Improve updateInputFlinger performance

This change improves the performance of the WindowInfosListenerInvoker work done on SurfaceFlinger's background executor thread. The primary optimization made is not sending a WindowInfosReportedListener with every call to WindowInfosListener.onWindowInfosChanged. Instead, we send a new interface, WindowInfosPublisher, and a unique listener id to listeners when they're added.  Listeners call WindowInfosPublisher.ackWindowInfosReceived with their id after processing each update.

From traces taken during development, the new code is a major improvement, taking about 15% of the time spent previously on SurfaceFlinger's background thread for sending window infos. Performance with this change seems roughly in line with the performance in T.

Bug: 290377931
Test: atest WindowInfosListenerTest
Test: atest WindowInfosListenerInvokerTest
Test: manually killing system server and checking valid state on restart
Change-Id: Ib39ba935727df0bc1ab4030bcfe8301de7e64805
(cherry picked from commit acd2258a5492a9e289fd7f4b8ea90543d6843a23)

17 files changed, 333 insertions, 242 deletions

diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index 342f132f0c..d7e7eb8ea1 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -73,6 +73,7 @@ filegroup {
         "android/gui/FocusRequest.aidl",
         "android/gui/InputApplicationInfo.aidl",
         "android/gui/IWindowInfosListener.aidl",
+        "android/gui/IWindowInfosPublisher.aidl",
         "android/gui/IWindowInfosReportedListener.aidl",
         "android/gui/WindowInfo.aidl",
         "android/gui/WindowInfosUpdate.aidl",
@@ -90,6 +91,7 @@ cc_library_static {
         "android/gui/FocusRequest.aidl",
         "android/gui/InputApplicationInfo.aidl",
         "android/gui/IWindowInfosListener.aidl",
+        "android/gui/IWindowInfosPublisher.aidl",
         "android/gui/IWindowInfosReportedListener.aidl",
         "android/gui/WindowInfosUpdate.aidl",
         "android/gui/WindowInfo.aidl",
@@ -136,6 +138,7 @@ aidl_library {
         "android/gui/FocusRequest.aidl",
         "android/gui/InputApplicationInfo.aidl",
         "android/gui/IWindowInfosListener.aidl",
+        "android/gui/IWindowInfosPublisher.aidl",
         "android/gui/IWindowInfosReportedListener.aidl",
         "android/gui/WindowInfo.aidl",
         "android/gui/WindowInfosUpdate.aidl",
diff --git a/libs/gui/WindowInfosListenerReporter.cpp b/libs/gui/WindowInfosListenerReporter.cpp
index 76e7b6e162..0929b8e120 100644
--- a/libs/gui/WindowInfosListenerReporter.cpp
+++ b/libs/gui/WindowInfosListenerReporter.cpp
@@ -22,7 +22,6 @@
 namespace android {
 
 using gui::DisplayInfo;
-using gui::IWindowInfosReportedListener;
 using gui::WindowInfo;
 using gui::WindowInfosListener;
 using gui::aidl_utils::statusTFromBinderStatus;
@@ -40,8 +39,13 @@ status_t WindowInfosListenerReporter::addWindowInfosListener(
     {
         std::scoped_lock lock(mListenersMutex);
         if (mWindowInfosListeners.empty()) {
-            binder::Status s = surfaceComposer->addWindowInfosListener(this);
+            gui::WindowInfosListenerInfo listenerInfo;
+            binder::Status s = surfaceComposer->addWindowInfosListener(this, &listenerInfo);
             status = statusTFromBinderStatus(s);
+            if (status == OK) {
+                mWindowInfosPublisher = std::move(listenerInfo.windowInfosPublisher);
+                mListenerId = listenerInfo.listenerId;
+            }
         }
 
         if (status == OK) {
@@ -85,8 +89,7 @@ status_t WindowInfosListenerReporter::removeWindowInfosListener(
 }
 
 binder::Status WindowInfosListenerReporter::onWindowInfosChanged(
-        const gui::WindowInfosUpdate& update,
-        const sp<IWindowInfosReportedListener>& windowInfosReportedListener) {
+        const gui::WindowInfosUpdate& update) {
     std::unordered_set<sp<WindowInfosListener>, gui::SpHash<WindowInfosListener>>
             windowInfosListeners;
 
@@ -104,9 +107,7 @@ binder::Status WindowInfosListenerReporter::onWindowInfosChanged(
         listener->onWindowInfosChanged(update);
     }
 
-    if (windowInfosReportedListener) {
-        windowInfosReportedListener->onWindowInfosReported();
-    }
+    mWindowInfosPublisher->ackWindowInfosReceived(update.vsyncId, mListenerId);
 
     return binder::Status::ok();
 }
@@ -114,7 +115,10 @@ binder::Status WindowInfosListenerReporter::onWindowInfosChanged(
 void WindowInfosListenerReporter::reconnect(const sp<gui::ISurfaceComposer>& composerService) {
     std::scoped_lock lock(mListenersMutex);
     if (!mWindowInfosListeners.empty()) {
-        composerService->addWindowInfosListener(this);
+        gui::WindowInfosListenerInfo listenerInfo;
+        composerService->addWindowInfosListener(this, &listenerInfo);
+        mWindowInfosPublisher = std::move(listenerInfo.windowInfosPublisher);
+        mListenerId = listenerInfo.listenerId;
     }
 }
 
diff --git a/libs/gui/aidl/android/gui/ISurfaceComposer.aidl b/libs/gui/aidl/android/gui/ISurfaceComposer.aidl
index ec3266ca83..539a1c140e 100644
--- a/libs/gui/aidl/android/gui/ISurfaceComposer.aidl
+++ b/libs/gui/aidl/android/gui/ISurfaceComposer.aidl
@@ -40,12 +40,14 @@ import android.gui.IScreenCaptureListener;
 import android.gui.ISurfaceComposerClient;
 import android.gui.ITunnelModeEnabledListener;
 import android.gui.IWindowInfosListener;
+import android.gui.IWindowInfosPublisher;
 import android.gui.LayerCaptureArgs;
 import android.gui.LayerDebugInfo;
 import android.gui.OverlayProperties;
 import android.gui.PullAtomData;
 import android.gui.ARect;
 import android.gui.StaticDisplayInfo;
+import android.gui.WindowInfosListenerInfo;
 
