Merge "Fix deadlock of main thread and Perfetto thread (LayerDataSource::OnStart)" into main (5dbd89c9) · Commits · e / os / android_frameworks_native

services/surfaceflinger/SurfaceFlinger.cpp

+14 −10

Original line number	Diff line number	Diff line
		@@ -946,15 +946,19 @@ void SurfaceFlinger::init() FTL_FAKE_GUARD(kMainThreadContext) {
		}));
		}));

		mLayerTracing.setTakeLayersSnapshotProtoFunction([&](uint32_t traceFlags) {
		auto snapshot = perfetto::protos::LayersSnapshotProto{};
		mScheduler
		->schedule([&]() FTL_FAKE_GUARD(mStateLock) FTL_FAKE_GUARD(kMainThreadContext) {
		snapshot = takeLayersSnapshotProto(traceFlags, TimePoint::now(),
		mLayerTracing.setTakeLayersSnapshotProtoFunction(
		[&](uint32_t traceFlags,
		const LayerTracing::OnLayersSnapshotCallback& onLayersSnapshot) {
		// Do not wait the future to avoid deadlocks
		// between main and Perfetto threads (b/313130597)
		static_cast<void>(mScheduler->schedule(
		[&, onLayersSnapshot]() FTL_FAKE_GUARD(mStateLock)
		FTL_FAKE_GUARD(kMainThreadContext) {
		auto snapshot =
		takeLayersSnapshotProto(traceFlags, TimePoint::now(),
		mLastCommittedVsyncId, true);
		})
		.wait();
		return snapshot;
		onLayersSnapshot(std::move(snapshot));
		}));
		});

		// Commit secondary display(s).

services/surfaceflinger/Tracing/LayerDataSource.cpp

+5 −2

Original line number	Diff line number	Diff line
		@@ -82,10 +82,13 @@ void LayerDataSource::OnFlush(const LayerDataSource::FlushArgs& args) {
		}
		}

		void LayerDataSource::OnStop(const LayerDataSource::StopArgs&) {
		void LayerDataSource::OnStop(const LayerDataSource::StopArgs& args) {
		ALOGD("Received OnStop event (mode = 0x%02x, flags = 0x%02x)", mMode, mFlags);
		if (auto* p = mLayerTracing.load()) {
		p->onStop(mMode);
		// In dump mode we need to defer the stop (through HandleStopAsynchronously()) till
		// the layers snapshot has been captured and written to perfetto. We must avoid writing
		// to perfetto within the OnStop callback to prevent deadlocks (b/313130597).
		p->onStop(mMode, mFlags, args.HandleStopAsynchronously());
		}
		}

services/surfaceflinger/Tracing/LayerTracing.cpp

+28 −10

Original line number	Diff line number	Diff line
		@@ -32,7 +32,7 @@
		namespace android {

		LayerTracing::LayerTracing() {
		mTakeLayersSnapshotProto = [](uint32_t) { return perfetto::protos::LayersSnapshotProto{}; };
		mTakeLayersSnapshotProto = [](uint32_t, const OnLayersSnapshotCallback&) {};
		LayerDataSource::Initialize(*this);
		}

		@@ -45,7 +45,7 @@ LayerTracing::~LayerTracing() {
		}

		void LayerTracing::setTakeLayersSnapshotProtoFunction(
		const std::function<perfetto::protos::LayersSnapshotProto(uint32_t)>& callback) {
		const std::function<void(uint32_t, const OnLayersSnapshotCallback&)>& callback) {
		mTakeLayersSnapshotProto = callback;
		}

