DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (5bfe22b4bd0d)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015
/* -*- 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 "mozilla/Atomics.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 "nsITimer.h"
#include "AsyncLogger.h"

namespace mozilla {

namespace media {
class ShutdownBlocker;
}

template <typename T>
class LinkedList;
class GraphRunner;

/**
 * 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
  virtual ~ControlMessage() { MOZ_COUNT_DTOR(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 nsITimerCallback,
                            public nsINamed {
 public:
  NS_DECL_THREADSAFE_ISUPPORTS
  NS_DECL_NSIMEMORYREPORTER
  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,
                               AbstractThread* aWindow);

  // 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(GraphDriver* aDriver) 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);
  /**
   * Append a ControlMessage to the message queue. This queue is drained
   * during RunInStableState; the messages will run on the graph thread.
   */
  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.
   */
  void ForceShutDown();

  /**
   * Sets mShutdownBlocker and makes it block shutdown.
   * Main thread only. Not idempotent.
   */
  void 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 aStateEnd, GraphTime aIterationEnd,
                               AudioMixer* aMixer) override;

  /**
   * Returns true if this MediaTrackGraph should keep running
   */
  IterationResult OneIterationImpl(GraphTime aStateEnd, 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();
  /**
   * Generate messages to the main thread to update it for all state changes.
   * mMonitor must be held.
   */
  void PrepareUpdatesToMainThreadState(bool aFinalUpdate);
  /**
   * 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_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);

  void NotifyWhenGraphStarted(RefPtr<AudioNodeTrack> aTrack,
                              MozPromiseHolder<GraphStartedPromise>&& aHolder);

  /**
   * Apply an AudioContext operation (suspend/resume/close), on the graph
   * thread.
   */
  void ApplyAudioContextOperationImpl(
      MediaTrack* aDestinationTrack, const nsTArray<MediaTrack*>& aTracks,
      dom::AudioContextOperation aOperation,
      MozPromiseHolder<AudioContextOperationPromise>&& aHolder);

  /**
   * Increment suspend count on aTrack and move it to mSuspendedTracks if
   * necessary.
   */
  void IncrementSuspendCount(MediaTrack* aTrack);
  /**
   * Increment suspend count on aTrack and move it to mTracks if
   * necessary.
   */
  void DecrementSuspendCount(MediaTrack* aTrack);

  /*
   * Move tracks from mTracks to mSuspendedTracks if suspending/closing an
   * AudioContext, or the inverse when resuming an AudioContext.
   */
  void SuspendOrResumeTracks(dom::AudioContextOperation aAudioContextOperation,
                             const nsTArray<MediaTrack*>& aTrackSet);

  /**
   * Determine if we have any audio tracks, or are about to add any audiotracks.
   */
  bool AudioTrackPresent();

  /**
   * 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.
   * Also sets mIsConsumed on every track.
   */
  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 TrackKeyAndVolume {
    MediaTrack* mTrack;
    void* mKey;
    float mVolume;
  };
  TrackTime PlayAudio(AudioMixer* aMixer, const TrackKeyAndVolume& aTkv,
                      GraphTime aPlayedTime);
  /* 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(CubebUtils::AudioDeviceID aID,
                          AudioDataListener* aListener);
  /* Called on the main thread when something requests audio from an input
   * audio device aID. */
  virtual nsresult OpenAudioInput(CubebUtils::AudioDeviceID aID,
                                  AudioDataListener* aListener) 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(Maybe<CubebUtils::AudioDeviceID>& aID,
                           AudioDataListener* aListener);
  /* 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(Maybe<CubebUtils::AudioDeviceID>& aID,
                               AudioDataListener* aListener) 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();

  /* 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 before the first Notify*Data after an
   * AudioCallbackDriver starts. */
  void NotifyStarted() 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) 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() {
    MOZ_ASSERT(OnGraphThreadOrNotRunning());

