firefox/dom/media/gtest/TestAudioTrackGraph.cpp

/* -*- 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 "MediaTrackGraphImpl.h"

#include "gmock/gmock.h"
#include "gtest/gtest-printers.h"
#include "gtest/gtest.h"

#include "CrossGraphPort.h"
#include "DeviceInputTrack.h"
#ifdef MOZ_WEBRTC
#  include "MediaEngineWebRTCAudio.h"
#endif  // MOZ_WEBRTC
#include "MockCubeb.h"
#include "mozilla/gtest/WaitFor.h"
#include "mozilla/Preferences.h"
#include "mozilla/SpinEventLoopUntil.h"
#include "WavDumper.h"

using namespace mozilla;
using testing::AtLeast;
using testing::Eq;
using testing::InSequence;
using testing::MockFunction;
using testing::Return;
using testing::StrEq;
using testing::StrictMock;

// Short-hand for InvokeAsync on the current thread.
#define InvokeAsync(f) InvokeAsync(GetCurrentSerialEventTarget(), __func__, f)

// Short-hand for DispatchToCurrentThread with a function.
#define DispatchFunction(f) \
  NS_DispatchToCurrentThread(NS_NewRunnableFunction(__func__, f))

// Short-hand for DispatchToCurrentThread with a method with arguments
#define DispatchMethod(t, m, args...) \
  NS_DispatchToCurrentThread(NewRunnableMethod(__func__, t, m, ##args))

// Short-hand for draining the current threads event queue, i.e. processing
// those runnables dispatched per above.
#define ProcessEventQueue()                     \
  while (NS_ProcessNextEvent(nullptr, false)) { \
  }

namespace {
#ifdef MOZ_WEBRTC
/*
 * Common ControlMessages
 */
struct StartInputProcessing : public ControlMessage {
  const RefPtr<AudioProcessingTrack> mProcessingTrack;
  const RefPtr<AudioInputProcessing> mInputProcessing;

  StartInputProcessing(AudioProcessingTrack* aTrack,
                       AudioInputProcessing* aInputProcessing)
      : ControlMessage(aTrack),
        mProcessingTrack(aTrack),
        mInputProcessing(aInputProcessing) {}
  void Run() override { mInputProcessing->Start(mTrack->Graph()); }
};

struct StopInputProcessing : public ControlMessage {
  const RefPtr<AudioInputProcessing> mInputProcessing;

  explicit StopInputProcessing(AudioProcessingTrack* aTrack,
                               AudioInputProcessing* aInputProcessing)
      : ControlMessage(aTrack), mInputProcessing(aInputProcessing) {}
  void Run() override { mInputProcessing->Stop(mTrack->Graph()); }
};

void QueueApplySettings(AudioProcessingTrack* aTrack,
                        AudioInputProcessing* aInputProcessing,
                        const MediaEnginePrefs& aSettings) {
  aTrack->QueueControlMessageWithNoShutdown(
      [inputProcessing = RefPtr{aInputProcessing}, aSettings,
       // If the track is not connected to a device then the particular
       // AudioDeviceID (nullptr) passed to ReevaluateInputDevice() is not
       // important.
       deviceId = aTrack->DeviceId().valueOr(nullptr),
       graph = aTrack->Graph()] {
        inputProcessing->ApplySettings(graph, deviceId, aSettings);
      });
}

void QueueExpectIsPassThrough(AudioProcessingTrack* aTrack,
                              AudioInputProcessing* aInputProcessing) {
  aTrack->QueueControlMessageWithNoShutdown(
      [inputProcessing = RefPtr{aInputProcessing}, graph = aTrack->Graph()] {
        EXPECT_EQ(inputProcessing->IsPassThrough(graph), true);
      });
}
#endif  // MOZ_WEBRTC

class GoFaster : public ControlMessage {
  MockCubeb* mCubeb;

 public:
  explicit GoFaster(MockCubeb* aCubeb)
      : ControlMessage(nullptr), mCubeb(aCubeb) {}
  void Run() override { mCubeb->GoFaster(); }
};

struct StartNonNativeInput : public ControlMessage {
  const RefPtr<NonNativeInputTrack> mInputTrack;
  RefPtr<AudioInputSource> mInputSource;

  StartNonNativeInput(NonNativeInputTrack* aInputTrack,
                      RefPtr<AudioInputSource>&& aInputSource)
      : ControlMessage(aInputTrack),
        mInputTrack(aInputTrack),
        mInputSource(std::move(aInputSource)) {}
  void Run() override { mInputTrack->StartAudio(std::move(mInputSource)); }
};

struct StopNonNativeInput : public ControlMessage {
  const RefPtr<NonNativeInputTrack> mInputTrack;

  explicit StopNonNativeInput(NonNativeInputTrack* aInputTrack)
      : ControlMessage(aInputTrack), mInputTrack(aInputTrack) {}
  void Run() override { mInputTrack->StopAudio(); }
};

// Helper for detecting when fallback driver has been switched away, for use
// with RunningMode::Manual.
class OnFallbackListener : public MediaTrackListener {
  const RefPtr<MediaTrack> mTrack;
  Atomic<bool> mOnFallback{true};

 public:
  explicit OnFallbackListener(MediaTrack* aTrack) : mTrack(aTrack) {}

  void Reset() { mOnFallback = true; }
  bool OnFallback() { return mOnFallback; }

  void NotifyOutput(MediaTrackGraph*, TrackTime) override {
    if (auto* ad =
            mTrack->GraphImpl()->CurrentDriver()->AsAudioCallbackDriver()) {
      mOnFallback = ad->OnFallback();
    }
  }
};

class MockAudioDataListener : public AudioDataListener {
 protected:
  ~MockAudioDataListener() = default;

 public:
  MockAudioDataListener() = default;

  MOCK_METHOD(uint32_t, RequestedInputChannelCount, (MediaTrackGraph*),
              (const));
  MOCK_METHOD(cubeb_input_processing_params, RequestedInputProcessingParams,
              (MediaTrackGraph*), (const));
  MOCK_METHOD(bool, IsVoiceInput, (MediaTrackGraph*), (const));
  MOCK_METHOD(void, DeviceChanged, (MediaTrackGraph*));
  MOCK_METHOD(void, Disconnect, (MediaTrackGraph*));
  MOCK_METHOD(void, NotifySetRequestedInputProcessingParams,
              (MediaTrackGraph*, int, cubeb_input_processing_params));
  MOCK_METHOD(void, NotifySetRequestedInputProcessingParamsResult,
              (MediaTrackGraph*, int,
               (const Result<cubeb_input_processing_params, int>&)));
};
}  // namespace

/*
 * The set of tests here are a bit special. In part because they're async and
 * depends on the graph thread to function. In part because they depend on main
 * thread stable state to send messages to the graph.
 *
 * Any message sent from the main thread to the graph through the graph's
 * various APIs are scheduled to run in stable state. Stable state occurs after
 * a task in the main thread eventloop has run to completion.
 *
 * Since gtests are generally sync and on main thread, calling into the graph
 * may schedule a stable state runnable but with no task in the eventloop to
 * trigger stable state. Therefore care must be taken to always call into the
 * graph from a task, typically via InvokeAsync or a dispatch to main thread.
 */

TEST(TestAudioTrackGraph, DifferentDeviceIDs)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* g1 = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::AUDIO_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      /*OutputDeviceID*/ nullptr, GetMainThreadSerialEventTarget());

  MediaTrackGraph* g2 = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::AUDIO_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      /*OutputDeviceID*/ reinterpret_cast<cubeb_devid>(1),
      GetMainThreadSerialEventTarget());

  MediaTrackGraph* g1_2 = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::AUDIO_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      /*OutputDeviceID*/ nullptr, GetMainThreadSerialEventTarget());

  MediaTrackGraph* g2_2 = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::AUDIO_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      /*OutputDeviceID*/ reinterpret_cast<cubeb_devid>(1),
      GetMainThreadSerialEventTarget());

  EXPECT_NE(g1, g2) << "Different graphs due to different device ids";
  EXPECT_EQ(g1, g1_2) << "Same graphs for same device ids";
  EXPECT_EQ(g2, g2_2) << "Same graphs for same device ids";

  for (MediaTrackGraph* g : {g1, g2}) {
    // Dummy track to make graph rolling. Add it and remove it to remove the
    // graph from the global hash table and let it shutdown.

    using SourceTrackPromise = MozPromise<SourceMediaTrack*, nsresult, true>;
    auto p = InvokeAsync([g] {
      return SourceTrackPromise::CreateAndResolve(
          g->CreateSourceTrack(MediaSegment::AUDIO), __func__);
    });

    WaitFor(cubeb->StreamInitEvent());
    RefPtr<SourceMediaTrack> dummySource = WaitFor(p).unwrap();

    DispatchMethod(dummySource, &SourceMediaTrack::Destroy);

    WaitFor(cubeb->StreamDestroyEvent());
  }
}

TEST(TestAudioTrackGraph, SetOutputDeviceID)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  // Set the output device id in GetInstance method confirm that it is the one
  // used in cubeb_stream_init.
  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::AUDIO_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      /*OutputDeviceID*/ reinterpret_cast<cubeb_devid>(2),
      GetMainThreadSerialEventTarget());

  // Dummy track to make graph rolling. Add it and remove it to remove the
  // graph from the global hash table and let it shutdown.
  RefPtr<SourceMediaTrack> dummySource;
  DispatchFunction(
      [&] { dummySource = graph->CreateSourceTrack(MediaSegment::AUDIO); });

  RefPtr<SmartMockCubebStream> stream = WaitFor(cubeb->StreamInitEvent());

  EXPECT_EQ(stream->GetOutputDeviceID(), reinterpret_cast<cubeb_devid>(2))
      << "After init confirm the expected output device id";

  // Test has finished, destroy the track to shutdown the MTG.
  DispatchMethod(dummySource, &SourceMediaTrack::Destroy);
  WaitFor(cubeb->StreamDestroyEvent());
}

TEST(TestAudioTrackGraph, StreamName)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  // Initialize a graph with a system thread driver to check that the stream
  // name survives the driver switch.
  MediaTrackGraphImpl* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      /*OutputDeviceID*/ reinterpret_cast<cubeb_devid>(1),
      GetMainThreadSerialEventTarget());
  nsLiteralCString name1("name1");
  graph->CurrentDriver()->SetStreamName(name1);

  // Dummy track to start the graph rolling and switch to an
  // AudioCallbackDriver.
  RefPtr<SourceMediaTrack> dummySource;
  DispatchFunction(
      [&] { dummySource = graph->CreateSourceTrack(MediaSegment::AUDIO); });

  RefPtr<SmartMockCubebStream> stream = WaitFor(cubeb->StreamInitEvent());
  EXPECT_STREQ(stream->StreamName(), name1.get());

  // Test a name change on an existing stream.
  nsLiteralCString name2("name2");
  DispatchFunction([&] {
    graph->QueueControlMessageWithNoShutdown(
        [&] { graph->CurrentDriver()->SetStreamName(name2); });
  });
  nsCString name = WaitFor(stream->NameSetEvent());
  EXPECT_EQ(name, name2);

  // Test has finished. Destroy the track to shutdown the MTG.
  DispatchMethod(dummySource, &SourceMediaTrack::Destroy);
  WaitFor(cubeb->StreamDestroyEvent());
}

TEST(TestAudioTrackGraph, NotifyDeviceStarted)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::AUDIO_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  RefPtr<SourceMediaTrack> dummySource;
  Unused << WaitFor(InvokeAsync([&] {
    // Dummy track to make graph rolling. Add it and remove it to remove the
    // graph from the global hash table and let it shutdown.
    dummySource = graph->CreateSourceTrack(MediaSegment::AUDIO);

    return graph->NotifyWhenDeviceStarted(nullptr);
  }));

  {
    MediaTrackGraphImpl* graph = dummySource->GraphImpl();
    MonitorAutoLock lock(graph->GetMonitor());
    EXPECT_TRUE(graph->CurrentDriver()->AsAudioCallbackDriver());
    EXPECT_TRUE(graph->CurrentDriver()->ThreadRunning());
  }

  // Test has finished, destroy the track to shutdown the MTG.
  DispatchMethod(dummySource, &SourceMediaTrack::Destroy);
  WaitFor(cubeb->StreamDestroyEvent());
}

TEST(TestAudioTrackGraph, NonNativeInputTrackStartAndStop)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  const CubebUtils::AudioDeviceID deviceId = (CubebUtils::AudioDeviceID)1;

  // Add a NonNativeInputTrack to graph, making graph create an output-only
  // AudioCallbackDriver since NonNativeInputTrack is an audio-type MediaTrack.
  RefPtr<NonNativeInputTrack> track;
  DispatchFunction([&] {
    track = new NonNativeInputTrack(graph->GraphRate(), deviceId,
                                    PRINCIPAL_HANDLE_NONE);
    graph->AddTrack(track);
  });

  RefPtr<SmartMockCubebStream> driverStream = WaitFor(cubeb->StreamInitEvent());
  EXPECT_FALSE(driverStream->mHasInput);
  EXPECT_TRUE(driverStream->mHasOutput);

  // Main test below:
  {
    const AudioInputSource::Id sourceId = 1;
    const uint32_t channels = 2;
    const TrackRate rate = 48000;

    // Start and stop the audio in NonNativeInputTrack.
    {
      struct DeviceInfo {
        uint32_t mChannelCount;
        AudioInputType mType;
      };
      using DeviceQueryPromise =
          MozPromise<DeviceInfo, nsresult, /* IsExclusive = */ true>;

      struct DeviceQueryMessage : public ControlMessage {
        const NonNativeInputTrack* mInputTrack;
        MozPromiseHolder<DeviceQueryPromise> mHolder;

        DeviceQueryMessage(NonNativeInputTrack* aInputTrack,
                           MozPromiseHolder<DeviceQueryPromise>&& aHolder)
            : ControlMessage(aInputTrack),
              mInputTrack(aInputTrack),
              mHolder(std::move(aHolder)) {}
        void Run() override {
          DeviceInfo info = {mInputTrack->NumberOfChannels(),
                             mInputTrack->DevicePreference()};
          // mHolder.Resolve(info, __func__);
          mTrack->GraphImpl()->Dispatch(NS_NewRunnableFunction(
              "TestAudioTrackGraph::DeviceQueryMessage",
              [holder = std::move(mHolder), devInfo = info]() mutable {
                holder.Resolve(devInfo, __func__);
              }));
        }
      };

      // No input channels and device preference before start.
      {
        MozPromiseHolder<DeviceQueryPromise> h;
        RefPtr<DeviceQueryPromise> p = h.Ensure(__func__);
        DispatchFunction([&] {
          track->GraphImpl()->AppendMessage(
              MakeUnique<DeviceQueryMessage>(track.get(), std::move(h)));
        });
        Result<DeviceInfo, nsresult> r = WaitFor(p);
        ASSERT_TRUE(r.isOk());
        DeviceInfo info = r.unwrap();

        EXPECT_EQ(info.mChannelCount, 0U);
        EXPECT_EQ(info.mType, AudioInputType::Unknown);
      }

      DispatchFunction([&] {
        track->GraphImpl()->AppendMessage(MakeUnique<StartNonNativeInput>(
            track.get(), MakeRefPtr<AudioInputSource>(
                             MakeRefPtr<AudioInputSourceListener>(track.get()),
                             sourceId, deviceId, channels, true /* voice */,
                             PRINCIPAL_HANDLE_NONE, rate, graph->GraphRate())));
      });
      RefPtr<SmartMockCubebStream> nonNativeStream =
          WaitFor(cubeb->StreamInitEvent());
      EXPECT_TRUE(nonNativeStream->mHasInput);
      EXPECT_FALSE(nonNativeStream->mHasOutput);
      EXPECT_EQ(nonNativeStream->GetInputDeviceID(), deviceId);
      EXPECT_EQ(nonNativeStream->InputChannels(), channels);
      EXPECT_EQ(nonNativeStream->SampleRate(), static_cast<uint32_t>(rate));

      // Input channels and device preference should be set after start.
      {
        MozPromiseHolder<DeviceQueryPromise> h;
        RefPtr<DeviceQueryPromise> p = h.Ensure(__func__);
        DispatchFunction([&] {
          track->GraphImpl()->AppendMessage(
              MakeUnique<DeviceQueryMessage>(track.get(), std::move(h)));
        });
        Result<DeviceInfo, nsresult> r = WaitFor(p);
        ASSERT_TRUE(r.isOk());
        DeviceInfo info = r.unwrap();

        EXPECT_EQ(info.mChannelCount, channels);
        EXPECT_EQ(info.mType, AudioInputType::Voice);
      }

      Unused << WaitFor(nonNativeStream->FramesProcessedEvent());

      DispatchFunction([&] {
        track->GraphImpl()->AppendMessage(
            MakeUnique<StopNonNativeInput>(track.get()));
      });
      RefPtr<SmartMockCubebStream> destroyedStream =
          WaitFor(cubeb->StreamDestroyEvent());
      EXPECT_EQ(destroyedStream.get(), nonNativeStream.get());