 /** @hide */
 interface ISurfaceComposer {
@@ -500,7 +502,7 @@ interface ISurfaceComposer {
      */
     int getMaxAcquiredBufferCount();
 
-    void addWindowInfosListener(IWindowInfosListener windowInfosListener);
+    WindowInfosListenerInfo addWindowInfosListener(IWindowInfosListener windowInfosListener);
 
     void removeWindowInfosListener(IWindowInfosListener windowInfosListener);
 
diff --git a/libs/gui/aidl/android/gui/WindowInfosListenerInfo.aidl b/libs/gui/aidl/android/gui/WindowInfosListenerInfo.aidl
new file mode 100644
index 0000000000..0ca13b768a
--- /dev/null
+++ b/libs/gui/aidl/android/gui/WindowInfosListenerInfo.aidl
@@ -0,0 +1,25 @@
+/**
+ * Copyright (c) 2023, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.gui;
+
+import android.gui.IWindowInfosPublisher;
+
+/** @hide */
+parcelable WindowInfosListenerInfo {
+    long listenerId;
+    IWindowInfosPublisher windowInfosPublisher;
+}
\ No newline at end of file
diff --git a/libs/gui/android/gui/IWindowInfosListener.aidl b/libs/gui/android/gui/IWindowInfosListener.aidl
index 400229d99f..07cb5ed0e6 100644
--- a/libs/gui/android/gui/IWindowInfosListener.aidl
+++ b/libs/gui/android/gui/IWindowInfosListener.aidl
@@ -16,11 +16,9 @@
 
 package android.gui;
 
-import android.gui.IWindowInfosReportedListener;
 import android.gui.WindowInfosUpdate;
 
 /** @hide */
 oneway interface IWindowInfosListener {
-    void onWindowInfosChanged(
-        in WindowInfosUpdate update, in @nullable IWindowInfosReportedListener windowInfosReportedListener);
+    void onWindowInfosChanged(in WindowInfosUpdate update);
 }
diff --git a/libs/gui/android/gui/IWindowInfosPublisher.aidl b/libs/gui/android/gui/IWindowInfosPublisher.aidl
new file mode 100644
index 0000000000..5a9c32845e
--- /dev/null
+++ b/libs/gui/android/gui/IWindowInfosPublisher.aidl
@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) 2023, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.gui;
+
+/** @hide */
+oneway interface IWindowInfosPublisher
+{
+    void ackWindowInfosReceived(long vsyncId, long listenerId);
+}
diff --git a/libs/gui/fuzzer/libgui_fuzzer_utils.h b/libs/gui/fuzzer/libgui_fuzzer_utils.h
index 8c003d8ad4..4c7d0562af 100644
--- a/libs/gui/fuzzer/libgui_fuzzer_utils.h
+++ b/libs/gui/fuzzer/libgui_fuzzer_utils.h
@@ -153,8 +153,8 @@ public:
     MOCK_METHOD(binder::Status, setOverrideFrameRate, (int32_t, float), (override));
     MOCK_METHOD(binder::Status, getGpuContextPriority, (int32_t*), (override));
     MOCK_METHOD(binder::Status, getMaxAcquiredBufferCount, (int32_t*), (override));
-    MOCK_METHOD(binder::Status, addWindowInfosListener, (const sp<gui::IWindowInfosListener>&),
-                (override));
+    MOCK_METHOD(binder::Status, addWindowInfosListener,
+                (const sp<gui::IWindowInfosListener>&, gui::WindowInfosListenerInfo*), (override));
     MOCK_METHOD(binder::Status, removeWindowInfosListener, (const sp<gui::IWindowInfosListener>&),
                 (override));
     MOCK_METHOD(binder::Status, getOverlaySupport, (gui::OverlayProperties*), (override));
diff --git a/libs/gui/include/gui/ISurfaceComposer.h b/libs/gui/include/gui/ISurfaceComposer.h
index 7c150d53d9..3ff6735926 100644
--- a/libs/gui/include/gui/ISurfaceComposer.h
+++ b/libs/gui/include/gui/ISurfaceComposer.h
@@ -26,6 +26,7 @@
 #include <android/gui/IScreenCaptureListener.h>
 #include <android/gui/ITunnelModeEnabledListener.h>
 #include <android/gui/IWindowInfosListener.h>
+#include <android/gui/IWindowInfosPublisher.h>
 #include <binder/IBinder.h>
 #include <binder/IInterface.h>
 #include <gui/ITransactionCompletedListener.h>
diff --git a/libs/gui/include/gui/WindowInfosListenerReporter.h b/libs/gui/include/gui/WindowInfosListenerReporter.h
index 38cb108912..684e21ad96 100644
--- a/libs/gui/include/gui/WindowInfosListenerReporter.h
+++ b/libs/gui/include/gui/WindowInfosListenerReporter.h
@@ -18,7 +18,7 @@
 
