dom/media/webaudio/AudioContext.h
author Karl Tomlinson <karlt+@karlt.net>
Fri, 11 Mar 2016 20:54:31 +1300
changeset 339691 4eb4787a255f77b6a734ef30ac9d59bae50fbe0f
parent 327360 e22b3043887ed36bf2c634c2924a7c8d39d226b1
permissions -rw-r--r--
bug 1255618 remove AudioContext from global window at unlink r?ehsan mDestination is cleared during unlink, which means that after that point the window can't do much with the AudioContext, nor should need to do so. MozReview-Commit-ID: E45aCpEfJEu

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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 AudioContext_h_
#define AudioContext_h_

#include "mozilla/dom/AudioChannelBinding.h"
#include "MediaBufferDecoder.h"
#include "mozilla/Attributes.h"
#include "mozilla/DOMEventTargetHelper.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/dom/TypedArray.h"
#include "nsAutoPtr.h"
#include "nsCOMPtr.h"
#include "nsCycleCollectionParticipant.h"
#include "nsHashKeys.h"
#include "nsTHashtable.h"
#include "js/TypeDecls.h"
#include "nsIMemoryReporter.h"

// X11 has a #define for CurrentTime. Unbelievable :-(.
// See dom/media/DOMMediaStream.h for more fun!
#ifdef CurrentTime
#undef CurrentTime
#endif

namespace WebCore {
  class PeriodicWave;
} // namespace WebCore

class nsPIDOMWindowInner;

namespace mozilla {

class DOMMediaStream;
class ErrorResult;
class MediaStream;
class MediaStreamGraph;
class AudioNodeStream;

namespace dom {

enum class AudioContextState : uint32_t;
class AnalyserNode;
class AudioBuffer;
class AudioBufferSourceNode;
class AudioDestinationNode;
class AudioListener;
class AudioNode;
class BiquadFilterNode;
class ChannelMergerNode;
class ChannelSplitterNode;
class ConvolverNode;
class DelayNode;
class DynamicsCompressorNode;
class GainNode;
class HTMLMediaElement;
class MediaElementAudioSourceNode;
class GlobalObject;
class MediaStreamAudioDestinationNode;
class MediaStreamAudioSourceNode;
class OscillatorNode;
class PannerNode;
class ScriptProcessorNode;
class StereoPannerNode;
class WaveShaperNode;
class PeriodicWave;
class Promise;
enum class OscillatorType : uint32_t;

// This is addrefed by the OscillatorNodeEngine on the main thread
// and then used from the MSG thread.
// It can be released either from the graph thread or the main thread.
class BasicWaveFormCache
{
public:
  explicit BasicWaveFormCache(uint32_t aSampleRate);
  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(BasicWaveFormCache)
  WebCore::PeriodicWave* GetBasicWaveForm(OscillatorType aType);
private:
  ~BasicWaveFormCache();
  RefPtr<WebCore::PeriodicWave> mSawtooth;
  RefPtr<WebCore::PeriodicWave> mSquare;
  RefPtr<WebCore::PeriodicWave> mTriangle;
  uint32_t mSampleRate;
};


/* This runnable allows the MSG to notify the main thread when audio is actually
 * flowing */
class StateChangeTask final : public nsRunnable
{
public:
  /* This constructor should be used when this event is sent from the main
   * thread. */
  StateChangeTask(AudioContext* aAudioContext, void* aPromise, AudioContextState aNewState);

  /* This constructor should be used when this event is sent from the audio
   * thread. */
  StateChangeTask(AudioNodeStream* aStream, void* aPromise, AudioContextState aNewState);

  NS_IMETHOD Run() override;

private:
  RefPtr<AudioContext> mAudioContext;
  void* mPromise;
  RefPtr<AudioNodeStream> mAudioNodeStream;
  AudioContextState mNewState;
};

enum class AudioContextOperation { Suspend, Resume, Close };

class AudioContext final : public DOMEventTargetHelper,
                           public nsIMemoryReporter
{
  AudioContext(nsPIDOMWindowInner* aParentWindow,
               bool aIsOffline,
               AudioChannel aChannel,
               uint32_t aNumberOfChannels = 0,
               uint32_t aLength = 0,
               float aSampleRate = 0.0f);
  ~AudioContext();

  nsresult Init();

public:
  typedef uint64_t AudioContextId;

  NS_DECL_ISUPPORTS_INHERITED
  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(AudioContext,
                                           DOMEventTargetHelper)
  MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf)

  nsPIDOMWindowInner* GetParentObject() const
  {
    return GetOwner();
  }

  void Shutdown(); // idempotent

  JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;

  using DOMEventTargetHelper::DispatchTrustedEvent;

