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.

Header

Mercurial (dcc6d7a0dc00)

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 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059
/* -*- 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/. */

#include <MediaStreamGraphImpl.h>
#include "mozilla/dom/AudioContext.h"
#include "CubebUtils.h"

#ifdef XP_MACOSX
#include <sys/sysctl.h>
#endif

extern mozilla::LazyLogModule gMediaStreamGraphLog;
#define STREAM_LOG(type, msg) MOZ_LOG(gMediaStreamGraphLog, type, msg)

// We don't use NSPR log here because we want this interleaved with adb logcat
// on Android/B2G
// #define ENABLE_LIFECYCLE_LOG
#ifdef ENABLE_LIFECYCLE_LOG
#ifdef ANDROID
#include "android/log.h"
#define LIFECYCLE_LOG(...)  __android_log_print(ANDROID_LOG_INFO, "Gecko - MSG" , __VA_ARGS__); printf(__VA_ARGS__);printf("\n");
#else
#define LIFECYCLE_LOG(...) printf(__VA_ARGS__);printf("\n");
#endif
#else
#define LIFECYCLE_LOG(...)
#endif

namespace mozilla {

struct AutoProfilerUnregisterThread
{
  // The empty ctor is used to silence a pre-4.8.0 GCC unused variable warning.
  AutoProfilerUnregisterThread()
  {
  }

  ~AutoProfilerUnregisterThread()
  {
    profiler_unregister_thread();
  }
};

GraphDriver::GraphDriver(MediaStreamGraphImpl* aGraphImpl)
  : mIterationStart(0),
    mIterationEnd(0),
    mGraphImpl(aGraphImpl),
    mWaitState(WAITSTATE_RUNNING),
    mCurrentTimeStamp(TimeStamp::Now()),
    mPreviousDriver(nullptr),
    mNextDriver(nullptr)
{ }

void GraphDriver::SetGraphTime(GraphDriver* aPreviousDriver,
                               GraphTime aLastSwitchNextIterationStart,
                               GraphTime aLastSwitchNextIterationEnd)
{
  // We set mIterationEnd here, because the first thing a driver do when it
  // does an iteration is to update graph times, so we are in fact setting
  // mIterationStart of the next iteration by setting the end of the previous
  // iteration.
  mIterationStart = aLastSwitchNextIterationStart;
  mIterationEnd = aLastSwitchNextIterationEnd;

  STREAM_LOG(LogLevel::Debug, ("Setting previous driver: %p (%s)", aPreviousDriver, aPreviousDriver->AsAudioCallbackDriver() ? "AudioCallbackDriver" : "SystemClockDriver"));
  MOZ_ASSERT(!mPreviousDriver);
  mPreviousDriver = aPreviousDriver;
}

void GraphDriver::SwitchAtNextIteration(GraphDriver* aNextDriver)
{
  // This is the situation where `mPreviousDriver` is an AudioCallbackDriver
  // that is switching device, and the graph has found the current driver is not
  // an AudioCallbackDriver, but tries to switch to a _new_ AudioCallbackDriver
  // because it found audio has to be output. In this case, simply ignore the
  // request to switch, since we know we will switch back to the old
  // AudioCallbackDriver when it has recovered from the device switching.
  if (aNextDriver->AsAudioCallbackDriver() &&
      mPreviousDriver &&
      mPreviousDriver->AsAudioCallbackDriver()->IsSwitchingDevice() &&
      mPreviousDriver != aNextDriver) {
    return;
  }
  LIFECYCLE_LOG("Switching to new driver: %p (%s)",
      aNextDriver, aNextDriver->AsAudioCallbackDriver() ?
      "AudioCallbackDriver" : "SystemClockDriver");
  mNextDriver = aNextDriver;
}

void GraphDriver::EnsureImmediateWakeUpLocked()
{
  mGraphImpl->GetMonitor().AssertCurrentThreadOwns();
  mWaitState = WAITSTATE_WAKING_UP;
  mGraphImpl->mGraphDriverAsleep = false; // atomic
  mGraphImpl->GetMonitor().Notify();
}

GraphTime
GraphDriver::StateComputedTime() const
{
  return mGraphImpl->mStateComputedTime;
}

void GraphDriver::EnsureNextIteration()
{
  mGraphImpl->EnsureNextIteration();
}

class MediaStreamGraphShutdownThreadRunnable : public nsRunnable {
public:
  explicit MediaStreamGraphShutdownThreadRunnable(GraphDriver* aDriver)
    : mDriver(aDriver)
  {
  }
  NS_IMETHOD Run()
  {
    MOZ_ASSERT(NS_IsMainThread());