      // No input channels and device preference after stop.
      {
        MozPromiseHolder<DeviceQueryPromise> h;
        RefPtr<DeviceQueryPromise> p = h.Ensure(__func__);
        DispatchFunction([&] {
          track->GraphImpl()->AppendMessage(
              MakeUnique<DeviceQueryMessage>(track.get(), std::move(h)));
        });
        Result<DeviceInfo, nsresult> r = WaitFor(p);
        ASSERT_TRUE(r.isOk());
        DeviceInfo info = r.unwrap();

        EXPECT_EQ(info.mChannelCount, 0U);
        EXPECT_EQ(info.mType, AudioInputType::Unknown);
      }
    }

    // Make sure the NonNativeInputTrack can restart and stop its audio.
    {
      DispatchFunction([&] {
        track->GraphImpl()->AppendMessage(MakeUnique<StartNonNativeInput>(
            track.get(), MakeRefPtr<AudioInputSource>(
                             MakeRefPtr<AudioInputSourceListener>(track.get()),
                             sourceId, deviceId, channels, true,
                             PRINCIPAL_HANDLE_NONE, rate, graph->GraphRate())));
      });
      RefPtr<SmartMockCubebStream> nonNativeStream =
          WaitFor(cubeb->StreamInitEvent());
      EXPECT_TRUE(nonNativeStream->mHasInput);
      EXPECT_FALSE(nonNativeStream->mHasOutput);
      EXPECT_EQ(nonNativeStream->GetInputDeviceID(), deviceId);
      EXPECT_EQ(nonNativeStream->InputChannels(), channels);
      EXPECT_EQ(nonNativeStream->SampleRate(), static_cast<uint32_t>(rate));

      Unused << WaitFor(nonNativeStream->FramesProcessedEvent());

      DispatchFunction([&] {
        track->GraphImpl()->AppendMessage(
            MakeUnique<StopNonNativeInput>(track.get()));
      });
      RefPtr<SmartMockCubebStream> destroyedStream =
          WaitFor(cubeb->StreamDestroyEvent());
      EXPECT_EQ(destroyedStream.get(), nonNativeStream.get());
    }
  }

  // Clean up.
  DispatchFunction([&] { track->Destroy(); });
  RefPtr<SmartMockCubebStream> destroyedStream =
      WaitFor(cubeb->StreamDestroyEvent());
  EXPECT_EQ(destroyedStream.get(), driverStream.get());
}

TEST(TestAudioTrackGraph, NonNativeInputTrackErrorCallback)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  const CubebUtils::AudioDeviceID deviceId = (CubebUtils::AudioDeviceID)1;

  // Add a NonNativeInputTrack to graph, making graph create an output-only
  // AudioCallbackDriver since NonNativeInputTrack is an audio-type MediaTrack.
  RefPtr<NonNativeInputTrack> track;
  DispatchFunction([&] {
    track = new NonNativeInputTrack(graph->GraphRate(), deviceId,
                                    PRINCIPAL_HANDLE_NONE);
    graph->AddTrack(track);
  });

  RefPtr<SmartMockCubebStream> driverStream = WaitFor(cubeb->StreamInitEvent());
  EXPECT_FALSE(driverStream->mHasInput);
  EXPECT_TRUE(driverStream->mHasOutput);

  // Main test below:
  {
    const AudioInputSource::Id sourceId = 1;
    const uint32_t channels = 2;
    const TrackRate rate = 48000;

    // Launch and start the non-native audio stream.
    DispatchFunction([&] {
      track->GraphImpl()->AppendMessage(MakeUnique<StartNonNativeInput>(
          track.get(), MakeRefPtr<AudioInputSource>(
                           MakeRefPtr<AudioInputSourceListener>(track.get()),
                           sourceId, deviceId, channels, true,
                           PRINCIPAL_HANDLE_NONE, rate, graph->GraphRate())));
    });
    RefPtr<SmartMockCubebStream> nonNativeStream =
        WaitFor(cubeb->StreamInitEvent());
    EXPECT_TRUE(nonNativeStream->mHasInput);
    EXPECT_FALSE(nonNativeStream->mHasOutput);
    EXPECT_EQ(nonNativeStream->GetInputDeviceID(), deviceId);
    EXPECT_EQ(nonNativeStream->InputChannels(), channels);
    EXPECT_EQ(nonNativeStream->SampleRate(), static_cast<uint32_t>(rate));

    // Make sure the audio stream is running.
    Unused << WaitFor(nonNativeStream->FramesProcessedEvent());

    // Force an error. This results in the audio stream destroying.
    DispatchFunction([&] { nonNativeStream->ForceError(); });
    WaitFor(nonNativeStream->ErrorForcedEvent());

    RefPtr<SmartMockCubebStream> destroyedStream =
        WaitFor(cubeb->StreamDestroyEvent());
    EXPECT_EQ(destroyedStream.get(), nonNativeStream.get());
  }

  // Make sure it's ok to call audio stop again.
  DispatchFunction([&] {
    track->GraphImpl()->AppendMessage(
        MakeUnique<StopNonNativeInput>(track.get()));
  });

  // Clean up.
  DispatchFunction([&] { track->Destroy(); });
  RefPtr<SmartMockCubebStream> destroyedStream =
      WaitFor(cubeb->StreamDestroyEvent());
  EXPECT_EQ(destroyedStream.get(), driverStream.get());
}

class TestDeviceInputConsumerTrack : public DeviceInputConsumerTrack {
 public:
  static TestDeviceInputConsumerTrack* Create(MediaTrackGraph* aGraph) {
    MOZ_RELEASE_ASSERT(NS_IsMainThread());
    TestDeviceInputConsumerTrack* track =
        new TestDeviceInputConsumerTrack(aGraph->GraphRate());
    aGraph->AddTrack(track);
    return track;
  }

  void Destroy() {
    MOZ_RELEASE_ASSERT(NS_IsMainThread());
    DisconnectDeviceInput();
    DeviceInputConsumerTrack::Destroy();
  }

  void ProcessInput(GraphTime aFrom, GraphTime aTo, uint32_t aFlags) override {
    MOZ_RELEASE_ASSERT(aFrom < aTo);

    if (mInputs.IsEmpty()) {
      GetData<AudioSegment>()->AppendNullData(aTo - aFrom);
    } else {
      MOZ_RELEASE_ASSERT(mInputs.Length() == 1);
      AudioSegment data;
      DeviceInputConsumerTrack::GetInputSourceData(data, aFrom, aTo);
      GetData<AudioSegment>()->AppendFrom(&data);
    }
  };

  uint32_t NumberOfChannels() const override {
    if (mInputs.IsEmpty()) {
      return 0;
    }
    DeviceInputTrack* t = mInputs[0]->GetSource()->AsDeviceInputTrack();
    MOZ_RELEASE_ASSERT(t);
    return t->NumberOfChannels();
  }

 private:
  explicit TestDeviceInputConsumerTrack(TrackRate aSampleRate)
      : DeviceInputConsumerTrack(aSampleRate) {}
};

TEST(TestAudioTrackGraph, DeviceChangedCallback)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graphImpl = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  class TestAudioDataListener : public StrictMock<MockAudioDataListener> {
   public:
    TestAudioDataListener(uint32_t aChannelCount, bool aIsVoice) {
      EXPECT_CALL(*this, RequestedInputChannelCount)
          .WillRepeatedly(Return(aChannelCount));
      EXPECT_CALL(*this, RequestedInputProcessingParams)
          .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_NONE));
      EXPECT_CALL(*this, IsVoiceInput).WillRepeatedly(Return(aIsVoice));
      {
        InSequence s;
        EXPECT_CALL(*this, DeviceChanged);
        EXPECT_CALL(*this, Disconnect);
      }
    }

   private:
    ~TestAudioDataListener() = default;
  };

  // Create a full-duplex AudioCallbackDriver by creating a NativeInputTrack.
  const CubebUtils::AudioDeviceID device1 = (CubebUtils::AudioDeviceID)1;
  RefPtr<TestAudioDataListener> listener1 = new TestAudioDataListener(1, false);
  RefPtr<TestDeviceInputConsumerTrack> track1 =
      TestDeviceInputConsumerTrack::Create(graphImpl);
  track1->ConnectDeviceInput(device1, listener1.get(), PRINCIPAL_HANDLE_NONE);

  EXPECT_TRUE(track1->ConnectedToNativeDevice());
  EXPECT_FALSE(track1->ConnectedToNonNativeDevice());
  auto started =
      InvokeAsync([&] { return graphImpl->NotifyWhenDeviceStarted(nullptr); });
  RefPtr<SmartMockCubebStream> stream1 = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream1->mHasInput);
  EXPECT_TRUE(stream1->mHasOutput);
  EXPECT_EQ(stream1->GetInputDeviceID(), device1);
  Unused << WaitFor(started);

  // Create a NonNativeInputTrack, and make sure its DeviceChangeCallback works.
  const CubebUtils::AudioDeviceID device2 = (CubebUtils::AudioDeviceID)2;
  RefPtr<TestAudioDataListener> listener2 = new TestAudioDataListener(2, true);
  RefPtr<TestDeviceInputConsumerTrack> track2 =
      TestDeviceInputConsumerTrack::Create(graphImpl);
  track2->ConnectDeviceInput(device2, listener2.get(), PRINCIPAL_HANDLE_NONE);

  EXPECT_FALSE(track2->ConnectedToNativeDevice());
  EXPECT_TRUE(track2->ConnectedToNonNativeDevice());
  RefPtr<SmartMockCubebStream> stream2 = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream2->mHasInput);
  EXPECT_FALSE(stream2->mHasOutput);
  EXPECT_EQ(stream2->GetInputDeviceID(), device2);

  // Produce a device-changed event for the NonNativeInputTrack.
  DispatchFunction([&] { stream2->ForceDeviceChanged(); });
  WaitFor(stream2->DeviceChangeForcedEvent());

  // Produce a device-changed event for the NativeInputTrack.
  DispatchFunction([&] { stream1->ForceDeviceChanged(); });
  WaitFor(stream1->DeviceChangeForcedEvent());

  // Destroy the NonNativeInputTrack.
  DispatchFunction([&] {
    track2->DisconnectDeviceInput();
    track2->Destroy();
  });
  RefPtr<SmartMockCubebStream> destroyedStream =
      WaitFor(cubeb->StreamDestroyEvent());
  EXPECT_EQ(destroyedStream.get(), stream2.get());

  // Destroy the NativeInputTrack.
  DispatchFunction([&] {
    track1->DisconnectDeviceInput();
    track1->Destroy();
  });
  destroyedStream = WaitFor(cubeb->StreamDestroyEvent());
  EXPECT_EQ(destroyedStream.get(), stream1.get());
}

// The native audio stream (a.k.a. GraphDriver) and the non-native audio stream
// should always be the same as the max requested input channel of its paired
// DeviceInputTracks. This test checks if the audio stream paired with the
// DeviceInputTrack will follow the max requested input channel or not.
//
// The main focus for this test is to make sure DeviceInputTrack::OpenAudio and
// ::CloseAudio works as what we expect. Besides, This test also confirms
// MediaTrackGraph::ReevaluateInputDevice works correctly by using a
// test-only AudioDataListener.
//
// This test is pretty similar to RestartAudioIfProcessingMaxChannelCountChanged
// below, which tests the same thing but using AudioProcessingTrack.
// AudioProcessingTrack is the consumer of the  DeviceInputTrack used in wild.
// It has its own customized AudioDataListener. However, it only tests when
// MOZ_WEBRTC is defined.
TEST(TestAudioTrackGraph, RestartAudioIfMaxChannelCountChanged)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());
  auto unforcer = WaitFor(cubeb->ForceAudioThread()).unwrap();
  Unused << unforcer;

  MediaTrackGraph* graphImpl = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  // A test-only AudioDataListener that simulates AudioInputProcessing's setter
  // and getter for the input channel count.
  class TestAudioDataListener : public StrictMock<MockAudioDataListener> {
   public:
    TestAudioDataListener(uint32_t aChannelCount, bool aIsVoice) {
      EXPECT_CALL(*this, RequestedInputChannelCount)
          .WillRepeatedly(Return(aChannelCount));
      EXPECT_CALL(*this, RequestedInputProcessingParams)
          .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_NONE));
      EXPECT_CALL(*this, IsVoiceInput).WillRepeatedly(Return(aIsVoice));
      EXPECT_CALL(*this, Disconnect);
    }
    // Main thread API
    void SetInputChannelCount(MediaTrackGraph* aGraph,
                              CubebUtils::AudioDeviceID aDevice,
                              uint32_t aChannelCount) {
      MOZ_RELEASE_ASSERT(NS_IsMainThread());
      static_cast<MediaTrackGraphImpl*>(aGraph)
          ->QueueControlMessageWithNoShutdown(
              [this, self = RefPtr(this), aGraph, aDevice, aChannelCount] {
                EXPECT_CALL(*this, RequestedInputChannelCount)
                    .WillRepeatedly(Return(aChannelCount));
                aGraph->ReevaluateInputDevice(aDevice);
              });
    }

   private:
    ~TestAudioDataListener() = default;
  };

  // Request a new input channel count and expect to have a new stream.
  auto setNewChannelCount = [&](const RefPtr<TestAudioDataListener>& aListener,
                                RefPtr<SmartMockCubebStream>& aStream,
                                uint32_t aChannelCount) {
    ASSERT_TRUE(!!aListener);
    ASSERT_TRUE(!!aStream);
    ASSERT_TRUE(aStream->mHasInput);
    ASSERT_NE(aChannelCount, 0U);

    const CubebUtils::AudioDeviceID device = aStream->GetInputDeviceID();

    bool destroyed = false;
    MediaEventListener destroyListener = cubeb->StreamDestroyEvent().Connect(
        AbstractThread::GetCurrent(),
        [&](const RefPtr<SmartMockCubebStream>& aDestroyed) {
          destroyed = aDestroyed.get() == aStream.get();
        });

    RefPtr<SmartMockCubebStream> newStream;
    MediaEventListener restartListener = cubeb->StreamInitEvent().Connect(
        AbstractThread::GetCurrent(),
        [&](const RefPtr<SmartMockCubebStream>& aCreated) {
          newStream = aCreated;
        });

    DispatchFunction([&] {
      aListener->SetInputChannelCount(graphImpl, device, aChannelCount);
    });

    SpinEventLoopUntil<ProcessFailureBehavior::IgnoreAndContinue>(
        "TEST(TestAudioTrackGraph, RestartAudioIfMaxChannelCountChanged) #1"_ns,
        [&] { return destroyed && newStream; });

    destroyListener.Disconnect();
    restartListener.Disconnect();

    aStream = newStream;
  };

  // Open a new track and expect to have a new stream.
  auto openTrack = [&](RefPtr<SmartMockCubebStream>& aCurrentStream,
                       RefPtr<TestDeviceInputConsumerTrack>& aTrack,
                       const RefPtr<TestAudioDataListener>& aListener,
                       CubebUtils::AudioDeviceID aDevice) {
    ASSERT_TRUE(!!aCurrentStream);
    ASSERT_TRUE(aCurrentStream->mHasInput);
    ASSERT_TRUE(!aTrack);
    ASSERT_TRUE(!!aListener);

    bool destroyed = false;
    MediaEventListener destroyListener = cubeb->StreamDestroyEvent().Connect(
        AbstractThread::GetCurrent(),
        [&](const RefPtr<SmartMockCubebStream>& aDestroyed) {
          destroyed = aDestroyed.get() == aCurrentStream.get();
        });

    RefPtr<SmartMockCubebStream> newStream;
    MediaEventListener restartListener = cubeb->StreamInitEvent().Connect(
        AbstractThread::GetCurrent(),
        [&](const RefPtr<SmartMockCubebStream>& aCreated) {
          newStream = aCreated;
        });

    aTrack = TestDeviceInputConsumerTrack::Create(graphImpl);
    aTrack->ConnectDeviceInput(aDevice, aListener.get(), PRINCIPAL_HANDLE_NONE);

    SpinEventLoopUntil<ProcessFailureBehavior::IgnoreAndContinue>(
        "TEST(TestAudioTrackGraph, RestartAudioIfMaxChannelCountChanged) #2"_ns,
        [&] { return destroyed && newStream; });

    destroyListener.Disconnect();
    restartListener.Disconnect();

    aCurrentStream = newStream;
  };

  // Test for the native input device first then non-native device. The
  // non-native device will be destroyed before the native device in case of
  // causing a driver switching.

