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| -rw-r--r-- | dom/media/MediaTrackGraphImpl.h | 1066 |
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diff --git a/dom/media/MediaTrackGraphImpl.h b/dom/media/MediaTrackGraphImpl.h new file mode 100644 index 0000000000..ffdadc7e5e --- /dev/null +++ b/dom/media/MediaTrackGraphImpl.h @@ -0,0 +1,1066 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this file, + * You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef MOZILLA_MEDIATRACKGRAPHIMPL_H_ +#define MOZILLA_MEDIATRACKGRAPHIMPL_H_ + +#include "MediaTrackGraph.h" + +#include "AudioMixer.h" +#include "GraphDriver.h" +#include "DeviceInputTrack.h" +#include "mozilla/Atomics.h" +#include "mozilla/Maybe.h" +#include "mozilla/Monitor.h" +#include "mozilla/TimeStamp.h" +#include "mozilla/UniquePtr.h" +#include "mozilla/WeakPtr.h" +#include "nsClassHashtable.h" +#include "nsIMemoryReporter.h" +#include "nsINamed.h" +#include "nsIRunnable.h" +#include "nsIThreadInternal.h" +#include "nsITimer.h" +#include "AsyncLogger.h" + +namespace mozilla { + +namespace media { +class ShutdownBlocker; +} + +class AudioContextOperationControlMessage; +template <typename T> +class LinkedList; +class GraphRunner; + +class DeviceInputTrackManager { + public: + DeviceInputTrackManager() = default; + + // Returns the current NativeInputTrack. + NativeInputTrack* GetNativeInputTrack(); + // Returns the DeviceInputTrack paired with the device of aID if it exists. + // Otherwise, returns nullptr. + DeviceInputTrack* GetDeviceInputTrack(CubebUtils::AudioDeviceID aID); + // Returns the first added NonNativeInputTrack if any. Otherwise, returns + // nullptr. + NonNativeInputTrack* GetFirstNonNativeInputTrack(); + // Adds DeviceInputTrack to the managing list. + void Add(DeviceInputTrack* aTrack); + // Removes DeviceInputTrack from the managing list. + void Remove(DeviceInputTrack* aTrack); + + private: + RefPtr<NativeInputTrack> mNativeInputTrack; + nsTArray<RefPtr<NonNativeInputTrack>> mNonNativeInputTracks; +}; + +/** + * A per-track update message passed from the media graph thread to the + * main thread. + */ +struct TrackUpdate { + RefPtr<MediaTrack> mTrack; + TrackTime mNextMainThreadCurrentTime; + bool mNextMainThreadEnded; +}; + +/** + * This represents a message run on the graph thread to modify track or graph + * state. These are passed from main thread to graph thread through + * AppendMessage(), or scheduled on the graph thread with + * RunMessageAfterProcessing(). A ControlMessage + * always has a weak reference to a particular affected track. + */ +class ControlMessage { + public: + explicit ControlMessage(MediaTrack* aTrack) : mTrack(aTrack) { + MOZ_COUNT_CTOR(ControlMessage); + } + // All these run on the graph thread + MOZ_COUNTED_DTOR_VIRTUAL(ControlMessage) + // Do the action of this message on the MediaTrackGraph thread. Any actions + // affecting graph processing should take effect at mProcessedTime. + // All track data for times < mProcessedTime has already been + // computed. + virtual void Run() = 0; + // RunDuringShutdown() is only relevant to messages generated on the main + // thread (for AppendMessage()). + // When we're shutting down the application, most messages are ignored but + // some cleanup messages should still be processed (on the main thread). + // This must not add new control messages to the graph. + virtual void RunDuringShutdown() {} + MediaTrack* GetTrack() { return mTrack; } + + protected: + // We do not hold a reference to mTrack. The graph will be holding a reference + // to the track until the Destroy message is processed. The last message + // referencing a track is the Destroy message for that track. + MediaTrack* mTrack; +}; + +class MessageBlock { + public: + nsTArray<UniquePtr<ControlMessage>> mMessages; +}; + +/** + * The implementation of a media track graph. This class is private to this + * file. It's not in the anonymous namespace because MediaTrack needs to + * be able to friend it. + * + * There can be multiple MediaTrackGraph per process: one per document. + * Additionaly, each OfflineAudioContext object creates its own MediaTrackGraph + * object too. + */ +class MediaTrackGraphImpl : public MediaTrackGraph, + public GraphInterface, + public nsIMemoryReporter, + public nsIThreadObserver, + public nsITimerCallback, + public nsINamed { + public: + NS_DECL_THREADSAFE_ISUPPORTS + NS_DECL_NSIMEMORYREPORTER + NS_DECL_NSITHREADOBSERVER + NS_DECL_NSITIMERCALLBACK + NS_DECL_NSINAMED + + /** + * Use aGraphDriverRequested with SYSTEM_THREAD_DRIVER or AUDIO_THREAD_DRIVER + * to create a MediaTrackGraph which provides support for real-time audio + * and/or video. Set it to OFFLINE_THREAD_DRIVER in order to create a + * non-realtime instance which just churns through its inputs and produces + * output. Those objects currently only support audio, and are used to + * implement OfflineAudioContext. They do not support MediaTrack inputs. + */ + explicit MediaTrackGraphImpl(GraphDriverType aGraphDriverRequested, + GraphRunType aRunTypeRequested, + TrackRate aSampleRate, uint32_t aChannelCount, + CubebUtils::AudioDeviceID aOutputDeviceID, + nsISerialEventTarget* aMainThread); + static MediaTrackGraphImpl* GetInstance( + GraphDriverType aGraphDriverRequested, uint64_t aWindowID, + bool aShouldResistFingerprinting, TrackRate aSampleRate, + CubebUtils::AudioDeviceID aOutputDeviceID, + nsISerialEventTarget* aMainThread); + static MediaTrackGraphImpl* GetInstanceIfExists( + uint64_t aWindowID, bool aShouldResistFingerprinting, + TrackRate aSampleRate, CubebUtils::AudioDeviceID aOutputDeviceID); + + // Intended only for assertions, either on graph thread or not running (in + // which case we must be on the main thread). + bool OnGraphThreadOrNotRunning() const override; + bool OnGraphThread() const override; + + bool Destroyed() const override; + +#ifdef DEBUG + /** + * True if we're on aDriver's thread, or if we're on mGraphRunner's thread + * and mGraphRunner is currently run by aDriver. + */ + bool InDriverIteration(const GraphDriver* aDriver) const override; +#endif + + /** + * Unregisters memory reporting and deletes this instance. This should be + * called instead of calling the destructor directly. + */ + void Destroy(); + + // Main thread only. + /** + * This runs every time we need to sync state from the media graph thread + * to the main thread while the main thread is not in the middle + * of a script. It runs during a "stable state" (per HTML5) or during + * an event posted to the main thread. + * The boolean affects which boolean controlling runnable dispatch is cleared + */ + void RunInStableState(bool aSourceIsMTG); + /** + * Ensure a runnable to run RunInStableState is posted to the appshell to + * run at the next stable state (per HTML5). + * See EnsureStableStateEventPosted. + */ + void EnsureRunInStableState(); + /** + * Called to apply a TrackUpdate to its track. + */ + void ApplyTrackUpdate(TrackUpdate* aUpdate) MOZ_REQUIRES(mMonitor); + /** + * Append a ControlMessage to the message queue. This queue is drained + * during RunInStableState; the messages will run on the graph thread. + */ + virtual void AppendMessage(UniquePtr<ControlMessage> aMessage); + + /** + * Dispatches a runnable from any thread to the correct main thread for this + * MediaTrackGraph. + */ + void Dispatch(already_AddRefed<nsIRunnable>&& aRunnable); + + /** + * Make this MediaTrackGraph enter forced-shutdown state. This state + * will be noticed by the media graph thread, which will shut down all tracks + * and other state controlled by the media graph thread. + * This is called during application shutdown, and on document unload if an + * AudioContext is using the graph. + */ + void ForceShutDown(); + + /** + * Sets mShutdownBlocker and makes it block shutdown. + * Main thread only. Not idempotent. Returns true if a blocker was added, + * false if this failed. + */ + bool AddShutdownBlocker(); + + /** + * Removes mShutdownBlocker and unblocks shutdown. + * Main thread only. Idempotent. + */ + void RemoveShutdownBlocker(); + + /** + * Called before the thread runs. + */ + void Init(); + + /** + * Respond to CollectReports with sizes collected on the graph thread. + */ + static void FinishCollectReports( + nsIHandleReportCallback* aHandleReport, nsISupports* aData, + const nsTArray<AudioNodeSizes>& aAudioTrackSizes); + + // The following methods run on the graph thread (or possibly the main thread + // if mLifecycleState > LIFECYCLE_RUNNING) + void CollectSizesForMemoryReport( + already_AddRefed<nsIHandleReportCallback> aHandleReport, + already_AddRefed<nsISupports> aHandlerData); + + /** + * Returns true if this MediaTrackGraph should keep running + */ + bool UpdateMainThreadState(); + + /** + * Proxy method called by GraphDriver to iterate the graph. + * If this graph was created with GraphRunType SINGLE_THREAD, mGraphRunner + * will take care of calling OneIterationImpl from its thread. Otherwise, + * OneIterationImpl is called directly. Output from the graph gets mixed into + * aMixer, if it is non-null. + */ + IterationResult OneIteration(GraphTime aStateTime, GraphTime aIterationEnd, + AudioMixer* aMixer) override; + + /** + * Returns true if this MediaTrackGraph should keep running + */ + IterationResult OneIterationImpl(GraphTime aStateTime, + GraphTime