    LIFECYCLE_LOG("MediaStreamGraphShutdownThreadRunnable for graph %p",
        mDriver->GraphImpl());
    // We can't release an audio driver on the main thread, because it can be
    // blocking.
    if (mDriver->AsAudioCallbackDriver()) {
      LIFECYCLE_LOG("Releasing audio driver off main thread.");
      RefPtr<AsyncCubebTask> releaseEvent =
        new AsyncCubebTask(mDriver->AsAudioCallbackDriver(),
                           AsyncCubebOperation::SHUTDOWN);
      mDriver = nullptr;
      releaseEvent->Dispatch();
    } else {
      LIFECYCLE_LOG("Dropping driver reference for SystemClockDriver.");
      mDriver = nullptr;
    }
    return NS_OK;
  }
private:
  RefPtr<GraphDriver> mDriver;
};

void GraphDriver::Shutdown()
{
  if (AsAudioCallbackDriver()) {
    LIFECYCLE_LOG("Releasing audio driver off main thread (GraphDriver::Shutdown).\n");
    RefPtr<AsyncCubebTask> releaseEvent =
      new AsyncCubebTask(AsAudioCallbackDriver(), AsyncCubebOperation::SHUTDOWN);
    releaseEvent->Dispatch();
  } else {
    Stop();
  }
}

ThreadedDriver::ThreadedDriver(MediaStreamGraphImpl* aGraphImpl)
  : GraphDriver(aGraphImpl)
{ }

ThreadedDriver::~ThreadedDriver()
{
  if (mThread) {
    mThread->Shutdown();
  }
}
class MediaStreamGraphInitThreadRunnable : public nsRunnable {
public:
  explicit MediaStreamGraphInitThreadRunnable(ThreadedDriver* aDriver)
    : mDriver(aDriver)
  {
  }
  NS_IMETHOD Run()
  {
    char aLocal;
    STREAM_LOG(LogLevel::Debug, ("Starting system thread"));
    profiler_register_thread("MediaStreamGraph", &aLocal);
    LIFECYCLE_LOG("Starting a new system driver for graph %p\n",
                  mDriver->mGraphImpl);
    if (mDriver->mPreviousDriver) {
      LIFECYCLE_LOG("%p releasing an AudioCallbackDriver(%p), for graph %p\n",
                    mDriver,
                    mDriver->mPreviousDriver.get(),
                    mDriver->GraphImpl());
      MOZ_ASSERT(!mDriver->AsAudioCallbackDriver());
      // Stop and release the previous driver off-main-thread, but only if we're
      // not in the situation where we've fallen back to a system clock driver
      // because the osx audio stack is currently switching output device.
      if (!mDriver->mPreviousDriver->AsAudioCallbackDriver()->IsSwitchingDevice()) {
        RefPtr<AsyncCubebTask> releaseEvent =
          new AsyncCubebTask(mDriver->mPreviousDriver->AsAudioCallbackDriver(), AsyncCubebOperation::SHUTDOWN);
        mDriver->mPreviousDriver = nullptr;
        releaseEvent->Dispatch();
      }
    } else {
      MonitorAutoLock mon(mDriver->mGraphImpl->GetMonitor());
      MOZ_ASSERT(mDriver->mGraphImpl->MessagesQueued(), "Don't start a graph without messages queued.");
      mDriver->mGraphImpl->SwapMessageQueues();
    }
    mDriver->RunThread();
    return NS_OK;
  }
private:
  RefPtr<ThreadedDriver> mDriver;
};

void
ThreadedDriver::Start()
{
  LIFECYCLE_LOG("Starting thread for a SystemClockDriver  %p\n", mGraphImpl);
  nsCOMPtr<nsIRunnable> event = new MediaStreamGraphInitThreadRunnable(this);
  // Note: mThread may be null during event->Run() if we pass to NewNamedThread!  See AudioInitTask
  nsresult rv = NS_NewNamedThread("MediaStreamGrph", getter_AddRefs(mThread));
  if (NS_SUCCEEDED(rv)) {
    mThread->Dispatch(event, NS_DISPATCH_NORMAL);
  }
}

void
ThreadedDriver::Resume()
{
  Start();
}

void
ThreadedDriver::Revive()
{
  // Note: only called on MainThread, without monitor
  // We know were weren't in a running state
  STREAM_LOG(LogLevel::Debug, ("AudioCallbackDriver reviving."));
  // If we were switching, switch now. Otherwise, tell thread to run the main
  // loop again.
  MonitorAutoLock mon(mGraphImpl->GetMonitor());
  if (mNextDriver) {
    mNextDriver->SetGraphTime(this, mIterationStart, mIterationEnd);
    mGraphImpl->SetCurrentDriver(mNextDriver);
    mNextDriver->Start();
  } else {
    nsCOMPtr<nsIRunnable> event = new MediaStreamGraphInitThreadRunnable(this);
    mThread->Dispatch(event, NS_DISPATCH_NORMAL);
  }
}

void
ThreadedDriver::Stop()
{
  NS_ASSERTION(NS_IsMainThread(), "Must be called on main thread");
  // mGraph's thread is not running so it's OK to do whatever here
  STREAM_LOG(LogLevel::Debug, ("Stopping threads for MediaStreamGraph %p", this));

  if (mThread) {
    mThread->Shutdown();
    mThread = nullptr;
  }
}

SystemClockDriver::SystemClockDriver(MediaStreamGraphImpl* aGraphImpl)
  : ThreadedDriver(aGraphImpl),
    mInitialTimeStamp(TimeStamp::Now()),
    mLastTimeStamp(TimeStamp::Now())
{}

