THREAD {
+    auto future = mScheduler->schedule([=]() FTL_FAKE_GUARD(mStateLock) {
         const auto display = getDisplayDeviceLocked(displayToken);
         if (!display) {
             ALOGE("Attempt to set power mode %d for invalid display token %p", mode,
@@ -4979,7 +4934,7 @@
 
         bool dumpLayers = true;
         {
-            TimedLock lock(mStateLock, s2ns(1), __FUNCTION__);
+            TimedLock lock(mStateLock, s2ns(1), __func__);
             if (!lock.locked()) {
                 StringAppendF(&result, "Dumping without lock after timeout: %s (%d)\n",
                               strerror(-lock.status), lock.status);
@@ -5067,8 +5022,6 @@
     mFrameTimeline->parseArgs(args, result);
 }
 
-// This should only be called from the main thread.  Otherwise it would need
-// the lock and should use mCurrentState rather than mDrawingState.
 void SurfaceFlinger::logFrameStats() {
     mDrawingState.traverse([&](Layer* layer) {
         layer->logFrameStats();
@@ -5226,7 +5179,7 @@
 }
 
 void SurfaceFlinger::dumpDisplayProto(LayersTraceProto& layersTraceProto) const {
-    for (const auto& [_, display] : ON_MAIN_THREAD(mDisplays)) {
+    for (const auto& [_, display] : FTL_FAKE_GUARD(mStateLock, mDisplays)) {
         DisplayProto* displayProto = layersTraceProto.add_displays();
         displayProto->set_id(display->getId().value);
         displayProto->set_name(display->getDisplayName());
@@ -5867,7 +5820,7 @@
                         int64_t startingTime =
                                 (fixedStartingTime) ? fixedStartingTime : systemTime();
                         mScheduler
-                                ->schedule([&]() MAIN_THREAD {
+                                ->schedule([&]() FTL_FAKE_GUARD(mStateLock) {
                                     mLayerTracing.notify("start", startingTime);
                                 })
                                 .wait();
@@ -5980,10 +5933,12 @@
                     switch (n = data.readInt32()) {
                         case 0:
                         case 1:
-                            ON_MAIN_THREAD(enableRefreshRateOverlay(static_cast<bool>(n)));
+                            FTL_FAKE_GUARD(mStateLock,
+                                           enableRefreshRateOverlay(static_cast<bool>(n)));
                             break;
                         default: {
-                            reply->writeBool(ON_MAIN_THREAD(isRefreshRateOverlayEnabled()));
+                            reply->writeBool(
+                                    FTL_FAKE_GUARD(mStateLock, isRefreshRateOverlayEnabled()));
                         }
                     }
                 });
@@ -6021,7 +5976,7 @@
                     return mScheduler
                             ->schedule([this] {
                                 const auto display =
-                                        ON_MAIN_THREAD(getDefaultDisplayDeviceLocked());
+                                        FTL_FAKE_GUARD(mStateLock, getDefaultDisplayDeviceLocked());
 
                                 // This is a little racy, but not in a way that hurts anything. As
                                 // we grab the defaultMode from the display manager policy, we could
@@ -6043,7 +5998,7 @@
                     return mScheduler
                             ->schedule([this] {
                                 const auto display =
-                                        ON_MAIN_THREAD(getDefaultDisplayDeviceLocked());
+                                        FTL_FAKE_GUARD(mStateLock, getDefaultDisplayDeviceLocked());
                                 constexpr bool kOverridePolicy = true;
                                 return setDesiredDisplayModeSpecsInternal(display, {},
                                                                           kOverridePolicy);
@@ -6159,7 +6114,7 @@
     // Update the overlay on the main thread to avoid race conditions with
     // mRefreshRateConfigs->getActiveMode()
     static_cast<void>(mScheduler->schedule([=] {
-        const auto display = ON_MAIN_THREAD(getDefaultDisplayDeviceLocked());
+        const auto display = FTL_FAKE_GUARD(mStateLock, getDefaultDisplayDeviceLocked());
         if (!display) {
             ALOGW("%s: default display is null", __func__);
             return;
@@ -6957,7 +6912,7 @@
     }
 
