commit bb448ce9aa521f9574d94c9ec2d57eb7d37382cb
author Dominik Laskowski <domlaskowski@google.com> Sat May 07 15:52:55 2022 -0700
committer Dominik Laskowski <domlaskowski@google.com> Mon May 16 08:13:25 2022 -0700
tree ce3b4e8cc398b8b38543908f423370450731c99a
parent 0f24a7c37b3e65996c9bb88c3e22038ae2ca58ef

SF: Do not duplicate fences per layer per frame

Convert the unique_fd of RenderEngineResult (and futures thereof) into
sp<Fence> such that postFramebuffer does not duplicate release/present
fences.

Remove a few copies of shared futures/pointers with std::move.

Bug: 232436803
Test: simpleperf (-33% cycles in sys_dup)
Change-Id: Ia7c6c8333a712441f3612fb5c720ea2932799636

services/surfaceflinger/RegionSamplingThread.cpp

diff --git a/services/surfaceflinger/RegionSamplingThread.cpp b/services/surfaceflinger/RegionSamplingThread.cpp
index e29e6ab..2487dbd 100644
--- a/services/surfaceflinger/RegionSamplingThread.cpp
+++ b/services/surfaceflinger/RegionSamplingThread.cpp
@@ -355,12 +355,15 @@
                                                              WRITEABLE);
     }
 
-    auto captureScreenResultFuture =
-            mFlinger.captureScreenCommon(std::move(renderAreaFuture), traverseLayers, buffer,
-                                         true /* regionSampling */, false /* grayscale */, nullptr);
-    auto& captureScreenResult = captureScreenResultFuture.get();
-    if (captureScreenResult.drawFence.ok()) {
-        sync_wait(captureScreenResult.drawFence.get(), -1);
+    constexpr bool kRegionSampling = true;
+    constexpr bool kGrayscale = false;
+
+    if (const auto fenceResult =
+                mFlinger.captureScreenCommon(std::move(renderAreaFuture), traverseLayers, buffer,
+                                             kRegionSampling, kGrayscale, nullptr)
+                        .get();
+        fenceResult.ok()) {
+        fenceResult.value()->waitForever(LOG_TAG);
     }
 
     std::vector<Descriptor> activeDescriptors;