  // Test for the native device.
  const CubebUtils::AudioDeviceID nativeDevice = (CubebUtils::AudioDeviceID)1;
  RefPtr<TestDeviceInputConsumerTrack> track1;
  RefPtr<TestAudioDataListener> listener1;
  RefPtr<SmartMockCubebStream> nativeStream;
  RefPtr<TestDeviceInputConsumerTrack> track2;
  RefPtr<TestAudioDataListener> listener2;
  {
    // Open a 1-channel NativeInputTrack.
    listener1 = new TestAudioDataListener(1, false);
    track1 = TestDeviceInputConsumerTrack::Create(graphImpl);
    track1->ConnectDeviceInput(nativeDevice, listener1.get(),
                               PRINCIPAL_HANDLE_NONE);

    EXPECT_TRUE(track1->ConnectedToNativeDevice());
    EXPECT_FALSE(track1->ConnectedToNonNativeDevice());
    auto started = InvokeAsync(
        [&] { return graphImpl->NotifyWhenDeviceStarted(nullptr); });
    nativeStream = WaitFor(cubeb->StreamInitEvent());
    EXPECT_TRUE(nativeStream->mHasInput);
    EXPECT_TRUE(nativeStream->mHasOutput);
    EXPECT_EQ(nativeStream->GetInputDeviceID(), nativeDevice);
    Unused << WaitFor(started);

    // Open a 2-channel NativeInputTrack and wait for a new driver since the
    // max-channel for the native device becomes 2 now.
    listener2 = new TestAudioDataListener(2, false);
    openTrack(nativeStream, track2, listener2, nativeDevice);
    EXPECT_EQ(nativeStream->InputChannels(), 2U);

    // Set the second NativeInputTrack to 1-channel and wait for a new driver
    // since the max-channel for the native device becomes 1 now.
    setNewChannelCount(listener2, nativeStream, 1);
    EXPECT_EQ(nativeStream->InputChannels(), 1U);

    // Set the first NativeInputTrack to 2-channel and wait for a new driver
    // since the max input channel for the native device becomes 2 now.
    setNewChannelCount(listener1, nativeStream, 2);
    EXPECT_EQ(nativeStream->InputChannels(), 2U);
  }

  // Test for the non-native device.
  {
    const CubebUtils::AudioDeviceID nonNativeDevice =
        (CubebUtils::AudioDeviceID)2;

    // Open a 1-channel NonNativeInputTrack.
    RefPtr<TestAudioDataListener> listener3 =
        new TestAudioDataListener(1, false);
    RefPtr<TestDeviceInputConsumerTrack> track3 =
        TestDeviceInputConsumerTrack::Create(graphImpl);
    track3->ConnectDeviceInput(nonNativeDevice, listener3.get(),
                               PRINCIPAL_HANDLE_NONE);
    EXPECT_FALSE(track3->ConnectedToNativeDevice());
    EXPECT_TRUE(track3->ConnectedToNonNativeDevice());

    RefPtr<SmartMockCubebStream> nonNativeStream =
        WaitFor(cubeb->StreamInitEvent());
    EXPECT_TRUE(nonNativeStream->mHasInput);
    EXPECT_FALSE(nonNativeStream->mHasOutput);
    EXPECT_EQ(nonNativeStream->GetInputDeviceID(), nonNativeDevice);
    EXPECT_EQ(nonNativeStream->InputChannels(), 1U);

    // Open a 2-channel NonNativeInputTrack and wait for a new stream since
    // the max-channel for the non-native device becomes 2 now.
    RefPtr<TestAudioDataListener> listener4 =
        new TestAudioDataListener(2, false);
    RefPtr<TestDeviceInputConsumerTrack> track4;
    openTrack(nonNativeStream, track4, listener4, nonNativeDevice);
    EXPECT_EQ(nonNativeStream->InputChannels(), 2U);
    EXPECT_EQ(nonNativeStream->GetInputDeviceID(), nonNativeDevice);

    // Set the second NonNativeInputTrack to 1-channel and wait for a new
    // driver since the max-channel for the non-native device becomes 1 now.
    setNewChannelCount(listener4, nonNativeStream, 1);
    EXPECT_EQ(nonNativeStream->InputChannels(), 1U);

    // Set the first NonNativeInputTrack to 2-channel and wait for a new
    // driver since the max input channel for the non-native device becomes 2
    // now.
    setNewChannelCount(listener3, nonNativeStream, 2);
    EXPECT_EQ(nonNativeStream->InputChannels(), 2U);

    // Close the second NonNativeInputTrack (1-channel) then the first one
    // (2-channel) so we won't result in another stream creation.
    DispatchFunction([&] {
      track4->DisconnectDeviceInput();
      track4->Destroy();
    });
    DispatchFunction([&] {
      track3->DisconnectDeviceInput();
      track3->Destroy();
    });
    RefPtr<SmartMockCubebStream> destroyedStream =
        WaitFor(cubeb->StreamDestroyEvent());
    EXPECT_EQ(destroyedStream.get(), nonNativeStream.get());
  }

  // Tear down for the native device.
  {
    // Close the second NativeInputTrack (1-channel) then the first one
    // (2-channel) so we won't have driver switching.
    DispatchFunction([&] {
      track2->DisconnectDeviceInput();
      track2->Destroy();
    });
    DispatchFunction([&] {
      track1->DisconnectDeviceInput();
      track1->Destroy();
    });
    RefPtr<SmartMockCubebStream> destroyedStream =
        WaitFor(cubeb->StreamDestroyEvent());
    EXPECT_EQ(destroyedStream.get(), nativeStream.get());
  }
}

// This test is pretty similar to SwitchNativeAudioProcessingTrack below, which
// tests the same thing but using AudioProcessingTrack. AudioProcessingTrack is
// the consumer of the  DeviceInputTrack used in wild. It has its own customized
// AudioDataListener. However, it only tests when MOZ_WEBRTC is defined.
TEST(TestAudioTrackGraph, SwitchNativeInputDevice)
{
  class TestAudioDataListener : public StrictMock<MockAudioDataListener> {
   public:
    TestAudioDataListener(uint32_t aChannelCount, bool aIsVoice) {
      EXPECT_CALL(*this, RequestedInputChannelCount)
          .WillRepeatedly(Return(aChannelCount));
      EXPECT_CALL(*this, RequestedInputProcessingParams)
          .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_NONE));
      EXPECT_CALL(*this, IsVoiceInput).WillRepeatedly(Return(aIsVoice));
    }

   private:
    ~TestAudioDataListener() = default;
  };

  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  auto switchNativeDevice =
      [&](RefPtr<SmartMockCubebStream>&& aCurrentNativeStream,
          RefPtr<TestDeviceInputConsumerTrack>& aCurrentNativeTrack,
          RefPtr<SmartMockCubebStream>& aNextNativeStream,
          RefPtr<TestDeviceInputConsumerTrack>& aNextNativeTrack) {
        ASSERT_TRUE(aCurrentNativeStream->mHasInput);
        ASSERT_TRUE(aCurrentNativeStream->mHasOutput);
        ASSERT_TRUE(aNextNativeStream->mHasInput);
        ASSERT_FALSE(aNextNativeStream->mHasOutput);

        std::cerr << "Switching native input from device "
                  << aCurrentNativeStream->GetInputDeviceID() << " to "
                  << aNextNativeStream->GetInputDeviceID() << std::endl;

        uint32_t destroyed = 0;
        MediaEventListener destroyListener =
            cubeb->StreamDestroyEvent().Connect(
                AbstractThread::GetCurrent(),
                [&](const RefPtr<SmartMockCubebStream>& aDestroyed) {
                  if (aDestroyed.get() == aCurrentNativeStream.get() ||
                      aDestroyed.get() == aNextNativeStream.get()) {
                    std::cerr << "cubeb stream " << aDestroyed.get()
                              << " (device " << aDestroyed->GetInputDeviceID()
                              << ") has been destroyed" << std::endl;
                    destroyed += 1;
                  }
                });

        RefPtr<SmartMockCubebStream> newStream;
        MediaEventListener restartListener = cubeb->StreamInitEvent().Connect(
            AbstractThread::GetCurrent(),
            [&](const RefPtr<SmartMockCubebStream>& aCreated) {
              // Make sure new stream has input, to prevent from getting a
              // temporary output-only AudioCallbackDriver after closing current
              // native device but before setting a new native input.
              if (aCreated->mHasInput) {
                ASSERT_TRUE(aCreated->mHasOutput);
                newStream = aCreated;
              }
            });

        std::cerr << "Close device " << aCurrentNativeStream->GetInputDeviceID()
                  << std::endl;
        DispatchFunction([&] {
          aCurrentNativeTrack->DisconnectDeviceInput();
          aCurrentNativeTrack->Destroy();
        });

        std::cerr << "Wait for the switching" << std::endl;
        SpinEventLoopUntil<ProcessFailureBehavior::IgnoreAndContinue>(
            "TEST(TestAudioTrackGraph, SwitchNativeInputDevice)"_ns,
            [&] { return destroyed >= 2 && newStream; });

        destroyListener.Disconnect();
        restartListener.Disconnect();

        aCurrentNativeStream = nullptr;
        aNextNativeStream = newStream;

        std::cerr << "Now the native input is device "
                  << aNextNativeStream->GetInputDeviceID() << std::endl;
      };

  // Open a DeviceInputConsumerTrack for device 1.
  const CubebUtils::AudioDeviceID device1 = (CubebUtils::AudioDeviceID)1;
  RefPtr<TestDeviceInputConsumerTrack> track1 =
      TestDeviceInputConsumerTrack::Create(graph);
  RefPtr<TestAudioDataListener> listener1 = new TestAudioDataListener(1, false);
  EXPECT_CALL(*listener1, Disconnect);
  track1->ConnectDeviceInput(device1, listener1, PRINCIPAL_HANDLE_NONE);
  EXPECT_EQ(track1->DeviceId().value(), device1);

  auto started =
      InvokeAsync([&] { return graph->NotifyWhenDeviceStarted(nullptr); });

  RefPtr<SmartMockCubebStream> stream1 = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream1->mHasInput);
  EXPECT_TRUE(stream1->mHasOutput);
  EXPECT_EQ(stream1->InputChannels(), 1U);
  EXPECT_EQ(stream1->GetInputDeviceID(), device1);
  Unused << WaitFor(started);
  std::cerr << "Device " << device1 << " is opened (stream " << stream1.get()
            << ")" << std::endl;

  // Open a DeviceInputConsumerTrack for device 2.
  const CubebUtils::AudioDeviceID device2 = (CubebUtils::AudioDeviceID)2;
  RefPtr<TestDeviceInputConsumerTrack> track2 =
      TestDeviceInputConsumerTrack::Create(graph);
  RefPtr<TestAudioDataListener> listener2 = new TestAudioDataListener(2, false);
  EXPECT_CALL(*listener2, Disconnect).Times(2);
  track2->ConnectDeviceInput(device2, listener2, PRINCIPAL_HANDLE_NONE);
  EXPECT_EQ(track2->DeviceId().value(), device2);

  RefPtr<SmartMockCubebStream> stream2 = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream2->mHasInput);
  EXPECT_FALSE(stream2->mHasOutput);
  EXPECT_EQ(stream2->InputChannels(), 2U);
  EXPECT_EQ(stream2->GetInputDeviceID(), device2);
  std::cerr << "Device " << device2 << " is opened (stream " << stream2.get()
            << ")" << std::endl;

  // Open a DeviceInputConsumerTrack for device 3.
  const CubebUtils::AudioDeviceID device3 = (CubebUtils::AudioDeviceID)3;
  RefPtr<TestDeviceInputConsumerTrack> track3 =
      TestDeviceInputConsumerTrack::Create(graph);
  RefPtr<TestAudioDataListener> listener3 = new TestAudioDataListener(1, false);
  EXPECT_CALL(*listener3, Disconnect).Times(2);
  track3->ConnectDeviceInput(device3, listener3, PRINCIPAL_HANDLE_NONE);
  EXPECT_EQ(track3->DeviceId().value(), device3);

  RefPtr<SmartMockCubebStream> stream3 = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream3->mHasInput);
  EXPECT_FALSE(stream3->mHasOutput);
  EXPECT_EQ(stream3->InputChannels(), 1U);
  EXPECT_EQ(stream3->GetInputDeviceID(), device3);
  std::cerr << "Device " << device3 << " is opened (stream " << stream3.get()
            << ")" << std::endl;

  // Close device 1, so the native input device is switched from device 1 to
  // device 2.
  switchNativeDevice(std::move(stream1), track1, stream2, track2);
  EXPECT_TRUE(stream2->mHasInput);
  EXPECT_TRUE(stream2->mHasOutput);
  EXPECT_EQ(stream2->InputChannels(), 2U);
  EXPECT_EQ(stream2->GetInputDeviceID(), device2);
  {
    NativeInputTrack* native = track2->Graph()->GetNativeInputTrackMainThread();
    ASSERT_TRUE(!!native);
    EXPECT_EQ(native->mDeviceId, device2);
  }

  // Close device 2, so the native input device is switched from device 2 to
  // device 3.
  switchNativeDevice(std::move(stream2), track2, stream3, track3);
  EXPECT_TRUE(stream3->mHasInput);
  EXPECT_TRUE(stream3->mHasOutput);
  EXPECT_EQ(stream3->InputChannels(), 1U);
  EXPECT_EQ(stream3->GetInputDeviceID(), device3);
  {
    NativeInputTrack* native = track3->Graph()->GetNativeInputTrackMainThread();
    ASSERT_TRUE(!!native);
    EXPECT_EQ(native->mDeviceId, device3);
  }

  // Clean up.
  std::cerr << "Close device " << device3 << std::endl;
  DispatchFunction([&] {
    track3->DisconnectDeviceInput();
    track3->Destroy();
  });
  RefPtr<SmartMockCubebStream> destroyedStream =
      WaitFor(cubeb->StreamDestroyEvent());
  EXPECT_EQ(destroyedStream.get(), stream3.get());
  {
    NativeInputTrack* native = graph->GetNativeInputTrackMainThread();
    ASSERT_TRUE(!native);
  }
  std::cerr << "No native input now" << std::endl;
}

#ifdef MOZ_WEBRTC
TEST(TestAudioTrackGraph, ErrorCallback)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  const CubebUtils::AudioDeviceID deviceId = (CubebUtils::AudioDeviceID)1;

  // Dummy track to make graph rolling. Add it and remove it to remove the
  // graph from the global hash table and let it shutdown.
  //
  // We open an input through this track so that there's something triggering
  // EnsureNextIteration on the fallback driver after the callback driver has
  // gotten the error, and to check that a replacement cubeb_stream receives
  // output from the graph.
  RefPtr<AudioProcessingTrack> processingTrack;
  RefPtr<AudioInputProcessing> listener;
  auto started = InvokeAsync([&] {
    processingTrack = AudioProcessingTrack::Create(graph);
    listener = new AudioInputProcessing(2);
    QueueExpectIsPassThrough(processingTrack, listener);
    processingTrack->SetInputProcessing(listener);
    processingTrack->GraphImpl()->AppendMessage(
        MakeUnique<StartInputProcessing>(processingTrack, listener));
    processingTrack->ConnectDeviceInput(deviceId, listener,
                                        PRINCIPAL_HANDLE_NONE);
    EXPECT_EQ(processingTrack->DeviceId().value(), deviceId);
    processingTrack->AddAudioOutput(reinterpret_cast<void*>(1), nullptr);
    return graph->NotifyWhenDeviceStarted(nullptr);
  });

  RefPtr<SmartMockCubebStream> stream = WaitFor(cubeb->StreamInitEvent());
  Result<bool, nsresult> rv = WaitFor(started);
  EXPECT_TRUE(rv.unwrapOr(false));

  // Force a cubeb state_callback error and see that we don't crash.
  DispatchFunction([&] { stream->ForceError(); });

  // Wait for the error to take effect, and the driver to restart and receive
  // output.
  bool errored = false;
  MediaEventListener errorListener = stream->ErrorForcedEvent().Connect(
      AbstractThread::GetCurrent(), [&] { errored = true; });
  stream = WaitFor(cubeb->StreamInitEvent());
  WaitFor(stream->FramesVerifiedEvent());
  // The error event is notified after CUBEB_STATE_ERROR triggers other
  // threads to init a new cubeb_stream, so there is a theoretical chance that
  // `errored` might not be set when `stream` is set.
  errorListener.Disconnect();
  EXPECT_TRUE(errored);

  // Clean up.
  DispatchFunction([&] {
    processingTrack->GraphImpl()->AppendMessage(
        MakeUnique<StopInputProcessing>(processingTrack, listener));
    processingTrack->DisconnectDeviceInput();
    processingTrack->Destroy();
  });
  WaitFor(cubeb->StreamDestroyEvent());
}

TEST(TestAudioTrackGraph, AudioProcessingTrack)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());
  auto unforcer = WaitFor(cubeb->ForceAudioThread()).unwrap();
  Unused << unforcer;

  // Start on a system clock driver, then switch to full-duplex in one go. If we
  // did output-then-full-duplex we'd risk a second NotifyWhenDeviceStarted
  // resolving early after checking the first audio driver only.
  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  const CubebUtils::AudioDeviceID deviceId = (CubebUtils::AudioDeviceID)1;

  RefPtr<AudioProcessingTrack> processingTrack;
  RefPtr<ProcessedMediaTrack> outputTrack;
  RefPtr<MediaInputPort> port;
  RefPtr<AudioInputProcessing> listener;
  auto p = InvokeAsync([&] {
    processingTrack = AudioProcessingTrack::Create(graph);
    outputTrack = graph->CreateForwardedInputTrack(MediaSegment::AUDIO);
    outputTrack->QueueSetAutoend(false);
    outputTrack->AddAudioOutput(reinterpret_cast<void*>(1), nullptr);
    port = outputTrack->AllocateInputPort(processingTrack);
    /* Primary graph: Open Audio Input through SourceMediaTrack */
    listener = new AudioInputProcessing(2);
    QueueExpectIsPassThrough(processingTrack, listener);
    processingTrack->SetInputProcessing(listener);
    processingTrack->GraphImpl()->AppendMessage(
        MakeUnique<StartInputProcessing>(processingTrack, listener));
    // Device id does not matter. Ignore.
    processingTrack->ConnectDeviceInput(deviceId, listener,
                                        PRINCIPAL_HANDLE_NONE);
    return graph->NotifyWhenDeviceStarted(nullptr);
  });