aIterationEnd, AudioMixer* aMixer); + + /** + * Called from the driver, when the graph thread is about to stop, to tell + * the main thread to attempt to begin cleanup. The main thread may either + * shutdown or revive the graph depending on whether it receives new + * messages. + */ + void SignalMainThreadCleanup(); + + /* This is the end of the current iteration, that is, the current time of the + * graph. */ + GraphTime IterationEnd() const; + + /** + * Ensure there is an event posted to the main thread to run RunInStableState. + * mMonitor must be held. + * See EnsureRunInStableState + */ + void EnsureStableStateEventPosted() MOZ_REQUIRES(mMonitor); + /** + * Generate messages to the main thread to update it for all state changes. + * mMonitor must be held. + */ + void PrepareUpdatesToMainThreadState(bool aFinalUpdate) + MOZ_REQUIRES(mMonitor); + /** + * If we are rendering in non-realtime mode, we don't want to send messages to + * the main thread at each iteration for performance reasons. We instead + * notify the main thread at the same rate + */ + bool ShouldUpdateMainThread(); + // The following methods are the various stages of RunThread processing. + /** + * Advance all track state to mStateComputedTime. + */ + void UpdateCurrentTimeForTracks(GraphTime aPrevCurrentTime); + /** + * Process chunks for all tracks and raise events for properties that have + * changed, such as principalId. + */ + void ProcessChunkMetadata(GraphTime aPrevCurrentTime); + /** + * Process chunks for the given track and interval, and raise events for + * properties that have changed, such as principalHandle. + */ + template <typename C, typename Chunk> + void ProcessChunkMetadataForInterval(MediaTrack* aTrack, C& aSegment, + TrackTime aStart, TrackTime aEnd); + /** + * Process graph messages in mFrontMessageQueue. + */ + void RunMessagesInQueue(); + /** + * Update track processing order and recompute track blocking until + * aEndBlockingDecisions. + */ + void UpdateGraph(GraphTime aEndBlockingDecisions); + + void SwapMessageQueues() MOZ_REQUIRES(mMonitor) { + MOZ_ASSERT(OnGraphThreadOrNotRunning()); + mMonitor.AssertCurrentThreadOwns(); + MOZ_ASSERT(mFrontMessageQueue.IsEmpty()); + mFrontMessageQueue.SwapElements(mBackMessageQueue); + if (!mFrontMessageQueue.IsEmpty()) { + EnsureNextIteration(); + } + } + /** + * Do all the processing and play the audio and video, from + * mProcessedTime to mStateComputedTime. + */ + void Process(AudioMixer* aMixer); + + /** + * For use during ProcessedMediaTrack::ProcessInput() or + * MediaTrackListener callbacks, when graph state cannot be changed. + * Schedules |aMessage| to run after processing, at a time when graph state + * can be changed. Graph thread. + */ + void RunMessageAfterProcessing(UniquePtr<ControlMessage> aMessage); + + /** + * Resolve the GraphStartedPromise when the driver has started processing on + * the audio thread after the device has started. + */ + void NotifyWhenGraphStarted(RefPtr<MediaTrack> aTrack, + MozPromiseHolder<GraphStartedPromise>&& aHolder); + + /** + * Apply an AudioContext operation (suspend/resume/close), on the graph + * thread. + */ + void ApplyAudioContextOperationImpl( + AudioContextOperationControlMessage* aMessage); + + /** + * Determine if we have any audio tracks, or are about to add any audiotracks. + */ + bool AudioTrackPresent(); + + /** + * Schedules a replacement GraphDriver in mNextDriver, if necessary. + */ + void CheckDriver(); + + /** + * Sort mTracks so that every track not in a cycle is after any tracks + * it depends on, and every track in a cycle is marked as being in a cycle. + */ + void UpdateTrackOrder(); + + /** + * Returns smallest value of t such that t is a multiple of + * WEBAUDIO_BLOCK_SIZE and t >= aTime. + */ + static GraphTime RoundUpToEndOfAudioBlock(GraphTime aTime); + /** + * Returns smallest value of t such that t is a multiple of + * WEBAUDIO_BLOCK_SIZE and t > aTime. + */ + static GraphTime RoundUpToNextAudioBlock(GraphTime aTime); + /** + * Produce data for all tracks >= aTrackIndex for the current time interval. + * Advances block by block, each iteration producing data for all tracks + * for a single block. + * This is called whenever we have an AudioNodeTrack in the graph. + */ + void ProduceDataForTracksBlockByBlock(uint32_t aTrackIndex, + TrackRate aSampleRate); + /** + * If aTrack will underrun between aTime, and aEndBlockingDecisions, returns + * the time at which the underrun will start. Otherwise return + * aEndBlockingDecisions. + */ + GraphTime WillUnderrun(MediaTrack* aTrack, GraphTime aEndBlockingDecisions); + + /** + * Given a graph time aTime, convert it to a