     auto future = mScheduler->schedule([=]() -> status_t {
-        const auto display = ON_MAIN_THREAD(getDisplayDeviceLocked(displayToken));
+        const auto display = FTL_FAKE_GUARD(mStateLock, getDisplayDeviceLocked(displayToken));
         if (!display) {
             ALOGE("Attempt to set desired display modes for invalid display token %p",
                   displayToken.get());
@@ -7202,7 +7157,7 @@
     if (const auto frameRateOverride = mScheduler->getFrameRateOverride(uid)) {
         refreshRate = *frameRateOverride;
     } else if (!getHwComposer().isHeadless()) {
-        if (const auto display = ON_MAIN_THREAD(getDefaultDisplayDeviceLocked())) {
+        if (const auto display = FTL_FAKE_GUARD(mStateLock, getDefaultDisplayDeviceLocked())) {
             refreshRate = display->refreshRateConfigs().getActiveMode()->getFps();
         }
     }
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index f2636b4..97b0e8d 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -64,6 +64,7 @@
 #include "Scheduler/Scheduler.h"
 #include "Scheduler/VsyncModulator.h"
 #include "SurfaceFlingerFactory.h"
+#include "ThreadContext.h"
 #include "TracedOrdinal.h"
 #include "Tracing/LayerTracing.h"
 #include "Tracing/TransactionTracing.h"
@@ -183,11 +184,6 @@
     std::atomic<nsecs_t> mLastSwapTime = 0;
 };
 
-struct SCOPED_CAPABILITY UnnecessaryLock {
-    explicit UnnecessaryLock(Mutex& mutex) ACQUIRE(mutex) {}
-    ~UnnecessaryLock() RELEASE() {}
-};
-
 class SurfaceFlinger : public BnSurfaceComposer,
                        public PriorityDumper,
                        private IBinder::DeathRecipient,
@@ -740,7 +736,7 @@
     void updateLayerGeometry();
 
     void updateInputFlinger();
-    void persistDisplayBrightness(bool needsComposite) REQUIRES(SF_MAIN_THREAD);
+    void persistDisplayBrightness(bool needsComposite) REQUIRES(kMainThreadContext);
     void buildWindowInfos(std::vector<gui::WindowInfo>& outWindowInfos,
                           std::vector<gui::DisplayInfo>& outDisplayInfos);
     void commitInputWindowCommands() REQUIRES(mStateLock);
@@ -973,7 +969,7 @@
     void setCompositorTimingSnapped(const DisplayStatInfo& stats,
                                     nsecs_t compositeToPresentLatency);
 
-    void postFrame();
+    void postFrame() REQUIRES(kMainThreadContext);
 
     /*
      * Display management
@@ -1088,7 +1084,7 @@
     void clearStatsLocked(const DumpArgs& args, std::string& result);
     void dumpTimeStats(const DumpArgs& args, bool asProto, std::string& result) const;
     void dumpFrameTimeline(const DumpArgs& args, std::string& result) const;
-    void logFrameStats();
+    void logFrameStats() REQUIRES(kMainThreadContext);
 
     void dumpVSync(std::string& result) const REQUIRES(mStateLock);
     void dumpStaticScreenStats(std::string& result) const;
@@ -1431,7 +1427,7 @@
         nsecs_t commitStart;
         nsecs_t compositeStart;
         nsecs_t presentEnd;
-    } mPowerHintSessionData GUARDED_BY(SF_MAIN_THREAD);
+    } mPowerHintSessionData GUARDED_BY(kMainThreadContext);
 
     nsecs_t mAnimationTransactionTimeout = s2ns(5);
 