 #include <android/gui/BnWindowInfosListener.h>
 #include <android/gui/ISurfaceComposer.h>
-#include <android/gui/IWindowInfosReportedListener.h>
+#include <android/gui/IWindowInfosPublisher.h>
 #include <binder/IBinder.h>
 #include <gui/SpHash.h>
 #include <gui/WindowInfosListener.h>
@@ -30,8 +30,7 @@ namespace android {
 class WindowInfosListenerReporter : public gui::BnWindowInfosListener {
 public:
     static sp<WindowInfosListenerReporter> getInstance();
-    binder::Status onWindowInfosChanged(const gui::WindowInfosUpdate& update,
-                                        const sp<gui::IWindowInfosReportedListener>&) override;
+    binder::Status onWindowInfosChanged(const gui::WindowInfosUpdate& update) override;
     status_t addWindowInfosListener(
             const sp<gui::WindowInfosListener>& windowInfosListener,
             const sp<gui::ISurfaceComposer>&,
@@ -47,5 +46,8 @@ private:
 
     std::vector<gui::WindowInfo> mLastWindowInfos GUARDED_BY(mListenersMutex);
     std::vector<gui::DisplayInfo> mLastDisplayInfos GUARDED_BY(mListenersMutex);
+
+    sp<gui::IWindowInfosPublisher> mWindowInfosPublisher;
+    int64_t mListenerId;
 };
 } // namespace android
diff --git a/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index 90c0a63286..567604dbec 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -1002,7 +1002,8 @@ public:
     }
 
     binder::Status addWindowInfosListener(
-            const sp<gui::IWindowInfosListener>& /*windowInfosListener*/) override {
+            const sp<gui::IWindowInfosListener>& /*windowInfosListener*/,
+            gui::WindowInfosListenerInfo* /*outInfo*/) override {
         return binder::Status::ok();
     }
 
diff --git a/services/surfaceflinger/BackgroundExecutor.cpp b/services/surfaceflinger/BackgroundExecutor.cpp
index 6ddf790d47..5a1ec6f501 100644
--- a/services/surfaceflinger/BackgroundExecutor.cpp
+++ b/services/surfaceflinger/BackgroundExecutor.cpp
@@ -20,6 +20,7 @@
 #define ATRACE_TAG ATRACE_TAG_GRAPHICS
 
 #include <utils/Log.h>
+#include <mutex>
 
 #include "BackgroundExecutor.h"
 
@@ -60,4 +61,17 @@ void BackgroundExecutor::sendCallbacks(Callbacks&& tasks) {
     LOG_ALWAYS_FATAL_IF(sem_post(&mSemaphore), "sem_post failed");
 }
 
+void BackgroundExecutor::flushQueue() {
+    std::mutex mutex;
+    std::condition_variable cv;
+    bool flushComplete = false;
+    sendCallbacks({[&]() {
+        std::scoped_lock lock{mutex};
+        flushComplete = true;
+        cv.notify_one();
+    }});
+    std::unique_lock<std::mutex> lock{mutex};
+    cv.wait(lock, [&]() { return flushComplete; });
+}
+
 } // namespace android
diff --git a/services/surfaceflinger/BackgroundExecutor.h b/services/surfaceflinger/BackgroundExecutor.h
index 0fae5a5c93..66b7d7a1fc 100644
--- a/services/surfaceflinger/BackgroundExecutor.h
+++ b/services/surfaceflinger/BackgroundExecutor.h
@@ -34,6 +34,7 @@ public:
     // Queues callbacks onto a work queue to be executed by a background thread.
     // This is safe to call from multiple threads.
     void sendCallbacks(Callbacks&& tasks);
+    void flushQueue();
 
 private:
     sem_t mSemaphore;
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 0710d875a9..de0034b8ac 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -6128,8 +6128,7 @@ void SurfaceFlinger::dumpAllLocked(const DumpArgs& args, const std::string& comp
                   ftl::to_underlying(windowInfosDebug.maxSendDelayVsyncId));
     StringAppendF(&result, "  max send delay (ns): %" PRId64 " ns\n",
                   windowInfosDebug.maxSendDelayDuration);
-    StringAppendF(&result, "  unsent messages: %" PRIu32 "\n",
-                  windowInfosDebug.pendingMessageCount);
+    StringAppendF(&result, "  unsent messages: %zu\n", windowInfosDebug.pendingMessageCount);
     result.append("\n");
 }
 
@@ -7969,9 +7968,9 @@ void SurfaceFlinger::onActiveDisplayChangedLocked(const DisplayDevice* inactiveD
                                    forceApplyPolicy);
 }
 
-status_t SurfaceFlinger::addWindowInfosListener(
-        const sp<IWindowInfosListener>& windowInfosListener) {
-    mWindowInfosListenerInvoker->addWindowInfosListener(windowInfosListener);
+status_t SurfaceFlinger::addWindowInfosListener(const sp<IWindowInfosListener>& windowInfosListener,
+                                                gui::WindowInfosListenerInfo* outInfo) {
+    mWindowInfosListenerInvoker->addWindowInfosListener(windowInfosListener, outInfo);
     setTransactionFlags(eInputInfoUpdateNeeded);
     return NO_ERROR;
 }
@@ -9054,7 +9053,8 @@ binder::Status SurfaceComposerAIDL::getMaxAcquiredBufferCount(int32_t* buffers)
 }
 
 binder::Status SurfaceComposerAIDL::addWindowInfosListener(
-        const sp<gui::IWindowInfosListener>& windowInfosListener) {
+        const sp<gui::IWindowInfosListener>& windowInfosListener,
+        gui::WindowInfosListenerInfo* outInfo) {
     status_t status;
     const int pid = IPCThreadState::self()->getCallingPid();
     const int uid = IPCThreadState::self()->getCallingUid();
@@ -9062,7 +9062,7 @@ binder::Status SurfaceComposerAIDL::addWindowInfosListener(
     // WindowInfosListeners
     if (uid == AID_SYSTEM || uid == AID_GRAPHICS ||
         checkPermission(sAccessSurfaceFlinger, pid, uid)) {
-        status = mFlinger->addWindowInfosListener(windowInfosListener);
+        status = mFlinger->addWindowInfosListener(windowInfosListener, outInfo);
     } else {
         status = PERMISSION_DENIED;
     }
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 19a1feb38d..f1759a5e52 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -613,7 +613,8 @@ private:
 
     status_t getMaxAcquiredBufferCount(int* buffers) const;
 
-    status_t addWindowInfosListener(const sp<gui::IWindowInfosListener>& windowInfosListener);
+    status_t addWindowInfosListener(const sp<gui::IWindowInfosListener>& windowInfosListener,
+                                    gui::WindowInfosListenerInfo* outResult);
     status_t removeWindowInfosListener(
             const sp<gui::IWindowInfosListener>& windowInfosListener) const;
 
