Bug 1644383 - add mutexs to avoid data race. r=media-playback-reviewers,padenot (9ee65e09) · Commits · The Tor Project / Applications / Tor Browser

dom/media/ipc/RemoteMediaDataDecoder.cpp

+15 −2

Original line number	Original line	Diff line number	Diff line
	@@ -18,7 +18,12 @@ namespace mozilla {
	##__VA_ARGS__)		##__VA_ARGS__)

	RemoteMediaDataDecoder::RemoteMediaDataDecoder(RemoteDecoderChild* aChild)		RemoteMediaDataDecoder::RemoteMediaDataDecoder(RemoteDecoderChild* aChild)
	: mChild(aChild) {		: mChild(aChild),
			mDescription("RemoteMediaDataDecoder"_ns),
			mProcessName("unknown"_ns),
			mCodecName("unknown"_ns),
			mIsHardwareAccelerated(false),
			mConversion(ConversionRequired::kNeedNone) {
	LOG("%p is created", this);		LOG("%p is created", this);
	}		}

	@@ -48,6 +53,7 @@ RefPtr<MediaDataDecoder::InitPromise> RemoteMediaDataDecoder::Init() {
	->Then(		->Then(
	RemoteDecoderManagerChild::GetManagerThread(), __func__,		RemoteDecoderManagerChild::GetManagerThread(), __func__,
	[self, this](TrackType aTrack) {		[self, this](TrackType aTrack) {
			MutexAutoLock lock(mMutex);
	// If shutdown has started in the meantime shutdown promise may		// If shutdown has started in the meantime shutdown promise may
	// be resloved before this task. In this case mChild will be null		// be resloved before this task. In this case mChild will be null
	// and the init promise has to be canceled.		// and the init promise has to be canceled.
	@@ -127,6 +133,7 @@ RefPtr<ShutdownPromise> RemoteMediaDataDecoder::Shutdown() {

	bool RemoteMediaDataDecoder::IsHardwareAccelerated(		bool RemoteMediaDataDecoder::IsHardwareAccelerated(
	nsACString& aFailureReason) const {		nsACString& aFailureReason) const {
			MutexAutoLock lock(mMutex);
	aFailureReason = mHardwareAcceleratedReason;		aFailureReason = mHardwareAcceleratedReason;
	return mIsHardwareAccelerated;		return mIsHardwareAccelerated;
	}		}
	@@ -145,18 +152,24 @@ void RemoteMediaDataDecoder::SetSeekThreshold(const media::TimeUnit& aTime) {

	MediaDataDecoder::ConversionRequired RemoteMediaDataDecoder::NeedsConversion()		MediaDataDecoder::ConversionRequired RemoteMediaDataDecoder::NeedsConversion()
	const {		const {
			MutexAutoLock lock(mMutex);
	return mConversion;		return mConversion;
	}		}

	nsCString RemoteMediaDataDecoder::GetDescriptionName() const {		nsCString RemoteMediaDataDecoder::GetDescriptionName() const {
			MutexAutoLock lock(mMutex);
	return mDescription;		return mDescription;
	}		}

	nsCString RemoteMediaDataDecoder::GetProcessName() const {		nsCString RemoteMediaDataDecoder::GetProcessName() const {
			MutexAutoLock lock(mMutex);
	return mProcessName;		return mProcessName;
	}		}

	nsCString RemoteMediaDataDecoder::GetCodecName() const { return mCodecName; }		nsCString RemoteMediaDataDecoder::GetCodecName() const {
			MutexAutoLock lock(mMutex);
			return mCodecName;
			}

	#undef LOG		#undef LOG

dom/media/ipc/RemoteMediaDataDecoder.h

+9 −7

Original line number	Original line	Diff line number	Diff line
	@@ -53,14 +53,16 @@ class RemoteMediaDataDecoder final
	// destructor when we can guarantee no other threads are accessing it). Only		// destructor when we can guarantee no other threads are accessing it). Only
	// read from the manager thread.		// read from the manager thread.
	RefPtr<RemoteDecoderChild> mChild;		RefPtr<RemoteDecoderChild> mChild;

			mutable Mutex mMutex{"RemoteMediaDataDecoder"};

	// Only ever written/modified during decoder initialisation.		// Only ever written/modified during decoder initialisation.
	// As such can be accessed from any threads after that.		nsCString mDescription MOZ_GUARDED_BY(mMutex);
	nsCString mDescription = "RemoteMediaDataDecoder"_ns;		nsCString mProcessName MOZ_GUARDED_BY(mMutex);
	nsCString mProcessName = "unknown"_ns;		nsCString mCodecName MOZ_GUARDED_BY(mMutex);
	nsCString mCodecName = "unknown"_ns;		bool mIsHardwareAccelerated MOZ_GUARDED_BY(mMutex);
	bool mIsHardwareAccelerated = false;		nsCString mHardwareAcceleratedReason MOZ_GUARDED_BY(mMutex);
	nsCString mHardwareAcceleratedReason;		ConversionRequired mConversion MOZ_GUARDED_BY(mMutex);
	ConversionRequired mConversion = ConversionRequired::kNeedNone;
	};		};

