onPostComposition doesnt need to run on layers without queued frames

If we didn't latch a buffer with this frame, we will just return
early from onPostComposition and so we can safe traversal overhead
by just iterating mLayersWithQueuedFrames directly.

Test: Existing tests pass. simpleperf
Bug: 186200583
Change-Id: I8f72100f15d2b381e2480ee4c40f6ba79030e092

1 files changed, 2 insertions, 2 deletions

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index f02f1e2864..123ff2c274 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2246,14 +2246,14 @@ void SurfaceFlinger::postComposition() {
         compositorTiming = getBE().mCompositorTiming;
     }
 
-    mDrawingState.traverse([&](Layer* layer) {
+    for (const auto& layer: mLayersWithQueuedFrames) {
         const bool frameLatched =
                 layer->onPostComposition(display, glCompositionDoneFenceTime,
                                          mPreviousPresentFences[0].fenceTime, compositorTiming);
         if (frameLatched) {
             recordBufferingStats(layer->getName(), layer->getOccupancyHistory(false));
         }
-    });
+    }
 
     std::vector<std::pair<std::shared_ptr<compositionengine::Display>, sp<HdrLayerInfoReporter>>>
             hdrInfoListeners;