@@ -1537,8 +1538,8 @@ public:
     binder::Status setOverrideFrameRate(int32_t uid, float frameRate) override;
     binder::Status getGpuContextPriority(int32_t* outPriority) override;
     binder::Status getMaxAcquiredBufferCount(int32_t* buffers) override;
-    binder::Status addWindowInfosListener(
-            const sp<gui::IWindowInfosListener>& windowInfosListener) override;
+    binder::Status addWindowInfosListener(const sp<gui::IWindowInfosListener>& windowInfosListener,
+                                          gui::WindowInfosListenerInfo* outInfo) override;
     binder::Status removeWindowInfosListener(
             const sp<gui::IWindowInfosListener>& windowInfosListener) override;
 
diff --git a/services/surfaceflinger/WindowInfosListenerInvoker.cpp b/services/surfaceflinger/WindowInfosListenerInvoker.cpp
index 20699ef123..7062a4e3a7 100644
--- a/services/surfaceflinger/WindowInfosListenerInvoker.cpp
+++ b/services/surfaceflinger/WindowInfosListenerInvoker.cpp
@@ -14,7 +14,9 @@
  * limitations under the License.
  */
 
-#include <ftl/small_vector.h>
+#include <android/gui/BnWindowInfosPublisher.h>
+#include <android/gui/IWindowInfosPublisher.h>
+#include <android/gui/WindowInfosListenerInfo.h>
 #include <gui/ISurfaceComposer.h>
 #include <gui/TraceUtils.h>
 #include <gui/WindowInfosUpdate.h>
@@ -23,162 +25,130 @@
 #include "BackgroundExecutor.h"
 #include "WindowInfosListenerInvoker.h"
 
+#undef ATRACE_TAG
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+
 namespace android {
 
 using gui::DisplayInfo;
 using gui::IWindowInfosListener;
 using gui::WindowInfo;
 
-using WindowInfosListenerVector = ftl::SmallVector<const sp<gui::IWindowInfosListener>, 3>;
-
-struct WindowInfosReportedListenerInvoker : gui::BnWindowInfosReportedListener,
-                                            IBinder::DeathRecipient {
-    WindowInfosReportedListenerInvoker(WindowInfosListenerVector windowInfosListeners,
-                                       WindowInfosReportedListenerSet windowInfosReportedListeners)
-          : mCallbacksPending(windowInfosListeners.size()),
-            mWindowInfosListeners(std::move(windowInfosListeners)),
-            mWindowInfosReportedListeners(std::move(windowInfosReportedListeners)) {}
+void WindowInfosListenerInvoker::addWindowInfosListener(sp<IWindowInfosListener> listener,
+                                                        gui::WindowInfosListenerInfo* outInfo) {
+    int64_t listenerId = mNextListenerId++;
+    outInfo->listenerId = listenerId;
+    outInfo->windowInfosPublisher = sp<gui::IWindowInfosPublisher>::fromExisting(this);
 
-    binder::Status onWindowInfosReported() override {
-        if (--mCallbacksPending == 0) {
-            for (const auto& listener : mWindowInfosReportedListeners) {
+    BackgroundExecutor::getInstance().sendCallbacks(
+            {[this, listener = std::move(listener), listenerId]() {
+                ATRACE_NAME("WindowInfosListenerInvoker::addWindowInfosListener");
                 sp<IBinder> asBinder = IInterface::asBinder(listener);
-                if (asBinder->isBinderAlive()) {
-                    listener->onWindowInfosReported();
-                }
-            }
-
-            auto wpThis = wp<WindowInfosReportedListenerInvoker>::fromExisting(this);
-            for (const auto& listener : mWindowInfosListeners) {
-                sp<IBinder> binder = IInterface::asBinder(listener);
-                binder->unlinkToDeath(wpThis);
-            }
-        }
-        return binder::Status::ok();
-    }
-
-    void binderDied(const wp<IBinder>&) { onWindowInfosReported(); }
-
-private:
-    std::atomic<size_t> mCallbacksPending;
-    static constexpr size_t kStaticCapacity = 3;
-    const WindowInfosListenerVector mWindowInfosListeners;
-    WindowInfosReportedListenerSet mWindowInfosReportedListeners;
-};
-
-void WindowInfosListenerInvoker::addWindowInfosListener(sp<IWindowInfosListener> listener) {
-    sp<IBinder> asBinder = IInterface::asBinder(listener);
-    asBinder->linkToDeath(sp<DeathRecipient>::fromExisting(this));
-
-    std::scoped_lock lock(mListenersMutex);
-    mWindowInfosListeners.try_emplace(asBinder, std::move(listener));
+                asBinder->linkToDeath(sp<DeathRecipient>::fromExisting(this));
+                mWindowInfosListeners.try_emplace(asBinder,
+                                                  std::make_pair(listenerId, std::move(listener)));
+            }});
 }
 
 void WindowInfosListenerInvoker::removeWindowInfosListener(
         const sp<IWindowInfosListener>& listener) {
-    sp<IBinder> asBinder = IInterface::asBinder(listener);
-
-    std::scoped_lock lock(mListenersMutex);
-    asBinder->unlinkToDeath(sp<DeathRecipient>::fromExisting(this));
-    mWindowInfosListeners.erase(asBinder);
+    BackgroundExecutor::getInstance().sendCallbacks({[this, listener]() {
+        ATRACE_NAME("WindowInfosListenerInvoker::removeWindowInfosListener");
+        sp<IBinder> asBinder = IInterface::asBinder(listener);
+        asBinder->unlinkToDeath(sp<DeathRecipient>::fromExisting(this));
+        mWindowInfosListeners.erase(asBinder);
+    }});
 }
 
