gecko/dom/media/MediaStreamGraphImpl.h

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/* -*- 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 {
int64_t mGraphUpdateIndex;
nsRefPtr<MediaStream> mStream;
StreamTime mNextMainThreadCurrentTime;
bool mNextMainThreadFinished;
};
/**
* This represents a message passed from the main thread to the graph thread.
* A ControlMessage always has a weak reference 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 mStateComputedTime.
// All stream data for times < mStateComputedTime has already been
// computed.
virtual void Run() = 0;
// 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:
int64_t mGraphUpdateIndex;
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
/**
* Set aRealtime to true in order to create a MediaStreamGraph which provides
* support for real-time audio and 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(bool aRealtime,
TrackRate aSampleRate,
DOMMediaStream::TrackTypeHints aHint,
dom::AudioChannel aChannel = dom::AudioChannel::Normal);
/**
* 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() {
// 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
}
/*
* This does the actual iteration: Message processing, MediaStream ordering,
* blocking computation and processing.
*/
void DoIteration();
bool OneIteration(GraphTime aFrom, GraphTime aTo,
GraphTime aStateFrom, GraphTime aStateEnd);
bool Running() {
mMonitor.AssertCurrentThreadOwns();
return mLifecycleState == LIFECYCLE_RUNNING;
}
// Get the message queue, from the current GraphDriver thread.
nsTArray<MessageBlock>& MessageQueue() {
mMonitor.AssertCurrentThreadOwns();
return mFrontMessageQueue;
}
/* This is the end of the current iteration, that is, the current time of the
* graph. */
GraphTime IterationEnd();
/**
* 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 the new current time.
*/
void UpdateCurrentTimeForStreams(GraphTime aPrevCurrentTime,
GraphTime aNextCurrentTime);
/**
* Process graph message for this iteration, update stream processing order,
* and recompute stream blocking until aEndBlockingDecisions.
*/
void UpdateGraph(GraphTime aEndBlockingDecisions);
void SwapMessageQueues() {
mMonitor.AssertCurrentThreadOwns();
mFrontMessageQueue.SwapElements(mBackMessageQueue);
}
/**
* Do all the processing and play the audio and video, ffrom aFrom to aTo.
*/
void Process(GraphTime aFrom, GraphTime aTo);
/**
* Update the consumption state of aStream to reflect whether its data
* is needed or not.
*/
void UpdateConsumptionState(SourceMediaStream* aStream);
/**
* Extract any state updates pending in aStream, and apply them.
*/
void ExtractPendingInput(SourceMediaStream* aStream,
GraphTime aDesiredUpToTime,
bool* aEnsureNextIteration);
/**
* Update "have enough data" flags in aStream.
*/
void UpdateBufferSufficiencyState(SourceMediaStream* aStream);
/**
* Mark aStream and all its inputs (recursively) as consumed.
*/
static void MarkConsumed(MediaStream* aStream);
/**
* 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();
/**
* Compute the blocking states of streams from mStateComputedTime
* until the desired future time aEndBlockingDecisions.
* Updates mStateComputedTime and sets MediaStream::mBlocked
* for all streams.
*/
void RecomputeBlocking(GraphTime aEndBlockingDecisions);
// The following methods are used to help RecomputeBlocking.
/**
* If aStream isn't already in aStreams, add it and recursively call
* AddBlockingRelatedStreamsToSet on all the streams whose blocking
* status could depend on or affect the state of aStream.
*/
void AddBlockingRelatedStreamsToSet(nsTArray<MediaStream*>* aStreams,
MediaStream* aStream);
/**
* Mark a stream blocked at time aTime. If this results in decisions that need
* to be revisited at some point in the future, *aEnd will be reduced to the
* first time in the future to recompute those decisions.
*/
void MarkStreamBlocking(MediaStream* aStream);
/**
* Recompute blocking for the streams in aStreams for the interval starting at aTime.
* If this results in decisions that need to be revisited at some point
* in the future, *aEnd will be reduced to the first time in the future to
* recompute those decisions.
*/
void RecomputeBlockingAt(const nsTArray<MediaStream*>& aStreams,
GraphTime aTime, GraphTime aEndBlockingDecisions,
GraphTime* aEnd);
/**
* 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 given 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,
GraphTime aFrom,
GraphTime aTo);
/**
* Returns true if aStream will underrun at aTime for its own playback.