#ifdef ANDROID
    if (!mInputDeviceUsers.GetValue(mInputDeviceID)) {
      return 0;
    }
#else
    if (!mInputDeviceID) {
      MOZ_ASSERT(mInputDeviceUsers.Count() == 0,
                 "If running on a platform other than android,"
                 "an explicit device id should be present");
      return 0;
    }
#endif
    uint32_t maxInputChannels = 0;
    // When/if we decide to support multiple input device per graph, this needs
    // loop over them.
    nsTArray<RefPtr<AudioDataListener>>* listeners =
        mInputDeviceUsers.GetValue(mInputDeviceID);
    MOZ_ASSERT(listeners);
    for (const auto& listener : *listeners) {
      maxInputChannels = std::max(maxInputChannels,
                                  listener->RequestedInputChannelCount(this));
    }
    return maxInputChannels;
  }

  AudioInputType AudioInputDevicePreference() {
    MOZ_ASSERT(OnGraphThreadOrNotRunning());

    if (!mInputDeviceUsers.GetValue(mInputDeviceID)) {
      return AudioInputType::Unknown;
    }
    bool voiceInput = false;
    // When/if we decide to support multiple input device per graph, this needs
    // loop over them.
    nsTArray<RefPtr<AudioDataListener>>* listeners =
        mInputDeviceUsers.GetValue(mInputDeviceID);
    MOZ_ASSERT(listeners);

    // If at least one track is considered to be voice,
    for (const auto& listener : *listeners) {
      voiceInput |= listener->IsVoiceInput(this);
    }
    if (voiceInput) {
      return AudioInputType::Voice;
    }
    return AudioInputType::Unknown;
  }

  CubebUtils::AudioDeviceID InputDeviceID() { return mInputDeviceID; }

  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 {
#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;

  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 input & output, or nullptr for default device.
   * A MediaTrackGraph always has an output (even if silent).
   * If `mInputDeviceUsers.Count() != 0`, this MediaTrackGraph wants audio
   * input.
   *
   * In any case, the number of channels to use can be queried (on the graph
   * thread) by AudioInputChannelCount() and AudioOutputChannelCount().
   */
  CubebUtils::AudioDeviceID mInputDeviceID;
  CubebUtils::AudioDeviceID mOutputDeviceID;
  // Maps AudioDeviceID to an array of their users (that are listeners). This is
  // used to deliver audio input frames and to notify the listeners that the
  // audio device that delivers the audio frames has changed.
  // This is only touched on the graph thread.
  nsDataHashtable<nsVoidPtrHashKey, nsTArray<RefPtr<AudioDataListener>>>
      mInputDeviceUsers;

  // 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;
  /**
   * 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 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;

  /* 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 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, 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 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;
  LifecycleState& LifecycleStateRef() {
#if DEBUG
    if (mGraphDriverRunning) {
      mMonitor.AssertCurrentThreadOwns();
    } else {
      MOZ_ASSERT(NS_IsMainThread());
    }
#endif
    return mLifecycleState;
  }
  const LifecycleState& LifecycleStateRef() const {
#if DEBUG
    if (mGraphDriverRunning) {
      mMonitor.AssertCurrentThreadOwns();
    } else {
      MOZ_ASSERT(NS_IsMainThread());
    }
#endif
    return mLifecycleState;
  }

  /**
   * True when we need to do a forced shutdown, during application shutdown or
   * when shutting down a non-realtime graph.
   * Only set on the graph thread.
   * Can be read safely on the thread currently owning the graph, as indicated
   * by mLifecycleState.
   */
  bool mForceShutDown;

  /**
   * 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;

  // 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<AbstractThread> mAbstractMainThread;

  // used to limit graph shutdown time
  // Only accessed on the main thread.
  nsCOMPtr<nsITimer> mShutdownTimer;

 private:
  virtual ~MediaTrackGraphImpl();

  MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf)

  /**
   * 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 = 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;
};

}  // namespace mozilla

#endif /* MEDIATRACKGRAPHIMPL_H_ */