tenfourfox/dom/media/MediaStreamGraphImpl.h
Cameron Kaiser c9b2922b70 hello FPR
2017-04-19 00:56:45 -07:00

780 lines
25 KiB
C++

/* -*- 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_MEDIASTREAMGRAPHIMPL_H_
#define MOZILLA_MEDIASTREAMGRAPHIMPL_H_
#include "MediaStreamGraph.h"
#include "mozilla/Monitor.h"
#include "mozilla/TimeStamp.h"
#include "nsIMemoryReporter.h"
#include "nsIThread.h"
#include "nsIRunnable.h"
#include "Latency.h"
#include "mozilla/WeakPtr.h"
#include "GraphDriver.h"
#include "AudioMixer.h"
namespace mozilla {
template <typename T>
class LinkedList;
#ifdef MOZ_WEBRTC
class AudioOutputObserver;
#endif
/**
* A per-stream update message passed from the media graph thread to the
* main thread.
*/
struct StreamUpdate
{
RefPtr<MediaStream> mStream;
StreamTime mNextMainThreadCurrentTime;
bool mNextMainThreadFinished;
};
/**
* This represents a message run on the graph thread to modify stream 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 stream.
*/
class ControlMessage
{
public:
explicit ControlMessage(MediaStream* aStream) : mStream(aStream)
{
MOZ_COUNT_CTOR(ControlMessage);
}
// All these run on the graph thread
virtual ~ControlMessage()
{
MOZ_COUNT_DTOR(ControlMessage);
}
// Do the action of this message on the MediaStreamGraph thread. Any actions
// affecting graph processing should take effect at mProcessedTime.
// All stream 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() {}
MediaStream* GetStream() { return mStream; }
protected:
// We do not hold a reference to mStream. The graph will be holding
// a reference to the stream until the Destroy message is processed. The
// last message referencing a stream is the Destroy message for that stream.
MediaStream* mStream;
};
class MessageBlock
{
public:
nsTArray<nsAutoPtr<ControlMessage> > mMessages;
};
/**
* The implementation of a media stream graph. This class is private to this
* file. It's not in the anonymous namespace because MediaStream needs to
* be able to friend it.
*
* Currently we have one global instance per process, and one per each
* OfflineAudioContext object.
*/
class MediaStreamGraphImpl : public MediaStreamGraph,
public nsIMemoryReporter
{
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIMEMORYREPORTER
/**
* Use aGraphDriverRequested with SYSTEM_THREAD_DRIVER or AUDIO_THREAD_DRIVER
* to create a MediaStreamGraph which provides support for real-time audio
* and/or video. Set it to false 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 MediaStream inputs.
*/
explicit MediaStreamGraphImpl(GraphDriverType aGraphDriverRequested,
TrackRate aSampleRate,
dom::AudioChannel aChannel);
/**
* 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 aSourceIsMSG);
/**
* 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 StreamUpdate to its stream.
*/
void ApplyStreamUpdate(StreamUpdate* aUpdate);
/**
* Append a ControlMessage to the message queue. This queue is drained
* during RunInStableState; the messages will run on the graph thread.
*/
void AppendMessage(ControlMessage* aMessage);
/**
* Make this MediaStreamGraph enter forced-shutdown state. This state
* will be noticed by the media graph thread, which will shut down all streams
* and other state controlled by the media graph thread.
* This is called during application shutdown.
*/
void ForceShutDown();
/**
* Shutdown() this MediaStreamGraph's threads and return when they've shut down.
*/
void ShutdownThreads();
/**
* Called before the thread runs.
*/
void Init();
// The following methods run on the graph thread (or possibly the main thread if
// mLifecycleState > LIFECYCLE_RUNNING)
void AssertOnGraphThreadOrNotRunning() const
{
// either we're on the right thread (and calling CurrentDriver() is safe),
// or we're going to assert anyways, so don't cross-check CurrentDriver
#ifdef DEBUG
// if all the safety checks fail, assert we own the monitor
if (!mDriver->OnThread()) {
if (!(mDetectedNotRunning &&
mLifecycleState > LIFECYCLE_RUNNING &&
NS_IsMainThread())) {
mMonitor.AssertCurrentThreadOwns();
}
}
#endif
}
void MaybeProduceMemoryReport();
/**
* Returns true if this MediaStreamGraph should keep running
*/
bool UpdateMainThreadState();
/**
* Returns true if this MediaStreamGraph should keep running
*/
bool OneIteration(GraphTime aStateEnd);
bool Running() const
{
mMonitor.AssertCurrentThreadOwns();
return mLifecycleState == LIFECYCLE_RUNNING;
}
/* 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();
/**
* Generate messages to the main thread to update it for all state changes.
