Introduce release buffer callback for BufferStateLayer
Currently BLAST clients use the TransactionCompleted callbacks to
determine when to release buffers. The TransactionCompleted callback
is overloaded. For transactions without buffers, the callback is
called when the transaction is applied on the server. If the
Transaction contains one or more buffers, the callback is called when
all the buffers are latched and ready to be presented. If we have
multiple buffers on multiple transactions, where one or more buffers
maybe dropped, the pending callbacks are called together. This may
delay signaling the client when a buffer can be released.
To fix this, we introduce a new buffer release callback that is
called as soon as a buffer is dropped by the server or when a new
buffer has been latched and the buffer will no longer be presented.
This new callback provides a graphic bufferid to identify the buffer
that can be released and a release fence to wait on.
BlastBufferQueue has been switched to use this new callback. Other
BLAST users continue to use the existing callback.
Test: go/wm-smoke
Test: atest ReleaseBufferCallbackTest
Bug: 178385281
Change-Id: Idd88e4994e543443198a5a8cfa0e3f5f67d5d482
diff --git a/services/surfaceflinger/BufferStateLayer.cpp b/services/surfaceflinger/BufferStateLayer.cpp
index 96a0c3c..89dfb6f 100644
--- a/services/surfaceflinger/BufferStateLayer.cpp
+++ b/services/surfaceflinger/BufferStateLayer.cpp
@@ -41,6 +41,16 @@
namespace android {
using PresentState = frametimeline::SurfaceFrame::PresentState;
+namespace {
+void callReleaseBufferCallback(const sp<ITransactionCompletedListener>& listener,
+ const sp<GraphicBuffer>& buffer, const sp<Fence>& releaseFence) {
+ if (!listener) {
+ return;
+ }
+ listener->onReleaseBuffer(buffer->getId(), releaseFence ? releaseFence : Fence::NO_FENCE);
+}
+} // namespace
+
// clang-format off
const std::array<float, 16> BufferStateLayer::IDENTITY_MATRIX{
1, 0, 0, 0,
@@ -65,7 +75,10 @@
// RenderEngine may have been using the buffer as an external texture
// after the client uncached the buffer.
auto& engine(mFlinger->getRenderEngine());
- engine.unbindExternalTextureBuffer(mBufferInfo.mBuffer->getId());
+ const uint64_t bufferId = mBufferInfo.mBuffer->getId();
+ engine.unbindExternalTextureBuffer(bufferId);
+ callReleaseBufferCallback(mDrawingState.releaseBufferListener, mBufferInfo.mBuffer,
+ mBufferInfo.mFence);
}
}
@@ -74,6 +87,7 @@
if (ch == nullptr) {
return OK;
}
+ ch->previousBufferId = mPreviousBufferId;
if (!ch->previousReleaseFence.get()) {
ch->previousReleaseFence = fence;
return OK;
@@ -190,6 +204,19 @@
handle->dequeueReadyTime = dequeueReadyTime;
}
+ // If there are multiple transactions in this frame, set the previous id on the earliest
+ // transacton. We don't need to pass in the released buffer id to multiple transactions.
+ // The buffer id does not have to correspond to any particular transaction as long as the
+ // listening end point is the same but the client expects the first transaction callback that
+ // replaces the presented buffer to contain the release fence. This follows the same logic.
+ // see BufferStateLayer::onLayerDisplayed.
+ for (auto& handle : mDrawingState.callbackHandles) {
+ if (handle->releasePreviousBuffer) {
+ handle->previousBufferId = mPreviousBufferId;
+ break;
+ }
+ }
+
std::vector<JankData> jankData;
jankData.reserve(mPendingJankClassifications.size());
while (!mPendingJankClassifications.empty()
@@ -344,8 +371,8 @@
bool BufferStateLayer::setBuffer(const sp<GraphicBuffer>& buffer, const sp<Fence>& acquireFence,
nsecs_t postTime, nsecs_t desiredPresentTime, bool isAutoTimestamp,
const client_cache_t& clientCacheId, uint64_t frameNumber,
- std::optional<nsecs_t> dequeueTime,
- const FrameTimelineInfo& info) {
+ std::optional<nsecs_t> dequeueTime, const FrameTimelineInfo& info,
+ const sp<ITransactionCompletedListener>& releaseBufferListener) {
ATRACE_CALL();
if (mCurrentState.buffer) {
@@ -353,7 +380,10 @@
if (mCurrentState.buffer != mDrawingState.buffer) {
// If mCurrentState has a buffer, and we are about to update again
// before swapping to drawing state, then the first buffer will be
- // dropped and we should decrement the pending buffer count.
+ // dropped and we should decrement the pending buffer count and
+ // call any release buffer callbacks if set.
+ callReleaseBufferCallback(mCurrentState.releaseBufferListener, mCurrentState.buffer,
+ mCurrentState.acquireFence);
decrementPendingBufferCount();
if (mCurrentState.bufferSurfaceFrameTX != nullptr) {
addSurfaceFrameDroppedForBuffer(mCurrentState.bufferSurfaceFrameTX);
@@ -361,9 +391,8 @@
}
}
}
-
mCurrentState.frameNumber = frameNumber;
-
+ mCurrentState.releaseBufferListener = releaseBufferListener;
mCurrentState.buffer = buffer;
mCurrentState.clientCacheId = clientCacheId;
mCurrentState.modified = true;
@@ -889,15 +918,16 @@
ATRACE_INT(mBlastTransactionName.c_str(), pendingBuffers);
}
-uint32_t BufferStateLayer::doTransaction(uint32_t flags) {
- if (mDrawingState.buffer != nullptr && mDrawingState.buffer != mBufferInfo.mBuffer) {
+void BufferStateLayer::bufferMayChange(sp<GraphicBuffer>& newBuffer) {
+ if (mDrawingState.buffer != nullptr && mDrawingState.buffer != mBufferInfo.mBuffer &&
+ newBuffer != mDrawingState.buffer) {
// If we are about to update mDrawingState.buffer but it has not yet latched
- // then we will drop a buffer and should decrement the pending buffer count.
- // This logic may not work perfectly in the face of a BufferStateLayer being the
- // deferred side of a deferred transaction, but we don't expect this use case.
+ // then we will drop a buffer and should decrement the pending buffer count and
+ // call any release buffer callbacks if set.
+ callReleaseBufferCallback(mDrawingState.releaseBufferListener, mDrawingState.buffer,
+ mDrawingState.acquireFence);
decrementPendingBufferCount();
}
- return Layer::doTransaction(flags);
}
} // namespace android