SystemClockDriver::~SystemClockDriver()
{ }

void
ThreadedDriver::RunThread()
{
  AutoProfilerUnregisterThread autoUnregister;

  bool stillProcessing = true;
  while (stillProcessing) {
    mIterationStart = IterationEnd();
    mIterationEnd += GetIntervalForIteration();

    GraphTime stateComputedTime = StateComputedTime();
    if (stateComputedTime < mIterationEnd) {
      STREAM_LOG(LogLevel::Warning, ("Media graph global underrun detected"));
      mIterationEnd = stateComputedTime;
    }

    if (mIterationStart >= mIterationEnd) {
      NS_ASSERTION(mIterationStart == mIterationEnd ,
                   "Time can't go backwards!");
      // This could happen due to low clock resolution, maybe?
      STREAM_LOG(LogLevel::Debug, ("Time did not advance"));
    }

    GraphTime nextStateComputedTime =
      mGraphImpl->RoundUpToNextAudioBlock(
        mIterationEnd + mGraphImpl->MillisecondsToMediaTime(AUDIO_TARGET_MS));
    if (nextStateComputedTime < stateComputedTime) {
      // A previous driver may have been processing further ahead of
      // iterationEnd.
      STREAM_LOG(LogLevel::Warning,
                 ("Prevent state from going backwards. interval[%ld; %ld] state[%ld; %ld]",
                  (long)mIterationStart, (long)mIterationEnd,
                  (long)stateComputedTime, (long)nextStateComputedTime));
      nextStateComputedTime = stateComputedTime;
    }
    STREAM_LOG(LogLevel::Debug,
               ("interval[%ld; %ld] state[%ld; %ld]",
               (long)mIterationStart, (long)mIterationEnd,
               (long)stateComputedTime, (long)nextStateComputedTime));

    stillProcessing = mGraphImpl->OneIteration(nextStateComputedTime);

    if (mNextDriver && stillProcessing) {
      STREAM_LOG(LogLevel::Debug, ("Switching to AudioCallbackDriver"));
      mNextDriver->SetGraphTime(this, mIterationStart, mIterationEnd);
      mGraphImpl->SetCurrentDriver(mNextDriver);
      mNextDriver->Start();
      return;
    }
  }
}

MediaTime
SystemClockDriver::GetIntervalForIteration()
{
  TimeStamp now = TimeStamp::Now();
  MediaTime interval =
    mGraphImpl->SecondsToMediaTime((now - mCurrentTimeStamp).ToSeconds());
  mCurrentTimeStamp = now;

  MOZ_LOG(gMediaStreamGraphLog, LogLevel::Verbose,
          ("Updating current time to %f (real %f, StateComputedTime() %f)",
           mGraphImpl->MediaTimeToSeconds(IterationEnd() + interval),
           (now - mInitialTimeStamp).ToSeconds(),
           mGraphImpl->MediaTimeToSeconds(StateComputedTime())));

  return interval;
}

TimeStamp
OfflineClockDriver::GetCurrentTimeStamp()
{
  MOZ_CRASH("This driver does not support getting the current timestamp.");
  return TimeStamp();
}

void
SystemClockDriver::WaitForNextIteration()
{
  mGraphImpl->GetMonitor().AssertCurrentThreadOwns();

  PRIntervalTime timeout = PR_INTERVAL_NO_TIMEOUT;
  TimeStamp now = TimeStamp::Now();
  if (mGraphImpl->mNeedAnotherIteration) {
    int64_t timeoutMS = MEDIA_GRAPH_TARGET_PERIOD_MS -
      int64_t((now - mCurrentTimeStamp).ToMilliseconds());
    // Make sure timeoutMS doesn't overflow 32 bits by waking up at
    // least once a minute, if we need to wake up at all
    timeoutMS = std::max<int64_t>(0, std::min<int64_t>(timeoutMS, 60*1000));
    timeout = PR_MillisecondsToInterval(uint32_t(timeoutMS));
    STREAM_LOG(LogLevel::Verbose, ("Waiting for next iteration; at %f, timeout=%f", (now - mInitialTimeStamp).ToSeconds(), timeoutMS/1000.0));
    if (mWaitState == WAITSTATE_WAITING_INDEFINITELY) {
      mGraphImpl->mGraphDriverAsleep = false; // atomic
    }
    mWaitState = WAITSTATE_WAITING_FOR_NEXT_ITERATION;
  } else {
    mGraphImpl->mGraphDriverAsleep = true; // atomic
    mWaitState = WAITSTATE_WAITING_INDEFINITELY;
  }
  if (timeout > 0) {
    mGraphImpl->GetMonitor().Wait(timeout);
    STREAM_LOG(LogLevel::Verbose, ("Resuming after timeout; at %f, elapsed=%f",
          (TimeStamp::Now() - mInitialTimeStamp).ToSeconds(),
          (TimeStamp::Now() - now).ToSeconds()));
  }

  if (mWaitState == WAITSTATE_WAITING_INDEFINITELY) {
    mGraphImpl->mGraphDriverAsleep = false; // atomic
  }
  mWaitState = WAITSTATE_RUNNING;
  mGraphImpl->mNeedAnotherIteration = false;
}

void
SystemClockDriver::WakeUp()
{
  mGraphImpl->GetMonitor().AssertCurrentThreadOwns();
  mWaitState = WAITSTATE_WAKING_UP;
  mGraphImpl->mGraphDriverAsleep = false; // atomic
  mGraphImpl->GetMonitor().Notify();
}