track time taking into + * account the time during which aTrack is scheduled to be blocked. + */ + TrackTime GraphTimeToTrackTimeWithBlocking(const MediaTrack* aTrack, + GraphTime aTime) const; + + /** + * If aTrack needs an audio track but doesn't have one, create it. + * If aTrack doesn't need an audio track but has one, destroy it. + */ + void CreateOrDestroyAudioTracks(MediaTrack* aTrack); + /** + * Queue audio (mix of track audio and silence for blocked intervals) + * to the audio output track. Returns the number of frames played. + */ + struct TrackAndKey { + MediaTrack* mTrack; + void* mKey; + }; + struct TrackKeyAndVolume { + MediaTrack* mTrack; + void* mKey; + float mVolume; + }; + TrackTime PlayAudio(AudioMixer* aMixer, const TrackKeyAndVolume& aTkv, + GraphTime aPlayedTime); + + /* Do not call this directly. For users who need to get a DeviceInputTrack, + * use DeviceInputTrack::OpenAudio() instead. This should only be used in + * DeviceInputTrack to get the existing DeviceInputTrack paired with the given + * device in this graph. Main thread only.*/ + DeviceInputTrack* GetDeviceInputTrackMainThread( + CubebUtils::AudioDeviceID aID); + + /* Do not call this directly. This should only be used in DeviceInputTrack to + * get the existing NativeInputTrackMain thread only.*/ + NativeInputTrack* GetNativeInputTrackMainThread(); + + /* Runs off a message on the graph thread when something requests audio from + * an input audio device of ID aID, and delivers the input audio frames to + * aListener. */ + void OpenAudioInputImpl(DeviceInputTrack* aTrack); + /* Called on the main thread when something requests audio from an input + * audio device aID. */ + virtual void OpenAudioInput(DeviceInputTrack* aTrack) override; + + /* Runs off a message on the graph when input audio from aID is not needed + * anymore, for a particular track. It can be that other tracks still need + * audio from this audio input device. */ + void CloseAudioInputImpl(DeviceInputTrack* aTrack); + /* Called on the main thread when input audio from aID is not needed + * anymore, for a particular track. It can be that other tracks still need + * audio from this audio input device. */ + virtual void CloseAudioInput(DeviceInputTrack* aTrack) override; + + /* Add or remove an audio output for this track. All tracks that have an + * audio output are mixed and written to a single audio output stream. */ + void RegisterAudioOutput(MediaTrack* aTrack, void* aKey); + void UnregisterAudioOutput(MediaTrack* aTrack, void* aKey); + void UnregisterAllAudioOutputs(MediaTrack* aTrack); + void SetAudioOutputVolume(MediaTrack* aTrack, void* aKey, float aVolume); + + /* Called on the graph thread when the input device settings should be + * reevaluated, for example, if the channel count of the input track should + * be changed. */ + void ReevaluateInputDevice(CubebUtils::AudioDeviceID aID); + + /* Called on the graph thread when there is new output data for listeners. + * This is the mixed audio output of this MediaTrackGraph. */ + void NotifyOutputData(AudioDataValue* aBuffer, size_t aFrames, + TrackRate aRate, uint32_t aChannels) override; + /* Called on the graph thread after an AudioCallbackDriver with an input + * stream has stopped. */ + void NotifyInputStopped() override; + /* Called on the graph thread when there is new input data for listeners. This + * is the raw audio input for this MediaTrackGraph. */ + void NotifyInputData(const AudioDataValue* aBuffer, size_t aFrames, + TrackRate aRate, uint32_t aChannels, + uint32_t aAlreadyBuffered) override; + /* Called every time there are changes to input/output audio devices like + * plug/unplug etc. This can be called on any thread, and posts a message to + * the main thread so that it can post a message to the graph thread. */ + void DeviceChanged() override; + /* Called every time there are changes to input/output audio devices. This is + * called on the graph thread. */ + void DeviceChangedImpl(); + + /** + * Compute how much track data we would like to buffer for aTrack. + */ + TrackTime GetDesiredBufferEnd(MediaTrack* aTrack); + /** + * Returns true when there are no active tracks. + */ + bool IsEmpty() const { + MOZ_ASSERT( + OnGraphThreadOrNotRunning() || + (NS_IsMainThread() && + LifecycleStateRef() >= LIFECYCLE_WAITING_FOR_MAIN_THREAD_CLEANUP)); + return mTracks.IsEmpty() && mSuspendedTracks.IsEmpty() && mPortCount == 0; + } + + /** + * Add aTrack to the graph and initializes its graph-specific state. + */ + void AddTrackGraphThread(MediaTrack* aTrack); + /** + * Remove aTrack from the graph. Ensures that pending messages about the + * track back to the main thread are