commit 6c1b7aca75e3fb0d45789b15007202493de6bc3d
author Ady Abraham <adyabr@google.com> Wed Mar 31 16:56:03 2021 -0700
committer Ady Abraham <adyabr@google.com> Fri Apr 02 22:30:12 2021 +0000
tree 33e2216ceb207348dad96465d653082b487547ec
parent d043c248649e8e9b51c73b6d3c02257882149dcc

SF: use FenceTime when possible

Fence::getSignalTime is calling a system call everytime,
where FenceTime caches the signal time.

This shows reduction in simpleperf for the main thread
2.23% -> 1.25%
Test: simpleperf for PIP + Notification shade expansion
Bug: 184378996

Change-Id: I182db2ddfcb7fdbde758f5d87357a16e60c1bb07

services/surfaceflinger/BufferStateLayer.cpp

diff --git a/services/surfaceflinger/BufferStateLayer.cpp b/services/surfaceflinger/BufferStateLayer.cpp
index a974dc4..d6becbf 100644
--- a/services/surfaceflinger/BufferStateLayer.cpp
+++ b/services/surfaceflinger/BufferStateLayer.cpp
@@ -432,10 +432,12 @@
 }
 
 bool BufferStateLayer::setAcquireFence(const sp<Fence>& fence) {
-    // The acquire fences of BufferStateLayers have already signaled before they are set
-    mCallbackHandleAcquireTime = fence->getSignalTime();
-
     mCurrentState.acquireFence = fence;
+    mCurrentState.acquireFenceTime = std::make_unique<FenceTime>(fence);
+
+    // The acquire fences of BufferStateLayers have already signaled before they are set
+    mCallbackHandleAcquireTime = mCurrentState.acquireFenceTime->getSignalTime();
+
     mCurrentState.modified = true;
     setTransactionFlags(eTransactionNeeded);
     return true;
@@ -691,7 +693,8 @@
         // bufferSurfaceFrame could be seen here if a pending state was applied successfully and we
         // are processing the next state.
         addSurfaceFramePresentedForBuffer(bufferSurfaceFrame,
-                                          mDrawingState.acquireFence->getSignalTime(), latchTime);
+                                          mDrawingState.acquireFenceTime->getSignalTime(),
+                                          latchTime);
     }
 
     mCurrentStateModified = false;