Remove main thread double hop from screenshots
The SF main thread is accessed twice during screenshots,
which leads to possible inconsistent states between jumps
onto the main thread. Removing the double hop preserves
correctness and reduces the amount of computation taking place
on the main thread. The only time the main thread should be
accessed should be when getting layer snapshots. All other
work related to screenshots can take place in a binder thread.
Bug: b/294936197, b/285553970
Test: atest SurfaceFlinger_test
Flag: com.android.graphics.surfaceflinger.flags.single_hop_screenshot
Change-Id: If9fd36f82c2d550bc0821b52fef3ea88b8099116
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 209d9bc..1230717 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -892,22 +892,35 @@
void attachReleaseFenceFutureToLayer(Layer* layer, LayerFE* layerFE, ui::LayerStack layerStack);
// Checks if a protected layer exists in a list of layers.
- bool layersHasProtectedLayer(const std::vector<std::pair<Layer*, sp<LayerFE>>>& layers) const;
+ bool layersHasProtectedLayer(const std::vector<sp<LayerFE>>& layers) const;
+
+ using OutputCompositionState = compositionengine::impl::OutputCompositionState;
+
+ std::optional<OutputCompositionState> getDisplayAndLayerSnapshotsFromMainThread(
+ RenderAreaBuilderVariant& renderAreaBuilder,
+ GetLayerSnapshotsFunction getLayerSnapshotsFn, std::vector<sp<LayerFE>>& layerFEs);
void captureScreenCommon(RenderAreaBuilderVariant, GetLayerSnapshotsFunction,
ui::Size bufferSize, ui::PixelFormat, bool allowProtected,
bool grayscale, const sp<IScreenCaptureListener>&);
- using OutputCompositionState = compositionengine::impl::OutputCompositionState;
+ std::optional<OutputCompositionState> getDisplayStateFromRenderAreaBuilder(
+ RenderAreaBuilderVariant& renderAreaBuilder) REQUIRES(kMainThreadContext);
- const sp<const DisplayDevice> getRenderAreaDisplay(RenderAreaBuilderVariant& renderAreaBuilder,
- OutputCompositionState& state)
- REQUIRES(kMainThreadContext);
-
- std::vector<std::pair<Layer*, sp<android::LayerFE>>> getLayerSnapshotsFromMainThread(
- GetLayerSnapshotsFunction getLayerSnapshotsFn) REQUIRES(kMainThreadContext);
+ // Legacy layer raw pointer is not safe to access outside the main thread.
+ // Creates a new vector consisting only of LayerFEs, which can be safely
+ // accessed outside the main thread.
+ std::vector<sp<LayerFE>> extractLayerFEs(
+ const std::vector<std::pair<Layer*, sp<LayerFE>>>& layers) const;
ftl::SharedFuture<FenceResult> captureScreenshot(
+ const RenderAreaBuilderVariant& renderAreaBuilder,
+ const std::shared_ptr<renderengine::ExternalTexture>& buffer, bool regionSampling,
+ bool grayscale, bool isProtected, const sp<IScreenCaptureListener>& captureListener,
+ std::optional<OutputCompositionState>& displayState,
+ std::vector<sp<LayerFE>>& layerFEs);
+
+ ftl::SharedFuture<FenceResult> captureScreenshotLegacy(
RenderAreaBuilderVariant, GetLayerSnapshotsFunction,
const std::shared_ptr<renderengine::ExternalTexture>&, bool regionSampling,
bool grayscale, bool isProtected, const sp<IScreenCaptureListener>&);
@@ -916,9 +929,9 @@
std::unique_ptr<const RenderArea>,
const std::shared_ptr<renderengine::ExternalTexture>&, bool regionSampling,
bool grayscale, bool isProtected, ScreenCaptureResults&,
- const sp<const DisplayDevice> display, const OutputCompositionState& state,
- std::vector<std::pair<Layer*, sp<android::LayerFE>>>& layers)
- REQUIRES(kMainThreadContext);
+ std::optional<OutputCompositionState>& displayState,
+ std::vector<std::pair<Layer*, sp<LayerFE>>>& layers,
+ std::vector<sp<LayerFE>>& layerFEs);
// If the uid provided is not UNSET_UID, the traverse will skip any layers that don't have a
// matching ownerUid