flushed. + */ + void RemoveTrackGraphThread(MediaTrack* aTrack); + /** + * Remove a track from the graph. Main thread. + */ + void RemoveTrack(MediaTrack* aTrack); + /** + * Remove aPort from the graph and release it. + */ + void DestroyPort(MediaInputPort* aPort); + /** + * Mark the media track order as dirty. + */ + void SetTrackOrderDirty() { + MOZ_ASSERT(OnGraphThreadOrNotRunning()); + mTrackOrderDirty = true; + } + + // Get the current maximum channel count. Graph thread only. + uint32_t AudioOutputChannelCount() const; + // Set a new maximum channel count. Graph thread only. + void SetMaxOutputChannelCount(uint32_t aMaxChannelCount); + + double AudioOutputLatency(); + + /** + * The audio input channel count for a MediaTrackGraph is the max of all the + * channel counts requested by the listeners. The max channel count is + * delivered to the listeners themselves, and they take care of downmixing. + */ + uint32_t AudioInputChannelCount(CubebUtils::AudioDeviceID aID); + + AudioInputType AudioInputDevicePreference(CubebUtils::AudioDeviceID aID); + + double MediaTimeToSeconds(GraphTime aTime) const { + NS_ASSERTION(aTime > -TRACK_TIME_MAX && aTime <= TRACK_TIME_MAX, + "Bad time"); + return static_cast<double>(aTime) / GraphRate(); + } + + /** + * Signal to the graph that the thread has paused indefinitly, + * or resumed. + */ + void PausedIndefinitly(); + void ResumedFromPaused(); + + /** + * Not safe to call off the MediaTrackGraph thread unless monitor is held! + */ + GraphDriver* CurrentDriver() const MOZ_NO_THREAD_SAFETY_ANALYSIS { +#ifdef DEBUG + if (!OnGraphThreadOrNotRunning()) { + mMonitor.AssertCurrentThreadOwns(); + } +#endif + return mDriver; + } + + /** + * Effectively set the new driver, while we are switching. + * It is only safe to call this at the very end of an iteration, when there + * has been a SwitchAtNextIteration call during the iteration. The driver + * should return and pass the control to the new driver shortly after. + * Monitor must be held. + */ + void SetCurrentDriver(GraphDriver* aDriver) { + MOZ_ASSERT_IF(mGraphDriverRunning, InDriverIteration(mDriver)); + MOZ_ASSERT_IF(!mGraphDriverRunning, NS_IsMainThread()); + MonitorAutoLock lock(GetMonitor()); + mDriver = aDriver; + } + + GraphDriver* NextDriver() const { + MOZ_ASSERT(OnGraphThread()); + return mNextDriver; + } + + bool Switching() const { return NextDriver(); } + + void SwitchAtNextIteration(GraphDriver* aNextDriver); + + Monitor& GetMonitor() { return mMonitor; } + + void EnsureNextIteration() { CurrentDriver()->EnsureNextIteration(); } + + // Capture API. This allows to get a mixed-down output for a window. + void RegisterCaptureTrackForWindow(uint64_t aWindowId, + ProcessedMediaTrack* aCaptureTrack); + void UnregisterCaptureTrackForWindow(uint64_t aWindowId); + already_AddRefed<MediaInputPort> ConnectToCaptureTrack( + uint64_t aWindowId, MediaTrack* aMediaTrack); + + Watchable<GraphTime>& CurrentTime() override; + + /** + * Interrupt any JS running on the graph thread. + * Called on the main thread when shutting down the graph. + */ + void InterruptJS(); + + class TrackSet { + public: + class iterator { + public: + explicit iterator(MediaTrackGraphImpl& aGraph) + : mGraph(&aGraph), mArrayNum(-1), mArrayIndex(0) { + ++(*this); + } + iterator() : mGraph(nullptr), mArrayNum(2), mArrayIndex(0) {} + MediaTrack* operator*() { return Array()->ElementAt(mArrayIndex); } + iterator operator++() { + ++mArrayIndex; + while (mArrayNum < 2 && + (mArrayNum < 0 || mArrayIndex >= Array()->Length())) { + ++mArrayNum; + mArrayIndex = 0; + } + return *this; + } + bool operator==(const iterator& aOther) const { + return mArrayNum == aOther.mArrayNum && + mArrayIndex == aOther.mArrayIndex; + } + bool operator!=(const iterator& aOther) const { + return !(*this == aOther); + } + + private: + nsTArray<MediaTrack*>* Array() { + return mArrayNum == 0 ? &mGraph->mTracks : &mGraph->mSuspendedTracks; + } + MediaTrackGraphImpl* mGraph; + int mArrayNum; + uint32_t mArrayIndex; + }; + + explicit TrackSet(MediaTrackGraphImpl& aGraph) : mGraph(aGraph) {} + iterator begin() { return iterator(mGraph); } + iterator end() { return iterator(); } + + private: + MediaTrackGraphImpl& mGraph; + }; + TrackSet AllTracks() { return TrackSet(*this); } + + // Data members + + /* + * If set, the GraphRunner class handles handing over data from audio + * callbacks to a common single thread, shared across GraphDrivers. + */ + const RefPtr<GraphRunner> mGraphRunner; + + /** + * Main-thread view of the number of tracks in this graph, for lifetime + * management. + * + * When this becomes zero, the graph is marked as forbidden to add more + * tracks to. It will be shut down shortly after. + */ + size_t mMainThreadTrackCount = 0; + + /** + * Main-thread view of the number of ports in this graph, to catch bugs. + * + * When this becomes zero, and mMainThreadTrackCount is 0, the graph is + * marked as forbidden to add more ControlMessages to. It will be shut down + * shortly after. + */ + size_t mMainThreadPortCount = 0; + + /** + * Graphs own owning references to their driver, until shutdown. When a driver + * switch occur, previous driver is either deleted, or it's ownership is + * passed to a event that will take care of the asynchronous cleanup, as + * audio track can take some time to shut down. + * Accessed on both the main thread and the graph thread; both read and write. + * Must hold monitor to access it. + */ + RefPtr<GraphDriver> mDriver; + + // Set during an iteration to switch driver after the iteration has finished. + // Should the current iteration be the last iteration, the next driver will be + // discarded. Access through SwitchAtNextIteration()/NextDriver(). Graph + // thread only. + RefPtr<GraphDriver> mNextDriver; + + // The following state is managed on the graph thread only, unless + // mLifecycleState > LIFECYCLE_RUNNING in which case the graph thread + // is not running and this state can be used from the main thread. + + /** + * The graph keeps a reference to each track. + * References are maintained manually to simplify reordering without + * unnecessary thread-safe refcount changes. + * Must satisfy OnGraphThreadOrNotRunning(). + */ + nsTArray<MediaTrack*> mTracks; + /** + * This stores MediaTracks that are part of suspended AudioContexts. + * mTracks and mSuspendTracks are disjoint sets: a track is either suspended + * or not suspended. Suspended tracks are not ordered in UpdateTrackOrder, + * and are therefore not doing any processing. + * Must satisfy OnGraphThreadOrNotRunning(). + */ + nsTArray<MediaTrack*> mSuspendedTracks; + /** + * Tracks from mFirstCycleBreaker to the end of mTracks produce output before + * they receive input. They correspond to DelayNodes that are in cycles. + */ + uint32_t mFirstCycleBreaker; + /** + * Blocking decisions have been computed up to this time. + * Between each iteration, this is the same as mProcessedTime. + */ + GraphTime mStateComputedTime = 0; + /** + * All track contents have been computed up to this time. + * The next batch of updates from the main thread will be processed + * at this time. This is behind mStateComputedTime during processing. + */ + GraphTime mProcessedTime = 0; + /** + * The end of the current iteration. Only access on the graph thread. + */ + GraphTime mIterationEndTime = 0; + /** + * The graph should stop processing at this time. + */ + GraphTime mEndTime; + /** + * Date of the last time we updated the main thread with the graph state. + */ + TimeStamp mLastMainThreadUpdate; + /** + * Number of active MediaInputPorts + */ + int32_t mPortCount; + /** + * Runnables to run after the next update to main thread state, but that are + * still waiting for the next iteration to finish. + */ + nsTArray<nsCOMPtr<nsIRunnable>> mPendingUpdateRunnables; + + /** + * Devices to use for cubeb output, or nullptr for default device. + * A MediaTrackGraph always has an output (even if silent). + * + * All mOutputDeviceID access is on the graph thread. + */ + CubebUtils::AudioDeviceID mOutputDeviceID; + + /** + * List of resume operations waiting for a switch to an AudioCallbackDriver. + */ + class PendingResumeOperation { + public: + explicit PendingResumeOperation( + AudioContextOperationControlMessage* aMessage); + void Apply(MediaTrackGraphImpl* aGraph); + void Abort(); + MediaTrack* DestinationTrack() const { return mDestinationTrack; } + + private: + RefPtr<MediaTrack> mDestinationTrack; + nsTArray<RefPtr<MediaTrack>> mTracks; + MozPromiseHolder<AudioContextOperationPromise> mHolder; + }; + AutoTArray<PendingResumeOperation, 1> mPendingResumeOperations; + + // mMonitor guards the data below. + // MediaTrackGraph normally does its work without holding mMonitor, so it is + // not safe to just grab mMonitor from some thread and start monkeying with + // the graph. Instead, communicate with the graph thread using provided + // mechanisms such as the ControlMessage queue. + Monitor mMonitor; + + // Data guarded by mMonitor (must always be accessed with mMonitor held, + // regardless of the value of mLifecycleState). + + /** + * State to copy to main thread + */ + nsTArray<TrackUpdate> mTrackUpdates MOZ_GUARDED_BY(mMonitor); + /** + * Runnables to run after the next update to main thread state. + */ + nsTArray<nsCOMPtr<nsIRunnable>> mUpdateRunnables