  RefPtr<SmartMockCubebStream> stream = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream->mHasInput);
  Unused << WaitFor(p);

  // Wait for a second worth of audio data. GoFaster is dispatched through a
  // ControlMessage so that it is called in the first audio driver iteration.
  // Otherwise the audio driver might be going very fast while the fallback
  // system clock driver is still in an iteration.
  DispatchFunction([&] {
    processingTrack->GraphImpl()->AppendMessage(MakeUnique<GoFaster>(cubeb));
  });
  uint32_t totalFrames = 0;
  WaitUntil(stream->FramesVerifiedEvent(), [&](uint32_t aFrames) {
    totalFrames += aFrames;
    return totalFrames > static_cast<uint32_t>(graph->GraphRate());
  });
  cubeb->DontGoFaster();

  // Clean up.
  DispatchFunction([&] {
    outputTrack->RemoveAudioOutput((void*)1);
    outputTrack->Destroy();
    port->Destroy();
    processingTrack->GraphImpl()->AppendMessage(
        MakeUnique<StopInputProcessing>(processingTrack, listener));
    processingTrack->DisconnectDeviceInput();
    processingTrack->Destroy();
  });

  uint32_t inputRate = stream->SampleRate();
  uint32_t inputFrequency = stream->InputFrequency();
  uint64_t preSilenceSamples;
  uint32_t estimatedFreq;
  uint32_t nrDiscontinuities;
  std::tie(preSilenceSamples, estimatedFreq, nrDiscontinuities) =
      WaitFor(stream->OutputVerificationEvent());

  EXPECT_EQ(estimatedFreq, inputFrequency);
  std::cerr << "PreSilence: " << preSilenceSamples << std::endl;
  // We buffer 128 frames. See NativeInputTrack::NotifyInputData.
  EXPECT_GE(preSilenceSamples, 128U);
  // If the fallback system clock driver is doing a graph iteration before the
  // first audio driver iteration comes in, that iteration is ignored and
  // results in zeros. It takes one fallback driver iteration *after* the audio
  // driver has started to complete the switch, *usually* resulting two
  // 10ms-iterations of silence; sometimes only one.
  EXPECT_LE(preSilenceSamples, 128U + 2 * inputRate / 100 /* 2*10ms */);
  // The waveform from AudioGenerator starts at 0, but we don't control its
  // ending, so we expect a discontinuity there.
  EXPECT_LE(nrDiscontinuities, 1U);
}

TEST(TestAudioTrackGraph, ReConnectDeviceInput)
{
  MockCubeb* cubeb = new MockCubeb(MockCubeb::RunningMode::Manual);
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  // 48k is a native processing rate, and avoids a resampling pass compared
  // to 44.1k. The resampler may add take a few frames to stabilize, which show
  // as unexected discontinuities in the test.
  const TrackRate rate = 48000;
  // Use a drift factor so that we don't dont produce perfect 10ms-chunks.
  // This will exercise whatever buffers are in the audio processing pipeline,
  // and the bookkeeping surrounding them.
  const long step = 10 * rate * 1111 / 1000 / PR_MSEC_PER_SEC;

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1, rate, nullptr,
      GetMainThreadSerialEventTarget());

  const CubebUtils::AudioDeviceID deviceId = (CubebUtils::AudioDeviceID)1;

  RefPtr<AudioProcessingTrack> processingTrack;
  RefPtr<ProcessedMediaTrack> outputTrack;
  RefPtr<MediaInputPort> port;
  RefPtr<AudioInputProcessing> listener;
  RefPtr<OnFallbackListener> fallbackListener;
  DispatchFunction([&] {
    processingTrack = AudioProcessingTrack::Create(graph);
    outputTrack = graph->CreateForwardedInputTrack(MediaSegment::AUDIO);
    outputTrack->QueueSetAutoend(false);
    outputTrack->AddAudioOutput(reinterpret_cast<void*>(1), nullptr);
    port = outputTrack->AllocateInputPort(processingTrack);

    const int32_t channelCount = 2;
    listener = new AudioInputProcessing(channelCount);
    processingTrack->SetInputProcessing(listener);
    processingTrack->GraphImpl()->AppendMessage(
        MakeUnique<StartInputProcessing>(processingTrack, listener));
    processingTrack->ConnectDeviceInput(deviceId, listener,
                                        PRINCIPAL_HANDLE_NONE);
    MediaEnginePrefs settings;
    settings.mChannels = channelCount;
    settings.mAgcOn = true;  // Turn off pass-through.
    // AGC1 Mode 0 interferes with AudioVerifier's frequency estimation
    // through zero-crossing counts.
    settings.mAgc2Forced = true;
    QueueApplySettings(processingTrack, listener, settings);

    fallbackListener = new OnFallbackListener(processingTrack);
    processingTrack->AddListener(fallbackListener);
  });

  RefPtr<SmartMockCubebStream> stream = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream->mHasInput);

  while (
      stream->State()
          .map([](cubeb_state aState) { return aState != CUBEB_STATE_STARTED; })
          .valueOr(true)) {
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Wait for the AudioCallbackDriver to come into effect.
  while (fallbackListener->OnFallback()) {
    EXPECT_EQ(stream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::Yes);
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Iterate for a second worth of audio data.
  for (long frames = 0; frames < graph->GraphRate(); frames += step) {
    stream->ManualDataCallback(step);
  }

  // Close the input to see that no asserts go off due to bad state.
  DispatchFunction([&] { processingTrack->DisconnectDeviceInput(); });

  // Dispatch the disconnect message.
  ProcessEventQueue();
  // Run the disconnect message.
  EXPECT_EQ(stream->ManualDataCallback(0),
            MockCubebStream::KeepProcessing::Yes);
  // Switch driver.
  auto initPromise = TakeN(cubeb->StreamInitEvent(), 1);
  EXPECT_EQ(stream->ManualDataCallback(0), MockCubebStream::KeepProcessing::No);
  std::tie(stream) = WaitFor(initPromise).unwrap()[0];
  EXPECT_FALSE(stream->mHasInput);

  while (
      stream->State()
          .map([](cubeb_state aState) { return aState != CUBEB_STATE_STARTED; })
          .valueOr(true)) {
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Wait for the new AudioCallbackDriver to come into effect.
  fallbackListener->Reset();
  while (fallbackListener->OnFallback()) {
    EXPECT_EQ(stream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::Yes);
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Output-only. Iterate for another second before unmuting.
  for (long frames = 0; frames < graph->GraphRate(); frames += step) {
    stream->ManualDataCallback(step);
  }

  // Re-open the input to again see that no asserts go off due to bad state.
  DispatchFunction([&] {
    // Device id does not matter. Ignore.
    processingTrack->ConnectDeviceInput(deviceId, listener,
                                        PRINCIPAL_HANDLE_NONE);
  });
  // Dispatch the connect message.
  ProcessEventQueue();
  // Run the connect message.
  EXPECT_EQ(stream->ManualDataCallback(0),
            MockCubebStream::KeepProcessing::Yes);
  // Switch driver.
  initPromise = TakeN(cubeb->StreamInitEvent(), 1);
  EXPECT_EQ(stream->ManualDataCallback(0), MockCubebStream::KeepProcessing::No);
  std::tie(stream) = WaitFor(initPromise).unwrap()[0];
  EXPECT_TRUE(stream->mHasInput);

  while (
      stream->State()
          .map([](cubeb_state aState) { return aState != CUBEB_STATE_STARTED; })
          .valueOr(true)) {
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Wait for the new AudioCallbackDriver to come into effect.
  fallbackListener->Reset();
  while (fallbackListener->OnFallback()) {
    EXPECT_EQ(stream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::Yes);
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Full-duplex. Iterate for another second before finishing.
  for (long frames = 0; frames < graph->GraphRate(); frames += step) {
    stream->ManualDataCallback(step);
  }

  // Clean up.
  DispatchFunction([&] {
    processingTrack->RemoveListener(fallbackListener);
    outputTrack->RemoveAudioOutput((void*)1);
    outputTrack->Destroy();
    port->Destroy();
    processingTrack->GraphImpl()->AppendMessage(
        MakeUnique<StopInputProcessing>(processingTrack, listener));
    processingTrack->DisconnectDeviceInput();
    processingTrack->Destroy();
  });

  // Dispatch the clean-up messages.
  ProcessEventQueue();
  // Run the clean-up messages.
  EXPECT_EQ(stream->ManualDataCallback(0),
            MockCubebStream::KeepProcessing::Yes);
  // Shut down driver.
  EXPECT_EQ(stream->ManualDataCallback(0), MockCubebStream::KeepProcessing::No);

  uint32_t inputFrequency = stream->InputFrequency();
  uint64_t preSilenceSamples;
  uint32_t estimatedFreq;
  uint32_t nrDiscontinuities;
  std::tie(preSilenceSamples, estimatedFreq, nrDiscontinuities) =
      WaitFor(stream->OutputVerificationEvent());

  EXPECT_EQ(estimatedFreq, inputFrequency);
  std::cerr << "PreSilence: " << preSilenceSamples << "\n";
  // We buffer 128 frames. See NativeInputTrack::NotifyInputData.
  // When not in passthrough the AudioInputProcessing packetizer also buffers
  // 10ms of silence, pulled in from NativeInputTrack when being run by the
  // fallback SystemClockDriver.
  EXPECT_EQ(preSilenceSamples, WEBAUDIO_BLOCK_SIZE + rate / 100);
  // The waveform from AudioGenerator starts at 0, but we don't control its
  // ending, so we expect a discontinuity there. Note that this check is only
  // for the waveform on the stream *after* re-opening the input.
  EXPECT_LE(nrDiscontinuities, 1U);
}

// Sum the signal to mono and compute the root mean square, in float32,
// regardless of the input format.
float rmsf32(AudioDataValue* aSamples, uint32_t aChannels, uint32_t aFrames) {
  float downmixed;
  float rms = 0.;
  uint32_t readIdx = 0;
  for (uint32_t i = 0; i < aFrames; i++) {
    downmixed = 0.;
    for (uint32_t j = 0; j < aChannels; j++) {
      downmixed += ConvertAudioSample<float>(aSamples[readIdx++]);
    }
    rms += downmixed * downmixed;
  }
  rms = rms / aFrames;
  return sqrt(rms);
}

TEST(TestAudioTrackGraph, AudioProcessingTrackDisabling)
{
  MockCubeb* cubeb = new MockCubeb(MockCubeb::RunningMode::Manual);
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  const CubebUtils::AudioDeviceID deviceId = (CubebUtils::AudioDeviceID)1;

  RefPtr<AudioProcessingTrack> processingTrack;
  RefPtr<ProcessedMediaTrack> outputTrack;
  RefPtr<MediaInputPort> port;
  RefPtr<AudioInputProcessing> listener;
  RefPtr<OnFallbackListener> fallbackListener;
  DispatchFunction([&] {
    processingTrack = AudioProcessingTrack::Create(graph);
    outputTrack = graph->CreateForwardedInputTrack(MediaSegment::AUDIO);
    outputTrack->QueueSetAutoend(false);
    outputTrack->AddAudioOutput(reinterpret_cast<void*>(1), nullptr);
    port = outputTrack->AllocateInputPort(processingTrack);
    /* Primary graph: Open Audio Input through SourceMediaTrack */
    listener = new AudioInputProcessing(2);
    QueueExpectIsPassThrough(processingTrack, listener);
    processingTrack->SetInputProcessing(listener);
    processingTrack->ConnectDeviceInput(deviceId, listener,
                                        PRINCIPAL_HANDLE_NONE);
    processingTrack->GraphImpl()->AppendMessage(
        MakeUnique<StartInputProcessing>(processingTrack, listener));
    fallbackListener = new OnFallbackListener(processingTrack);
    processingTrack->AddListener(fallbackListener);
  });

  ProcessEventQueue();

  RefPtr<SmartMockCubebStream> stream = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream->mHasInput);

  while (
      stream->State()
          .map([](cubeb_state aState) { return aState != CUBEB_STATE_STARTED; })
          .valueOr(true)) {
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Wait for the AudioCallbackDriver to come into effect.
  while (fallbackListener->OnFallback()) {
    EXPECT_EQ(stream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::Yes);
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  stream->SetOutputRecordingEnabled(true);

  // Wait for a second worth of audio data.
  const long step = graph->GraphRate() / 100;  // 10ms
  for (long frames = 0; frames < graph->GraphRate(); frames += step) {
    stream->ManualDataCallback(step);
  }

  const uint32_t ITERATION_COUNT = 5;
  uint32_t iterations = ITERATION_COUNT;
  DisabledTrackMode nextMode = DisabledTrackMode::SILENCE_BLACK;
  while (iterations--) {
    // toggle the track enabled mode, wait a second, do this ITERATION_COUNT
    // times
    DispatchFunction([&] {
      processingTrack->SetDisabledTrackMode(nextMode);
      if (nextMode == DisabledTrackMode::SILENCE_BLACK) {
        nextMode = DisabledTrackMode::ENABLED;
      } else {
        nextMode = DisabledTrackMode::SILENCE_BLACK;
      }
    });

    ProcessEventQueue();

    for (long frames = 0; frames < graph->GraphRate(); frames += step) {
      stream->ManualDataCallback(step);
    }
  }

  // Clean up.
  DispatchFunction([&] {
    outputTrack->RemoveAudioOutput((void*)1);
    outputTrack->Destroy();
    port->Destroy();
    processingTrack->GraphImpl()->AppendMessage(
        MakeUnique<StopInputProcessing>(processingTrack, listener));
    processingTrack->RemoveListener(fallbackListener);
    processingTrack->DisconnectDeviceInput();
    processingTrack->Destroy();
  });

  ProcessEventQueue();

  // Close the input and switch driver.
  while (stream->ManualDataCallback(0) != MockCubebStream::KeepProcessing::No) {
    std::cerr << "Waiting for switch...\n";
  }

  uint64_t preSilenceSamples;
  uint32_t estimatedFreq;
  uint32_t nrDiscontinuities;
  std::tie(preSilenceSamples, estimatedFreq, nrDiscontinuities) =
      WaitFor(stream->OutputVerificationEvent());

  auto data = stream->TakeRecordedOutput();

  // check that there is non-silence and silence at the expected time in the
  // stereo recording, while allowing for a bit of scheduling uncertainty, by
  // checking half a second after the theoretical muting/unmuting.
  // non-silence starts around: 0s, 2s, 4s
  // silence start around: 1s, 3s, 5s
  // To detect silence or non-silence, we compute the RMS of the signal for
  // 100ms.
  float noisyTime_s[] = {0.5, 2.5, 4.5};
  float silenceTime_s[] = {1.5, 3.5, 5.5};

  uint32_t rate = graph->GraphRate();
  for (float& time : noisyTime_s) {
    uint32_t startIdx = time * rate * 2 /* stereo */;
    EXPECT_NE(rmsf32(&(data[startIdx]), 2, rate / 10), 0.0);
  }

  for (float& time : silenceTime_s) {
    uint32_t startIdx = time * rate * 2 /* stereo */;
    EXPECT_EQ(rmsf32(&(data[startIdx]), 2, rate / 10), 0.0);
  }
}

TEST(TestAudioTrackGraph, SetRequestedInputChannelCount)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  // Open a 2-channel native input stream.
  const CubebUtils::AudioDeviceID device1 = (CubebUtils::AudioDeviceID)1;
  RefPtr<AudioProcessingTrack> track1 = AudioProcessingTrack::Create(graph);
  RefPtr<AudioInputProcessing> listener1 = new AudioInputProcessing(2);
  track1->SetInputProcessing(listener1);
  QueueExpectIsPassThrough(track1, listener1);
  track1->GraphImpl()->AppendMessage(
      MakeUnique<StartInputProcessing>(track1, listener1));
  track1->ConnectDeviceInput(device1, listener1, PRINCIPAL_HANDLE_NONE);
  EXPECT_EQ(track1->DeviceId().value(), device1);

  auto started =
      InvokeAsync([&] { return graph->NotifyWhenDeviceStarted(nullptr); });

  RefPtr<SmartMockCubebStream> stream1 = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream1->mHasInput);
  EXPECT_TRUE(stream1->mHasOutput);
  EXPECT_EQ(stream1->InputChannels(), 2U);
  EXPECT_EQ(stream1->GetInputDeviceID(), device1);
  Unused << WaitFor(started);

