commit 9689e2f6cefc158a493ff58ccacda0333f823939
author Yiwei Zhang <zzyiwei@google.com> Fri May 11 12:33:23 2018 -0700
committer Yiwei Zhang <zzyiwei@google.com> Tue Oct 23 10:28:29 2018 -0700
tree 415ada0799f551ad5e2811f7aa498a936cd42a76
parent ce6ebc04e9d2d684f4783c1c1a8a7f29ac4f036c

SF TimeStats: optimize mTimeStatsTracker to use layerID as hash key

The current mTimeStatsTracker map is using layer name as the hash key,
which is not as fast and reliable as the unique layer sequence id.

Test: dumpsys SurfaceFlinger --timestats <see go/sf-timestats for args>
Bug: b/79872109
Change-Id: I409414909e7dd7ee11b37a35a441c070cfce3fa6

services/surfaceflinger/BufferLayer.cpp

diff --git a/services/surfaceflinger/BufferLayer.cpp b/services/surfaceflinger/BufferLayer.cpp
index a0a07ec..397540a 100644
--- a/services/surfaceflinger/BufferLayer.cpp
+++ b/services/surfaceflinger/BufferLayer.cpp
@@ -71,7 +71,7 @@
         destroyAllHwcLayers();
     }
 
-    mTimeStats.onDestroy(getName().c_str());
+    mTimeStats.onDestroy(getSequence());
 }
 
 void BufferLayer::useSurfaceDamage() {
@@ -293,8 +293,8 @@
     nsecs_t desiredPresentTime = getDesiredPresentTime();
     mFrameTracker.setDesiredPresentTime(desiredPresentTime);
 
-    const std::string layerName(getName().c_str());
-    mTimeStats.setDesiredTime(layerName, mCurrentFrameNumber, desiredPresentTime);
+    const int32_t layerID = getSequence();
+    mTimeStats.setDesiredTime(layerID, mCurrentFrameNumber, desiredPresentTime);
 
     std::shared_ptr<FenceTime> frameReadyFence = getCurrentFenceTime();
     if (frameReadyFence->isValid()) {
@@ -306,14 +306,14 @@
     }
 
     if (presentFence->isValid()) {
-        mTimeStats.setPresentFence(layerName, mCurrentFrameNumber, presentFence);
+        mTimeStats.setPresentFence(layerID, mCurrentFrameNumber, presentFence);
         mFrameTracker.setActualPresentFence(std::shared_ptr<FenceTime>(presentFence));
     } else if (mFlinger->getHwComposer().isConnected(HWC_DISPLAY_PRIMARY)) {
         // The HWC doesn't support present fences, so use the refresh
         // timestamp instead.
         const nsecs_t actualPresentTime =
                 mFlinger->getHwComposer().getRefreshTimestamp(HWC_DISPLAY_PRIMARY);
-        mTimeStats.setPresentTime(layerName, mCurrentFrameNumber, actualPresentTime);
+        mTimeStats.setPresentTime(layerID, mCurrentFrameNumber, actualPresentTime);
         mFrameTracker.setActualPresentTime(actualPresentTime);
     }