* mMonitor must be held.
*/
void PrepareUpdatesToMainThreadState(bool aFinalUpdate);
/**
* Returns false if there is any stream that has finished but not yet finished
* playing out.
*/
bool AllFinishedStreamsNotified();
/**
* 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 stream state to mStateComputedTime.
*/
void UpdateCurrentTimeForStreams(GraphTime aPrevCurrentTime);
/**
* Process graph messages in mFrontMessageQueue.
*/
void RunMessagesInQueue();
/**
* Update stream processing order and recompute stream blocking until
* aEndBlockingDecisions.
*/
void UpdateGraph(GraphTime aEndBlockingDecisions);
void SwapMessageQueues()
{
MOZ_ASSERT(CurrentDriver()->OnThread());
MOZ_ASSERT(mFrontMessageQueue.IsEmpty());
mMonitor.AssertCurrentThreadOwns();
mFrontMessageQueue.SwapElements(mBackMessageQueue);
}
/**
* Do all the processing and play the audio and video, from
* mProcessedTime to mStateComputedTime.
*/
void Process();
/**
* Extract any state updates pending in aStream, and apply them.
*/
void ExtractPendingInput(SourceMediaStream* aStream,
GraphTime aDesiredUpToTime,
bool* aEnsureNextIteration);
/**
* For use during ProcessedMediaStream::ProcessInput() or
* MediaStreamListener 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(nsAutoPtr<ControlMessage> aMessage);
/**
* Called when a suspend/resume/close operation has been completed, on the
* graph thread.
*/
void AudioContextOperationCompleted(MediaStream* aStream,
void* aPromise,
dom::AudioContextOperation aOperation);
/**
* Apply and AudioContext operation (suspend/resume/closed), on the graph
* thread.
*/
void ApplyAudioContextOperationImpl(MediaStream* aDestinationStream,
const nsTArray<MediaStream*>& aStreams,
dom::AudioContextOperation aOperation,
void* aPromise);
/**
* Increment suspend count on aStream and move it to mSuspendedStreams if
* necessary.
*/
void IncrementSuspendCount(MediaStream* aStream);
/**
* Increment suspend count on aStream and move it to mStreams if
* necessary.
*/
void DecrementSuspendCount(MediaStream* aStream);
/*
* Move streams from the mStreams to mSuspendedStream if suspending/closing an
* AudioContext, or the inverse when resuming an AudioContext.
*/
void SuspendOrResumeStreams(dom::AudioContextOperation aAudioContextOperation,
const nsTArray<MediaStream*>& aStreamSet);
/**
* Sort mStreams so that every stream not in a cycle is after any streams
* it depends on, and every stream in a cycle is marked as being in a cycle.
* Also sets mIsConsumed on every stream.
*/
void UpdateStreamOrder();
/**
* Returns smallest value of t such that t is a multiple of
* WEBAUDIO_BLOCK_SIZE and t > aTime.
*/
GraphTime RoundUpToNextAudioBlock(GraphTime aTime);
/**
* Produce data for all streams >= aStreamIndex for the current time interval.
* Advances block by block, each iteration producing data for all streams
* for a single block.
* This is called whenever we have an AudioNodeStream in the graph.
*/
void ProduceDataForStreamsBlockByBlock(uint32_t aStreamIndex,
TrackRate aSampleRate);
/**
* If aStream will underrun between aTime, and aEndBlockingDecisions, returns
* the time at which the underrun will start. Otherwise return
* aEndBlockingDecisions.
*/
GraphTime WillUnderrun(MediaStream* aStream, GraphTime aEndBlockingDecisions);
/**
* Given a graph time aTime, convert it to a stream time taking into
* account the time during which aStream is scheduled to be blocked.
*/
StreamTime GraphTimeToStreamTimeWithBlocking(MediaStream* aStream, GraphTime aTime);
/**
* Call NotifyHaveCurrentData on aStream's listeners.
*/
void NotifyHasCurrentData(MediaStream* aStream);
/**
* If aStream needs an audio stream but doesn't have one, create it.
* If aStream doesn't need an audio stream but has one, destroy it.
*/
void CreateOrDestroyAudioStreams(MediaStream* aStream);
/**
* Queue audio (mix of stream audio and silence for blocked intervals)
* to the audio output stream. Returns the number of frames played.
*/
StreamTime PlayAudio(MediaStream* aStream);
/**
* Set the correct current video frame for stream aStream.
*/
void PlayVideo(MediaStream* aStream);
/**
* No more data will be forthcoming for aStream. The stream will end
* at the current buffer end point. The StreamBuffer's tracks must be
* explicitly set to finished by the caller.
