SF: Only latch buffers after fence signals am: 1ce6581ac7 (0fdb0158) · Commits · e / os / android_frameworks_native

services/surfaceflinger/Layer.cpp

+28 −1

Original line number	Diff line number	Diff line
		@@ -1098,6 +1098,25 @@ uint64_t Layer::getHeadFrameNumber() const {
		}
		}

		bool Layer::headFenceHasSignaled() const {
		#ifdef USE_HWC2
		Mutex::Autolock lock(mQueueItemLock);
		if (mQueueItems.empty()) {
		return true;
		}
		if (mQueueItems[0].mIsDroppable) {
		// Even though this buffer's fence may not have signaled yet, it could
		// be replaced by another buffer before it has a chance to, which means
		// that it's possible to get into a situation where a buffer is never
		// able to be latched. To avoid this, grab this buffer anyway.
		return true;
		}
		return mQueueItems[0].mFence->getSignalTime() != INT64_MAX;
		#else
		return true;
		#endif
		}

		bool Layer::addSyncPoint(const std::shared_ptr<SyncPoint>& point) {
		if (point->getFrameNumber() <= mCurrentFrameNumber) {
		// Don't bother with a SyncPoint, since we've already latched the
		@@ -1355,9 +1374,10 @@ bool Layer::applyPendingStates(State* stateToCommit) {

		void Layer::notifyAvailableFrames() {
		auto headFrameNumber = getHeadFrameNumber();
		bool headFenceSignaled = headFenceHasSignaled();
		Mutex::Autolock lock(mLocalSyncPointMutex);
		for (auto& point : mLocalSyncPoints) {
		if (headFrameNumber >= point->getFrameNumber()) {
		if (headFrameNumber >= point->getFrameNumber() && headFenceSignaled) {
		point->setFrameAvailable();
		}
		}
		@@ -1754,6 +1774,13 @@ Region Layer::latchBuffer(bool& recomputeVisibleRegions)
		return outDirtyRegion;
		}

		// If the head buffer's acquire fence hasn't signaled yet, return and
		// try again later
		if (!headFenceHasSignaled()) {
		mFlinger->signalLayerUpdate();
		return outDirtyRegion;
		}

		// Capture the old state of the layer for comparisons later
		const State& s(getDrawingState());
		const bool oldOpacity = isOpaque(s);

services/surfaceflinger/Layer.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -510,6 +510,7 @@ private:
		std::list<std::shared_ptr<SyncPoint>> mRemoteSyncPoints;

		uint64_t getHeadFrameNumber() const;
		bool headFenceHasSignaled() const;

		// Returns false if the relevant frame has already been latched
		bool addSyncPoint(const std::shared_ptr<SyncPoint>& point);