	} // namespace mozilla		} // namespace mozilla

dom/media/platforms/wrappers/MediaChangeMonitor.cpp

+7 −0

Original line number	Original line	Diff line number	Diff line
	@@ -668,6 +668,7 @@ RefPtr<ShutdownPromise> MediaChangeMonitor::ShutdownDecoder() {
	AssertOnThread();		AssertOnThread();
	mConversionRequired.reset();		mConversionRequired.reset();
	if (mDecoder) {		if (mDecoder) {
			MutexAutoLock lock(mMutex);
	RefPtr<MediaDataDecoder> decoder = std::move(mDecoder);		RefPtr<MediaDataDecoder> decoder = std::move(mDecoder);
	return decoder->Shutdown();		return decoder->Shutdown();
	}		}
	@@ -715,6 +716,7 @@ MediaChangeMonitor::CreateDecoder() {
	->Then(		->Then(
	GetCurrentSerialEventTarget(), __func__,		GetCurrentSerialEventTarget(), __func__,
	[self = RefPtr{this}, this](RefPtr<MediaDataDecoder>&& aDecoder) {		[self = RefPtr{this}, this](RefPtr<MediaDataDecoder>&& aDecoder) {
			MutexAutoLock lock(mMutex);
	mDecoder = std::move(aDecoder);		mDecoder = std::move(aDecoder);
	DDLINKCHILD("decoder", mDecoder.get());		DDLINKCHILD("decoder", mDecoder.get());
	return CreateDecoderPromise::CreateAndResolve(true, __func__);		return CreateDecoderPromise::CreateAndResolve(true, __func__);
	@@ -963,6 +965,11 @@ void MediaChangeMonitor::FlushThenShutdownDecoder(
	->Track(mFlushRequest);		->Track(mFlushRequest);
	}		}

			MediaDataDecoder* MediaChangeMonitor::GetDecoderOnNonOwnerThread() const {
			MutexAutoLock lock(mMutex);
			return mDecoder;
			}

	#undef LOG		#undef LOG

	} // namespace mozilla		} // namespace mozilla

dom/media/platforms/wrappers/MediaChangeMonitor.h

+20 −10

Original line number	Original line	Diff line number	Diff line
	@@ -41,34 +41,34 @@ class MediaChangeMonitor final
	RefPtr<ShutdownPromise> Shutdown() override;		RefPtr<ShutdownPromise> Shutdown() override;
	bool IsHardwareAccelerated(nsACString& aFailureReason) const override;		bool IsHardwareAccelerated(nsACString& aFailureReason) const override;
	nsCString GetDescriptionName() const override {		nsCString GetDescriptionName() const override {
	if (mDecoder) {		if (RefPtr<MediaDataDecoder> decoder = GetDecoderOnNonOwnerThread()) {
	return mDecoder->GetDescriptionName();		return decoder->GetDescriptionName();
	}		}
	return "MediaChangeMonitor decoder (pending)"_ns;		return "MediaChangeMonitor decoder (pending)"_ns;
	}		}
	nsCString GetProcessName() const override {		nsCString GetProcessName() const override {
	if (mDecoder) {		if (RefPtr<MediaDataDecoder> decoder = GetDecoderOnNonOwnerThread()) {
	return mDecoder->GetProcessName();		return decoder->GetProcessName();
	}		}
	return "MediaChangeMonitor"_ns;		return "MediaChangeMonitor"_ns;
	}		}
	nsCString GetCodecName() const override {		nsCString GetCodecName() const override {
	if (mDecoder) {		if (RefPtr<MediaDataDecoder> decoder = GetDecoderOnNonOwnerThread()) {
	return mDecoder->GetCodecName();		return decoder->GetCodecName();
	}		}
	return "MediaChangeMonitor"_ns;		return "MediaChangeMonitor"_ns;
	}		}
	void SetSeekThreshold(const media::TimeUnit& aTime) override;		void SetSeekThreshold(const media::TimeUnit& aTime) override;
	bool SupportDecoderRecycling() const override {		bool SupportDecoderRecycling() const override {
	if (mDecoder) {		if (RefPtr<MediaDataDecoder> decoder = GetDecoderOnNonOwnerThread()) {
	return mDecoder->SupportDecoderRecycling();		return decoder->SupportDecoderRecycling();
	}		}
	return false;		return false;
	}		}

	ConversionRequired NeedsConversion() const override {		ConversionRequired NeedsConversion() const override {
	if (mDecoder) {		if (RefPtr<MediaDataDecoder> decoder = GetDecoderOnNonOwnerThread()) {
	return mDecoder->NeedsConversion();		return decoder->NeedsConversion();
	}		}
	// Default so no conversion is performed.		// Default so no conversion is performed.
	return ConversionRequired::kNeedNone;		return ConversionRequired::kNeedNone;
	@@ -97,6 +97,9 @@ class MediaChangeMonitor final
	MOZ_ASSERT(!mThread \|\| mThread->IsOnCurrentThread());		MOZ_ASSERT(!mThread \|\| mThread->IsOnCurrentThread());
	}		}

			// This is used for getting decoder debug info on other threads. Thread-safe.
			MediaDataDecoder* GetDecoderOnNonOwnerThread() const;

	bool CanRecycleDecoder() const;		bool CanRecycleDecoder() const;

	typedef MozPromise<bool, MediaResult, true /* exclusive */>		typedef MozPromise<bool, MediaResult, true /* exclusive */>
	@@ -137,6 +140,13 @@ class MediaChangeMonitor final
	const CreateDecoderParamsForAsync mParams;		const CreateDecoderParamsForAsync mParams;
	// Keep any seek threshold set for after decoder creation and initialization.		// Keep any seek threshold set for after decoder creation and initialization.
	Maybe<media::TimeUnit> mPendingSeekThreshold;		Maybe<media::TimeUnit> mPendingSeekThreshold;

			// This lock is used for mDecoder specifically, but it doens't need to be used
			// for every places accessing mDecoder which is mostly on the owner thread.
			// However, when requesting decoder debug info, it can happen on other
			// threads, so we need this mutex to avoid the data race of
			// creating/destroying decoder and accessing decoder's debug info.
			mutable Mutex MOZ_ANNOTATED mMutex{"MediaChangeMonitor"};
	};		};

	} // namespace mozilla		} // namespace mozilla