BlastBufferQueue: Pass client dequeue times to SurfaceFlinger

SF keeps track of client dequeue, queue, acquire etc. timestamps to
construct frame rendering timelines for developers. With BBQ, SF no
longer has access to this data, so pass the dequeue time along with
the buffers.

Ideally this data should flow to the perfetto trace directly from the client
but this is a temp solution while some perf issues with client logging
is sorted out.

Bug: 176931912
Test: manual tests
Change-Id: Ic88170c1fb20850662cb99325ac42b7232a02817

1 files changed, 20 insertions, 0 deletions

diff --git a/libs/gui/BLASTBufferQueue.cpp b/libs/gui/BLASTBufferQueue.cpp
index eaa47f9680..f4b5a26033 100644
--- a/libs/gui/BLASTBufferQueue.cpp
+++ b/libs/gui/BLASTBufferQueue.cpp
@@ -354,6 +354,16 @@ void BLASTBufferQueue::processNextBufferLocked(bool useNextTransaction) {
         t->setAutoRefresh(mSurfaceControl, bufferItem.mAutoRefresh);
         mAutoRefresh = bufferItem.mAutoRefresh;
     }
+    {
+        std::unique_lock _lock{mTimestampMutex};
+        auto dequeueTime = mDequeueTimestamps.find(buffer->getId());
+        if (dequeueTime != mDequeueTimestamps.end()) {
+            Parcel p;
+            p.writeInt64(dequeueTime->second);
+            t->setMetadata(mSurfaceControl, METADATA_DEQUEUE_TIME, p);
+            mDequeueTimestamps.erase(dequeueTime);
+        }
+    }
 
     auto mergeTransaction =
             [&t, currentFrameNumber = bufferItem.mFrameNumber](
@@ -412,6 +422,16 @@ void BLASTBufferQueue::onFrameReplaced(const BufferItem& item) {
     // Do nothing since we are not storing unacquired buffer items locally.
 }
 
+void BLASTBufferQueue::onFrameDequeued(const uint64_t bufferId) {
+    std::unique_lock _lock{mTimestampMutex};
+    mDequeueTimestamps[bufferId] = systemTime();
+};
+
+void BLASTBufferQueue::onFrameCancelled(const uint64_t bufferId) {
+    std::unique_lock _lock{mTimestampMutex};
+    mDequeueTimestamps.erase(bufferId);
+};
+
 void BLASTBufferQueue::setNextTransaction(SurfaceComposerClient::Transaction* t) {
     std::lock_guard _lock{mMutex};
     mNextTransaction = t;