  // Open a 1-channel non-native input stream.
  const CubebUtils::AudioDeviceID device2 = (CubebUtils::AudioDeviceID)2;
  RefPtr<AudioProcessingTrack> track2 = AudioProcessingTrack::Create(graph);
  RefPtr<AudioInputProcessing> listener2 = new AudioInputProcessing(1);
  track2->SetInputProcessing(listener2);
  QueueExpectIsPassThrough(track2, listener2);
  track2->GraphImpl()->AppendMessage(
      MakeUnique<StartInputProcessing>(track2, listener2));
  track2->ConnectDeviceInput(device2, listener2, PRINCIPAL_HANDLE_NONE);
  EXPECT_EQ(track2->DeviceId().value(), device2);

  RefPtr<SmartMockCubebStream> stream2 = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream2->mHasInput);
  EXPECT_FALSE(stream2->mHasOutput);
  EXPECT_EQ(stream2->InputChannels(), 1U);
  EXPECT_EQ(stream2->GetInputDeviceID(), device2);

  // Request a new input channel count. This should re-create new input stream
  // accordingly.
  auto setNewChannelCount = [&](const RefPtr<AudioProcessingTrack> aTrack,
                                const RefPtr<AudioInputProcessing>& aListener,
                                RefPtr<SmartMockCubebStream>& aStream,
                                int32_t aChannelCount) {
    bool destroyed = false;
    MediaEventListener destroyListener = cubeb->StreamDestroyEvent().Connect(
        AbstractThread::GetCurrent(),
        [&](const RefPtr<SmartMockCubebStream>& aDestroyed) {
          destroyed = aDestroyed.get() == aStream.get();
        });

    RefPtr<SmartMockCubebStream> newStream;
    MediaEventListener restartListener = cubeb->StreamInitEvent().Connect(
        AbstractThread::GetCurrent(),
        [&](const RefPtr<SmartMockCubebStream>& aCreated) {
          newStream = aCreated;
        });

    MediaEnginePrefs settings;
    settings.mChannels = aChannelCount;
    QueueApplySettings(aTrack, aListener, settings);

    SpinEventLoopUntil<ProcessFailureBehavior::IgnoreAndContinue>(
        "TEST(TestAudioTrackGraph, SetRequestedInputChannelCount)"_ns,
        [&] { return destroyed && newStream; });

    destroyListener.Disconnect();
    restartListener.Disconnect();

    aStream = newStream;
  };

  // Set the native input stream's input channel count to 1.
  setNewChannelCount(track1, listener1, stream1, 1);
  EXPECT_TRUE(stream1->mHasInput);
  EXPECT_TRUE(stream1->mHasOutput);
  EXPECT_EQ(stream1->InputChannels(), 1U);
  EXPECT_EQ(stream1->GetInputDeviceID(), device1);

  // Set the non-native input stream's input channel count to 2.
  setNewChannelCount(track2, listener2, stream2, 2);
  EXPECT_TRUE(stream2->mHasInput);
  EXPECT_FALSE(stream2->mHasOutput);
  EXPECT_EQ(stream2->InputChannels(), 2U);
  EXPECT_EQ(stream2->GetInputDeviceID(), device2);

  // Close the non-native input stream.
  DispatchFunction([&] {
    track2->GraphImpl()->AppendMessage(
        MakeUnique<StopInputProcessing>(track2, listener2));
    track2->DisconnectDeviceInput();
    track2->Destroy();
  });
  RefPtr<SmartMockCubebStream> destroyed = WaitFor(cubeb->StreamDestroyEvent());
  EXPECT_EQ(destroyed.get(), stream2.get());

  // Close the native input stream.
  DispatchFunction([&] {
    track1->GraphImpl()->AppendMessage(
        MakeUnique<StopInputProcessing>(track1, listener1));
    track1->DisconnectDeviceInput();
    track1->Destroy();
  });
  destroyed = WaitFor(cubeb->StreamDestroyEvent());
  EXPECT_EQ(destroyed.get(), stream1.get());
}

// The native audio stream (a.k.a. GraphDriver) and the non-native audio stream
// should always be the same as the max requested input channel of its paired
// AudioProcessingTracks. This test checks if the audio stream paired with the
// AudioProcessingTrack will follow the max requested input channel or not.
//
// This test is pretty similar to RestartAudioIfMaxChannelCountChanged above,
// which makes sure the related DeviceInputTrack operations for the test here
// works correctly. Instead of using a test-only AudioDataListener, we use
// AudioInputProcessing here to simulate the real world use case.
TEST(TestAudioTrackGraph, RestartAudioIfProcessingMaxChannelCountChanged)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());
  auto unforcer = WaitFor(cubeb->ForceAudioThread()).unwrap();
  Unused << unforcer;

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  // Request a new input channel count and expect to have a new stream.
  auto setNewChannelCount = [&](const RefPtr<AudioProcessingTrack>& aTrack,
                                const RefPtr<AudioInputProcessing>& aListener,
                                RefPtr<SmartMockCubebStream>& aStream,
                                int32_t aChannelCount) {
    ASSERT_TRUE(!!aTrack);
    ASSERT_TRUE(!!aListener);
    ASSERT_TRUE(!!aStream);
    ASSERT_TRUE(aStream->mHasInput);
    ASSERT_NE(aChannelCount, 0);

    bool destroyed = false;
    MediaEventListener destroyListener = cubeb->StreamDestroyEvent().Connect(
        AbstractThread::GetCurrent(),
        [&](const RefPtr<SmartMockCubebStream>& aDestroyed) {
          destroyed = aDestroyed.get() == aStream.get();
        });

    RefPtr<SmartMockCubebStream> newStream;
    MediaEventListener restartListener = cubeb->StreamInitEvent().Connect(
        AbstractThread::GetCurrent(),
        [&](const RefPtr<SmartMockCubebStream>& aCreated) {
          newStream = aCreated;
        });

    MediaEnginePrefs settings;
    settings.mChannels = aChannelCount;
    QueueApplySettings(aTrack, aListener, settings);

    SpinEventLoopUntil<ProcessFailureBehavior::IgnoreAndContinue>(
        "TEST(TestAudioTrackGraph, RestartAudioIfProcessingMaxChannelCountChanged) #1"_ns,
        [&] { return destroyed && newStream; });

    destroyListener.Disconnect();
    restartListener.Disconnect();

    aStream = newStream;
  };

  // Open a new track and expect to have a new stream.
  auto openTrack = [&](RefPtr<SmartMockCubebStream>& aCurrentStream,
                       RefPtr<AudioProcessingTrack>& aTrack,
                       RefPtr<AudioInputProcessing>& aListener,
                       CubebUtils::AudioDeviceID aDevice,
                       uint32_t aChannelCount) {
    ASSERT_TRUE(!!aCurrentStream);
    ASSERT_TRUE(aCurrentStream->mHasInput);
    ASSERT_TRUE(aChannelCount > aCurrentStream->InputChannels());
    ASSERT_TRUE(!aTrack);
    ASSERT_TRUE(!aListener);

    bool destroyed = false;
    MediaEventListener destroyListener = cubeb->StreamDestroyEvent().Connect(
        AbstractThread::GetCurrent(),
        [&](const RefPtr<SmartMockCubebStream>& aDestroyed) {
          destroyed = aDestroyed.get() == aCurrentStream.get();
        });

    RefPtr<SmartMockCubebStream> newStream;
    MediaEventListener restartListener = cubeb->StreamInitEvent().Connect(
        AbstractThread::GetCurrent(),
        [&](const RefPtr<SmartMockCubebStream>& aCreated) {
          newStream = aCreated;
        });

    aTrack = AudioProcessingTrack::Create(graph);
    aListener = new AudioInputProcessing(aChannelCount);
    aTrack->SetInputProcessing(aListener);
    QueueExpectIsPassThrough(aTrack, aListener);
    aTrack->GraphImpl()->AppendMessage(
        MakeUnique<StartInputProcessing>(aTrack, aListener));

    DispatchFunction([&] {
      aTrack->ConnectDeviceInput(aDevice, aListener, PRINCIPAL_HANDLE_NONE);
    });

    SpinEventLoopUntil<ProcessFailureBehavior::IgnoreAndContinue>(
        "TEST(TestAudioTrackGraph, RestartAudioIfProcessingMaxChannelCountChanged) #2"_ns,
        [&] { return destroyed && newStream; });

    destroyListener.Disconnect();
    restartListener.Disconnect();

    aCurrentStream = newStream;
  };

  // Test for the native input device first then non-native device. The
  // non-native device will be destroyed before the native device in case of
  // causing a native-device-switching.

  // Test for the native device.
  const CubebUtils::AudioDeviceID nativeDevice = (CubebUtils::AudioDeviceID)1;
  RefPtr<AudioProcessingTrack> track1;
  RefPtr<AudioInputProcessing> listener1;
  RefPtr<SmartMockCubebStream> nativeStream;
  RefPtr<AudioProcessingTrack> track2;
  RefPtr<AudioInputProcessing> listener2;
  {
    // Open a 1-channel AudioProcessingTrack for the native device.
    track1 = AudioProcessingTrack::Create(graph);
    listener1 = new AudioInputProcessing(1);
    track1->SetInputProcessing(listener1);
    QueueExpectIsPassThrough(track1, listener1);
    track1->GraphImpl()->AppendMessage(
        MakeUnique<StartInputProcessing>(track1, listener1));
    track1->ConnectDeviceInput(nativeDevice, listener1, PRINCIPAL_HANDLE_NONE);
    EXPECT_EQ(track1->DeviceId().value(), nativeDevice);

    auto started =
        InvokeAsync([&] { return graph->NotifyWhenDeviceStarted(nullptr); });

    nativeStream = WaitFor(cubeb->StreamInitEvent());
    EXPECT_TRUE(nativeStream->mHasInput);
    EXPECT_TRUE(nativeStream->mHasOutput);
    EXPECT_EQ(nativeStream->InputChannels(), 1U);
    EXPECT_EQ(nativeStream->GetInputDeviceID(), nativeDevice);
    Unused << WaitFor(started);

    // Open a 2-channel AudioProcessingTrack for the native device and wait for
    // a new driver since the max-channel for the native device becomes 2 now.
    openTrack(nativeStream, track2, listener2, nativeDevice, 2);
    EXPECT_EQ(nativeStream->InputChannels(), 2U);

    // Set the second AudioProcessingTrack for the native device to 1-channel
    // and wait for a new driver since the max-channel for the native device
    // becomes 1 now.
    setNewChannelCount(track2, listener2, nativeStream, 1);
    EXPECT_EQ(nativeStream->InputChannels(), 1U);

    // Set the first AudioProcessingTrack for the native device to 2-channel and
    // wait for a new driver since the max input channel for the native device
    // becomes 2 now.
    setNewChannelCount(track1, listener1, nativeStream, 2);
    EXPECT_EQ(nativeStream->InputChannels(), 2U);
  }

  // Test for the non-native device.
  {
    const CubebUtils::AudioDeviceID nonNativeDevice =
        (CubebUtils::AudioDeviceID)2;

    // Open a 1-channel AudioProcessingTrack for the non-native device.
    RefPtr<AudioProcessingTrack> track3 = AudioProcessingTrack::Create(graph);
    RefPtr<AudioInputProcessing> listener3 = new AudioInputProcessing(1);
    track3->SetInputProcessing(listener3);
    QueueExpectIsPassThrough(track3, listener3);
    track3->GraphImpl()->AppendMessage(
        MakeUnique<StartInputProcessing>(track3, listener3));
    track3->ConnectDeviceInput(nonNativeDevice, listener3,
                               PRINCIPAL_HANDLE_NONE);
    EXPECT_EQ(track3->DeviceId().value(), nonNativeDevice);

    RefPtr<SmartMockCubebStream> nonNativeStream =
        WaitFor(cubeb->StreamInitEvent());
    EXPECT_TRUE(nonNativeStream->mHasInput);
    EXPECT_FALSE(nonNativeStream->mHasOutput);
    EXPECT_EQ(nonNativeStream->InputChannels(), 1U);
    EXPECT_EQ(nonNativeStream->GetInputDeviceID(), nonNativeDevice);

    // Open a 2-channel AudioProcessingTrack for the non-native device and wait
    // for a new stream since the max-channel for the non-native device becomes
    // 2 now.
    RefPtr<AudioProcessingTrack> track4;
    RefPtr<AudioInputProcessing> listener4;
    openTrack(nonNativeStream, track4, listener4, nonNativeDevice, 2);
    EXPECT_EQ(nonNativeStream->InputChannels(), 2U);
    EXPECT_EQ(nonNativeStream->GetInputDeviceID(), nonNativeDevice);

    // Set the second AudioProcessingTrack for the non-native to 1-channel and
    // wait for a new driver since the max-channel for the non-native device
    // becomes 1 now.
    setNewChannelCount(track4, listener4, nonNativeStream, 1);
    EXPECT_EQ(nonNativeStream->InputChannels(), 1U);
    EXPECT_EQ(nonNativeStream->GetInputDeviceID(), nonNativeDevice);

    // Set the first AudioProcessingTrack for the non-native device to 2-channel
    // and wait for a new driver since the max input channel for the non-native
    // device becomes 2 now.
    setNewChannelCount(track3, listener3, nonNativeStream, 2);
    EXPECT_EQ(nonNativeStream->InputChannels(), 2U);
    EXPECT_EQ(nonNativeStream->GetInputDeviceID(), nonNativeDevice);

    // Close the second AudioProcessingTrack (1-channel) for the non-native
    // device then the first one (2-channel) so we won't result in another
    // stream creation.
    DispatchFunction([&] {
      track4->GraphImpl()->AppendMessage(
          MakeUnique<StopInputProcessing>(track4, listener4));
      track4->DisconnectDeviceInput();
      track4->Destroy();
    });
    DispatchFunction([&] {
      track3->GraphImpl()->AppendMessage(
          MakeUnique<StopInputProcessing>(track3, listener3));
      track3->DisconnectDeviceInput();
      track3->Destroy();
    });
    RefPtr<SmartMockCubebStream> destroyedStream =
        WaitFor(cubeb->StreamDestroyEvent());
    EXPECT_EQ(destroyedStream.get(), nonNativeStream.get());
  }

  // Tear down for the native device.
  {
    // Close the second AudioProcessingTrack (1-channel) for the native device
    // then the first one (2-channel) so we won't have driver switching.
    DispatchFunction([&] {
      track2->GraphImpl()->AppendMessage(
          MakeUnique<StopInputProcessing>(track2, listener2));
      track2->DisconnectDeviceInput();
      track2->Destroy();
    });
    DispatchFunction([&] {
      track1->GraphImpl()->AppendMessage(
          MakeUnique<StopInputProcessing>(track1, listener1));
      track1->DisconnectDeviceInput();
      track1->Destroy();
    });
    RefPtr<SmartMockCubebStream> destroyedStream =
        WaitFor(cubeb->StreamDestroyEvent());
    EXPECT_EQ(destroyedStream.get(), nativeStream.get());
  }
}

TEST(TestAudioTrackGraph, SetInputChannelCountBeforeAudioCallbackDriver)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  // Set the input channel count of AudioInputProcessing, which will force
  // MediaTrackGraph to re-evaluate input device, when the MediaTrackGraph is
  // driven by the SystemClockDriver.

  const CubebUtils::AudioDeviceID deviceId = (CubebUtils::AudioDeviceID)1;
  RefPtr<AudioProcessingTrack> track;
  RefPtr<AudioInputProcessing> listener;
  DispatchFunction([&] {
    track = AudioProcessingTrack::Create(graph);
    listener = new AudioInputProcessing(2);
    QueueExpectIsPassThrough(track, listener);
    track->SetInputProcessing(listener);

    MediaEnginePrefs settings;
    settings.mChannels = 1;
    QueueApplySettings(track, listener, settings);
  });

  // Wait for AudioCallbackDriver to init output-only stream.
  RefPtr<SmartMockCubebStream> stream = WaitFor(cubeb->StreamInitEvent());
  EXPECT_FALSE(stream->mHasInput);
  EXPECT_TRUE(stream->mHasOutput);

  // Open a full-duplex AudioCallbackDriver.
  RefPtr<MediaInputPort> port;
  DispatchFunction([&] {
    track->GraphImpl()->AppendMessage(
        MakeUnique<StartInputProcessing>(track, listener));
    track->ConnectDeviceInput(deviceId, listener, PRINCIPAL_HANDLE_NONE);
  });

  stream = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream->mHasInput);
  EXPECT_TRUE(stream->mHasOutput);
  EXPECT_EQ(stream->InputChannels(), 1U);

  Unused << WaitFor(
      InvokeAsync([&] { return graph->NotifyWhenDeviceStarted(nullptr); }));

  // Clean up.
  DispatchFunction([&] {
    track->GraphImpl()->AppendMessage(
        MakeUnique<StopInputProcessing>(track, listener));
    track->DisconnectDeviceInput();
    track->Destroy();
  });
  Unused << WaitFor(cubeb->StreamDestroyEvent());
}

TEST(TestAudioTrackGraph, StartAudioDeviceBeforeStartingAudioProcessing)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  // Create a duplex AudioCallbackDriver
  const CubebUtils::AudioDeviceID deviceId = (CubebUtils::AudioDeviceID)1;
  RefPtr<AudioProcessingTrack> track;
  RefPtr<AudioInputProcessing> listener;
  DispatchFunction([&] {
    track = AudioProcessingTrack::Create(graph);
    listener = new AudioInputProcessing(2);
    QueueExpectIsPassThrough(track, listener);
    track->SetInputProcessing(listener);
    // Start audio device without starting audio processing.
    track->ConnectDeviceInput(deviceId, listener, PRINCIPAL_HANDLE_NONE);
  });

