commit 99599940f68158aeef735d8763980d0dbd397b51
author Ady Abraham <adyabr@google.com> Wed Jan 27 20:27:23 2021 -0800
committer Ady Abraham <adyabr@google.com> Fri Jan 29 18:03:58 2021 +0000
tree b8620b3a33b7d51223a4a22707d1bab2669de793
parent 31999efbac943af5c43c64a6929d5fe5857c6532

SurfaceFlinger: move sync_wait for screen capture to client

Free up time from the SF's main thread by moving the fence waiting
to the client.

Test: Observe systrace of region sample thread
Test: adb shell screencap
Test: Recents takes the screenshot
Test: Rotate device
Test: Volume + power down for screenshot
Bug: 178649983
Change-Id: I0a4991c013375b1f354e0728a06ca30a835b0422

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 4225e92..27df232 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -5851,23 +5851,18 @@
         if (!renderArea) {
             ALOGW("Skipping screen capture because of invalid render area.");
             captureResults.result = NO_MEMORY;
-            captureListener->onScreenCaptureComplete(captureResults);
+            captureListener->onScreenCaptureCompleted(captureResults);
             return;
         }
 
         status_t result = NO_ERROR;
-        int syncFd = -1;
         renderArea->render([&] {
-            result = renderScreenImplLocked(*renderArea, traverseLayers, buffer, forSystem, &syncFd,
+            result = renderScreenImplLocked(*renderArea, traverseLayers, buffer, forSystem,
                                             regionSampling, captureResults);
         });
 
-        if (result == NO_ERROR) {
-            sync_wait(syncFd, -1);
-            close(syncFd);
-        }
         captureResults.result = result;
-        captureListener->onScreenCaptureComplete(captureResults);
+        captureListener->onScreenCaptureCompleted(captureResults);
     }));
 
     return NO_ERROR;
@@ -5876,7 +5871,7 @@
 status_t SurfaceFlinger::renderScreenImplLocked(const RenderArea& renderArea,
                                                 TraverseLayersFunction traverseLayers,
                                                 const sp<GraphicBuffer>& buffer, bool forSystem,
-                                                int* outSyncFd, bool regionSampling,
+                                                bool regionSampling,
                                                 ScreenCaptureResults& captureResults) {
     ATRACE_CALL();
 
@@ -5985,14 +5980,14 @@
     getRenderEngine().drawLayers(clientCompositionDisplay, clientCompositionLayerPointers, buffer,
                                  /*useFramebufferCache=*/false, std::move(bufferFence), &drawFence);
 
-    *outSyncFd = drawFence.release();
-
-    if (*outSyncFd >= 0) {
-        sp<Fence> releaseFence = new Fence(dup(*outSyncFd));
+    if (drawFence >= 0) {
+        sp<Fence> releaseFence = new Fence(dup(drawFence));
         for (auto* layer : renderedLayers) {
             layer->onLayerDisplayed(releaseFence);
         }
     }
+
+    captureResults.fence = new Fence(drawFence.release());
     // Always switch back to unprotected context.
     getRenderEngine().useProtectedContext(false);