Merge "Account for release callbacks when determing if sync is finished" into tm-qpr-dev
diff --git a/libs/gui/BLASTBufferQueue.cpp b/libs/gui/BLASTBufferQueue.cpp
index dbccf30..aba81f6 100644
--- a/libs/gui/BLASTBufferQueue.cpp
+++ b/libs/gui/BLASTBufferQueue.cpp
@@ -287,18 +287,17 @@
 
                 // We need to check if we were waiting for a transaction callback in order to
                 // process any pending buffers and unblock. It's possible to get transaction
-                // callbacks for previous requests so we need to ensure the frame from this
-                // transaction callback matches the last acquired buffer. Since acquireNextBuffer
-                // will stop processing buffers when mWaitForTransactionCallback is set, we know
-                // that mLastAcquiredFrameNumber is the frame we're waiting on.
-                // We also want to check if mNextTransaction is null because it's possible another
+                // callbacks for previous requests so we need to ensure that there are no pending
+                // frame numbers that were in a sync. We remove the frame from mSyncedFrameNumbers
+                // set and then check if it's empty. If there are no more pending syncs, we can
+                // proceed with flushing the shadow queue.
+                // We also want to check if mSyncTransaction is null because it's possible another
                 // sync request came in while waiting, but it hasn't started processing yet. In that
                 // case, we don't actually want to flush the frames in between since they will get
                 // processed and merged with the sync transaction and released earlier than if they
                 // were sent to SF
-                if (mWaitForTransactionCallback && mSyncTransaction == nullptr &&
-                    currFrameNumber >= mLastAcquiredFrameNumber) {
-                    mWaitForTransactionCallback = false;
+                mSyncedFrameNumbers.erase(currFrameNumber);
+                if (mSyncedFrameNumbers.empty() && mSyncTransaction == nullptr) {
                     flushShadowQueue();
                 }
             } else {
@@ -416,9 +415,11 @@
         const auto releasedBuffer = mPendingRelease.front();
         mPendingRelease.pop_front();
         releaseBuffer(releasedBuffer.callbackId, releasedBuffer.releaseFence);
-        // Don't process the transactions here if mWaitForTransactionCallback is set. Instead, let
-        // onFrameAvailable handle processing them since it will merge with the syncTransaction.
-        if (!mWaitForTransactionCallback) {
+        // Don't process the transactions here if mSyncedFrameNumbers is not empty. That means
+        // are still transactions that have sync buffers in them that have not been applied or
+        // dropped. Instead, let onFrameAvailable handle processing them since it will merge with
+        // the syncTransaction.
+        if (mSyncedFrameNumbers.empty()) {
             acquireNextBufferLocked(std::nullopt);
         }
     }
@@ -442,6 +443,9 @@
     BQA_LOGV("released %s", callbackId.to_string().c_str());
     mBufferItemConsumer->releaseBuffer(it->second, releaseFence);
     mSubmitted.erase(it);
+    // Remove the frame number from mSyncedFrameNumbers since we can get a release callback
+    // without getting a transaction committed if the buffer was dropped.
+    mSyncedFrameNumbers.erase(callbackId.framenumber);
 }
 
 void BLASTBufferQueue::acquireNextBufferLocked(
@@ -608,7 +612,7 @@
 }
 
 void BLASTBufferQueue::flushAndWaitForFreeBuffer(std::unique_lock<std::mutex>& lock) {
-    if (mWaitForTransactionCallback && mNumFrameAvailable > 0) {
+    if (!mSyncedFrameNumbers.empty() && mNumFrameAvailable > 0) {
         // We are waiting on a previous sync's transaction callback so allow another sync
         // transaction to proceed.
         //
@@ -635,6 +639,8 @@
 void BLASTBufferQueue::onFrameAvailable(const BufferItem& item) {
     std::function<void(SurfaceComposerClient::Transaction*)> prevCallback = nullptr;
     SurfaceComposerClient::Transaction* prevTransaction = nullptr;
+    bool waitForTransactionCallback = !mSyncedFrameNumbers.empty();
+
     {
         BBQ_TRACE();
         std::unique_lock _lock{mMutex};
@@ -666,7 +672,7 @@
 
         // add to shadow queue
         mNumFrameAvailable++;
-        if (mWaitForTransactionCallback && mNumFrameAvailable >= 2) {
+        if (waitForTransactionCallback && mNumFrameAvailable >= 2) {
             acquireAndReleaseBuffer();
         }
         ATRACE_INT(mQueuedBufferTrace.c_str(),
@@ -683,14 +689,14 @@
             incStrong((void*)transactionCommittedCallbackThunk);
             mSyncTransaction->addTransactionCommittedCallback(transactionCommittedCallbackThunk,
                                                               static_cast<void*>(this));
-            mWaitForTransactionCallback = true;
+            mSyncedFrameNumbers.emplace(item.mFrameNumber);
             if (mAcquireSingleBuffer) {
                 prevCallback = mTransactionReadyCallback;
                 prevTransaction = mSyncTransaction;
                 mTransactionReadyCallback = nullptr;
                 mSyncTransaction = nullptr;
             }
-        } else if (!mWaitForTransactionCallback) {
+        } else if (!waitForTransactionCallback) {
             acquireNextBufferLocked(std::nullopt);
         }
     }
@@ -1097,9 +1103,9 @@
     }
 