  RefPtr<SmartMockCubebStream> stream = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream->mHasInput);
  EXPECT_TRUE(stream->mHasOutput);

  // Wait for a second to make sure audio output callback has been fired.
  DispatchFunction(
      [&] { track->GraphImpl()->AppendMessage(MakeUnique<GoFaster>(cubeb)); });
  {
    uint32_t totalFrames = 0;
    WaitUntil(stream->FramesProcessedEvent(), [&](uint32_t aFrames) {
      totalFrames += aFrames;
      return totalFrames > static_cast<uint32_t>(graph->GraphRate());
    });
  }
  cubeb->DontGoFaster();

  // Start the audio processing.
  DispatchFunction([&] {
    track->GraphImpl()->AppendMessage(
        MakeUnique<StartInputProcessing>(track, listener));
  });

  // Wait for a second to make sure audio output callback has been fired.
  DispatchFunction(
      [&] { track->GraphImpl()->AppendMessage(MakeUnique<GoFaster>(cubeb)); });
  {
    uint32_t totalFrames = 0;
    WaitUntil(stream->FramesProcessedEvent(), [&](uint32_t aFrames) {
      totalFrames += aFrames;
      return totalFrames > static_cast<uint32_t>(graph->GraphRate());
    });
  }
  cubeb->DontGoFaster();

  // Clean up.
  DispatchFunction([&] {
    track->DisconnectDeviceInput();
    track->Destroy();
  });
  Unused << WaitFor(cubeb->StreamDestroyEvent());
}

TEST(TestAudioTrackGraph, StopAudioProcessingBeforeStoppingAudioDevice)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  // Create a duplex AudioCallbackDriver
  const CubebUtils::AudioDeviceID deviceId = (CubebUtils::AudioDeviceID)1;
  RefPtr<AudioProcessingTrack> track;
  RefPtr<AudioInputProcessing> listener;
  DispatchFunction([&] {
    track = AudioProcessingTrack::Create(graph);
    listener = new AudioInputProcessing(2);
    QueueExpectIsPassThrough(track, listener);
    track->SetInputProcessing(listener);
    track->GraphImpl()->AppendMessage(
        MakeUnique<StartInputProcessing>(track, listener));
    track->ConnectDeviceInput(deviceId, listener, PRINCIPAL_HANDLE_NONE);
  });

  RefPtr<SmartMockCubebStream> stream = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream->mHasInput);
  EXPECT_TRUE(stream->mHasOutput);

  // Wait for a second to make sure audio output callback has been fired.
  DispatchFunction(
      [&] { track->GraphImpl()->AppendMessage(MakeUnique<GoFaster>(cubeb)); });
  {
    uint32_t totalFrames = 0;
    WaitUntil(stream->FramesProcessedEvent(), [&](uint32_t aFrames) {
      totalFrames += aFrames;
      return totalFrames > static_cast<uint32_t>(graph->GraphRate());
    });
  }
  cubeb->DontGoFaster();

  // Stop the audio processing
  DispatchFunction([&] {
    track->GraphImpl()->AppendMessage(
        MakeUnique<StopInputProcessing>(track, listener));
  });

  // Wait for a second to make sure audio output callback has been fired.
  DispatchFunction(
      [&] { track->GraphImpl()->AppendMessage(MakeUnique<GoFaster>(cubeb)); });
  {
    uint32_t totalFrames = 0;
    WaitUntil(stream->FramesProcessedEvent(), [&](uint32_t aFrames) {
      totalFrames += aFrames;
      return totalFrames > static_cast<uint32_t>(graph->GraphRate());
    });
  }
  cubeb->DontGoFaster();

  // Clean up.
  DispatchFunction([&] {
    track->DisconnectDeviceInput();
    track->Destroy();
  });
  Unused << WaitFor(cubeb->StreamDestroyEvent());
}

// This test is pretty similar to SwitchNativeInputDevice above, which makes
// sure the related DeviceInputTrack operations for the test here works
// correctly. Instead of using a test-only DeviceInputTrack consumer, we use
// AudioProcessingTrack here to simulate the real world use case.
TEST(TestAudioTrackGraph, SwitchNativeAudioProcessingTrack)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  auto switchNativeDevice =
      [&](RefPtr<SmartMockCubebStream>&& aCurrentNativeStream,
          RefPtr<AudioProcessingTrack>& aCurrentNativeTrack,
          RefPtr<AudioInputProcessing>& aCurrentNativeListener,
          RefPtr<SmartMockCubebStream>& aNextNativeStream,
          RefPtr<AudioProcessingTrack>& aNextNativeTrack) {
        ASSERT_TRUE(aCurrentNativeStream->mHasInput);
        ASSERT_TRUE(aCurrentNativeStream->mHasOutput);
        ASSERT_TRUE(aNextNativeStream->mHasInput);
        ASSERT_FALSE(aNextNativeStream->mHasOutput);

        std::cerr << "Switching native input from device "
                  << aCurrentNativeStream->GetInputDeviceID() << " to "
                  << aNextNativeStream->GetInputDeviceID() << std::endl;

        uint32_t destroyed = 0;
        MediaEventListener destroyListener =
            cubeb->StreamDestroyEvent().Connect(
                AbstractThread::GetCurrent(),
                [&](const RefPtr<SmartMockCubebStream>& aDestroyed) {
                  if (aDestroyed.get() == aCurrentNativeStream.get() ||
                      aDestroyed.get() == aNextNativeStream.get()) {
                    std::cerr << "cubeb stream " << aDestroyed.get()
                              << " (device " << aDestroyed->GetInputDeviceID()
                              << ") has been destroyed" << std::endl;
                    destroyed += 1;
                  }
                });

        RefPtr<SmartMockCubebStream> newStream;
        MediaEventListener restartListener = cubeb->StreamInitEvent().Connect(
            AbstractThread::GetCurrent(),
            [&](const RefPtr<SmartMockCubebStream>& aCreated) {
              // Make sure new stream has input, to prevent from getting a
              // temporary output-only AudioCallbackDriver after closing current
              // native device but before setting a new native input.
              if (aCreated->mHasInput) {
                ASSERT_TRUE(aCreated->mHasOutput);
                newStream = aCreated;
              }
            });

        std::cerr << "Close device " << aCurrentNativeStream->GetInputDeviceID()
                  << std::endl;
        DispatchFunction([&] {
          aCurrentNativeTrack->GraphImpl()->AppendMessage(
              MakeUnique<StopInputProcessing>(aCurrentNativeTrack,
                                              aCurrentNativeListener));
          aCurrentNativeTrack->DisconnectDeviceInput();
          aCurrentNativeTrack->Destroy();
        });

        std::cerr << "Wait for the switching" << std::endl;
        SpinEventLoopUntil<ProcessFailureBehavior::IgnoreAndContinue>(
            "TEST(TestAudioTrackGraph, SwitchNativeAudioProcessingTrack)"_ns,
            [&] { return destroyed >= 2 && newStream; });

        destroyListener.Disconnect();
        restartListener.Disconnect();

        aCurrentNativeStream = nullptr;
        aNextNativeStream = newStream;

        std::cerr << "Now the native input is device "
                  << aNextNativeStream->GetInputDeviceID() << std::endl;
      };

  // Open a AudioProcessingTrack for device 1.
  const CubebUtils::AudioDeviceID device1 = (CubebUtils::AudioDeviceID)1;
  RefPtr<AudioProcessingTrack> track1 = AudioProcessingTrack::Create(graph);
  RefPtr<AudioInputProcessing> listener1 = new AudioInputProcessing(1);
  track1->SetInputProcessing(listener1);
  QueueExpectIsPassThrough(track1, listener1);
  track1->GraphImpl()->AppendMessage(
      MakeUnique<StartInputProcessing>(track1, listener1));
  track1->ConnectDeviceInput(device1, listener1, PRINCIPAL_HANDLE_NONE);
  EXPECT_EQ(track1->DeviceId().value(), device1);

  auto started =
      InvokeAsync([&] { return graph->NotifyWhenDeviceStarted(nullptr); });

  RefPtr<SmartMockCubebStream> stream1 = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream1->mHasInput);
  EXPECT_TRUE(stream1->mHasOutput);
  EXPECT_EQ(stream1->InputChannels(), 1U);
  EXPECT_EQ(stream1->GetInputDeviceID(), device1);
  Unused << WaitFor(started);
  std::cerr << "Device " << device1 << " is opened (stream " << stream1.get()
            << ")" << std::endl;

  // Open a AudioProcessingTrack for device 2.
  const CubebUtils::AudioDeviceID device2 = (CubebUtils::AudioDeviceID)2;
  RefPtr<AudioProcessingTrack> track2 = AudioProcessingTrack::Create(graph);
  RefPtr<AudioInputProcessing> listener2 = new AudioInputProcessing(2);
  track2->SetInputProcessing(listener2);
  QueueExpectIsPassThrough(track2, listener2);
  track2->GraphImpl()->AppendMessage(
      MakeUnique<StartInputProcessing>(track2, listener2));
  track2->ConnectDeviceInput(device2, listener2, PRINCIPAL_HANDLE_NONE);
  EXPECT_EQ(track2->DeviceId().value(), device2);

  RefPtr<SmartMockCubebStream> stream2 = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream2->mHasInput);
  EXPECT_FALSE(stream2->mHasOutput);
  EXPECT_EQ(stream2->InputChannels(), 2U);
  EXPECT_EQ(stream2->GetInputDeviceID(), device2);
  std::cerr << "Device " << device2 << " is opened (stream " << stream2.get()
            << ")" << std::endl;

  // Open a AudioProcessingTrack for device 3.
  const CubebUtils::AudioDeviceID device3 = (CubebUtils::AudioDeviceID)3;
  RefPtr<AudioProcessingTrack> track3 = AudioProcessingTrack::Create(graph);
  RefPtr<AudioInputProcessing> listener3 = new AudioInputProcessing(1);
  track3->SetInputProcessing(listener3);
  QueueExpectIsPassThrough(track3, listener3);
  track3->GraphImpl()->AppendMessage(
      MakeUnique<StartInputProcessing>(track3, listener3));
  track3->ConnectDeviceInput(device3, listener3, PRINCIPAL_HANDLE_NONE);
  EXPECT_EQ(track3->DeviceId().value(), device3);

  RefPtr<SmartMockCubebStream> stream3 = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream3->mHasInput);
  EXPECT_FALSE(stream3->mHasOutput);
  EXPECT_EQ(stream3->InputChannels(), 1U);
  EXPECT_EQ(stream3->GetInputDeviceID(), device3);
  std::cerr << "Device " << device3 << " is opened (stream " << stream3.get()
            << ")" << std::endl;

  // Close device 1, so the native input device is switched from device 1 to
  // device 2.
  switchNativeDevice(std::move(stream1), track1, listener1, stream2, track2);
  EXPECT_TRUE(stream2->mHasInput);
  EXPECT_TRUE(stream2->mHasOutput);
  EXPECT_EQ(stream2->InputChannels(), 2U);
  EXPECT_EQ(stream2->GetInputDeviceID(), device2);
  {
    NativeInputTrack* native = track2->Graph()->GetNativeInputTrackMainThread();
    ASSERT_TRUE(!!native);
    EXPECT_EQ(native->mDeviceId, device2);
  }

  // Close device 2, so the native input device is switched from device 2 to
  // device 3.
  switchNativeDevice(std::move(stream2), track2, listener2, stream3, track3);
  EXPECT_TRUE(stream3->mHasInput);
  EXPECT_TRUE(stream3->mHasOutput);
  EXPECT_EQ(stream3->InputChannels(), 1U);
  EXPECT_EQ(stream3->GetInputDeviceID(), device3);
  {
    NativeInputTrack* native = track3->Graph()->GetNativeInputTrackMainThread();
    ASSERT_TRUE(!!native);
    EXPECT_EQ(native->mDeviceId, device3);
  }

  // Clean up.
  std::cerr << "Close device " << device3 << std::endl;
  DispatchFunction([&] {
    track3->GraphImpl()->AppendMessage(
        MakeUnique<StopInputProcessing>(track3, listener3));
    track3->DisconnectDeviceInput();
    track3->Destroy();
  });
  RefPtr<SmartMockCubebStream> destroyedStream =
      WaitFor(cubeb->StreamDestroyEvent());
  EXPECT_EQ(destroyedStream.get(), stream3.get());
  {
    NativeInputTrack* native = graph->GetNativeInputTrackMainThread();
    ASSERT_TRUE(!native);
  }
  std::cerr << "No native input now" << std::endl;
}

void TestCrossGraphPort(uint32_t aInputRate, uint32_t aOutputRate,
                        float aDriftFactor, uint32_t aRunTimeSeconds = 10,
                        uint32_t aNumExpectedUnderruns = 0) {
  std::cerr << "TestCrossGraphPort input: " << aInputRate
            << ", output: " << aOutputRate << ", driftFactor: " << aDriftFactor
            << std::endl;

  MockCubeb* cubeb = new MockCubeb(MockCubeb::RunningMode::Manual);
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  /* Primary graph: Create the graph. */
  MediaTrackGraph* primary = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER,
      /*Window ID*/ 1, aInputRate, nullptr, GetMainThreadSerialEventTarget());

  /* Partner graph: Create the graph. */
  MediaTrackGraph* partner = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1, aOutputRate,
      /*OutputDeviceID*/ reinterpret_cast<cubeb_devid>(1),
      GetMainThreadSerialEventTarget());

  const CubebUtils::AudioDeviceID inputDeviceId = (CubebUtils::AudioDeviceID)1;

  RefPtr<AudioProcessingTrack> processingTrack;
  RefPtr<AudioInputProcessing> listener;
  RefPtr<OnFallbackListener> primaryFallbackListener;
  DispatchFunction([&] {
    /* Primary graph: Create input track and open it */
    processingTrack = AudioProcessingTrack::Create(primary);
    listener = new AudioInputProcessing(2);
    QueueExpectIsPassThrough(processingTrack, listener);
    processingTrack->SetInputProcessing(listener);
    processingTrack->GraphImpl()->AppendMessage(
        MakeUnique<StartInputProcessing>(processingTrack, listener));
    processingTrack->ConnectDeviceInput(inputDeviceId, listener,
                                        PRINCIPAL_HANDLE_NONE);
    primaryFallbackListener = new OnFallbackListener(processingTrack);
    processingTrack->AddListener(primaryFallbackListener);
  });

  RefPtr<SmartMockCubebStream> inputStream = WaitFor(cubeb->StreamInitEvent());

  while (
      inputStream->State()
          .map([](cubeb_state aState) { return aState != CUBEB_STATE_STARTED; })
          .valueOr(true)) {
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Wait for the primary AudioCallbackDriver to come into effect.
  while (primaryFallbackListener->OnFallback()) {
    EXPECT_EQ(inputStream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::Yes);
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  RefPtr<CrossGraphTransmitter> transmitter;
  RefPtr<MediaInputPort> port;
  RefPtr<CrossGraphReceiver> receiver;
  RefPtr<OnFallbackListener> partnerFallbackListener;
  DispatchFunction([&] {
    processingTrack->RemoveListener(primaryFallbackListener);

    /* Partner graph: Create CrossGraphReceiver */
    receiver = partner->CreateCrossGraphReceiver(primary->GraphRate());

    /* Primary graph: Create CrossGraphTransmitter */
    transmitter = primary->CreateCrossGraphTransmitter(receiver);

    /* How the input track connects to another ProcessedMediaTrack.
     * Check in MediaManager how it is connected to AudioStreamTrack. */
    port = transmitter->AllocateInputPort(processingTrack);
    receiver->AddAudioOutput((void*)1, partner->PrimaryOutputDeviceID(), 0);

    partnerFallbackListener = new OnFallbackListener(receiver);
    receiver->AddListener(partnerFallbackListener);
  });

  RefPtr<SmartMockCubebStream> partnerStream =
      WaitFor(cubeb->StreamInitEvent());

  while (
      partnerStream->State()
          .map([](cubeb_state aState) { return aState != CUBEB_STATE_STARTED; })
          .valueOr(true)) {
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Process the CrossGraphTransmitter on the primary graph.
  EXPECT_EQ(inputStream->ManualDataCallback(0),
            MockCubebStream::KeepProcessing::Yes);