diff --git a/services/surfaceflinger/ThreadContext.h b/services/surfaceflinger/ThreadContext.h
new file mode 100644
index 0000000..85c379d
--- /dev/null
+++ b/services/surfaceflinger/ThreadContext.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+namespace android {
+
+// Enforces exclusive access by the main thread.
+constexpr class [[clang::capability("mutex")]] {
+} kMainThreadContext;
+
+} // namespace android
diff --git a/services/surfaceflinger/fuzzer/surfaceflinger_fuzzers_utils.h b/services/surfaceflinger/fuzzer/surfaceflinger_fuzzers_utils.h
index 1d0f62b..a80aca2 100644
--- a/services/surfaceflinger/fuzzer/surfaceflinger_fuzzers_utils.h
+++ b/services/surfaceflinger/fuzzer/surfaceflinger_fuzzers_utils.h
@@ -22,6 +22,7 @@
 #include <compositionengine/impl/CompositionEngine.h>
 #include <compositionengine/impl/Display.h>
 #include <compositionengine/impl/OutputLayerCompositionState.h>
+#include <ftl/fake_guard.h>
 #include <gui/LayerDebugInfo.h>
 #include <gui/ScreenCaptureResults.h>
 #include <gui/SurfaceComposerClient.h>
@@ -50,6 +51,7 @@
 #include "SurfaceFlinger.h"
 #include "SurfaceFlingerDefaultFactory.h"
 #include "SurfaceInterceptor.h"
+#include "ThreadContext.h"
 #include "TimeStats/TimeStats.h"
 
 #include "renderengine/mock/RenderEngine.h"
@@ -445,7 +447,7 @@
         mFlinger->clearStatsLocked(dumpArgs, result);
 
         mFlinger->dumpTimeStats(dumpArgs, fdp->ConsumeBool(), result);
-        mFlinger->logFrameStats();
+        FTL_FAKE_GUARD(kMainThreadContext, mFlinger->logFrameStats());
 
         result = fdp->ConsumeRandomLengthString().c_str();
         mFlinger->dumpFrameTimeline(dumpArgs, result);
@@ -651,7 +653,7 @@
         updateCompositorTiming(&mFdp);
 
         mFlinger->setCompositorTimingSnapped({}, mFdp.ConsumeIntegral<nsecs_t>());
-        mFlinger->postFrame();
+        FTL_FAKE_GUARD(kMainThreadContext, mFlinger->postFrame());
         mFlinger->calculateExpectedPresentTime({});
 
