commit be0f948bd3b780e1a70e57eb01113ec897f99264
author Ady Abraham <adyabr@google.com> Wed Apr 24 15:41:53 2019 -0700
committer Ady Abraham <adyabr@google.com> Mon Apr 29 18:01:19 2019 -0700
tree 7670d86fdea1997faae5a87921e7b241cca65b9e
parent dde87c4a326d0480aef0420f04c160b9d5d5096e

SurfaceFlinger: support negative phase offset

Store the last 2 present frames to accommodate negative phase offsets.

Test: systrace
Bug: 130191039
Change-Id: Ie4460d4a1b14a2a12f5d2f3c1542e0b837cb761c

services/surfaceflinger/SurfaceFlinger.h

diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 72e2ff9..fc89f53 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -824,6 +824,8 @@
         return hwcDisplayId ? getHwComposer().toPhysicalDisplayId(*hwcDisplayId) : std::nullopt;
     }
 
+    bool previousFrameMissed();
+
     /*
      * Debugging & dumpsys
      */
@@ -956,7 +958,7 @@
     std::vector<sp<Layer>> mLayersWithQueuedFrames;
     // Tracks layers that need to update a display's dirty region.
     std::vector<sp<Layer>> mLayersPendingRefresh;
-    sp<Fence> mPreviousPresentFence = Fence::NO_FENCE;
+    std::array<sp<Fence>, 2> mPreviousPresentFences = {Fence::NO_FENCE, Fence::NO_FENCE};
     // True if in the previous frame at least one layer was composed via the GPU.
     bool mHadClientComposition = false;
     // True if in the previous frame at least one layer was composed via HW Composer.