  // Wait for the partner AudioCallbackDriver to come into effect.
  while (partnerFallbackListener->OnFallback()) {
    EXPECT_EQ(partnerStream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::Yes);
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  DispatchFunction([&] { receiver->RemoveListener(partnerFallbackListener); });
  ProcessEventQueue();

  nsIThread* currentThread = NS_GetCurrentThread();
  cubeb_state inputState = CUBEB_STATE_STARTED;
  MediaEventListener inputStateListener = inputStream->StateEvent().Connect(
      currentThread, [&](cubeb_state aState) { inputState = aState; });
  cubeb_state partnerState = CUBEB_STATE_STARTED;
  MediaEventListener partnerStateListener = partnerStream->StateEvent().Connect(
      currentThread, [&](cubeb_state aState) { partnerState = aState; });

  const media::TimeUnit runtime = media::TimeUnit::FromSeconds(aRunTimeSeconds);
  // 10ms per iteration.
  const media::TimeUnit step = media::TimeUnit::FromSeconds(0.01);
  {
    media::TimeUnit pos = media::TimeUnit::Zero();
    long inputFrames = 0;
    long outputFrames = 0;
    while (pos < runtime) {
      pos += step;
      const long newInputFrames = pos.ToTicksAtRate(aInputRate);
      const long newOutputFrames =
          (pos.MultDouble(aDriftFactor)).ToTicksAtRate(aOutputRate);
      EXPECT_EQ(inputStream->ManualDataCallback(newInputFrames - inputFrames),
                MockCubebStream::KeepProcessing::Yes);
      EXPECT_EQ(
          partnerStream->ManualDataCallback(newOutputFrames - outputFrames),
          MockCubebStream::KeepProcessing::Yes);

      inputFrames = newInputFrames;
      outputFrames = newOutputFrames;
    }
  }

  DispatchFunction([&] {
    // Clean up on MainThread
    receiver->RemoveAudioOutput((void*)1);
    receiver->Destroy();
    transmitter->Destroy();
    port->Destroy();
    processingTrack->GraphImpl()->AppendMessage(
        MakeUnique<StopInputProcessing>(processingTrack, listener));
    processingTrack->DisconnectDeviceInput();
    processingTrack->Destroy();
  });

  ProcessEventQueue();

  EXPECT_EQ(inputStream->ManualDataCallback(0),
            MockCubebStream::KeepProcessing::Yes);
  EXPECT_EQ(partnerStream->ManualDataCallback(0),
            MockCubebStream::KeepProcessing::Yes);

  EXPECT_EQ(inputStream->ManualDataCallback(128),
            MockCubebStream::KeepProcessing::No);
  EXPECT_EQ(partnerStream->ManualDataCallback(128),
            MockCubebStream::KeepProcessing::No);

  uint32_t inputFrequency = inputStream->InputFrequency();

  uint64_t preSilenceSamples;
  float estimatedFreq;
  uint32_t nrDiscontinuities;
  std::tie(preSilenceSamples, estimatedFreq, nrDiscontinuities) =
      WaitFor(partnerStream->OutputVerificationEvent());

  EXPECT_NEAR(estimatedFreq, inputFrequency / aDriftFactor, 5);
  // Note that pre-silence is in the output rate. The buffering is on the input
  // side. There is one block buffered in NativeInputTrack. Then
  // AudioDriftCorrection sets its pre-buffering so that *after* the first
  // resample of real input data, the buffer contains enough data to match the
  // desired level, which is initially 50ms. I.e. silence = buffering -
  // inputStep + outputStep. Note that the steps here are rounded up to block
  // size.
  const media::TimeUnit inputBuffering(WEBAUDIO_BLOCK_SIZE, aInputRate);
  const media::TimeUnit buffering =
      media::TimeUnit::FromSeconds(0.05).ToBase(aInputRate);
  const media::TimeUnit inputStepSize(
      MediaTrackGraphImpl::RoundUpToEndOfAudioBlock(
          step.ToTicksAtRate(aInputRate)),
      aInputRate);
  const media::TimeUnit outputStepSize =
      media::TimeUnit(MediaTrackGraphImpl::RoundUpToEndOfAudioBlock(
                          step.ToBase(aOutputRate)
                              .MultDouble(aDriftFactor)
                              .ToTicksAtRate(aOutputRate)),
                      aOutputRate)
          .ToBase(aInputRate);
  const uint32_t expectedPreSilence =
      (outputStepSize + inputBuffering + buffering - inputStepSize)
          .ToBase(aInputRate)
          .ToBase<media::TimeUnit::CeilingPolicy>(aOutputRate)
          .ToTicksAtRate(aOutputRate);
  // Use a margin of 0.1% of the expected pre-silence, since the resampler is
  // adapting to drift and will process the pre-silence frames. Because of
  // rounding errors, we don't use a margin lower than 1.
  const uint32_t margin = std::max(1U, expectedPreSilence / 1000);
  EXPECT_NEAR(preSilenceSamples, expectedPreSilence, margin);
  // The waveform from AudioGenerator starts at 0, but we don't control its
  // ending, so we expect a discontinuity there. For each expected underrun
  // there could be an additional 2 discontinuities (start and end of the silent
  // period).
  EXPECT_LE(nrDiscontinuities, 1U + 2 * aNumExpectedUnderruns);

  SpinEventLoopUntil("streams have stopped"_ns, [&] {
    return inputState == CUBEB_STATE_STOPPED &&
           partnerState == CUBEB_STATE_STOPPED;
  });
  inputStateListener.Disconnect();
  partnerStateListener.Disconnect();
}

TEST(TestAudioTrackGraph, CrossGraphPort)
{
  TestCrossGraphPort(44100, 44100, 1);
  TestCrossGraphPort(44100, 44100, 1.006);
  TestCrossGraphPort(44100, 44100, 0.994);

  TestCrossGraphPort(48000, 44100, 1);
  TestCrossGraphPort(48000, 44100, 1.006);
  TestCrossGraphPort(48000, 44100, 0.994);

  TestCrossGraphPort(44100, 48000, 1);
  TestCrossGraphPort(44100, 48000, 1.006);
  TestCrossGraphPort(44100, 48000, 0.994);

  TestCrossGraphPort(52110, 17781, 1);
  TestCrossGraphPort(52110, 17781, 1.006);
  TestCrossGraphPort(52110, 17781, 0.994);
}

TEST(TestAudioTrackGraph, CrossGraphPortUnderrun)
{
  TestCrossGraphPort(44100, 44100, 1.01, 30, 1);
  TestCrossGraphPort(44100, 44100, 1.03, 40, 3);

  TestCrossGraphPort(48000, 44100, 1.01, 30, 1);
  TestCrossGraphPort(48000, 44100, 1.03, 40, 3);

  TestCrossGraphPort(44100, 48000, 1.01, 30, 1);
  TestCrossGraphPort(44100, 48000, 1.03, 40, 3);

  TestCrossGraphPort(52110, 17781, 1.01, 30, 1);
  TestCrossGraphPort(52110, 17781, 1.03, 40, 3);
}

TEST(TestAudioTrackGraph, SecondaryOutputDevice)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  const TrackRate primaryRate = 48000;
  const TrackRate secondaryRate = 44100;  // for secondary output device

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER,
      /*Window ID*/ 1, primaryRate, nullptr, GetMainThreadSerialEventTarget());

  RefPtr<AudioProcessingTrack> processingTrack;
  RefPtr<AudioInputProcessing> listener;
  DispatchFunction([&] {
    /* Create an input track and connect it to a device */
    processingTrack = AudioProcessingTrack::Create(graph);
    listener = new AudioInputProcessing(2);
    QueueExpectIsPassThrough(processingTrack, listener);
    processingTrack->SetInputProcessing(listener);
    processingTrack->GraphImpl()->AppendMessage(
        MakeUnique<StartInputProcessing>(processingTrack, listener));
    processingTrack->ConnectDeviceInput(nullptr, listener,
                                        PRINCIPAL_HANDLE_NONE);
  });
  RefPtr<SmartMockCubebStream> primaryStream =
      WaitFor(cubeb->StreamInitEvent());

  const void* secondaryDeviceID = CubebUtils::AudioDeviceID(2);
  DispatchFunction([&] {
    processingTrack->AddAudioOutput(nullptr, secondaryDeviceID, secondaryRate);
    processingTrack->SetAudioOutputVolume(nullptr, 0.f);
  });
  RefPtr<SmartMockCubebStream> secondaryStream =
      WaitFor(cubeb->StreamInitEvent());
  EXPECT_EQ(secondaryStream->GetOutputDeviceID(), secondaryDeviceID);
  EXPECT_EQ(static_cast<TrackRate>(secondaryStream->SampleRate()),
            secondaryRate);

  nsIThread* currentThread = NS_GetCurrentThread();
  uint32_t audioFrames = 0;  // excludes pre-silence
  MediaEventListener audioListener =
      secondaryStream->FramesVerifiedEvent().Connect(
          currentThread, [&](uint32_t aFrames) { audioFrames += aFrames; });

  // Wait for 100ms of pre-silence to verify that SetAudioOutputVolume() is
  // effective.
  uint32_t processedFrames = 0;
  WaitUntil(secondaryStream->FramesProcessedEvent(), [&](uint32_t aFrames) {
    processedFrames += aFrames;
    return processedFrames > static_cast<uint32_t>(secondaryRate / 10);
  });
  EXPECT_EQ(audioFrames, 0U) << "audio frames at zero volume";

  secondaryStream->SetOutputRecordingEnabled(true);
  DispatchFunction(
      [&] { processingTrack->SetAudioOutputVolume(nullptr, 1.f); });

  // Wait for enough audio after initial silence to check the frequency.
  SpinEventLoopUntil("200ms of audio"_ns, [&] {
    return audioFrames > static_cast<uint32_t>(secondaryRate / 5);
  });
  audioListener.Disconnect();

  // Stop recording now so as not to record the discontinuity when the
  // CrossGraphReceiver is removed from the secondary graph before its
  // AudioCallbackDriver is stopped.
  secondaryStream->SetOutputRecordingEnabled(false);

  DispatchFunction([&] { processingTrack->RemoveAudioOutput(nullptr); });
  WaitFor(secondaryStream->OutputVerificationEvent());
  // The frequency from OutputVerificationEvent() is estimated by
  // AudioVerifier from a zero-crossing count.  When the discontinuity from
  // the volume change is resampled, the discontinuity presents as
  // oscillations, which increase the zero-crossing count and corrupt the
  // frequency estimate.  Trim off sufficient leading from the output to
  // remove this discontinuity.
  uint32_t channelCount = secondaryStream->OutputChannels();
  nsTArray<AudioDataValue> output = secondaryStream->TakeRecordedOutput();
  size_t leadingIndex = 0;
  for (; leadingIndex < output.Length() && output[leadingIndex] == 0.f;
       leadingIndex += channelCount) {
  };
  leadingIndex += 10 * channelCount;  // skip discontinuity oscillations
  EXPECT_LT(leadingIndex, output.Length());
  auto trimmed = Span(output).From(std::min(leadingIndex, output.Length()));
  size_t frameCount = trimmed.Length() / channelCount;
  uint32_t inputFrequency = primaryStream->InputFrequency();
  AudioVerifier<AudioDataValue> verifier(secondaryRate, inputFrequency);
  verifier.AppendDataInterleaved(trimmed.Elements(), frameCount, channelCount);
  EXPECT_EQ(verifier.EstimatedFreq(), inputFrequency);
  // AudioVerifier considers the previous value before the initial sample to
  // be zero and so considers any initial sample >> 0 to be a discontinuity.
  EXPECT_EQ(verifier.CountDiscontinuities(), 1U);

  DispatchFunction([&] {
    // Clean up
    processingTrack->GraphImpl()->AppendMessage(
        MakeUnique<StopInputProcessing>(processingTrack, listener));
    processingTrack->DisconnectDeviceInput();
    processingTrack->Destroy();
  });
  WaitFor(primaryStream->OutputVerificationEvent());
}

// Test when AudioInputProcessing expects clock drift
TEST(TestAudioInputProcessing, ClockDriftExpectation)
{
  MockCubeb* cubeb = new MockCubeb();
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  const TrackRate rate = 44100;

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER,
      /*Window ID*/ 1, rate, nullptr, GetMainThreadSerialEventTarget());

  auto createInputProcessing =
      [&](CubebUtils::AudioDeviceID aDeviceID,
          RefPtr<AudioProcessingTrack>* aProcessingTrack,
          RefPtr<AudioInputProcessing>* aInputProcessing) {
        /* Create an input track and connect it to a device */
        const int32_t channelCount = 2;
        RefPtr processingTrack = AudioProcessingTrack::Create(graph);
        RefPtr inputProcessing = new AudioInputProcessing(channelCount);
        processingTrack->SetInputProcessing(inputProcessing);
        MediaEnginePrefs settings;
        settings.mChannels = channelCount;
        settings.mAecOn = true;
        QueueApplySettings(processingTrack, inputProcessing, settings);
        processingTrack->GraphImpl()->AppendMessage(
            MakeUnique<StartInputProcessing>(processingTrack, inputProcessing));
        processingTrack->ConnectDeviceInput(aDeviceID, inputProcessing,
                                            PRINCIPAL_HANDLE_NONE);
        aProcessingTrack->swap(processingTrack);
        aInputProcessing->swap(inputProcessing);
      };

  // Native input, which uses a duplex stream
  RefPtr<AudioProcessingTrack> processingTrack1;
  RefPtr<AudioInputProcessing> inputProcessing1;
  DispatchFunction([&] {
    createInputProcessing(nullptr, &processingTrack1, &inputProcessing1);
  });
  // Non-native input
  const auto* nonNativeInputDeviceID = CubebUtils::AudioDeviceID(1);
  RefPtr<AudioProcessingTrack> processingTrack2;
  RefPtr<AudioInputProcessing> inputProcessing2;
  DispatchFunction([&] {
    createInputProcessing(nonNativeInputDeviceID, &processingTrack2,
                          &inputProcessing2);
    processingTrack2->AddAudioOutput(nullptr, nullptr, rate);
  });

  RefPtr<SmartMockCubebStream> primaryStream;
  RefPtr<SmartMockCubebStream> nonNativeInputStream;
  WaitUntil(cubeb->StreamInitEvent(),
            [&](RefPtr<SmartMockCubebStream>&& stream) {
              if (stream->OutputChannels() > 0) {
                primaryStream = std::move(stream);
                return false;
              }
              nonNativeInputStream = std::move(stream);
              return true;
            });
  EXPECT_EQ(nonNativeInputStream->GetInputDeviceID(), nonNativeInputDeviceID);

  // Wait until non-native input signal reaches the output, when input
  // processing has run and so has been configured.
  WaitFor(primaryStream->FramesVerifiedEvent());

  const void* secondaryOutputDeviceID = CubebUtils::AudioDeviceID(2);
  DispatchFunction([&] {
    // Check input processing config with output to primary device.
    processingTrack1->QueueControlMessageWithNoShutdown([&] {
      EXPECT_FALSE(inputProcessing1->HadAECAndDrift());
      EXPECT_TRUE(inputProcessing2->HadAECAndDrift());
    });

    // Switch output to a secondary device.
    processingTrack2->RemoveAudioOutput(nullptr);
    processingTrack2->AddAudioOutput(nullptr, secondaryOutputDeviceID, rate);
  });

  RefPtr<SmartMockCubebStream> secondaryOutputStream =
      WaitFor(cubeb->StreamInitEvent());
  EXPECT_EQ(secondaryOutputStream->GetOutputDeviceID(),
            secondaryOutputDeviceID);

  WaitFor(secondaryOutputStream->FramesVerifiedEvent());
  DispatchFunction([&] {
    // Check input processing config with output to secondary device.
    processingTrack1->QueueControlMessageWithNoShutdown([&] {
      EXPECT_TRUE(inputProcessing1->HadAECAndDrift());
      EXPECT_TRUE(inputProcessing2->HadAECAndDrift());
    });
  });

  auto destroyInputProcessing = [&](AudioProcessingTrack* aProcessingTrack,
                                    AudioInputProcessing* aInputProcessing) {
    aProcessingTrack->GraphImpl()->AppendMessage(
        MakeUnique<StopInputProcessing>(aProcessingTrack, aInputProcessing));
    aProcessingTrack->DisconnectDeviceInput();
    aProcessingTrack->Destroy();
  };

  DispatchFunction([&] {
    // Clean up
    destroyInputProcessing(processingTrack1, inputProcessing1);
    destroyInputProcessing(processingTrack2, inputProcessing2);
  });
  // Wait for stream stop to ensure that expectations have been checked.
  WaitFor(nonNativeInputStream->OutputVerificationEvent());
}
#endif  // MOZ_WEBRTC

TEST(TestAudioTrackGraph, PlatformProcessing)
{
  constexpr cubeb_input_processing_params allParams =
      CUBEB_INPUT_PROCESSING_PARAM_ECHO_CANCELLATION |
      CUBEB_INPUT_PROCESSING_PARAM_NOISE_SUPPRESSION |
      CUBEB_INPUT_PROCESSING_PARAM_AUTOMATIC_GAIN_CONTROL |
      CUBEB_INPUT_PROCESSING_PARAM_VOICE_ISOLATION;
  MockCubeb* cubeb = new MockCubeb(MockCubeb::RunningMode::Manual);
  cubeb->SetSupportedInputProcessingParams(allParams, CUBEB_OK);
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  const CubebUtils::AudioDeviceID device = (CubebUtils::AudioDeviceID)1;

  // Set up mock listener.
  RefPtr<MockAudioDataListener> listener = MakeRefPtr<MockAudioDataListener>();
  EXPECT_CALL(*listener, IsVoiceInput).WillRepeatedly(Return(true));
  EXPECT_CALL(*listener, RequestedInputChannelCount).WillRepeatedly(Return(1));
  EXPECT_CALL(*listener, RequestedInputProcessingParams)
      .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_ECHO_CANCELLATION));
  EXPECT_CALL(*listener, Disconnect);