  // Constructor for regular AudioContext
  static already_AddRefed<AudioContext>
  Constructor(const GlobalObject& aGlobal, ErrorResult& aRv);

  // Constructor for regular AudioContext. A default audio channel is needed.
  static already_AddRefed<AudioContext>
  Constructor(const GlobalObject& aGlobal,
              AudioChannel aChannel,
              ErrorResult& aRv);

  // Constructor for offline AudioContext
  static already_AddRefed<AudioContext>
  Constructor(const GlobalObject& aGlobal,
              uint32_t aNumberOfChannels,
              uint32_t aLength,
              float aSampleRate,
              ErrorResult& aRv);

  // AudioContext methods

  AudioDestinationNode* Destination() const
  {
    return mDestination;
  }

  float SampleRate() const
  {
    return mSampleRate;
  }

  bool ShouldSuspendNewStream() const { return mSuspendCalled; }

  double CurrentTime() const;

  AudioListener* Listener();

  AudioContextState State() const { return mAudioContextState; }

  // Those three methods return a promise to content, that is resolved when an
  // (possibly long) operation is completed on the MSG (and possibly other)
  // thread(s). To avoid having to match the calls and asychronous result when
  // the operation is completed, we keep a reference to the promises on the main
  // thread, and then send the promises pointers down the MSG thread, as a void*
  // (to make it very clear that the pointer is to merely be treated as an ID).
  // When back on the main thread, we can resolve or reject the promise, by
  // casting it back to a `Promise*` while asserting we're back on the main
  // thread and removing the reference we added.
  already_AddRefed<Promise> Suspend(ErrorResult& aRv);
  already_AddRefed<Promise> Resume(ErrorResult& aRv);
  already_AddRefed<Promise> Close(ErrorResult& aRv);
  IMPL_EVENT_HANDLER(statechange)

  already_AddRefed<AudioBufferSourceNode> CreateBufferSource(ErrorResult& aRv);

  already_AddRefed<AudioBuffer>
  CreateBuffer(JSContext* aJSContext, uint32_t aNumberOfChannels,
               uint32_t aLength, float aSampleRate,
               ErrorResult& aRv);

  already_AddRefed<MediaStreamAudioDestinationNode>
  CreateMediaStreamDestination(ErrorResult& aRv);

  already_AddRefed<ScriptProcessorNode>
  CreateScriptProcessor(uint32_t aBufferSize,
                        uint32_t aNumberOfInputChannels,
                        uint32_t aNumberOfOutputChannels,
                        ErrorResult& aRv);

  already_AddRefed<StereoPannerNode>
  CreateStereoPanner(ErrorResult& aRv);

  already_AddRefed<AnalyserNode>
  CreateAnalyser(ErrorResult& aRv);

  already_AddRefed<GainNode>
  CreateGain(ErrorResult& aRv);

  already_AddRefed<WaveShaperNode>
  CreateWaveShaper(ErrorResult& aRv);

  already_AddRefed<MediaElementAudioSourceNode>
  CreateMediaElementSource(HTMLMediaElement& aMediaElement, ErrorResult& aRv);
  already_AddRefed<MediaStreamAudioSourceNode>
  CreateMediaStreamSource(DOMMediaStream& aMediaStream, ErrorResult& aRv);

  already_AddRefed<DelayNode>
  CreateDelay(double aMaxDelayTime, ErrorResult& aRv);

  already_AddRefed<PannerNode>
  CreatePanner(ErrorResult& aRv);

  already_AddRefed<ConvolverNode>
  CreateConvolver(ErrorResult& aRv);

  already_AddRefed<ChannelSplitterNode>
  CreateChannelSplitter(uint32_t aNumberOfOutputs, ErrorResult& aRv);

  already_AddRefed<ChannelMergerNode>
  CreateChannelMerger(uint32_t aNumberOfInputs, ErrorResult& aRv);

  already_AddRefed<DynamicsCompressorNode>
  CreateDynamicsCompressor(ErrorResult& aRv);

  already_AddRefed<BiquadFilterNode>
  CreateBiquadFilter(ErrorResult& aRv);

  already_AddRefed<OscillatorNode>
  CreateOscillator(ErrorResult& aRv);

  already_AddRefed<PeriodicWave>
  CreatePeriodicWave(const Float32Array& aRealData, const Float32Array& aImagData,
                     ErrorResult& aRv);

  already_AddRefed<Promise>
  DecodeAudioData(const ArrayBuffer& aBuffer,
                  const Optional<OwningNonNull<DecodeSuccessCallback> >& aSuccessCallback,
                  const Optional<OwningNonNull<DecodeErrorCallback> >& aFailureCallback,
                  ErrorResult& aRv);