 void WindowInfosListenerInvoker::binderDied(const wp<IBinder>& who) {
-    std::scoped_lock lock(mListenersMutex);
-    mWindowInfosListeners.erase(who);
+    BackgroundExecutor::getInstance().sendCallbacks({[this, who]() {
+        ATRACE_NAME("WindowInfosListenerInvoker::binderDied");
+        auto it = mWindowInfosListeners.find(who);
+        int64_t listenerId = it->second.first;
+        mWindowInfosListeners.erase(who);
+
+        std::vector<int64_t> vsyncIds;
+        for (auto& [vsyncId, state] : mUnackedState) {
+            if (std::find(state.unackedListenerIds.begin(), state.unackedListenerIds.end(),
+                          listenerId) != state.unackedListenerIds.end()) {
+                vsyncIds.push_back(vsyncId);
+            }
+        }
+
+        for (int64_t vsyncId : vsyncIds) {
+            ackWindowInfosReceived(vsyncId, listenerId);
+        }
+    }});
 }
 
 void WindowInfosListenerInvoker::windowInfosChanged(
         gui::WindowInfosUpdate update, WindowInfosReportedListenerSet reportedListeners,
         bool forceImmediateCall) {
-    WindowInfosListenerVector listeners;
-    {
-        std::scoped_lock lock{mMessagesMutex};
-
-        if (!mDelayInfo) {
-            mDelayInfo = DelayInfo{
-                    .vsyncId = update.vsyncId,
-                    .frameTime = update.timestamp,
-            };
-        }
-
-        // If there are unacked messages and this isn't a forced call, then return immediately.
-        // If a forced window infos change doesn't happen first, the update will be sent after
-        // the WindowInfosReportedListeners are called. If a forced window infos change happens or
-        // if there are subsequent delayed messages before this update is sent, then this message
-        // will be dropped and the listeners will only be called with the latest info. This is done
-        // to reduce the amount of binder memory used.
-        if (mActiveMessageCount > 0 && !forceImmediateCall) {
-            mDelayedUpdate = std::move(update);
-            mReportedListeners.merge(reportedListeners);
-            return;
-        }
-
-        if (mDelayedUpdate) {
-            mDelayedUpdate.reset();
-        }
+    if (!mDelayInfo) {
+        mDelayInfo = DelayInfo{
+                .vsyncId = update.vsyncId,
+                .frameTime = update.timestamp,
+        };
+    }
 
-        {
-            std::scoped_lock lock{mListenersMutex};
-            for (const auto& [_, listener] : mWindowInfosListeners) {
-                listeners.push_back(listener);
-            }
-        }
-        if (CC_UNLIKELY(listeners.empty())) {
-            mReportedListeners.merge(reportedListeners);
-            mDelayInfo.reset();
-            return;
-        }
+    // If there are unacked messages and this isn't a forced call, then return immediately.
+    // If a forced window infos change doesn't happen first, the update will be sent after
+    // the WindowInfosReportedListeners are called. If a forced window infos change happens or
+    // if there are subsequent delayed messages before this update is sent, then this message
+    // will be dropped and the listeners will only be called with the latest info. This is done
+    // to reduce the amount of binder memory used.
+    if (!mUnackedState.empty() && !forceImmediateCall) {
+        mDelayedUpdate = std::move(update);
+        mReportedListeners.merge(reportedListeners);
+        return;
+    }
 
-        reportedListeners.insert(sp<WindowInfosListenerInvoker>::fromExisting(this));
-        reportedListeners.merge(mReportedListeners);
-        mReportedListeners.clear();
+    if (mDelayedUpdate) {
+        mDelayedUpdate.reset();
+    }
 
-        mActiveMessageCount++;
-        updateMaxSendDelay();
+    if (CC_UNLIKELY(mWindowInfosListeners.empty())) {
+        mReportedListeners.merge(reportedListeners);
         mDelayInfo.reset();
+        return;
     }
 
-    auto reportedInvoker =
-            sp<WindowInfosReportedListenerInvoker>::make(listeners, std::move(reportedListeners));
-
-    for (const auto& listener : listeners) {
-        sp<IBinder> asBinder = IInterface::asBinder(listener);
+    reportedListeners.merge(mReportedListeners);
+    mReportedListeners.clear();
+
+    // Update mUnackedState to include the message we're about to send
+    auto [it, _] = mUnackedState.try_emplace(update.vsyncId,
+                                             UnackedState{.reportedListeners =
+                                                                  std::move(reportedListeners)});
+    auto& unackedState = it->second;
+    for (auto& pair : mWindowInfosListeners) {
+        int64_t listenerId = pair.second.first;
+        unackedState.unackedListenerIds.push_back(listenerId);
+    }
 
-        // linkToDeath is used here to ensure that the windowInfosReportedListeners
-        // are called even if one of the windowInfosListeners dies before
-        // calling onWindowInfosReported.
-        asBinder->linkToDeath(reportedInvoker);
+    mDelayInfo.reset();
+    updateMaxSendDelay();
 
-        auto status = listener->onWindowInfosChanged(update, reportedInvoker);
+    // Call the listeners
+    for (auto& pair : mWindowInfosListeners) {
+        auto& [listenerId, listener] = pair.second;
+        auto status = listener->onWindowInfosChanged(update);
         if (!status.isOk()) {
-            reportedInvoker->onWindowInfosReported();
+            ackWindowInfosReceived(update.vsyncId, listenerId);
         }
     }
 }
 
-binder::Status WindowInfosListenerInvoker::onWindowInfosReported() {
-    BackgroundExecutor::getInstance().sendCallbacks({[this]() {
-        gui::WindowInfosUpdate update;
-        {
-            std::scoped_lock lock{mMessagesMutex};
-            mActiveMessageCount--;
-            if (!mDelayedUpdate || mActiveMessageCount > 0) {
-                return;
-            }
-            update = std::move(*mDelayedUpdate);
-            mDelayedUpdate.reset();
-        }
-        windowInfosChanged(std::move(update), {}, false);
-    }});
-    return binder::Status::ok();
-}
-
 WindowInfosListenerInvoker::DebugInfo WindowInfosListenerInvoker::getDebugInfo() {
-    std::scoped_lock lock{mMessagesMutex};
-    updateMaxSendDelay();
-    mDebugInfo.pendingMessageCount = mActiveMessageCount;
-    return mDebugInfo;
+    DebugInfo result;
+    BackgroundExecutor::getInstance().sendCallbacks({[&, this]() {
+        ATRACE_NAME("WindowInfosListenerInvoker::getDebugInfo");
+        updateMaxSendDelay();
+        result = mDebugInfo;
+        result.pendingMessageCount = mUnackedState.size();
+    }});
+    BackgroundExecutor::getInstance().flushQueue();
+    return result;
 }
 
 void WindowInfosListenerInvoker::updateMaxSendDelay() {
@@ -192,4 +162,41 @@ void WindowInfosListenerInvoker::updateMaxSendDelay() {
     }
 }
 
