commit de66dc7269e7963db68d46be3128ad2544759917
author Vishnu Nair <vishnun@google.com> Thu Jun 17 17:54:41 2021 -0700
committer Vishnu Nair <vishnun@google.com> Fri Jun 18 11:14:24 2021 -0700
tree 3bd2c8ad40bb3a89d965b3f37d6706538302f446
parent 9c187a35a2aba822878d94d80493e067c3685f5f

Don't update BufferQueue FrameEventStats when a frame is dropped

Update BlastBufferQueue to match BQ logic. This change in behaviour
was causing a dEQP test failure which relied on actual present timestamps
to generate future desired present timestamps. If a buffer was dropped,
the actual present timestamp retrieved would be 0 causing cascading failures.

Test: atest BLASTFrameEventHistoryTest
Test: CtsDeqpTestCases:dEQP-VK.wsi.android.display_timing.fifo#display_timing
Bug: 186200443
Change-Id: I9589d6e43c5f6dfbe93702b7c43a8fff8712fe24

libs/gui/BLASTBufferQueue.cpp

diff --git a/libs/gui/BLASTBufferQueue.cpp b/libs/gui/BLASTBufferQueue.cpp
index b9a293f..70d8208 100644
--- a/libs/gui/BLASTBufferQueue.cpp
+++ b/libs/gui/BLASTBufferQueue.cpp
@@ -255,15 +255,18 @@
 
                 mTransformHint = stat.transformHint;
                 mBufferItemConsumer->setTransformHint(mTransformHint);
-                mBufferItemConsumer
-                        ->updateFrameTimestamps(stat.frameEventStats.frameNumber,
-                                                stat.frameEventStats.refreshStartTime,
-                                                stat.frameEventStats.gpuCompositionDoneFence,
-                                                stat.presentFence, stat.previousReleaseFence,
-                                                stat.frameEventStats.compositorTiming,
-                                                stat.latchTime,
-                                                stat.frameEventStats.dequeueReadyTime);
-
+                // Update frametime stamps if the frame was latched and presented, indicated by a
+                // valid latch time.
+                if (stat.latchTime > 0) {
+                    mBufferItemConsumer
+                            ->updateFrameTimestamps(stat.frameEventStats.frameNumber,
+                                                    stat.frameEventStats.refreshStartTime,
+                                                    stat.frameEventStats.gpuCompositionDoneFence,
+                                                    stat.presentFence, stat.previousReleaseFence,
+                                                    stat.frameEventStats.compositorTiming,
+                                                    stat.latchTime,
+                                                    stat.frameEventStats.dequeueReadyTime);
+                }
                 currFrameNumber = stat.frameEventStats.frameNumber;
 
                 if (mTransactionCompleteCallback &&