         mFlinger->enableHalVirtualDisplays(mFdp.ConsumeBool());
diff --git a/services/surfaceflinger/tests/fakehwc/Android.bp b/services/surfaceflinger/tests/fakehwc/Android.bp
index 168b576..704815d 100644
--- a/services/surfaceflinger/tests/fakehwc/Android.bp
+++ b/services/surfaceflinger/tests/fakehwc/Android.bp
@@ -28,6 +28,7 @@
         "android.hardware.graphics.mapper@3.0",
         "android.hardware.graphics.mapper@4.0",
         "android.hardware.power@1.3",
+        "android.hardware.power-V2-cpp",
         "libbase",
         "libbinder",
         "libbinder_ndk",
diff --git a/services/surfaceflinger/tests/unittests/AidlPowerHalWrapperTest.cpp b/services/surfaceflinger/tests/unittests/AidlPowerHalWrapperTest.cpp
new file mode 100644
index 0000000..e25a0ae
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/AidlPowerHalWrapperTest.cpp
@@ -0,0 +1,266 @@
+/*
+ * Copyright 2022 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.
+ */
+
+#undef LOG_TAG
+#define LOG_TAG "AidlPowerHalWrapperTest"
+
+#include <android/hardware/power/IPower.h>
+#include <android/hardware/power/IPowerHintSession.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <algorithm>
+#include <chrono>
+#include <memory>
+#include "DisplayHardware/PowerAdvisor.h"
+#include "android/hardware/power/WorkDuration.h"
+#include "binder/Status.h"
+#include "log/log_main.h"
+#include "mock/DisplayHardware/MockIPower.h"
+#include "mock/DisplayHardware/MockIPowerHintSession.h"
+#include "utils/Timers.h"
+
+using namespace android;
+using namespace android::Hwc2::mock;
+using namespace android::hardware::power;
+using namespace std::chrono_literals;
+using namespace testing;
+
+namespace android::Hwc2::impl {
+
+class AidlPowerHalWrapperTest : public testing::Test {
+public:
+    void SetUp() override;
+
+protected:
+    std::unique_ptr<AidlPowerHalWrapper> mWrapper = nullptr;
+    sp<NiceMock<MockIPower>> mMockHal = nullptr;
+    sp<NiceMock<MockIPowerHintSession>> mMockSession = nullptr;
+    void verifyAndClearExpectations();
+    void sendActualWorkDurationGroup(std::vector<WorkDuration> durations,
+                                     std::chrono::nanoseconds sleepBeforeLastSend);
+};
+
+void AidlPowerHalWrapperTest::SetUp() {
+    mMockHal = new NiceMock<MockIPower>();
+    mMockSession = new NiceMock<MockIPowerHintSession>();
+    ON_CALL(*mMockHal.get(), getHintSessionPreferredRate(_)).WillByDefault(Return(Status::ok()));
+    mWrapper = std::make_unique<AidlPowerHalWrapper>(mMockHal);
+}
+
+void AidlPowerHalWrapperTest::verifyAndClearExpectations() {
+    Mock::VerifyAndClearExpectations(mMockHal.get());
+    Mock::VerifyAndClearExpectations(mMockSession.get());
+}
+
+void AidlPowerHalWrapperTest::sendActualWorkDurationGroup(
+        std::vector<WorkDuration> durations, std::chrono::nanoseconds sleepBeforeLastSend) {
+    for (size_t i = 0; i < durations.size(); i++) {
+        if (i == durations.size() - 1) {
+            std::this_thread::sleep_for(sleepBeforeLastSend);
+        }
+        auto duration = durations[i];
+        mWrapper->sendActualWorkDuration(duration.durationNanos, duration.timeStampNanos);
+    }
+}
+WorkDuration toWorkDuration(std::chrono::nanoseconds durationNanos, int64_t timeStampNanos) {
+    WorkDuration duration;
+    duration.durationNanos = durationNanos.count();
+    duration.timeStampNanos = timeStampNanos;
+    return duration;
+}
+
+namespace {
+TEST_F(AidlPowerHalWrapperTest, supportsPowerHintSession) {
+    ASSERT_TRUE(mWrapper->supportsPowerHintSession());
+    Mock::VerifyAndClearExpectations(mMockHal.get());
+    ON_CALL(*mMockHal.get(), getHintSessionPreferredRate(_))
+            .WillByDefault(Return(Status::fromExceptionCode(Status::Exception::EX_ILLEGAL_STATE)));
+    auto newWrapper = AidlPowerHalWrapper(mMockHal);
+    EXPECT_FALSE(newWrapper.supportsPowerHintSession());
+}
+
+TEST_F(AidlPowerHalWrapperTest, startPowerHintSession) {
+    ASSERT_TRUE(mWrapper->supportsPowerHintSession());
+    std::vector<int32_t> threadIds = {1, 2};
+    mWrapper->setPowerHintSessionThreadIds(threadIds);
+    EXPECT_CALL(*mMockHal.get(), createHintSession(_, _, threadIds, _, _))
+            .WillOnce(DoAll(SetArgPointee<4>(mMockSession), Return(Status::ok())));
+    EXPECT_TRUE(mWrapper->startPowerHintSession());
+    EXPECT_FALSE(mWrapper->startPowerHintSession());
+}
+
+TEST_F(AidlPowerHalWrapperTest, restartNewPoserHintSessionWithNewThreadIds) {