OfflineClockDriver::OfflineClockDriver(MediaStreamGraphImpl* aGraphImpl, GraphTime aSlice)
  : ThreadedDriver(aGraphImpl),
    mSlice(aSlice)
{

}

class MediaStreamGraphShutdownThreadRunnable2 : public nsRunnable {
public:
  explicit MediaStreamGraphShutdownThreadRunnable2(nsIThread* aThread)
    : mThread(aThread)
  {
  }
  NS_IMETHOD Run()
  {
    MOZ_ASSERT(NS_IsMainThread());
    MOZ_ASSERT(mThread);

    mThread->Shutdown();
    mThread = nullptr;
    return NS_OK;
  }
private:
  nsCOMPtr<nsIThread> mThread;
};

OfflineClockDriver::~OfflineClockDriver()
{
  // transfer the ownership of mThread to the event
  // XXX should use .forget()/etc
  if (mThread) {
    nsCOMPtr<nsIRunnable> event = new MediaStreamGraphShutdownThreadRunnable2(mThread);
    mThread = nullptr;
    NS_DispatchToMainThread(event);
  }
}

MediaTime
OfflineClockDriver::GetIntervalForIteration()
{
  return mGraphImpl->MillisecondsToMediaTime(mSlice);
}

void
OfflineClockDriver::WaitForNextIteration()
{
  // No op: we want to go as fast as possible when we are offline
}

void
OfflineClockDriver::WakeUp()
{
  MOZ_ASSERT(false, "An offline graph should not have to wake up.");
}

AsyncCubebTask::AsyncCubebTask(AudioCallbackDriver* aDriver, AsyncCubebOperation aOperation)
  : mDriver(aDriver),
    mOperation(aOperation),
    mShutdownGrip(aDriver->GraphImpl())
{
  NS_WARN_IF_FALSE(mDriver->mAudioStream || aOperation == INIT, "No audio stream !");
}

AsyncCubebTask::~AsyncCubebTask()
{
}

NS_IMETHODIMP
AsyncCubebTask::Run()
{
  MOZ_ASSERT(mThread);
  if (NS_IsMainThread()) {
    mThread->Shutdown(); // can't shutdown from the thread itself, darn
    // don't null out mThread!
    // See bug 999104.  we must hold a ref to the thread across Dispatch()
    // since the internal mthread ref could be released while processing
    // the Dispatch(), and Dispatch/PutEvent itself doesn't hold a ref; it
    // assumes the caller does.
    return NS_OK;
  }

  MOZ_ASSERT(mDriver);

  switch(mOperation) {
    case AsyncCubebOperation::INIT: {
      LIFECYCLE_LOG("AsyncCubebOperation::INIT\n");
      mDriver->Init();
      mDriver->CompleteAudioContextOperations(mOperation);
      break;
    }
    case AsyncCubebOperation::SHUTDOWN: {
      LIFECYCLE_LOG("AsyncCubebOperation::SHUTDOWN\n");
      mDriver->Stop();

      mDriver->CompleteAudioContextOperations(mOperation);

      mDriver = nullptr;
      mShutdownGrip = nullptr;
      break;
    }
    default:
      MOZ_CRASH("Operation not implemented.");
  }

  // and now kill this thread
  NS_DispatchToMainThread(this);

  return NS_OK;
}

StreamAndPromiseForOperation::StreamAndPromiseForOperation(MediaStream* aStream,
                                          void* aPromise,
                                          dom::AudioContextOperation aOperation)
  : mStream(aStream)
  , mPromise(aPromise)
  , mOperation(aOperation)
{
  // MOZ_ASSERT(aPromise);
}

AudioCallbackDriver::AudioCallbackDriver(MediaStreamGraphImpl* aGraphImpl)
  : GraphDriver(aGraphImpl)
  , mSampleRate(0)
  , mIterationDurationMS(MEDIA_GRAPH_TARGET_PERIOD_MS)
  , mStarted(false)
  , mAudioChannel(aGraphImpl->AudioChannel())
  , mInCallback(false)
  , mPauseRequested(false)
  , mMicrophoneActive(false)
#ifdef XP_MACOSX
  , mCallbackReceivedWhileSwitching(0)
#endif
{
  STREAM_LOG(LogLevel::Debug, ("AudioCallbackDriver ctor for graph %p", aGraphImpl));
}

AudioCallbackDriver::~AudioCallbackDriver()
{
  MOZ_ASSERT(mPromisesForOperation.IsEmpty());
}

void
AudioCallbackDriver::Init()
{
  cubeb_stream_params params;
  uint32_t latency;

