Reorder release fence attachment for non-threaded RE

Changes when release fences are attached to layers for non-threaded
RenderEngine to ensure that fences are added and fired in the same
hop to the main thread. This removes the dependency on legacy screenshot
code and prevents a deadlock where screenshot requests are blocked on
the main thread while the main thread is blocked on the previous
screenshot request finishing.

Bug: b/351894825
Test: atest SurfaceFlinger_test
Flag: EXEMPT refactor and for flag removal
Change-Id: If9d4134aba1106484f94231c5104a57a605147b8

1 files changed, 5 insertions, 6 deletions

diff --git a/services/surfaceflinger/RegionSamplingThread.cpp b/services/surfaceflinger/RegionSamplingThread.cpp
index 011fd9e20a..08f831c8e5 100644
--- a/services/surfaceflinger/RegionSamplingThread.cpp
+++ b/services/surfaceflinger/RegionSamplingThread.cpp
@@ -354,14 +354,13 @@ void RegionSamplingThread::captureSample() {
                               RenderArea::Options::CAPTURE_SECURE_LAYERS);
 
     FenceResult fenceResult;
-    if (FlagManager::getInstance().single_hop_screenshot() &&
-        mFlinger.mRenderEngine->isThreaded()) {
-        std::vector<sp<LayerFE>> layerFEs;
-        auto displayState = mFlinger.getSnapshotsFromMainThread(renderAreaBuilder,
-                                                                getLayerSnapshotsFn, layerFEs);
+    if (FlagManager::getInstance().single_hop_screenshot()) {
+        std::vector<std::pair<Layer*, sp<LayerFE>>> layers;
+        auto displayState =
+                mFlinger.getSnapshotsFromMainThread(renderAreaBuilder, getLayerSnapshotsFn, layers);
         fenceResult = mFlinger.captureScreenshot(renderAreaBuilder, buffer, kRegionSampling,
                                                  kGrayscale, kIsProtected, kAttachGainmap, nullptr,
-                                                 displayState, layerFEs)
+                                                 displayState, layers)
                               .get();
     } else {
         fenceResult = mFlinger.captureScreenshotLegacy(renderAreaBuilder, getLayerSnapshotsFn,