+    ASSERT_TRUE(mWrapper->supportsPowerHintSession());
+
+    std::vector<int32_t> threadIds = {1, 2};
+    EXPECT_CALL(*mMockHal.get(), createHintSession(_, _, threadIds, _, _))
+            .WillOnce(DoAll(SetArgPointee<4>(mMockSession), Return(Status::ok())));
+    mWrapper->setPowerHintSessionThreadIds(threadIds);
+    EXPECT_EQ(mWrapper->getPowerHintSessionThreadIds(), threadIds);
+    ASSERT_TRUE(mWrapper->startPowerHintSession());
+    verifyAndClearExpectations();
+
+    threadIds = {2, 3};
+    EXPECT_CALL(*mMockHal.get(), createHintSession(_, _, threadIds, _, _))
+            .WillOnce(DoAll(SetArgPointee<4>(mMockSession), Return(Status::ok())));
+    EXPECT_CALL(*mMockSession.get(), close()).Times(1);
+    mWrapper->setPowerHintSessionThreadIds(threadIds);
+    EXPECT_EQ(mWrapper->getPowerHintSessionThreadIds(), threadIds);
+    verifyAndClearExpectations();
+
+    EXPECT_CALL(*mMockHal.get(), createHintSession(_, _, threadIds, _, _)).Times(0);
+    EXPECT_CALL(*mMockSession.get(), close()).Times(0);
+    mWrapper->setPowerHintSessionThreadIds(threadIds);
+    verifyAndClearExpectations();
+}
+
+TEST_F(AidlPowerHalWrapperTest, setTargetWorkDuration) {
+    ASSERT_TRUE(mWrapper->supportsPowerHintSession());
+
+    std::vector<int32_t> threadIds = {1, 2};
+    mWrapper->setPowerHintSessionThreadIds(threadIds);
+    EXPECT_CALL(*mMockHal.get(), createHintSession(_, _, threadIds, _, _))
+            .WillOnce(DoAll(SetArgPointee<4>(mMockSession), Return(Status::ok())));
+    ASSERT_TRUE(mWrapper->startPowerHintSession());
+    verifyAndClearExpectations();
+
+    std::chrono::nanoseconds base = 100ms;
+    // test cases with target work duration and whether it should update hint against baseline 100ms
+    const std::vector<std::pair<std::chrono::nanoseconds, bool>> testCases = {{0ms, false},
+                                                                              {-1ms, false},
+                                                                              {200ms, true},
+                                                                              {2ms, true},
+                                                                              {96ms, false},
+                                                                              {104ms, false}};
+
+    for (const auto& test : testCases) {
+        // reset to 100ms baseline
+        mWrapper->setTargetWorkDuration(1);
+        mWrapper->setTargetWorkDuration(base.count());
+
+        auto target = test.first;
+        EXPECT_CALL(*mMockSession.get(), updateTargetWorkDuration(target.count()))
+                .Times(test.second ? 1 : 0);
+        mWrapper->setTargetWorkDuration(target.count());
+        verifyAndClearExpectations();
+    }
+}
+
+TEST_F(AidlPowerHalWrapperTest, setTargetWorkDuration_shouldReconnectOnError) {
+    ASSERT_TRUE(mWrapper->supportsPowerHintSession());
+
+    std::vector<int32_t> threadIds = {1, 2};
+    mWrapper->setPowerHintSessionThreadIds(threadIds);
+    EXPECT_CALL(*mMockHal.get(), createHintSession(_, _, threadIds, _, _))
+            .WillOnce(DoAll(SetArgPointee<4>(mMockSession), Return(Status::ok())));
+    ASSERT_TRUE(mWrapper->startPowerHintSession());
+    verifyAndClearExpectations();
+
+    EXPECT_CALL(*mMockSession.get(), updateTargetWorkDuration(1))
+            .WillOnce(Return(Status::fromExceptionCode(Status::Exception::EX_ILLEGAL_STATE)));
+    mWrapper->setTargetWorkDuration(1);
+    EXPECT_TRUE(mWrapper->shouldReconnectHAL());
+}
+
+TEST_F(AidlPowerHalWrapperTest, sendActualWorkDuration) {
+    ASSERT_TRUE(mWrapper->supportsPowerHintSession());
+
+    std::vector<int32_t> threadIds = {1, 2};
+    mWrapper->setPowerHintSessionThreadIds(threadIds);
+    EXPECT_CALL(*mMockHal.get(), createHintSession(_, _, threadIds, _, _))
+            .WillOnce(DoAll(SetArgPointee<4>(mMockSession), Return(Status::ok())));
+    ASSERT_TRUE(mWrapper->startPowerHintSession());
+    verifyAndClearExpectations();
+
+    auto base = toWorkDuration(100ms, 0);
+    // test cases with actual work durations and whether it should update hint against baseline
+    // 100ms
+    const std::vector<std::pair<std::vector<std::pair<std::chrono::nanoseconds, nsecs_t>>, bool>>
+            testCases = {{{{-1ms, 100}}, false},
+                         {{{91ms, 100}}, false},
+                         {{{109ms, 100}}, false},
+                         {{{100ms, 100}, {200ms, 200}}, true},