  MOZ_ASSERT(!NS_IsMainThread(),
      "This is blocking and should never run on the main thread.");

  mSampleRate = params.rate = CubebUtils::PreferredSampleRate();

#if defined(__ANDROID__)
#if defined(MOZ_B2G)
  params.stream_type = CubebUtils::ConvertChannelToCubebType(mAudioChannel);
#else
  params.stream_type = CUBEB_STREAM_TYPE_MUSIC;
#endif
  if (params.stream_type == CUBEB_STREAM_TYPE_MAX) {
    NS_WARNING("Bad stream type");
    return;
  }
#else
  (void)mAudioChannel;
#endif

  params.channels = mGraphImpl->AudioChannelCount();
  if (AUDIO_OUTPUT_FORMAT == AUDIO_FORMAT_S16) {
    params.format = CUBEB_SAMPLE_S16NE;
  } else {
    params.format = CUBEB_SAMPLE_FLOAT32NE;
  }

  if (cubeb_get_min_latency(CubebUtils::GetCubebContext(), params, &latency) != CUBEB_OK) {
    NS_WARNING("Could not get minimal latency from cubeb.");
  }

  cubeb_stream* stream;
  if (cubeb_stream_init(CubebUtils::GetCubebContext(), &stream,
                        "AudioCallbackDriver", params, latency,
                        DataCallback_s, StateCallback_s, this) == CUBEB_OK) {
    mAudioStream.own(stream);
  } else {
    NS_WARNING("Could not create a cubeb stream for MediaStreamGraph, falling back to a SystemClockDriver");
    // Fall back to a driver using a normal thread. If needed,
    // the graph will try to re-open an audio stream later.
    mNextDriver = new SystemClockDriver(GraphImpl());
    mNextDriver->SetGraphTime(this, mIterationStart, mIterationEnd);
    // We're not using SwitchAtNextIteration here, because there
    // won't be a next iteration if we don't restart things manually:
    // the audio stream just signaled that it's in error state.
    mGraphImpl->SetCurrentDriver(mNextDriver);
    DebugOnly<bool> found = mGraphImpl->RemoveMixerCallback(this);
    NS_WARN_IF_FALSE(!found, "Mixer callback not added when switching?");
    mNextDriver->Start();
    return;
  }

  cubeb_stream_register_device_changed_callback(mAudioStream,
                                                AudioCallbackDriver::DeviceChangedCallback_s);

  StartStream();

  STREAM_LOG(LogLevel::Debug, ("AudioCallbackDriver started."));
}


void
AudioCallbackDriver::Destroy()
{
  STREAM_LOG(LogLevel::Debug, ("AudioCallbackDriver destroyed."));
  mAudioStream.reset();
}

void
AudioCallbackDriver::Resume()
{
  STREAM_LOG(LogLevel::Debug, ("Resuming audio threads for MediaStreamGraph %p", mGraphImpl));
  if (cubeb_stream_start(mAudioStream) != CUBEB_OK) {
    NS_WARNING("Could not start cubeb stream for MSG.");
  }
}

void
AudioCallbackDriver::Start()
{
  // If this is running on the main thread, we can't open the stream directly,
  // because it is a blocking operation.
  if (NS_IsMainThread()) {
    STREAM_LOG(LogLevel::Debug, ("Starting audio threads for MediaStreamGraph %p from a new thread.", mGraphImpl));
    RefPtr<AsyncCubebTask> initEvent =
      new AsyncCubebTask(this, AsyncCubebOperation::INIT);
    initEvent->Dispatch();
  } else {
    STREAM_LOG(LogLevel::Debug, ("Starting audio threads for MediaStreamGraph %p from the previous driver's thread", mGraphImpl));
    Init();

    // Check if we need to resolve promises because the driver just got switched
    // because of a resuming AudioContext
    if (!mPromisesForOperation.IsEmpty()) {
      CompleteAudioContextOperations(AsyncCubebOperation::INIT);
    }

    if (mPreviousDriver) {
      nsCOMPtr<nsIRunnable> event =
        new MediaStreamGraphShutdownThreadRunnable(mPreviousDriver);
      mPreviousDriver = nullptr;
      NS_DispatchToMainThread(event);
    }
  }
}

void
AudioCallbackDriver::StartStream()
{
  if (cubeb_stream_start(mAudioStream) != CUBEB_OK) {
    MOZ_CRASH("Could not start cubeb stream for MSG.");
  }