MOZ_GUARDED_BY(mMonitor); + /** + * A list of batches of messages to process. Each batch is processed + * as an atomic unit. + */ + /* + * Message queue processed by the MTG thread during an iteration. + * Accessed on graph thread only. + */ + nsTArray<MessageBlock> mFrontMessageQueue; + /* + * Message queue in which the main thread appends messages. + * Access guarded by mMonitor. + */ + nsTArray<MessageBlock> mBackMessageQueue MOZ_GUARDED_BY(mMonitor); + + /* True if there will messages to process if we swap the message queues. */ + bool MessagesQueued() const MOZ_REQUIRES(mMonitor) { + mMonitor.AssertCurrentThreadOwns(); + return !mBackMessageQueue.IsEmpty(); + } + /** + * This enum specifies where this graph is in its lifecycle. This is used + * to control shutdown. + * Shutdown is tricky because it can happen in two different ways: + * 1) Shutdown due to inactivity. RunThread() detects that it has no + * pending messages and no tracks, and exits. The next RunInStableState() + * checks if there are new pending messages from the main thread (true only + * if new track creation raced with shutdown); if there are, it revives + * RunThread(), otherwise it commits to shutting down the graph. New track + * creation after this point will create a new graph. An async event is + * dispatched to Shutdown() the graph's threads and then delete the graph + * object. + * 2) Forced shutdown at application shutdown, completion of a non-realtime + * graph, or document unload. A flag is set, RunThread() detects the flag + * and exits, the next RunInStableState() detects the flag, and dispatches + * the async event to Shutdown() the graph's threads. However the graph + * object is not deleted. New messages for the graph are processed + * synchronously on the main thread if necessary. When the last track is + * destroyed, the graph object is deleted. + * + * This should be kept in sync with the LifecycleState_str array in + * MediaTrackGraph.cpp + */ + enum LifecycleState { + // The graph thread hasn't started yet. + LIFECYCLE_THREAD_NOT_STARTED, + // RunThread() is running normally. + LIFECYCLE_RUNNING, + // In the following states, the graph thread is not running so + // all "graph thread only" state in this class can be used safely + // on the main thread. + // RunThread() has exited and we're waiting for the next + // RunInStableState(), at which point we can clean up the main-thread + // side of the graph. + LIFECYCLE_WAITING_FOR_MAIN_THREAD_CLEANUP, + // RunInStableState() posted a ShutdownRunnable, and we're waiting for it + // to shut down the graph thread(s). + LIFECYCLE_WAITING_FOR_THREAD_SHUTDOWN, + // Graph threads have shut down but we're waiting for remaining tracks + // to be destroyed. Only happens during application shutdown and on + // completed non-realtime graphs, since normally we'd only shut down a + // realtime graph when it has no tracks. + LIFECYCLE_WAITING_FOR_TRACK_DESTRUCTION + }; + + /** + * Modified only in mMonitor. Transitions to + * LIFECYCLE_WAITING_FOR_MAIN_THREAD_CLEANUP occur on the graph thread at + * the end of an iteration. All other transitions occur on the main thread. + */ + LifecycleState mLifecycleState MOZ_GUARDED_BY(mMonitor); + LifecycleState& LifecycleStateRef() MOZ_NO_THREAD_SAFETY_ANALYSIS { +#if DEBUG + if (mGraphDriverRunning) { + mMonitor.AssertCurrentThreadOwns(); + } else { + MOZ_ASSERT(NS_IsMainThread()); + } +#endif + return mLifecycleState; + } + const LifecycleState& LifecycleStateRef() const + MOZ_NO_THREAD_SAFETY_ANALYSIS { +#if DEBUG + if (mGraphDriverRunning) { + mMonitor.AssertCurrentThreadOwns(); + } else { + MOZ_ASSERT(NS_IsMainThread()); + } +#endif + return mLifecycleState; + } + + /** + * True once the graph thread has received the message from ForceShutDown(). + * This is checked in the decision to shut down the + * graph thread so that control messages dispatched before forced shutdown + * are processed on the graph thread. + * Only set on the graph thread. + * Can be read safely on the thread currently owning the graph, as indicated + * by mLifecycleState. + */ + bool mForceShutDownReceived = false; + /** + * true when InterruptJS() has been called, because shutdown (normal or + * forced) has commenced. Set on the main thread under mMonitor and read on + * the graph thread under mMonitor. + **/ + bool mInterruptJSCalled MOZ_GUARDED_BY(mMonitor) = false; + + /** + * Remove this blocker to unblock shutdown. + * Only accessed on the main thread. + **/ + RefPtr<media::ShutdownBlocker> mShutdownBlocker; + + /** + * True when we have posted an event to the main thread to run + * RunInStableState() and the event hasn't run yet. + * Accessed