* aEndBlockingDecisions is when we plan to stop making blocking decisions.
* *aEnd will be reduced to the first time in the future to recompute these
* decisions.
*/
bool WillUnderrun(MediaStream* aStream, GraphTime aTime,
GraphTime aEndBlockingDecisions, GraphTime* aEnd);
/**
* 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 GraphTimeToStreamTime(MediaStream* aStream, GraphTime aTime);
/**
* Given a graph time aTime, convert it to a stream time taking into
* account the time during which aStream is scheduled to be blocked, and
* when we don't know whether it's blocked or not, we assume it's not blocked.
*/
StreamTime GraphTimeToStreamTimeOptimistic(MediaStream* aStream, GraphTime aTime);
enum {
INCLUDE_TRAILING_BLOCKED_INTERVAL = 0x01
};
/**
* Given a stream time aTime, convert it to a graph time taking into
* account the time during which aStream is scheduled to be blocked.
* aTime must be <= mStateComputedTime since blocking decisions
* are only known up to that point.
* If aTime is exactly at the start of a blocked interval, then the blocked
* interval is included in the time returned if and only if
* aFlags includes INCLUDE_TRAILING_BLOCKED_INTERVAL.
*/
GraphTime StreamTimeToGraphTime(MediaStream* aStream, StreamTime aTime,
uint32_t aFlags = 0);
/**
* Get the current audio position of the stream's audio output.
*/
GraphTime GetAudioPosition(MediaStream* aStream);
/**
* 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(GraphTime aAudioOutputStartTime, 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, GraphTime aFrom, GraphTime aTo);
/**
* 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() { return mStreams.IsEmpty() && mPortCount == 0; }
// For use by control messages, on graph thread only.
/**
* Identify which graph update index we are currently processing.
*/
int64_t GetProcessingGraphUpdateIndex() { return mProcessingGraphUpdateIndex; }
/**
* Add aStream to the graph and initializes its graph-specific state.
*/
void AddStream(MediaStream* aStream);
/**
* Remove aStream from the graph. Ensures that pending messages about the
* stream back to the main thread are flushed.
*/
void RemoveStream(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() { return 2; }
double MediaTimeToSeconds(GraphTime aTime)
{
NS_ASSERTION(0 <= aTime && aTime <= STREAM_TIME_MAX, "Bad time");
return static_cast<double>(aTime)/GraphRate();
}
GraphTime SecondsToMediaTime(double aS)
{
NS_ASSERTION(0 <= aS && aS <= TRACK_TICKS_MAX/TRACK_RATE_MAX,
"Bad seconds");
return GraphRate() * aS;
}
GraphTime MillisecondsToMediaTime(int32_t aMS)
{
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() {
AssertOnGraphThreadOrNotRunning();
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.
* 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
}
}
// 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.
*/
nsRefPtr<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;
/**
* 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;
/**
* Date of the last time we updated the main thread with the graph state.
*/
TimeStamp mLastMainThreadUpdate;
/**
* Which update batch we are currently processing.
*/
int64_t mProcessingGraphUpdateIndex;
/**
* 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. */
nsTArray<MessageBlock> mFrontMessageQueue;
/* Message queue in which the main thread appends messages. */
nsTArray<MessageBlock> mBackMessageQueue;
/* True if there will messages to process if we swap the message queues. */
bool MessagesQueued() {
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;
/**
* Used to flush any accumulated data when the output streams
* may have stalled (on Mac after an output device change)
*/
bool mFlushSourcesNow;
bool mFlushSourcesOnNextIteration;
// 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
*/
nsRefPtr<AsyncLatencyLogger> mLatencyLog;
AudioMixer mMixer;
#ifdef MOZ_WEBRTC
nsRefPtr<AudioOutputObserver> mFarendObserverRef;
#endif
uint32_t 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.
*/
nsRefPtr<MediaStreamGraphImpl> mSelfRef;
/**
* Used to pass memory report information across threads.
*/
nsTArray<AudioNodeSizes> mAudioStreamSizes;
/**
* 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
// We use uint32_t instead AudioChannel because this is just used as key for
// the hashtable gGraphs.
uint32_t mAudioChannel;
};
}
#endif /* MEDIASTREAMGRAPHIMPL_H_ */