  {
    MonitorAutoLock mon(mGraphImpl->GetMonitor());
    mStarted = true;
    mWaitState = WAITSTATE_RUNNING;
  }
}

void
AudioCallbackDriver::Stop()
{
  if (cubeb_stream_stop(mAudioStream) != CUBEB_OK) {
    NS_WARNING("Could not stop cubeb stream for MSG.");
  }
}

void
AudioCallbackDriver::Revive()
{
  // Note: only called on MainThread, without monitor
  // We know were weren't in a running state
  STREAM_LOG(LogLevel::Debug, ("AudioCallbackDriver reviving."));
  // If we were switching, switch now. Otherwise, start the audio thread again.
  MonitorAutoLock mon(mGraphImpl->GetMonitor());
  if (mNextDriver) {
    mNextDriver->SetGraphTime(this, mIterationStart, mIterationEnd);
    mGraphImpl->SetCurrentDriver(mNextDriver);
    mNextDriver->Start();
  } else {
    STREAM_LOG(LogLevel::Debug, ("Starting audio threads for MediaStreamGraph %p from a new thread.", mGraphImpl));
    RefPtr<AsyncCubebTask> initEvent =
      new AsyncCubebTask(this, AsyncCubebOperation::INIT);
    initEvent->Dispatch();
  }
}

void AudioCallbackDriver::WaitForNextIteration()
{
}

void
AudioCallbackDriver::WakeUp()
{
  mGraphImpl->GetMonitor().AssertCurrentThreadOwns();
  mGraphImpl->GetMonitor().Notify();
}

/* static */ long
AudioCallbackDriver::DataCallback_s(cubeb_stream* aStream,
                                    void* aUser, void* aBuffer,
                                    long aFrames)
{
  AudioCallbackDriver* driver = reinterpret_cast<AudioCallbackDriver*>(aUser);
  return driver->DataCallback(static_cast<AudioDataValue*>(aBuffer), aFrames);
}

/* static */ void
AudioCallbackDriver::StateCallback_s(cubeb_stream* aStream, void * aUser,
                                     cubeb_state aState)
{
  AudioCallbackDriver* driver = reinterpret_cast<AudioCallbackDriver*>(aUser);
  driver->StateCallback(aState);
}

/* static */ void
AudioCallbackDriver::DeviceChangedCallback_s(void* aUser)
{
  AudioCallbackDriver* driver = reinterpret_cast<AudioCallbackDriver*>(aUser);
  driver->DeviceChangedCallback();
}

bool AudioCallbackDriver::InCallback() {
  return mInCallback;
}

AudioCallbackDriver::AutoInCallback::AutoInCallback(AudioCallbackDriver* aDriver)
  : mDriver(aDriver)
{
  mDriver->mInCallback = true;
}

AudioCallbackDriver::AutoInCallback::~AutoInCallback() {
  mDriver->mInCallback = false;
}

#ifdef XP_MACOSX
bool
AudioCallbackDriver::OSXDeviceSwitchingWorkaround()
{
  MonitorAutoLock mon(GraphImpl()->GetMonitor());
  if (mSelfReference) {
    // Apparently, depending on the osx version, on device switch, the
    // callback is called "some" number of times, and then stops being called,
    // and then gets called again. 10 is to be safe, it's a low-enough number
    // of milliseconds anyways (< 100ms)
    //STREAM_LOG(LogLevel::Debug, ("Callbacks during switch: %d", mCallbackReceivedWhileSwitching+1));
    if (mCallbackReceivedWhileSwitching++ >= 10) {
      STREAM_LOG(LogLevel::Debug, ("Got %d callbacks, switching back to CallbackDriver", mCallbackReceivedWhileSwitching));
      // If we have a self reference, we have fallen back temporarily on a
      // system clock driver, but we just got called back, that means the osx
      // audio backend has switched to the new device.
      // Ask the graph to switch back to the previous AudioCallbackDriver
      // (`this`), and when the graph has effectively switched, we can drop
      // the self reference and unref the SystemClockDriver we fallen back on.
      if (GraphImpl()->CurrentDriver() == this) {
        mSelfReference.Drop(this);
        mNextDriver = nullptr;
      } else {
        GraphImpl()->CurrentDriver()->SwitchAtNextIteration(this);
      }

    }
    return true;
  }

  return false;
}
#endif // XP_MACOSX

long
AudioCallbackDriver::DataCallback(AudioDataValue* aBuffer, long aFrames)
{
  bool stillProcessing;

  if (mPauseRequested) {
    PodZero(aBuffer, aFrames * mGraphImpl->AudioChannelCount());
    return aFrames;
  }

#ifdef XP_MACOSX
  if (OSXDeviceSwitchingWorkaround()) {
    PodZero(aBuffer, aFrames * mGraphImpl->AudioChannelCount());
    return aFrames;
  }
#endif

#ifdef DEBUG
  // DebugOnly<> doesn't work here... it forces an initialization that will cause
  // mInCallback to be set back to false before we exit the statement.  Do it by
  // hand instead.
  AutoInCallback aic(this);
#endif

  GraphTime stateComputedTime = StateComputedTime();
  if (stateComputedTime == 0) {
    MonitorAutoLock mon(mGraphImpl->GetMonitor());
    // Because this function is called during cubeb_stream_init (to prefill the
    // audio buffers), it can be that we don't have a message here (because this
    // driver is the first one for this graph), and the graph would exit. Simply
    // return here until we have messages.
    if (!mGraphImpl->MessagesQueued()) {
      PodZero(aBuffer, aFrames * mGraphImpl->AudioChannelCount());
      return aFrames;
    }
    mGraphImpl->SwapMessageQueues();
  }

  uint32_t durationMS = aFrames * 1000 / mSampleRate;