+                         {{{100ms, 500}, {100ms, 600}, {3ms, 600}}, true}};
+
+    for (const auto& test : testCases) {
+        // reset actual duration
+        sendActualWorkDurationGroup({base}, 80ms);
+
+        auto raw = test.first;
+        std::vector<WorkDuration> durations(raw.size());
+        std::transform(raw.begin(), raw.end(), durations.begin(),
+                       [](std::pair<std::chrono::nanoseconds, nsecs_t> d) {
+                           return toWorkDuration(d.first, d.second);
+                       });
+        EXPECT_CALL(*mMockSession.get(), reportActualWorkDuration(durations))
+                .Times(test.second ? 1 : 0);
+        sendActualWorkDurationGroup(durations, 0ms);
+        verifyAndClearExpectations();
+    }
+}
+
+TEST_F(AidlPowerHalWrapperTest, sendActualWorkDuration_exceedsStaleTime) {
+    ASSERT_TRUE(mWrapper->supportsPowerHintSession());
+
+    std::vector<int32_t> threadIds = {1, 2};
+    mWrapper->setPowerHintSessionThreadIds(threadIds);
+    EXPECT_CALL(*mMockHal.get(), createHintSession(_, _, threadIds, _, _))
+            .WillOnce(DoAll(SetArgPointee<4>(mMockSession), Return(Status::ok())));
+    ASSERT_TRUE(mWrapper->startPowerHintSession());
+    verifyAndClearExpectations();
+
+    auto base = toWorkDuration(100ms, 0);
+    // test cases with actual work durations and whether it should update hint against baseline
+    // 100ms
+    const std::vector<std::pair<std::vector<std::pair<std::chrono::nanoseconds, nsecs_t>>, bool>>
+            testCases = {{{{91ms, 100}}, true}, {{{109ms, 100}}, true}};
+
+    for (const auto& test : testCases) {
+        // reset actual duration
+        sendActualWorkDurationGroup({base}, 80ms);
+
+        auto raw = test.first;
+        std::vector<WorkDuration> durations(raw.size());
+        std::transform(raw.begin(), raw.end(), durations.begin(),
+                       [](std::pair<std::chrono::nanoseconds, nsecs_t> d) {
+                           return toWorkDuration(d.first, d.second);
+                       });
+        EXPECT_CALL(*mMockSession.get(), reportActualWorkDuration(durations))
+                .Times(test.second ? 1 : 0);
+        sendActualWorkDurationGroup(durations, 80ms);
+        verifyAndClearExpectations();
+    }
+}
+
+TEST_F(AidlPowerHalWrapperTest, sendActualWorkDuration_shouldReconnectOnError) {
+    ASSERT_TRUE(mWrapper->supportsPowerHintSession());
+
+    std::vector<int32_t> threadIds = {1, 2};
+    mWrapper->setPowerHintSessionThreadIds(threadIds);
+    EXPECT_CALL(*mMockHal.get(), createHintSession(_, _, threadIds, _, _))
+            .WillOnce(DoAll(SetArgPointee<4>(mMockSession), Return(Status::ok())));
+    ASSERT_TRUE(mWrapper->startPowerHintSession());
+    verifyAndClearExpectations();
+    WorkDuration duration;
+    duration.durationNanos = 1;
+    EXPECT_CALL(*mMockSession.get(), reportActualWorkDuration(_))
+            .WillOnce(Return(Status::fromExceptionCode(Status::Exception::EX_ILLEGAL_STATE)));
+    sendActualWorkDurationGroup({duration}, 0ms);
+    EXPECT_TRUE(mWrapper->shouldReconnectHAL());
+}
+
+} // namespace
+} // namespace android::Hwc2::impl
diff --git a/services/surfaceflinger/tests/unittests/Android.bp b/services/surfaceflinger/tests/unittests/Android.bp
index 1eea023..cc9d48c 100644
--- a/services/surfaceflinger/tests/unittests/Android.bp
+++ b/services/surfaceflinger/tests/unittests/Android.bp
@@ -26,6 +26,8 @@
     srcs: [
         "mock/DisplayHardware/MockComposer.cpp",
         "mock/DisplayHardware/MockHWC2.cpp",
+        "mock/DisplayHardware/MockIPower.cpp",
+        "mock/DisplayHardware/MockIPowerHintSession.cpp",
         "mock/DisplayHardware/MockPowerAdvisor.cpp",
         "mock/MockEventThread.cpp",
         "mock/MockFrameTimeline.cpp",
@@ -67,6 +69,7 @@
         ":libsurfaceflinger_mock_sources",
         ":libsurfaceflinger_sources",
         "libsurfaceflinger_unittest_main.cpp",
+        "AidlPowerHalWrapperTest.cpp",
         "CachingTest.cpp",
         "CompositionTest.cpp",
         "DispSyncSourceTest.cpp",
diff --git a/services/surfaceflinger/tests/unittests/DisplayDevice_SetDisplayBrightnessTest.cpp b/services/surfaceflinger/tests/unittests/DisplayDevice_SetDisplayBrightnessTest.cpp
index 73c60e1..225ad16 100644
--- a/services/surfaceflinger/tests/unittests/DisplayDevice_SetDisplayBrightnessTest.cpp
+++ b/services/surfaceflinger/tests/unittests/DisplayDevice_SetDisplayBrightnessTest.cpp
@@ -19,6 +19,7 @@
 