     // Clear sync states
-    if (mWaitForTransactionCallback) {
-        BQA_LOGD("mWaitForTransactionCallback cleared");
-        mWaitForTransactionCallback = false;
+    if (!mSyncedFrameNumbers.empty()) {
+        BQA_LOGD("mSyncedFrameNumbers cleared");
+        mSyncedFrameNumbers.clear();
     }
 
     if (mSyncTransaction != nullptr) {
diff --git a/libs/gui/include/gui/BLASTBufferQueue.h b/libs/gui/include/gui/BLASTBufferQueue.h
index 9328a54..9d28791 100644
--- a/libs/gui/include/gui/BLASTBufferQueue.h
+++ b/libs/gui/include/gui/BLASTBufferQueue.h
@@ -251,7 +251,6 @@
     std::queue<sp<SurfaceControl>> mSurfaceControlsWithPendingCallback GUARDED_BY(mMutex);
 
     uint32_t mCurrentMaxAcquiredBufferCount;
-    bool mWaitForTransactionCallback GUARDED_BY(mMutex) = false;
 
     // Flag to determine if syncTransaction should only acquire a single buffer and then clear or
     // continue to acquire buffers until explicitly cleared
@@ -279,6 +278,8 @@
     uint64_t mLastAppliedFrameNumber = 0;
 
     std::function<void(bool)> mTransactionHangCallback;
+
+    std::unordered_set<uint64_t> mSyncedFrameNumbers GUARDED_BY(mMutex);
 };
 
 } // namespace android
diff --git a/libs/gui/tests/BLASTBufferQueue_test.cpp b/libs/gui/tests/BLASTBufferQueue_test.cpp
index cb7e94c..b993289 100644
--- a/libs/gui/tests/BLASTBufferQueue_test.cpp
+++ b/libs/gui/tests/BLASTBufferQueue_test.cpp
@@ -161,6 +161,10 @@
         ASSERT_EQ(numFramesSubmitted, mBlastBufferQueueAdapter->mSubmitted.size());
     }
 
+    void mergeWithNextTransaction(Transaction* merge, uint64_t frameNumber) {
+        mBlastBufferQueueAdapter->mergeWithNextTransaction(merge, frameNumber);
+    }
+
 private:
     sp<TestBLASTBufferQueue> mBlastBufferQueueAdapter;
 };
@@ -1111,6 +1115,39 @@
     ASSERT_TRUE(receivedCallback);
 }
 
+TEST_F(BLASTBufferQueueTest, SyncNextTransactionDropBuffer) {
+    uint8_t r = 255;
+    uint8_t g = 0;
+    uint8_t b = 0;
+
+    BLASTBufferQueueHelper adapter(mSurfaceControl, mDisplayWidth, mDisplayHeight);
+
+    sp<IGraphicBufferProducer> igbProducer;
+    setUpProducer(adapter, igbProducer);
+
+    Transaction sync;
+    adapter.setSyncTransaction(sync);
+    queueBuffer(igbProducer, 0, 255, 0, 0);
+
+    // Merge a transaction that has a complete callback into the next frame so we can get notified
+    // when to take a screenshot
+    CallbackHelper transactionCallback;
+    Transaction t;
+    t.addTransactionCompletedCallback(transactionCallback.function,
+                                      transactionCallback.getContext());
+    adapter.mergeWithNextTransaction(&t, 2);
+    queueBuffer(igbProducer, r, g, b, 0);
+
+    // Drop the buffer, but ensure the next one continues to get processed.
+    sync.setBuffer(mSurfaceControl, nullptr);
+
+    CallbackData callbackData;
+    transactionCallback.getCallbackData(&callbackData);
+    ASSERT_EQ(NO_ERROR, captureDisplay(mCaptureArgs, mCaptureResults));
+    ASSERT_NO_FATAL_FAILURE(
+            checkScreenCapture(r, g, b, {0, 0, (int32_t)mDisplayWidth, (int32_t)mDisplayHeight}));
+}
+
 // This test will currently fail because the old surfacecontrol will steal the last presented buffer
 // until the old surface control is destroyed. This is not necessarily a bug but to document a
 // limitation with the update API and to test any changes to make the api more robust. The current