  // For now, simply average the duration with the previous
  // duration so there is some damping against sudden changes.
  if (!mIterationDurationMS) {
    mIterationDurationMS = durationMS;
  } else {
    mIterationDurationMS = (mIterationDurationMS*3) + durationMS;
    mIterationDurationMS /= 4;
  }

  mBuffer.SetBuffer(aBuffer, aFrames);
  // fill part or all with leftover data from last iteration (since we
  // align to Audio blocks)
  mScratchBuffer.Empty(mBuffer);
  // if we totally filled the buffer (and mScratchBuffer isn't empty),
  // we don't need to run an iteration and if we do so we may overflow.
  if (mBuffer.Available()) {

    // State computed time is decided by the audio callback's buffer length. We
    // compute the iteration start and end from there, trying to keep the amount
    // of buffering in the graph constant.
    GraphTime nextStateComputedTime =
      mGraphImpl->RoundUpToNextAudioBlock(stateComputedTime + mBuffer.Available());

    mIterationStart = mIterationEnd;
    // inGraph is the number of audio frames there is between the state time and
    // the current time, i.e. the maximum theoretical length of the interval we
    // could use as [mIterationStart; mIterationEnd].
    GraphTime inGraph = stateComputedTime - mIterationStart;
    // We want the interval [mIterationStart; mIterationEnd] to be before the
    // interval [stateComputedTime; nextStateComputedTime]. We also want
    // the distance between these intervals to be roughly equivalent each time, to
    // ensure there is no clock drift between current time and state time. Since
    // we can't act on the state time because we have to fill the audio buffer, we
    // reclock the current time against the state time, here.
    mIterationEnd = mIterationStart + 0.8 * inGraph;

    STREAM_LOG(LogLevel::Debug, ("interval[%ld; %ld] state[%ld; %ld] (frames: %ld) (durationMS: %u) (duration ticks: %ld)\n",
                              (long)mIterationStart, (long)mIterationEnd,
                              (long)stateComputedTime, (long)nextStateComputedTime,
                              (long)aFrames, (uint32_t)durationMS,
                              (long)(nextStateComputedTime - stateComputedTime)));

    mCurrentTimeStamp = TimeStamp::Now();

    if (stateComputedTime < mIterationEnd) {
      STREAM_LOG(LogLevel::Warning, ("Media graph global underrun detected"));
      mIterationEnd = stateComputedTime;
    }

    stillProcessing = mGraphImpl->OneIteration(nextStateComputedTime);
  } else {
    NS_WARNING("DataCallback buffer filled entirely from scratch buffer, skipping iteration.");
    stillProcessing = true;
  }

  mBuffer.BufferFilled();

  if (mNextDriver && stillProcessing) {
    {
      // If the audio stream has not been started by the previous driver or
      // the graph itself, keep it alive.
      MonitorAutoLock mon(mGraphImpl->GetMonitor());
      if (!IsStarted()) {
        return aFrames;
      }
    }
    STREAM_LOG(LogLevel::Debug, ("Switching to system driver."));
    mNextDriver->SetGraphTime(this, mIterationStart, mIterationEnd);
    mGraphImpl->SetCurrentDriver(mNextDriver);
    mNextDriver->Start();
    // Returning less than aFrames starts the draining and eventually stops the
    // audio thread. This function will never get called again.
    return aFrames - 1;
  }

  if (!stillProcessing) {
    LIFECYCLE_LOG("Stopping audio thread for MediaStreamGraph %p", this);
    return aFrames - 1;
  }
  return aFrames;
}

void
AudioCallbackDriver::StateCallback(cubeb_state aState)
{
  STREAM_LOG(LogLevel::Debug, ("AudioCallbackDriver State: %d", aState));
  if (aState == CUBEB_STATE_ERROR) {
    // Fall back to a driver using a normal thread.
    MonitorAutoLock lock(GraphImpl()->GetMonitor());
    SystemClockDriver* nextDriver = new SystemClockDriver(GraphImpl());
    mNextDriver = nextDriver;
    DebugOnly<bool> found = mGraphImpl->RemoveMixerCallback(this);
    nextDriver->SetGraphTime(this, mIterationStart, mIterationEnd);
    mGraphImpl->SetCurrentDriver(nextDriver);
    nextDriver->Start();
  }
}

void
AudioCallbackDriver::MixerCallback(AudioDataValue* aMixedBuffer,
                                   AudioSampleFormat aFormat,
                                   uint32_t aChannels,
                                   uint32_t aFrames,
                                   uint32_t aSampleRate)
{
  uint32_t toWrite = mBuffer.Available();

  if (!mBuffer.Available()) {
    NS_WARNING("DataCallback buffer full, expect frame drops.");
  }

  MOZ_ASSERT(mBuffer.Available() <= aFrames);

  mBuffer.WriteFrames(aMixedBuffer, mBuffer.Available());
  MOZ_ASSERT(mBuffer.Available() == 0, "Missing frames to fill audio callback's buffer.");