 #include "DisplayTransactionTestHelpers.h"
 
+#include <ftl/fake_guard.h>
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
@@ -35,7 +36,7 @@
 };
 
 TEST_F(SetDisplayBrightnessTest, persistDisplayBrightnessNoComposite) {
-    MainThreadScopedGuard fakeMainThreadGuard(SF_MAIN_THREAD);
+    ftl::FakeGuard guard(kMainThreadContext);
     sp<DisplayDevice> displayDevice = getDisplayDevice();
 
     EXPECT_EQ(std::nullopt, displayDevice->getStagedBrightness());
@@ -52,7 +53,7 @@
 }
 
 TEST_F(SetDisplayBrightnessTest, persistDisplayBrightnessWithComposite) {
-    MainThreadScopedGuard fakeMainThreadGuard(SF_MAIN_THREAD);
+    ftl::FakeGuard guard(kMainThreadContext);
     sp<DisplayDevice> displayDevice = getDisplayDevice();
 
     EXPECT_EQ(std::nullopt, displayDevice->getStagedBrightness());
@@ -70,7 +71,7 @@
 }
 
 TEST_F(SetDisplayBrightnessTest, persistDisplayBrightnessWithCompositeShortCircuitsOnNoOp) {
-    MainThreadScopedGuard fakeMainThreadGuard(SF_MAIN_THREAD);
+    ftl::FakeGuard guard(kMainThreadContext);
     sp<DisplayDevice> displayDevice = getDisplayDevice();
 