		@@ -62,7 +62,10 @@ void LayerTracing::onStart(Mode mode, uint32_t flags) {
		// It might take a while before a layers change occurs and a "spontaneous" snapshot is
		// taken. Let's manually take a snapshot, so that the trace's first entry will contain
		// the current layers state.
		addProtoSnapshotToOstream(mTakeLayersSnapshotProto(flags), Mode::MODE_ACTIVE);
		auto onLayersSnapshot = [this](perfetto::protos::LayersSnapshotProto&& snapshot) {
		addProtoSnapshotToOstream(std::move(snapshot), Mode::MODE_ACTIVE);
		};
		mTakeLayersSnapshotProto(flags, onLayersSnapshot);
		ALOGD("Started active tracing (traced initial snapshot)");
		break;
		}
		@@ -89,9 +92,7 @@ void LayerTracing::onStart(Mode mode, uint32_t flags) {
		break;
		}
		case Mode::MODE_DUMP: {
		auto snapshot = mTakeLayersSnapshotProto(flags);
		addProtoSnapshotToOstream(std::move(snapshot), Mode::MODE_DUMP);
		ALOGD("Started dump tracing (dumped single snapshot)");
		ALOGD("Started dump tracing");
		break;
		}
		default: {
		@@ -125,10 +126,27 @@ void LayerTracing::onFlush(Mode mode, uint32_t flags, bool isBugreport) {
		ALOGD("Flushed generated tracing");
		}

		void LayerTracing::onStop(Mode mode) {
		if (mode == Mode::MODE_ACTIVE) {
		void LayerTracing::onStop(Mode mode, uint32_t flags, std::function<void()>&& deferredStopDone) {
		switch (mode) {
		case Mode::MODE_ACTIVE: {
		mIsActiveTracingStarted.store(false);
		deferredStopDone();
		ALOGD("Stopped active tracing");
		break;
		}
		case Mode::MODE_DUMP: {
		auto onLayersSnapshot = [this, deferredStopDone = std::move(deferredStopDone)](
		perfetto::protos::LayersSnapshotProto&& snapshot) {
		addProtoSnapshotToOstream(std::move(snapshot), Mode::MODE_DUMP);
		deferredStopDone();
		ALOGD("Stopped dump tracing (written single snapshot)");
		};
		mTakeLayersSnapshotProto(flags, onLayersSnapshot);
		break;
		}
		default: {
		deferredStopDone();
		}
		}
		}

services/surfaceflinger/Tracing/LayerTracing.h

+4 −3

Original line number	Diff line number	Diff line
		@@ -87,6 +87,7 @@ EOF
		class LayerTracing {
		public:
		using Mode = perfetto::protos::pbzero::SurfaceFlingerLayersConfig::Mode;
		using OnLayersSnapshotCallback = std::function<void(perfetto::protos::LayersSnapshotProto&&)>;

		enum Flag : uint32_t {
		TRACE_INPUT = 1 << 1,
		@@ -102,7 +103,7 @@ public:
		LayerTracing(std::ostream&);
		~LayerTracing();
		void setTakeLayersSnapshotProtoFunction(
		const std::function<perfetto::protos::LayersSnapshotProto(uint32_t)>&);
		const std::function<void(uint32_t, const OnLayersSnapshotCallback&)>&);
		void setTransactionTracing(TransactionTracing&);

		// Start event from perfetto data source
		@@ -110,7 +111,7 @@ public:
		// Flush event from perfetto data source
		void onFlush(Mode mode, uint32_t flags, bool isBugreport);
		// Stop event from perfetto data source
		void onStop(Mode mode);
		void onStop(Mode mode, uint32_t flags, std::function<void()>&& deferredStopDone);

		void addProtoSnapshotToOstream(perfetto::protos::LayersSnapshotProto&& snapshot, Mode mode);
		bool isActiveTracingStarted() const;
		@@ -123,7 +124,7 @@ private:
		void writeSnapshotToPerfetto(const perfetto::protos::LayersSnapshotProto& snapshot, Mode mode);
		bool checkAndUpdateLastVsyncIdWrittenToPerfetto(Mode mode, std::int64_t vsyncId);

		std::function<perfetto::protos::LayersSnapshotProto(uint32_t)> mTakeLayersSnapshotProto;
		std::function<void(uint32_t, const OnLayersSnapshotCallback&)> mTakeLayersSnapshotProto;
		TransactionTracing* mTransactionTracing;

		std::atomic<bool> mIsActiveTracingStarted{false};