Merge "Reduce heap allocations in BLASTBufferQueue." into main (8ce652f7) · Commits · e / os / android_frameworks_native

include/ftl/small_map.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -234,6 +234,12 @@ class SmallMap final {
		//
		bool erase(const key_type& key) { return erase(key, begin()); }

		// Removes a mapping.
		//
		// The last() and end() iterators, as well as those to the erased mapping, are invalidated.
		//
		void erase(iterator it) { map_.unstable_erase(it); }

		// Removes all mappings.
		//
		// All iterators are invalidated.

libs/gui/BLASTBufferQueue.cpp

+7 −9

Original line number	Diff line number	Diff line
		@@ -415,14 +415,12 @@ void BLASTBufferQueue::transactionCallback(nsecs_t /latchTime/, const sp<Fence
		stat.frameEventStats.dequeueReadyTime);
		}
		auto currFrameNumber = stat.frameEventStats.frameNumber;
		std::vector<ReleaseCallbackId> staleReleases;
		for (const auto& [key, value]: mSubmitted) {
		if (currFrameNumber > key.framenumber) {
		staleReleases.push_back(key);
		// Release stale buffers.
		for (const auto& [key, _] : mSubmitted) {
		if (currFrameNumber <= key.framenumber) {
		continue; // not stale.
		}
		}
		for (const auto& staleRelease : staleReleases) {
		releaseBufferCallbackLocked(staleRelease,
		releaseBufferCallbackLocked(key,
		stat.previousReleaseFence
		? stat.previousReleaseFence
		: Fence::NO_FENCE,
		@@ -618,7 +616,7 @@ status_t BLASTBufferQueue::acquireNextBufferLocked(
		mNumAcquired++;
		mLastAcquiredFrameNumber = bufferItem.mFrameNumber;
		ReleaseCallbackId releaseCallbackId(buffer->getId(), mLastAcquiredFrameNumber);
		mSubmitted[releaseCallbackId] = bufferItem;
		mSubmitted.emplace_or_replace(releaseCallbackId, bufferItem);

		bool needsDisconnect = false;
		mBufferItemConsumer->getConnectionEvents(bufferItem.mFrameNumber, &needsDisconnect);
		@@ -851,7 +849,7 @@ void BLASTBufferQueue::onFrameReplaced(const BufferItem& item) {

		void BLASTBufferQueue::onFrameDequeued(const uint64_t bufferId) {
		std::lock_guard _lock{mTimestampMutex};
		mDequeueTimestamps[bufferId] = systemTime();
		mDequeueTimestamps.emplace_or_replace(bufferId, systemTime());
		};

		void BLASTBufferQueue::onFrameCancelled(const uint64_t bufferId) {

libs/gui/include/gui/BLASTBufferQueue.h

+8 −3

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@
		#include <optional>
		#include <queue>

		#include <ftl/small_map.h>
		#include <gui/BufferItem.h>
		#include <gui/BufferItemConsumer.h>
		#include <gui/IGraphicBufferConsumer.h>
		@@ -36,6 +37,10 @@

		namespace android {

		// Sizes determined empirically to avoid allocations during common activity.
		constexpr size_t kSubmittedBuffersMapSizeHint = 8;
		constexpr size_t kDequeueTimestampsMapSizeHint = 32;

		class BLASTBufferQueue;
		class BufferItemConsumer;

		@@ -206,7 +211,7 @@ private:

		// Keep a reference to the submitted buffers so we can release when surfaceflinger drops the
		// buffer or the buffer has been presented and a new buffer is ready to be presented.
		std::unordered_map<ReleaseCallbackId, BufferItem, ReleaseBufferCallbackIdHash> mSubmitted
		ftl::SmallMap<ReleaseCallbackId, BufferItem, kSubmittedBuffersMapSizeHint> mSubmitted
		GUARDED_BY(mMutex);

		// Keep a queue of the released buffers instead of immediately releasing
		@@ -291,8 +296,8 @@ private:
		std::mutex mTimestampMutex;
		// Tracks buffer dequeue times by the client. This info is sent to SurfaceFlinger which uses
		// it for debugging purposes.
		std::unordered_map<uint64_t /* bufferId */, nsecs_t> mDequeueTimestamps
		GUARDED_BY(mTimestampMutex);
		ftl::SmallMap<uint64_t /* bufferId */, nsecs_t, kDequeueTimestampsMapSizeHint>
		mDequeueTimestamps GUARDED_BY(mTimestampMutex);

		// Keep track of SurfaceControls that have submitted a transaction and BBQ is waiting on a
		// callback for them.