     EXPECT_EQ(std::nullopt, displayDevice->getStagedBrightness());
diff --git a/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockIPower.cpp b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockIPower.cpp
new file mode 100644
index 0000000..2323ebb
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockIPower.cpp
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2022 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 "mock/DisplayHardware/MockIPower.h"
+
+namespace android::Hwc2::mock {
+
+// Explicit default instantiation is recommended.
+MockIPower::MockIPower() = default;
+
+} // namespace android::Hwc2::mock
diff --git a/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockIPower.h b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockIPower.h
new file mode 100644
index 0000000..0ddc90d
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockIPower.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "binder/Status.h"
+
+#include <android/hardware/power/IPower.h>
+#include <gmock/gmock.h>
+
+using android::binder::Status;
+using android::hardware::power::Boost;
+using android::hardware::power::IPower;
+using android::hardware::power::IPowerHintSession;
+using android::hardware::power::Mode;
+
+namespace android::Hwc2::mock {
+
+class MockIPower : public IPower {
+public:
+    MockIPower();
+
+    MOCK_METHOD(Status, isBoostSupported, (Boost boost, bool* ret), (override));
+    MOCK_METHOD(Status, setBoost, (Boost boost, int32_t durationMs), (override));
+    MOCK_METHOD(Status, isModeSupported, (Mode mode, bool* ret), (override));
+    MOCK_METHOD(Status, setMode, (Mode mode, bool enabled), (override));
+    MOCK_METHOD(Status, createHintSession,
+                (int32_t tgid, int32_t uid, const std::vector<int32_t>& threadIds,
+                 int64_t durationNanos, sp<IPowerHintSession>* session),
+                (override));
+    MOCK_METHOD(Status, getHintSessionPreferredRate, (int64_t * rate), (override));
+    MOCK_METHOD(int32_t, getInterfaceVersion, (), (override));
+    MOCK_METHOD(std::string, getInterfaceHash, (), (override));
+    MOCK_METHOD(IBinder*, onAsBinder, (), (override));
+};
+
+} // namespace android::Hwc2::mock
diff --git a/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockIPowerHintSession.cpp b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockIPowerHintSession.cpp
new file mode 100644
index 0000000..770bc15
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockIPowerHintSession.cpp
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2022 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 "mock/DisplayHardware/MockIPowerHintSession.h"
+
+namespace android::Hwc2::mock {
+
+// Explicit default instantiation is recommended.
+MockIPowerHintSession::MockIPowerHintSession() = default;
+
+} // namespace android::Hwc2::mock
diff --git a/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockIPowerHintSession.h b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockIPowerHintSession.h
new file mode 100644
index 0000000..439f6f4
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockIPowerHintSession.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "binder/Status.h"
+
+#include <android/hardware/power/IPower.h>
+#include <gmock/gmock.h>
+
+using android::binder::Status;
+using android::hardware::power::IPowerHintSession;
+
+using namespace android::hardware::power;
+
+namespace android::Hwc2::mock {
+
+class MockIPowerHintSession : public IPowerHintSession {
+public:
+    MockIPowerHintSession();
+
+    MOCK_METHOD(IBinder*, onAsBinder, (), (override));
+    MOCK_METHOD(Status, pause, (), (override));
+    MOCK_METHOD(Status, resume, (), (override));
+    MOCK_METHOD(Status, close, (), (override));
+    MOCK_METHOD(int32_t, getInterfaceVersion, (), (override));
+    MOCK_METHOD(std::string, getInterfaceHash, (), (override));
+    MOCK_METHOD(Status, updateTargetWorkDuration, (int64_t), (override));
+    MOCK_METHOD(Status, reportActualWorkDuration, (const ::std::vector<WorkDuration>&), (override));
+};
+
+} // namespace android::Hwc2::mock