+binder::Status WindowInfosListenerInvoker::ackWindowInfosReceived(int64_t vsyncId,
+                                                                  int64_t listenerId) {
+    BackgroundExecutor::getInstance().sendCallbacks({[this, vsyncId, listenerId]() {
+        ATRACE_NAME("WindowInfosListenerInvoker::ackWindowInfosReceived");
+        auto it = mUnackedState.find(vsyncId);
+        if (it == mUnackedState.end()) {
+            return;
+        }
+
+        auto& state = it->second;
+        state.unackedListenerIds.unstable_erase(std::find(state.unackedListenerIds.begin(),
+                                                          state.unackedListenerIds.end(),
+                                                          listenerId));
+        if (!state.unackedListenerIds.empty()) {
+            return;
+        }
+
+        WindowInfosReportedListenerSet reportedListeners{std::move(state.reportedListeners)};
+        mUnackedState.erase(vsyncId);
+
+        for (const auto& reportedListener : reportedListeners) {
+            sp<IBinder> asBinder = IInterface::asBinder(reportedListener);
+            if (asBinder->isBinderAlive()) {
+                reportedListener->onWindowInfosReported();
+            }
+        }
+
+        if (!mDelayedUpdate || !mUnackedState.empty()) {
+            return;
+        }
+        gui::WindowInfosUpdate update{std::move(*mDelayedUpdate)};
+        mDelayedUpdate.reset();
+        windowInfosChanged(std::move(update), {}, false);
+    }});
+    return binder::Status::ok();
+}
+
 } // namespace android
diff --git a/services/surfaceflinger/WindowInfosListenerInvoker.h b/services/surfaceflinger/WindowInfosListenerInvoker.h
index bc465a3a2b..f36b0edd7d 100644
--- a/services/surfaceflinger/WindowInfosListenerInvoker.h
+++ b/services/surfaceflinger/WindowInfosListenerInvoker.h
@@ -19,11 +19,12 @@
 #include <optional>
 #include <unordered_set>
 
-#include <android/gui/BnWindowInfosReportedListener.h>
+#include <android/gui/BnWindowInfosPublisher.h>
 #include <android/gui/IWindowInfosListener.h>
 #include <android/gui/IWindowInfosReportedListener.h>
 #include <binder/IBinder.h>
 #include <ftl/small_map.h>
+#include <ftl/small_vector.h>
 #include <gui/SpHash.h>
 #include <utils/Mutex.h>
 
@@ -35,22 +36,22 @@ using WindowInfosReportedListenerSet =
         std::unordered_set<sp<gui::IWindowInfosReportedListener>,
                            gui::SpHash<gui::IWindowInfosReportedListener>>;
 
-class WindowInfosListenerInvoker : public gui::BnWindowInfosReportedListener,
+class WindowInfosListenerInvoker : public gui::BnWindowInfosPublisher,
                                    public IBinder::DeathRecipient {
 public:
-    void addWindowInfosListener(sp<gui::IWindowInfosListener>);
+    void addWindowInfosListener(sp<gui::IWindowInfosListener>, gui::WindowInfosListenerInfo*);
     void removeWindowInfosListener(const sp<gui::IWindowInfosListener>& windowInfosListener);
 
     void windowInfosChanged(gui::WindowInfosUpdate update,
                             WindowInfosReportedListenerSet windowInfosReportedListeners,
                             bool forceImmediateCall);
 
-    binder::Status onWindowInfosReported() override;
+    binder::Status ackWindowInfosReceived(int64_t, int64_t) override;
 
     struct DebugInfo {
         VsyncId maxSendDelayVsyncId;
         nsecs_t maxSendDelayDuration;
-        uint32_t pendingMessageCount;
+        size_t pendingMessageCount;
     };
     DebugInfo getDebugInfo();
 
@@ -58,24 +59,28 @@ protected:
     void binderDied(const wp<IBinder>& who) override;
 
 private:
-    std::mutex mListenersMutex;
-
     static constexpr size_t kStaticCapacity = 3;
-    ftl::SmallMap<wp<IBinder>, const sp<gui::IWindowInfosListener>, kStaticCapacity>
-            mWindowInfosListeners GUARDED_BY(mListenersMutex);
+    std::atomic<int64_t> mNextListenerId{0};
+    ftl::SmallMap<wp<IBinder>, const std::pair<int64_t, sp<gui::IWindowInfosListener>>,
+                  kStaticCapacity>
+            mWindowInfosListeners;
 
-    std::mutex mMessagesMutex;
-    uint32_t mActiveMessageCount GUARDED_BY(mMessagesMutex) = 0;
-    std::optional<gui::WindowInfosUpdate> mDelayedUpdate GUARDED_BY(mMessagesMutex);
+    std::optional<gui::WindowInfosUpdate> mDelayedUpdate;
     WindowInfosReportedListenerSet mReportedListeners;
 
-    DebugInfo mDebugInfo GUARDED_BY(mMessagesMutex);
+    struct UnackedState {
+        ftl::SmallVector<int64_t, kStaticCapacity> unackedListenerIds;
+        WindowInfosReportedListenerSet reportedListeners;
+    };
+    ftl::SmallMap<int64_t /* vsyncId */, UnackedState, 5> mUnackedState;
+
+    DebugInfo mDebugInfo;
     struct DelayInfo {
         int64_t vsyncId;
         nsecs_t frameTime;
     };
-    std::optional<DelayInfo> mDelayInfo GUARDED_BY(mMessagesMutex);
-    void updateMaxSendDelay() REQUIRES(mMessagesMutex);
+    std::optional<DelayInfo> mDelayInfo;
+    void updateMaxSendDelay();
 };
 