  DebugOnly<uint32_t> written = mScratchBuffer.Fill(aMixedBuffer + toWrite * aChannels, aFrames - toWrite);
  NS_WARN_IF_FALSE(written == aFrames - toWrite, "Dropping frames.");
};

void AudioCallbackDriver::PanOutputIfNeeded(bool aMicrophoneActive)
{
#ifdef XP_MACOSX
  cubeb_device* out;
  int rv;
  char name[128];
  size_t length = sizeof(name);

  rv = sysctlbyname("hw.model", name, &length, NULL, 0);
  if (rv) {
    return;
  }

  if (!strncmp(name, "MacBookPro", 10)) {
    if (cubeb_stream_get_current_device(mAudioStream, &out) == CUBEB_OK) {
      // Check if we are currently outputing sound on external speakers.
      if (!strcmp(out->output_name, "ispk")) {
        // Pan everything to the right speaker.
        if (aMicrophoneActive) {
          if (cubeb_stream_set_panning(mAudioStream, 1.0) != CUBEB_OK) {
            NS_WARNING("Could not pan audio output to the right.");
          }
        } else {
          if (cubeb_stream_set_panning(mAudioStream, 0.0) != CUBEB_OK) {
            NS_WARNING("Could not pan audio output to the center.");
          }
        }
      } else {
        if (cubeb_stream_set_panning(mAudioStream, 0.0) != CUBEB_OK) {
          NS_WARNING("Could not pan audio output to the center.");
        }
      }
      cubeb_stream_device_destroy(mAudioStream, out);
    }
  }
#endif
}

void
AudioCallbackDriver::DeviceChangedCallback() {
  MonitorAutoLock mon(mGraphImpl->GetMonitor());
  PanOutputIfNeeded(mMicrophoneActive);
  // On OSX, changing the output device causes the audio thread to no call the
  // audio callback, so we're unable to process real-time input data, and this
  // results in latency building up.
  // We switch to a system driver until audio callbacks are called again, so we
  // still pull from the input stream, so that everything works apart from the
  // audio output.
#ifdef XP_MACOSX
  // Don't bother doing the device switching dance if the graph is not RUNNING
  // (starting up, shutting down), because we haven't started pulling from the
  // SourceMediaStream.
  if (!GraphImpl()->Running()) {
    return;
  }

  if (mSelfReference) {
    return;
  }
  STREAM_LOG(LogLevel::Error, ("Switching to SystemClockDriver during output switch"));
  mSelfReference.Take(this);
  mCallbackReceivedWhileSwitching = 0;
  mNextDriver = new SystemClockDriver(GraphImpl());
  mNextDriver->SetGraphTime(this, mIterationStart, mIterationEnd);
  mGraphImpl->SetCurrentDriver(mNextDriver);
  mNextDriver->Start();
#endif
}

void
AudioCallbackDriver::SetMicrophoneActive(bool aActive)
{
  MonitorAutoLock mon(mGraphImpl->GetMonitor());

  mMicrophoneActive = aActive;

  PanOutputIfNeeded(mMicrophoneActive);
}

uint32_t
AudioCallbackDriver::IterationDuration()
{
  // The real fix would be to have an API in cubeb to give us the number. Short
  // of that, we approximate it here. bug 1019507
  return mIterationDurationMS;
}

bool
AudioCallbackDriver::IsStarted() {
  mGraphImpl->GetMonitor().AssertCurrentThreadOwns();
  return mStarted;
}

void
AudioCallbackDriver::EnqueueStreamAndPromiseForOperation(MediaStream* aStream,
                                          void* aPromise,
                                          dom::AudioContextOperation aOperation)
{
  MonitorAutoLock mon(mGraphImpl->GetMonitor());
  mPromisesForOperation.AppendElement(StreamAndPromiseForOperation(aStream,
                                                                   aPromise,
                                                                   aOperation));
}

void AudioCallbackDriver::CompleteAudioContextOperations(AsyncCubebOperation aOperation)
{
  nsAutoTArray<StreamAndPromiseForOperation, 1> array;

  // We can't lock for the whole function because AudioContextOperationCompleted
  // will grab the monitor
  {
    MonitorAutoLock mon(GraphImpl()->GetMonitor());
    array.SwapElements(mPromisesForOperation);
  }

  for (uint32_t i = 0; i < array.Length(); i++) {
    StreamAndPromiseForOperation& s = array[i];
    if ((aOperation == AsyncCubebOperation::INIT &&
         s.mOperation == dom::AudioContextOperation::Resume) ||
        (aOperation == AsyncCubebOperation::SHUTDOWN &&
         s.mOperation != dom::AudioContextOperation::Resume)) {

      GraphImpl()->AudioContextOperationCompleted(s.mStream,
                                                  s.mPromise,
                                                  s.mOperation);
      array.RemoveElementAt(i);
      i--;
    }
  }

  if (!array.IsEmpty()) {
    MonitorAutoLock mon(GraphImpl()->GetMonitor());
    mPromisesForOperation.AppendElements(array);
  }
}


} // namespace mozilla