  // OfflineAudioContext methods
  already_AddRefed<Promise> StartRendering(ErrorResult& aRv);
  IMPL_EVENT_HANDLER(complete)

  bool IsOffline() const { return mIsOffline; }

  MediaStreamGraph* Graph() const;
  MediaStream* DestinationStream() const;

  // Nodes register here if they will produce sound even if they have silent
  // or no input connections.  The AudioContext will keep registered nodes
  // alive until the context is collected.  This takes care of "playing"
  // references and "tail-time" references.
  void RegisterActiveNode(AudioNode* aNode);
  // Nodes unregister when they have finished producing sound for the
  // foreseeable future.
  // Do NOT call UnregisterActiveNode from an AudioNode destructor.
  // If the destructor is called, then the Node has already been unregistered.
  // The destructor may be called during hashtable enumeration, during which
  // unregistering would not be safe.
  void UnregisterActiveNode(AudioNode* aNode);

  void UnregisterAudioBufferSourceNode(AudioBufferSourceNode* aNode);
  void UnregisterPannerNode(PannerNode* aNode);
  void UpdatePannerSource();

  uint32_t MaxChannelCount() const;

  void Mute() const;
  void Unmute() const;

  JSObject* GetGlobalJSObject() const;

  AudioChannel MozAudioChannelType() const;

  AudioChannel TestAudioChannelInAudioNodeStream();

  void RegisterNode(AudioNode* aNode);
  void UnregisterNode(AudioNode* aNode);

  void OnStateChanged(void* aPromise, AudioContextState aNewState);

  BasicWaveFormCache* GetBasicWaveFormCache();

  IMPL_EVENT_HANDLER(mozinterruptbegin)
  IMPL_EVENT_HANDLER(mozinterruptend)

private:
  void DisconnectFromWindow();
  void RemoveFromDecodeQueue(WebAudioDecodeJob* aDecodeJob);
  void ShutdownDecoder();

  size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
  NS_IMETHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                            nsISupports* aData, bool aAnonymize) override;

  friend struct ::mozilla::WebAudioDecodeJob;

  bool CheckClosed(ErrorResult& aRv);

  nsTArray<MediaStream*> GetAllStreams() const;

private:
  // Each AudioContext has an id, that is passed down the MediaStreams that
  // back the AudioNodes, so we can easily compute the set of all the
  // MediaStreams for a given context, on the MediasStreamGraph side.
  const AudioContextId mId;
  // Note that it's important for mSampleRate to be initialized before
  // mDestination, as mDestination's constructor needs to access it!
  const float mSampleRate;
  AudioContextState mAudioContextState;
  RefPtr<AudioDestinationNode> mDestination;
  RefPtr<AudioListener> mListener;
  nsTArray<RefPtr<WebAudioDecodeJob> > mDecodeJobs;
  // This array is used to keep the suspend/resume/close promises alive until
  // they are resolved, so we can safely pass them accross threads.
  nsTArray<RefPtr<Promise>> mPromiseGripArray;
  // See RegisterActiveNode.  These will keep the AudioContext alive while it
  // is rendering and the window remains alive.
  nsTHashtable<nsRefPtrHashKey<AudioNode> > mActiveNodes;
  // Raw (non-owning) references to all AudioNodes for this AudioContext.
  nsTHashtable<nsPtrHashKey<AudioNode> > mAllNodes;
  // Hashsets containing all the PannerNodes, to compute the doppler shift.
  // These are weak pointers.
  nsTHashtable<nsPtrHashKey<PannerNode> > mPannerNodes;
  // Cache to avoid recomputing basic waveforms all the time.
  RefPtr<BasicWaveFormCache> mBasicWaveFormCache;
  // Number of channels passed in the OfflineAudioContext ctor.
  uint32_t mNumberOfChannels;
  bool mIsOffline;
  bool mIsStarted;
  bool mIsShutDown;
  // Close has been called, reject suspend and resume call.
  bool mCloseCalled;
  // Suspend has been called with no following resume.
  bool mSuspendCalled;
};

static const dom::AudioContext::AudioContextId NO_AUDIO_CONTEXT = 0;

} // namespace dom
} // namespace mozilla

#endif