 } // namespace android
diff --git a/services/surfaceflinger/tests/unittests/WindowInfosListenerInvokerTest.cpp b/services/surfaceflinger/tests/unittests/WindowInfosListenerInvokerTest.cpp
index af4971b063..c7b845e668 100644
--- a/services/surfaceflinger/tests/unittests/WindowInfosListenerInvokerTest.cpp
+++ b/services/surfaceflinger/tests/unittests/WindowInfosListenerInvokerTest.cpp
@@ -15,35 +15,23 @@ protected:
     WindowInfosListenerInvokerTest() : mInvoker(sp<WindowInfosListenerInvoker>::make()) {}
 
     ~WindowInfosListenerInvokerTest() {
-        std::mutex mutex;
-        std::condition_variable cv;
-        bool flushComplete = false;
         // Flush the BackgroundExecutor thread to ensure any scheduled tasks are complete.
         // Otherwise, references those tasks hold may go out of scope before they are done
         // executing.
-        BackgroundExecutor::getInstance().sendCallbacks({[&]() {
-            std::scoped_lock lock{mutex};
-            flushComplete = true;
-            cv.notify_one();
-        }});
-        std::unique_lock<std::mutex> lock{mutex};
-        cv.wait(lock, [&]() { return flushComplete; });
+        BackgroundExecutor::getInstance().flushQueue();
     }
 
     sp<WindowInfosListenerInvoker> mInvoker;
 };
 
-using WindowInfosUpdateConsumer = std::function<void(const gui::WindowInfosUpdate&,
-                                                     const sp<gui::IWindowInfosReportedListener>&)>;
+using WindowInfosUpdateConsumer = std::function<void(const gui::WindowInfosUpdate&)>;
 
 class Listener : public gui::BnWindowInfosListener {
 public:
     Listener(WindowInfosUpdateConsumer consumer) : mConsumer(std::move(consumer)) {}
 
-    binder::Status onWindowInfosChanged(
-            const gui::WindowInfosUpdate& update,
-            const sp<gui::IWindowInfosReportedListener>& reportedListener) override {
-        mConsumer(update, reportedListener);
+    binder::Status onWindowInfosChanged(const gui::WindowInfosUpdate& update) override {
+        mConsumer(update);
         return binder::Status::ok();
     }
 
@@ -58,15 +46,17 @@ TEST_F(WindowInfosListenerInvokerTest, callsSingleListener) {
 
     int callCount = 0;
 
-    mInvoker->addWindowInfosListener(
-            sp<Listener>::make([&](const gui::WindowInfosUpdate&,
-                                   const sp<gui::IWindowInfosReportedListener>& reportedListener) {
-                std::scoped_lock lock{mutex};
-                callCount++;
-                cv.notify_one();
+    gui::WindowInfosListenerInfo listenerInfo;
+    mInvoker->addWindowInfosListener(sp<Listener>::make([&](const gui::WindowInfosUpdate& update) {
+                                         std::scoped_lock lock{mutex};
+                                         callCount++;
+                                         cv.notify_one();
 
-                reportedListener->onWindowInfosReported();
-            }));
+                                         listenerInfo.windowInfosPublisher
+                                                 ->ackWindowInfosReceived(update.vsyncId,
+                                                                          listenerInfo.listenerId);
+                                     }),
+                                     &listenerInfo);
 
     BackgroundExecutor::getInstance().sendCallbacks(
             {[this]() { mInvoker->windowInfosChanged({}, {}, false); }});
@@ -81,21 +71,27 @@ TEST_F(WindowInfosListenerInvokerTest, callsMultipleListeners) {
     std::mutex mutex;
     std::condition_variable cv;
 
-    int callCount = 0;
-    const int expectedCallCount = 3;
-
-    for (int i = 0; i < expectedCallCount; i++) {
-        mInvoker->addWindowInfosListener(sp<Listener>::make(
-                [&](const gui::WindowInfosUpdate&,
-                    const sp<gui::IWindowInfosReportedListener>& reportedListener) {
-                    std::scoped_lock lock{mutex};
-                    callCount++;
-                    if (callCount == expectedCallCount) {
-                        cv.notify_one();
-                    }
-
-                    reportedListener->onWindowInfosReported();
-                }));
+    size_t callCount = 0;
+    const size_t expectedCallCount = 3;
+    std::vector<gui::WindowInfosListenerInfo> listenerInfos{expectedCallCount,
+                                                            gui::WindowInfosListenerInfo{}};
+
+    for (size_t i = 0; i < expectedCallCount; i++) {
+        mInvoker->addWindowInfosListener(sp<Listener>::make([&, &listenerInfo = listenerInfos[i]](
+                                                                    const gui::WindowInfosUpdate&
+                                                                            update) {
+                                             std::scoped_lock lock{mutex};
+                                             callCount++;
+                                             if (callCount == expectedCallCount) {
+                                                 cv.notify_one();
+                                             }
+
+                                             listenerInfo.windowInfosPublisher
+                                                     ->ackWindowInfosReceived(update.vsyncId,
+                                                                              listenerInfo
+                                                                                      .listenerId);
+                                         }),
+                                         &listenerInfos[i]);
     }
 
     BackgroundExecutor::getInstance().sendCallbacks(
@@ -114,17 +110,20 @@ TEST_F(WindowInfosListenerInvokerTest, delaysUnackedCall) {
 
     int callCount = 0;
 