*/
void FinishStream(MediaStream* aStream);
/**
* Compute how much stream data we would like to buffer for aStream.
*/
StreamTime GetDesiredBufferEnd(MediaStream* aStream);
/**
* Returns true when there are no active streams.
*/
bool IsEmpty() const
{
return mStreams.IsEmpty() && mSuspendedStreams.IsEmpty() && mPortCount == 0;
}
/**
* Add aStream to the graph and initializes its graph-specific state.
*/
void AddStreamGraphThread(MediaStream* aStream);
/**
* Remove aStream from the graph. Ensures that pending messages about the
* stream back to the main thread are flushed.
*/
void RemoveStreamGraphThread(MediaStream* aStream);
/**
* Remove aPort from the graph and release it.
*/
void DestroyPort(MediaInputPort* aPort);
/**
* Mark the media stream order as dirty.
*/
void SetStreamOrderDirty()
{
mStreamOrderDirty = true;
}
// Always stereo for now.
uint32_t AudioChannelCount() const { return 2; }
double MediaTimeToSeconds(GraphTime aTime) const
{
NS_ASSERTION(aTime > -STREAM_TIME_MAX && aTime <= STREAM_TIME_MAX,
"Bad time");
return static_cast<double>(aTime)/GraphRate();
}
GraphTime SecondsToMediaTime(double aS) const
{
NS_ASSERTION(0 <= aS && aS <= TRACK_TICKS_MAX/TRACK_RATE_MAX,
"Bad seconds");
return GraphRate() * aS;
}
GraphTime MillisecondsToMediaTime(int32_t aMS) const
{
return RateConvertTicksRoundDown(GraphRate(), 1000, aMS);
}
/**
* Signal to the graph that the thread has paused indefinitly,
* or resumed.
*/
void PausedIndefinitly();
void ResumedFromPaused();
/**
* Not safe to call off the MediaStreamGraph thread unless monitor is held!
*/
GraphDriver* CurrentDriver() const
{
AssertOnGraphThreadOrNotRunning();
return mDriver;
}
bool RemoveMixerCallback(MixerCallbackReceiver* aReceiver)
{
return mMixer.RemoveCallback(aReceiver);
}
/**
* 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.
* We can also switch from Revive() (on MainThread), in which case the
* monitor is held
*/
void SetCurrentDriver(GraphDriver* aDriver)
{
AssertOnGraphThreadOrNotRunning();
mDriver = aDriver;
}
Monitor& GetMonitor()
{
return mMonitor;
}
void EnsureNextIteration()
{
mNeedAnotherIteration = true; // atomic
if (mGraphDriverAsleep) { // atomic
MonitorAutoLock mon(mMonitor);
CurrentDriver()->WakeUp(); // Might not be the same driver; might have woken already
}
}
void EnsureNextIterationLocked()
{
mNeedAnotherIteration = true; // atomic
if (mGraphDriverAsleep) { // atomic
CurrentDriver()->WakeUp(); // Might not be the same driver; might have woken already
}
}
// Capture Stream API. This allows to get a mixed-down output for a window.
void RegisterCaptureStreamForWindow(uint64_t aWindowId,
ProcessedMediaStream* aCaptureStream);
void UnregisterCaptureStreamForWindow(uint64_t aWindowId);
already_AddRefed<MediaInputPort>
ConnectToCaptureStream(uint64_t aWindowId, MediaStream* aMediaStream);
class StreamSet {
public:
class iterator {
public:
explicit iterator(MediaStreamGraphImpl& aGraph)
: mGraph(&aGraph), mArrayNum(-1), mArrayIndex(0)
{
++(*this);
}
iterator() : mGraph(nullptr), mArrayNum(2), mArrayIndex(0) {}
MediaStream* 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<MediaStream*>* Array()
{
return mArrayNum == 0 ? &mGraph->mStreams : &mGraph->mSuspendedStreams;
}
MediaStreamGraphImpl* mGraph;
int mArrayNum;
uint32_t mArrayIndex;
};
explicit StreamSet(MediaStreamGraphImpl& aGraph) : mGraph(aGraph) {}
iterator begin() { return iterator(mGraph); }
iterator end() { return iterator(); }
private:
MediaStreamGraphImpl& mGraph;
};
StreamSet AllStreams() { return StreamSet(*this); }
// Data members
//
/**
* 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 stream can take some time to shut down.
*/
RefPtr<GraphDriver> mDriver;
// 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 stream.
* References are maintained manually to simplify reordering without
* unnecessary thread-safe refcount changes.