on both main and MTG thread, mMonitor must be held. + */ + bool mPostedRunInStableStateEvent MOZ_GUARDED_BY(mMonitor); + + /** + * The JSContext of the graph thread. Set under mMonitor on only the graph + * or GraphRunner thread. Once set this does not change until reset when + * the thread is about to exit. Read under mMonitor on the main thread to + * interrupt running JS for forced shutdown. + **/ + JSContext* mJSContext MOZ_GUARDED_BY(mMonitor) = nullptr; + + // Main thread only + + /** + * Messages posted by the current event loop task. These are forwarded to + * the media graph thread during RunInStableState. We can't forward them + * immediately because we want all messages between stable states to be + * processed as an atomic batch. + */ + nsTArray<UniquePtr<ControlMessage>> mCurrentTaskMessageQueue; + /** + * True from when RunInStableState sets mLifecycleState to LIFECYCLE_RUNNING, + * until RunInStableState has determined that mLifecycleState is > + * LIFECYCLE_RUNNING. + */ + Atomic<bool> mGraphDriverRunning; + /** + * True when a stable state runner has been posted to the appshell to run + * RunInStableState at the next stable state. + * Only accessed on the main thread. + */ + bool mPostedRunInStableState; + /** + * True when processing real-time audio/video. False when processing + * non-realtime audio. + */ + const bool mRealtime; + /** + * True when a change has happened which requires us to recompute the track + * blocking order. + */ + bool mTrackOrderDirty; + const RefPtr<nsISerialEventTarget> mMainThread; + + // used to limit graph shutdown time + // Only accessed on the main thread. + nsCOMPtr<nsITimer> mShutdownTimer; + + protected: + virtual ~MediaTrackGraphImpl(); + + private: + MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf) + + // Set a new native iput device when the current native input device is close. + // Main thread only. + void SetNewNativeInput(); + + /** + * This class uses manual memory management, and all pointers to it are raw + * pointers. However, in order for it to implement nsIMemoryReporter, it needs + * to implement nsISupports and so be ref-counted. So it maintains a single + * nsRefPtr to itself, giving it a ref-count of 1 during its entire lifetime, + * and Destroy() nulls this self-reference in order to trigger self-deletion. + */ + RefPtr<MediaTrackGraphImpl> mSelfRef; + + struct WindowAndTrack { + uint64_t mWindowId; + RefPtr<ProcessedMediaTrack> mCaptureTrackSink; + }; + /** + * Track for window audio capture. + */ + nsTArray<WindowAndTrack> mWindowCaptureTracks; + /** + * Tracks that have their audio output mixed and written to an audio output + * device. + */ + nsTArray<TrackKeyAndVolume> mAudioOutputs; + + /** + * Global volume scale. Used when running tests so that the output is not too + * loud. + */ + const float mGlobalVolume; + +#ifdef DEBUG + /** + * Used to assert when AppendMessage() runs ControlMessages synchronously. + */ + bool mCanRunMessagesSynchronously; +#endif + + /** + * The graph's main-thread observable graph time. + * Updated by the stable state runnable after each iteration. + */ + Watchable<GraphTime> mMainThreadGraphTime; + + /** + * Set based on mProcessedTime at end of iteration. + * Read by stable state runnable on main thread. Protected by mMonitor. + */ + GraphTime mNextMainThreadGraphTime MOZ_GUARDED_BY(mMonitor) = 0; + + /** + * Cached audio output latency, in seconds. Main thread only. This is reset + * whenever the audio device running this MediaTrackGraph changes. + */ + double mAudioOutputLatency; + + /** + * The max audio output channel count the default audio output device + * supports. This is cached here because it can be expensive to query. The + * cache is invalidated when the device is changed. This is initialized in the + * ctor, and the read/write only on the graph thread. + */ + uint32_t mMaxOutputChannelCount; + + /** + * Manage the native or non-native input device in graph. Main thread only. + */ + DeviceInputTrackManager mDeviceInputTrackManagerMainThread; + + /** + * Manage the native or non-native input device in graph. Graph thread only. + */ + DeviceInputTrackManager mDeviceInputTrackManagerGraphThread; +}; + +} // namespace mozilla + +template <> +class nsDefaultComparator<mozilla::MediaTrackGraphImpl::TrackKeyAndVolume, + mozilla::MediaTrackGraphImpl::TrackAndKey> { + public: + bool Equals( + const mozilla::MediaTrackGraphImpl::TrackKeyAndVolume& aElement, + const mozilla::MediaTrackGraphImpl::TrackAndKey& aTrackAndKey) const { + return aElement.mTrack == aTrackAndKey.mTrack && + aElement.mKey == aTrackAndKey.mKey; + } +}; + +#endif /* MEDIATRACKGRAPHIMPL_H_ */ |