-    // Simulate a slow ack by not calling the WindowInfosReportedListener.
-    mInvoker->addWindowInfosListener(sp<Listener>::make(
-            [&](const gui::WindowInfosUpdate&, const sp<gui::IWindowInfosReportedListener>&) {
-                std::scoped_lock lock{mutex};
-                callCount++;
-                cv.notify_one();
-            }));
+    // Simulate a slow ack by not calling IWindowInfosPublisher.ackWindowInfosReceived
+    gui::WindowInfosListenerInfo listenerInfo;
+    mInvoker->addWindowInfosListener(sp<Listener>::make([&](const gui::WindowInfosUpdate&) {
+                                         std::scoped_lock lock{mutex};
+                                         callCount++;
+                                         cv.notify_one();
+                                     }),
+                                     &listenerInfo);
 
     BackgroundExecutor::getInstance().sendCallbacks({[&]() {
-        mInvoker->windowInfosChanged({}, {}, false);
-        mInvoker->windowInfosChanged({}, {}, false);
+        mInvoker->windowInfosChanged(gui::WindowInfosUpdate{{}, {}, /* vsyncId= */ 0, 0}, {},
+                                     false);
+        mInvoker->windowInfosChanged(gui::WindowInfosUpdate{{}, {}, /* vsyncId= */ 1, 0}, {},
+                                     false);
     }});
 
     {
@@ -134,7 +133,7 @@ TEST_F(WindowInfosListenerInvokerTest, delaysUnackedCall) {
     EXPECT_EQ(callCount, 1);
 
     // Ack the first message.
-    mInvoker->onWindowInfosReported();
+    listenerInfo.windowInfosPublisher->ackWindowInfosReceived(0, listenerInfo.listenerId);
 
     {
         std::unique_lock lock{mutex};
@@ -152,19 +151,21 @@ TEST_F(WindowInfosListenerInvokerTest, sendsForcedMessage) {
     int callCount = 0;
     const int expectedCallCount = 2;
 
-    // Simulate a slow ack by not calling the WindowInfosReportedListener.
-    mInvoker->addWindowInfosListener(sp<Listener>::make(
-            [&](const gui::WindowInfosUpdate&, const sp<gui::IWindowInfosReportedListener>&) {
-                std::scoped_lock lock{mutex};
-                callCount++;
-                if (callCount == expectedCallCount) {
-                    cv.notify_one();
-                }
-            }));
+    // Simulate a slow ack by not calling IWindowInfosPublisher.ackWindowInfosReceived
+    gui::WindowInfosListenerInfo listenerInfo;
+    mInvoker->addWindowInfosListener(sp<Listener>::make([&](const gui::WindowInfosUpdate&) {
+                                         std::scoped_lock lock{mutex};
+                                         callCount++;
+                                         if (callCount == expectedCallCount) {
+                                             cv.notify_one();
+                                         }
+                                     }),
+                                     &listenerInfo);
 
     BackgroundExecutor::getInstance().sendCallbacks({[&]() {
-        mInvoker->windowInfosChanged({}, {}, false);
-        mInvoker->windowInfosChanged({}, {}, true);
+        mInvoker->windowInfosChanged(gui::WindowInfosUpdate{{}, {}, /* vsyncId= */ 0, 0}, {},
+                                     false);
+        mInvoker->windowInfosChanged(gui::WindowInfosUpdate{{}, {}, /* vsyncId= */ 1, 0}, {}, true);
     }});
 
     {
@@ -182,14 +183,14 @@ TEST_F(WindowInfosListenerInvokerTest, skipsDelayedMessage) {
 
     int64_t lastUpdateId = -1;
 
-    // Simulate a slow ack by not calling the WindowInfosReportedListener.
-    mInvoker->addWindowInfosListener(
-            sp<Listener>::make([&](const gui::WindowInfosUpdate& update,
-                                   const sp<gui::IWindowInfosReportedListener>&) {
-                std::scoped_lock lock{mutex};
-                lastUpdateId = update.vsyncId;
-                cv.notify_one();
-            }));
+    // Simulate a slow ack by not calling IWindowInfosPublisher.ackWindowInfosReceived
+    gui::WindowInfosListenerInfo listenerInfo;
+    mInvoker->addWindowInfosListener(sp<Listener>::make([&](const gui::WindowInfosUpdate& update) {
+                                         std::scoped_lock lock{mutex};
+                                         lastUpdateId = update.vsyncId;
+                                         cv.notify_one();
+                                     }),
+                                     &listenerInfo);
 
     BackgroundExecutor::getInstance().sendCallbacks({[&]() {
         mInvoker->windowInfosChanged({{}, {}, /* vsyncId= */ 1, 0}, {}, false);
@@ -204,7 +205,7 @@ TEST_F(WindowInfosListenerInvokerTest, skipsDelayedMessage) {
     EXPECT_EQ(lastUpdateId, 1);
 
     // Ack the first message. The third update should be sent.
-    mInvoker->onWindowInfosReported();
+    listenerInfo.windowInfosPublisher->ackWindowInfosReceived(1, listenerInfo.listenerId);
 
     {
         std::unique_lock lock{mutex};
@@ -225,14 +226,17 @@ TEST_F(WindowInfosListenerInvokerTest, noListeners) {
     // delayed.
     BackgroundExecutor::getInstance().sendCallbacks({[&]() {
         mInvoker->windowInfosChanged({}, {}, false);
-        mInvoker->addWindowInfosListener(sp<Listener>::make(
-                [&](const gui::WindowInfosUpdate&, const sp<gui::IWindowInfosReportedListener>&) {
-                    std::scoped_lock lock{mutex};
-                    callCount++;
-                    cv.notify_one();
-                }));
-        mInvoker->windowInfosChanged({}, {}, false);
+        gui::WindowInfosListenerInfo listenerInfo;
+        mInvoker->addWindowInfosListener(sp<Listener>::make([&](const gui::WindowInfosUpdate&) {
+                                             std::scoped_lock lock{mutex};
+                                             callCount++;
+                                             cv.notify_one();
+                                         }),
+                                         &listenerInfo);
     }});
+    BackgroundExecutor::getInstance().flushQueue();
+    BackgroundExecutor::getInstance().sendCallbacks(
+            {[&]() { mInvoker->windowInfosChanged({}, {}, false); }});
 
     {
         std::unique_lock lock{mutex};