commit aef1de99600e7a68101227ab901526f2334dfdfb
author Vishnu Nair <vishnun@google.com> Thu Oct 22 12:15:53 2020 -0700
committer Vishnu Nair <vishnun@google.com> Thu Oct 22 12:15:53 2020 -0700
tree 411789de8087bf68da64267ea0c4cc82552f2cf0
parent e0a064b66428c8da8a6fd6bd3693c3577d66772d

BlastBufferQueue: Handle onFrameReplaced

If a buffer is replaced, we should not call onFrameAvailable
which will incorrectly increase the number of buffers BBQ
expects to acquire.

Test: manual tests, atest CtsWindowManagerDeviceTestCases, check that we are not stuck in onFrameAvailable
Change-Id: Ib6fc3b11905fbf24c2528e14b1fb2409d1f43ff6

libs/gui/BLASTBufferQueue.cpp

diff --git a/libs/gui/BLASTBufferQueue.cpp b/libs/gui/BLASTBufferQueue.cpp
index c8e1f3d..0ebf852 100644
--- a/libs/gui/BLASTBufferQueue.cpp
+++ b/libs/gui/BLASTBufferQueue.cpp
@@ -302,13 +302,13 @@
     return item.mCrop;
 }
 
-void BLASTBufferQueue::onFrameAvailable(const BufferItem& /*item*/) {
+void BLASTBufferQueue::onFrameAvailable(const BufferItem& item) {
     ATRACE_CALL();
     std::unique_lock _lock{mMutex};
 
     const bool nextTransactionSet = mNextTransaction != nullptr;
-    BQA_LOGV("onFrameAvailable nextTransactionSet=%s mFlushShadowQueue=%s",
-             toString(nextTransactionSet), toString(mFlushShadowQueue));
+    BQA_LOGV("onFrameAvailable framenumber=%" PRIu64 " nextTransactionSet=%s mFlushShadowQueue=%s",
+             item.mFrameNumber, toString(nextTransactionSet), toString(mFlushShadowQueue));
 
     if (nextTransactionSet || mFlushShadowQueue) {
         while (mNumFrameAvailable > 0 || maxBuffersAcquired()) {
@@ -322,6 +322,11 @@
     processNextBufferLocked(true);
 }
 
+void BLASTBufferQueue::onFrameReplaced(const BufferItem& item) {
+    BQA_LOGV("onFrameReplaced framenumber=%" PRIu64, item.mFrameNumber);
+    // Do nothing since we are not storing unacquired buffer items locally.
+}
+
 void BLASTBufferQueue::setNextTransaction(SurfaceComposerClient::Transaction* t) {
     std::lock_guard _lock{mMutex};
     mNextTransaction = t;

libs/gui/include/gui/BLASTBufferQueue.h

diff --git a/libs/gui/include/gui/BLASTBufferQueue.h b/libs/gui/include/gui/BLASTBufferQueue.h
index 1410b12..51ba6b1 100644
--- a/libs/gui/include/gui/BLASTBufferQueue.h
+++ b/libs/gui/include/gui/BLASTBufferQueue.h
@@ -75,7 +75,7 @@
     sp<Surface> getSurface();
 
     void onBufferFreed(const wp<GraphicBuffer>&/* graphicBuffer*/) override { /* TODO */ }
-    void onFrameReplaced(const BufferItem& item) override {onFrameAvailable(item);}
+    void onFrameReplaced(const BufferItem& item) override;
     void onFrameAvailable(const BufferItem& item) override;
 
     void transactionCallback(nsecs_t latchTime, const sp<Fence>& presentFence,