commit e524dd9d136049bbca78c2e148b5556ad3c128eb
author Melody Hsu <melodymhsu@google.com> Tue Aug 27 22:27:29 2024 +0000
committer Melody Hsu <melodymhsu@google.com> Tue Nov 12 04:57:24 2024 +0000
tree 8c15c6e2e9c559ba4cd297c14d803e770f85303a
parent 027013d8a68d0e754ef8c17dde5abf744505f5e2

Recover from buffer stuffing for canned animations

Buffer stuffing occurs when SurfaceFlinger misses a frame, but the
client continues to produce buffers at the same rate, causing a
greater risk for jank to occur. Recovery is achieved for canned
animations by adjusting the animation timeline on the client side so
that SurfaceFlinger is no longer behind.

Use SF backdoor command 1045 to inject jank.
Usage: adb shell service call SurfaceFlinger 1045 f 1

Bug: b/294922229
Test: atest EventThreadTest
Test: presubmit, manually check perfetto traces
Flag: android.view.flags.buffer_stuffing_recovery
Change-Id: I38f0eb3d6ef1331e07d6022fa3a0e16c556ba06f

libs/gui/tests/DisplayEventStructLayout_test.cpp

diff --git a/libs/gui/tests/DisplayEventStructLayout_test.cpp b/libs/gui/tests/DisplayEventStructLayout_test.cpp
index 29eeaa8..791f471 100644
--- a/libs/gui/tests/DisplayEventStructLayout_test.cpp
+++ b/libs/gui/tests/DisplayEventStructLayout_test.cpp
@@ -36,15 +36,16 @@
     CHECK_OFFSET(DisplayEventReceiver::Event::VSync, vsyncData.frameInterval, 8);
     CHECK_OFFSET(DisplayEventReceiver::Event::VSync, vsyncData.preferredFrameTimelineIndex, 16);
     CHECK_OFFSET(DisplayEventReceiver::Event::VSync, vsyncData.frameTimelinesLength, 20);
-    CHECK_OFFSET(DisplayEventReceiver::Event::VSync, vsyncData.frameTimelines, 24);
-    CHECK_OFFSET(DisplayEventReceiver::Event::VSync, vsyncData.frameTimelines[0].vsyncId, 24);
+    CHECK_OFFSET(DisplayEventReceiver::Event::VSync, vsyncData.numberQueuedBuffers, 24);
+    CHECK_OFFSET(DisplayEventReceiver::Event::VSync, vsyncData.frameTimelines, 32);
+    CHECK_OFFSET(DisplayEventReceiver::Event::VSync, vsyncData.frameTimelines[0].vsyncId, 32);
     CHECK_OFFSET(DisplayEventReceiver::Event::VSync, vsyncData.frameTimelines[0].deadlineTimestamp,
-                 32);
+                 40);
     CHECK_OFFSET(DisplayEventReceiver::Event::VSync,
-                 vsyncData.frameTimelines[0].expectedPresentationTime, 40);
+                 vsyncData.frameTimelines[0].expectedPresentationTime, 48);
     // Also test the offsets of the last frame timeline. A loop is not used because the non-const
     // index cannot be used in static_assert.
-    const int lastFrameTimelineOffset = /* Start of array */ 24 +
+    const int lastFrameTimelineOffset = /* Start of array */ 32 +
             (VsyncEventData::kFrameTimelinesCapacity - 1) * /* Size of FrameTimeline */ 24;
     CHECK_OFFSET(DisplayEventReceiver::Event::VSync,
                  vsyncData.frameTimelines[VsyncEventData::kFrameTimelinesCapacity - 1].vsyncId,