*/
nsTArray<MediaStream*> mStreams;
/**
* This stores MediaStreams that are part of suspended AudioContexts.
* mStreams and mSuspendStream are disjoint sets: a stream is either suspended
* or not suspended. Suspended streams are not ordered in UpdateStreamOrder,
* and are therefore not doing any processing.
*/
nsTArray<MediaStream*> mSuspendedStreams;
/**
* Suspended AudioContext IDs
*/
nsTHashtable<nsUint64HashKey> mSuspendedContexts;
/**
* Streams from mFirstCycleBreaker to the end of mStreams 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 stream 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;
/**
* Date of the last time we updated the main thread with the graph state.
*/
TimeStamp mLastMainThreadUpdate;
/**
* Number of active MediaInputPorts
*/
int32_t mPortCount;
// True if the graph needs another iteration after the current iteration.
Atomic<bool> mNeedAnotherIteration;
// GraphDriver may need a WakeUp() if something changes
Atomic<bool> mGraphDriverAsleep;
// mMonitor guards the data below.
// MediaStreamGraph 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<StreamUpdate> mStreamUpdates;
/**
* Runnables to run after the next update to main thread state.
*/
nsTArray<nsCOMPtr<nsIRunnable> > mUpdateRunnables;
/**
* A list of batches of messages to process. Each batch is processed
* as an atomic unit.
*/
/*
* Message queue processed by the MSG 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;
/* True if there will messages to process if we swap the message queues. */
bool MessagesQueued() const
{
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 streams, and exits. The next RunInStableState()
* checks if there are new pending messages from the main thread (true only
* if new stream creation raced with shutdown); if there are, it revives
* RunThread(), otherwise it commits to shutting down the graph. New stream
* 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, or completion of a
* non-realtime graph. 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 stream is destroyed, the
* graph object is deleted.
*
* This should be kept in sync with the LifecycleState_str array in
* MediaStreamGraph.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 streams
// 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 streams.
LIFECYCLE_WAITING_FOR_STREAM_DESTRUCTION
};
LifecycleState mLifecycleState;
/**
* The graph should stop processing at or after this time.
*/
GraphTime mEndTime;
/**
* True when we need to do a forced shutdown during application shutdown.
*/
bool mForceShutDown;
/**
* True when we have posted an event to the main thread to run
* RunInStableState() and the event hasn't run yet.
*/
bool mPostedRunInStableStateEvent;
// 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<nsAutoPtr<ControlMessage> > mCurrentTaskMessageQueue;
/**
* True when RunInStableState has determined that mLifecycleState is >
* LIFECYCLE_RUNNING. Since only the main thread can reset mLifecycleState to
* LIFECYCLE_RUNNING, this can be relied on to not change unexpectedly.
*/
bool mDetectedNotRunning;
/**
* True when a stable state runner has been posted to the appshell to run
* RunInStableState at the next stable state.
*/
bool mPostedRunInStableState;
/**
* True when processing real-time audio/video. False when processing non-realtime
* audio.
*/
bool mRealtime;
/**
* True when a non-realtime MediaStreamGraph has started to process input. This
* value is only accessed on the main thread.
*/
bool mNonRealtimeProcessing;
/**
* True when a change has happened which requires us to recompute the stream
* blocking order.
*/
bool mStreamOrderDirty;
/**
* Hold a ref to the Latency logger
*/
RefPtr<AsyncLatencyLogger> mLatencyLog;
AudioMixer mMixer;
#ifdef MOZ_WEBRTC
RefPtr<AudioOutputObserver> mFarendObserverRef;
#endif
dom::AudioChannel AudioChannel() const { return mAudioChannel; }
private:
virtual ~MediaStreamGraphImpl();
MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf)
/**
* Used to signal that a memory report has been requested.
*/
Monitor mMemoryReportMonitor;
/**
* 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<MediaStreamGraphImpl> mSelfRef;
/**
* Used to pass memory report information across threads.
*/
nsTArray<AudioNodeSizes> mAudioStreamSizes;
struct WindowAndStream
{
uint64_t mWindowId;
RefPtr<ProcessedMediaStream> mCaptureStreamSink;
};
/**
* Stream for window audio capture.
*/
nsTArray<WindowAndStream> mWindowCaptureStreams;
/**
* Indicates that the MSG thread should gather data for a memory report.
*/
bool mNeedsMemoryReport;
#ifdef DEBUG
/**
* Used to assert when AppendMessage() runs ControlMessages synchronously.
*/
bool mCanRunMessagesSynchronously;
#endif
dom::AudioChannel mAudioChannel;
};
} // namespace mozilla
#endif /* MEDIASTREAMGRAPHIMPL_H_ */