  // Expectations.
  const Result<cubeb_input_processing_params, int> notSupportedResult(
      Err(CUBEB_ERROR_NOT_SUPPORTED));
  const Result<cubeb_input_processing_params, int> errorResult(
      Err(CUBEB_ERROR));
  const Result<cubeb_input_processing_params, int> noneResult(
      CUBEB_INPUT_PROCESSING_PARAM_NONE);
  const Result<cubeb_input_processing_params, int> echoResult(
      CUBEB_INPUT_PROCESSING_PARAM_ECHO_CANCELLATION);
  const Result<cubeb_input_processing_params, int> noiseResult(
      CUBEB_INPUT_PROCESSING_PARAM_NOISE_SUPPRESSION);
  Atomic<int> numProcessingParamsResults(0);
  {
    InSequence s;
    // On first driver start.
    EXPECT_CALL(*listener,
                NotifySetRequestedInputProcessingParams(
                    graph, 1, CUBEB_INPUT_PROCESSING_PARAM_ECHO_CANCELLATION));
    EXPECT_CALL(*listener, NotifySetRequestedInputProcessingParamsResult(
                               graph, 1, Eq(std::ref(echoResult))))
        .WillOnce([&] { ++numProcessingParamsResults; });
    // After requesting something else.
    EXPECT_CALL(*listener,
                NotifySetRequestedInputProcessingParams(
                    graph, 2, CUBEB_INPUT_PROCESSING_PARAM_NOISE_SUPPRESSION));
    EXPECT_CALL(*listener, NotifySetRequestedInputProcessingParamsResult(
                               graph, 2, Eq(std::ref(noiseResult))))
        .WillOnce([&] { ++numProcessingParamsResults; });
    // After error request.
    EXPECT_CALL(*listener,
                NotifySetRequestedInputProcessingParams(
                    graph, 3, CUBEB_INPUT_PROCESSING_PARAM_ECHO_CANCELLATION));
    EXPECT_CALL(*listener, NotifySetRequestedInputProcessingParamsResult(
                               graph, 3, Eq(std::ref(errorResult))))
        .WillOnce([&] { ++numProcessingParamsResults; });
    // After requesting None, because of the previous error.
    EXPECT_CALL(*listener, NotifySetRequestedInputProcessingParams(
                               graph, 4, CUBEB_INPUT_PROCESSING_PARAM_NONE));
    EXPECT_CALL(*listener, NotifySetRequestedInputProcessingParamsResult(
                               graph, 4, Eq(std::ref(noneResult))))
        .WillOnce([&] { ++numProcessingParamsResults; });
    // After driver switch.
    EXPECT_CALL(*listener, NotifySetRequestedInputProcessingParamsResult(
                               graph, 4, Eq(std::ref(noneResult))))
        .WillOnce([&] { ++numProcessingParamsResults; });
    // After requesting something not supported.
    EXPECT_CALL(*listener,
                NotifySetRequestedInputProcessingParams(
                    graph, 5, CUBEB_INPUT_PROCESSING_PARAM_ECHO_CANCELLATION));
    EXPECT_CALL(*listener, NotifySetRequestedInputProcessingParamsResult(
                               graph, 5, Eq(std::ref(noneResult))))
        .WillOnce([&] { ++numProcessingParamsResults; });
    // After requesting something with backend not supporting processing params.
    EXPECT_CALL(*listener,
                NotifySetRequestedInputProcessingParams(
                    graph, 6, CUBEB_INPUT_PROCESSING_PARAM_NOISE_SUPPRESSION));
    EXPECT_CALL(*listener, NotifySetRequestedInputProcessingParamsResult(
                               graph, 6, Eq(std::ref(notSupportedResult))))
        .WillOnce([&] { ++numProcessingParamsResults; });
  }

  // Open a device.
  RefPtr<TestDeviceInputConsumerTrack> track;
  RefPtr<OnFallbackListener> fallbackListener;
  DispatchFunction([&] {
    track = TestDeviceInputConsumerTrack::Create(graph);
    track->ConnectDeviceInput(device, listener, PRINCIPAL_HANDLE_NONE);
    fallbackListener = new OnFallbackListener(track);
    track->AddListener(fallbackListener);
  });

  RefPtr<SmartMockCubebStream> stream = WaitFor(cubeb->StreamInitEvent());
  EXPECT_TRUE(stream->mHasInput);
  EXPECT_TRUE(stream->mHasOutput);
  EXPECT_EQ(stream->InputChannels(), 1U);
  EXPECT_EQ(stream->GetInputDeviceID(), device);

  while (
      stream->State()
          .map([](cubeb_state aState) { return aState != CUBEB_STATE_STARTED; })
          .valueOr(true)) {
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  const auto waitForResult = [&](int aNumResult) {
    while (numProcessingParamsResults < aNumResult) {
      EXPECT_EQ(stream->ManualDataCallback(0),
                MockCubebStream::KeepProcessing::Yes);
      NS_ProcessNextEvent();
      std::this_thread::sleep_for(std::chrono::milliseconds(1));
    }
  };

  // Wait for the AudioCallbackDriver to come into effect.
  while (fallbackListener->OnFallback()) {
    EXPECT_EQ(stream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::Yes);
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Wait for the first result after driver creation.
  waitForResult(1);

  // Request new processing params.
  EXPECT_CALL(*listener, RequestedInputProcessingParams)
      .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_NOISE_SUPPRESSION));
  waitForResult(2);

  // Test with returning error on new request.
  cubeb->SetInputProcessingApplyRv(CUBEB_ERROR);
  EXPECT_CALL(*listener, RequestedInputProcessingParams)
      .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_ECHO_CANCELLATION));
  waitForResult(3);

  // Test unsetting all params.
  cubeb->SetInputProcessingApplyRv(CUBEB_OK);
  EXPECT_CALL(*listener, RequestedInputProcessingParams)
      .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_NONE));
  waitForResult(4);

  // Switch driver.
  EXPECT_CALL(*listener, RequestedInputChannelCount).WillRepeatedly(Return(2));
  DispatchFunction([&] {
    track->QueueControlMessageWithNoShutdown(
        [&] { graph->ReevaluateInputDevice(device); });
  });
  ProcessEventQueue();
  // Process the reevaluation message.
  EXPECT_EQ(stream->ManualDataCallback(0),
            MockCubebStream::KeepProcessing::Yes);
  // Perform the switch.
  auto initPromise = TakeN(cubeb->StreamInitEvent(), 1);
  EXPECT_EQ(stream->ManualDataCallback(0), MockCubebStream::KeepProcessing::No);
  std::tie(stream) = WaitFor(initPromise).unwrap()[0];
  EXPECT_TRUE(stream->mHasInput);
  EXPECT_TRUE(stream->mHasOutput);
  EXPECT_EQ(stream->InputChannels(), 2U);
  EXPECT_EQ(stream->GetInputDeviceID(), device);

  while (
      stream->State()
          .map([](cubeb_state aState) { return aState != CUBEB_STATE_STARTED; })
          .valueOr(true)) {
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Wait for the new AudioCallbackDriver to come into effect.
  fallbackListener->Reset();
  while (fallbackListener->OnFallback()) {
    EXPECT_EQ(stream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::Yes);
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Wait for the first result after driver creation.
  waitForResult(5);

  // Test requesting something not supported.
  cubeb->SetSupportedInputProcessingParams(
      CUBEB_INPUT_PROCESSING_PARAM_NOISE_SUPPRESSION |
          CUBEB_INPUT_PROCESSING_PARAM_AUTOMATIC_GAIN_CONTROL |
          CUBEB_INPUT_PROCESSING_PARAM_VOICE_ISOLATION,
      CUBEB_OK);
  EXPECT_CALL(*listener, RequestedInputProcessingParams)
      .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_ECHO_CANCELLATION));
  waitForResult(6);

  // Test requesting something when unsupported by backend.
  cubeb->SetSupportedInputProcessingParams(CUBEB_INPUT_PROCESSING_PARAM_NONE,
                                           CUBEB_ERROR_NOT_SUPPORTED);
  EXPECT_CALL(*listener, RequestedInputProcessingParams)
      .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_NOISE_SUPPRESSION));
  waitForResult(7);

  // Clean up.
  DispatchFunction([&] {
    track->RemoveListener(fallbackListener);
    track->Destroy();
  });
  ProcessEventQueue();
  // Process the destroy message.
  EXPECT_EQ(stream->ManualDataCallback(0),
            MockCubebStream::KeepProcessing::Yes);
  // Shut down.
  EXPECT_EQ(stream->ManualDataCallback(0), MockCubebStream::KeepProcessing::No);
  RefPtr<SmartMockCubebStream> destroyedStream =
      WaitFor(cubeb->StreamDestroyEvent());
  EXPECT_EQ(destroyedStream.get(), stream.get());
  {
    NativeInputTrack* native = graph->GetNativeInputTrackMainThread();
    ASSERT_TRUE(!native);
  }
}

TEST(TestAudioTrackGraph, PlatformProcessingNonNativeToNativeSwitch)
{
  constexpr cubeb_input_processing_params allParams =
      CUBEB_INPUT_PROCESSING_PARAM_ECHO_CANCELLATION |
      CUBEB_INPUT_PROCESSING_PARAM_NOISE_SUPPRESSION |
      CUBEB_INPUT_PROCESSING_PARAM_AUTOMATIC_GAIN_CONTROL |
      CUBEB_INPUT_PROCESSING_PARAM_VOICE_ISOLATION;
  MockCubeb* cubeb = new MockCubeb(MockCubeb::RunningMode::Manual);
  cubeb->SetSupportedInputProcessingParams(allParams, CUBEB_OK);
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::SYSTEM_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  const CubebUtils::AudioDeviceID firstDevice = (CubebUtils::AudioDeviceID)1;
  const CubebUtils::AudioDeviceID secondDevice = (CubebUtils::AudioDeviceID)2;

  // Set up mock listeners.
  RefPtr<MockAudioDataListener> firstListener =
      MakeRefPtr<MockAudioDataListener>();
  EXPECT_CALL(*firstListener, IsVoiceInput).WillRepeatedly(Return(true));
  EXPECT_CALL(*firstListener, RequestedInputChannelCount)
      .WillRepeatedly(Return(1));
  EXPECT_CALL(*firstListener, RequestedInputProcessingParams)
      .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_NONE));

  RefPtr<MockAudioDataListener> secondListener =
      MakeRefPtr<MockAudioDataListener>();
  EXPECT_CALL(*secondListener, IsVoiceInput).WillRepeatedly(Return(true));
  EXPECT_CALL(*secondListener, RequestedInputChannelCount)
      .WillRepeatedly(Return(1));
  EXPECT_CALL(*secondListener, RequestedInputProcessingParams)
      .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_ECHO_CANCELLATION));

  // Expectations.
  const Result<cubeb_input_processing_params, int> noneResult(
      CUBEB_INPUT_PROCESSING_PARAM_NONE);
  const Result<cubeb_input_processing_params, int> echoResult(
      CUBEB_INPUT_PROCESSING_PARAM_ECHO_CANCELLATION);
  const Result<cubeb_input_processing_params, int> noiseResult(
      CUBEB_INPUT_PROCESSING_PARAM_NOISE_SUPPRESSION);
  Atomic<int> numProcessingParamsResults(0);
  {
    InSequence s;
    // On first driver start.
    EXPECT_CALL(*firstListener, NotifySetRequestedInputProcessingParamsResult(
                                    graph, 0, Eq(std::ref(noneResult))))
        .WillOnce([&] { ++numProcessingParamsResults; });
    // After param update.
    EXPECT_CALL(*firstListener,
                NotifySetRequestedInputProcessingParams(
                    graph, 1, CUBEB_INPUT_PROCESSING_PARAM_NOISE_SUPPRESSION));
    EXPECT_CALL(*firstListener, NotifySetRequestedInputProcessingParamsResult(
                                    graph, 1, Eq(std::ref(noiseResult))))
        .WillOnce([&] { ++numProcessingParamsResults; });
    // After second param update.
    EXPECT_CALL(*firstListener,
                NotifySetRequestedInputProcessingParams(
                    graph, 2, CUBEB_INPUT_PROCESSING_PARAM_NONE));
    EXPECT_CALL(*firstListener, NotifySetRequestedInputProcessingParamsResult(
                                    graph, 2, Eq(std::ref(noneResult))))
        .WillOnce([&] { ++numProcessingParamsResults; });
    // On non-native device's start.
    EXPECT_CALL(*secondListener,
                NotifySetRequestedInputProcessingParams(
                    graph, 1, CUBEB_INPUT_PROCESSING_PARAM_ECHO_CANCELLATION));
    EXPECT_CALL(*secondListener, NotifySetRequestedInputProcessingParamsResult(
                                     graph, 1, Eq(std::ref(echoResult))))
        .WillOnce([&] { ++numProcessingParamsResults; });
    // After switch to native device for second device.
    EXPECT_CALL(*firstListener, Disconnect);
    EXPECT_CALL(*secondListener, Disconnect);
    EXPECT_CALL(*secondListener,
                NotifySetRequestedInputProcessingParams(
                    graph, 1, CUBEB_INPUT_PROCESSING_PARAM_ECHO_CANCELLATION));
    EXPECT_CALL(*secondListener, NotifySetRequestedInputProcessingParamsResult(
                                     graph, 1, Eq(std::ref(echoResult))))
        .WillOnce([&] { ++numProcessingParamsResults; });
    // After param update.
    EXPECT_CALL(*secondListener,
                NotifySetRequestedInputProcessingParams(
                    graph, 2, CUBEB_INPUT_PROCESSING_PARAM_NOISE_SUPPRESSION));
    EXPECT_CALL(*secondListener, NotifySetRequestedInputProcessingParamsResult(
                                     graph, 2, Eq(std::ref(noiseResult))))
        .WillOnce([&] { ++numProcessingParamsResults; });
    EXPECT_CALL(*secondListener, Disconnect);
  }

  // Open the first input device. It will be the native device of the graph.
  RefPtr<TestDeviceInputConsumerTrack> firstTrack;
  RefPtr<OnFallbackListener> fallbackListener;
  DispatchFunction([&] {
    firstTrack = TestDeviceInputConsumerTrack::Create(graph);
    firstTrack->ConnectDeviceInput(firstDevice, firstListener,
                                   PRINCIPAL_HANDLE_NONE);
    fallbackListener = new OnFallbackListener(firstTrack);
    firstTrack->AddListener(fallbackListener);
  });

  RefPtr<SmartMockCubebStream> nativeStream = WaitFor(cubeb->StreamInitEvent());
  RefPtr<SmartMockCubebStream> nonNativeStream;
  EXPECT_TRUE(nativeStream->mHasInput);
  EXPECT_TRUE(nativeStream->mHasOutput);
  EXPECT_EQ(nativeStream->InputChannels(), 1U);
  EXPECT_EQ(nativeStream->GetInputDeviceID(), firstDevice);

  while (
      nativeStream->State()
          .map([](cubeb_state aState) { return aState != CUBEB_STATE_STARTED; })
          .valueOr(true)) {
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Wait for the AudioCallbackDriver to come into effect.
  while (fallbackListener->OnFallback()) {
    EXPECT_EQ(nativeStream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::Yes);
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  const auto waitForResult = [&](int aNumResult) {
    while (numProcessingParamsResults < aNumResult) {
      EXPECT_EQ(nativeStream->ManualDataCallback(0),
                MockCubebStream::KeepProcessing::Yes);
      if (nonNativeStream) {
        EXPECT_EQ(nonNativeStream->ManualDataCallback(0),
                  MockCubebStream::KeepProcessing::Yes);
      }
      NS_ProcessNextEvent();
      std::this_thread::sleep_for(std::chrono::milliseconds(1));
    }
  };

  // Wait for the first result after driver creation.
  waitForResult(1);

  // Request new processing params.
  EXPECT_CALL(*firstListener, RequestedInputProcessingParams)
      .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_NOISE_SUPPRESSION));
  waitForResult(2);

  // Again request new processing params, to move the processing params
  // generation of the first device higher so as to avoid ambiguity with the
  // processing params generation of the second device.
  EXPECT_CALL(*firstListener, RequestedInputProcessingParams)
      .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_NONE));
  waitForResult(3);

  // Open the second input device. It will be a non-native device of the graph.
  RefPtr<TestDeviceInputConsumerTrack> secondTrack;
  DispatchFunction([&] {
    secondTrack = TestDeviceInputConsumerTrack::Create(graph);
    secondTrack->ConnectDeviceInput(secondDevice, secondListener,
                                    PRINCIPAL_HANDLE_NONE);
    secondTrack->AddListener(fallbackListener);
  });

  auto initPromise = TakeN(cubeb->StreamInitEvent(), 1);
  DispatchFunction([&] {
    // TakeN dispatches a task that runs SpinEventLoopUntil while blocking the
    // caller. Make sure any event loop spinning that needs to be intertwined
    // with driving the graph runs in a nested task, so as to not block the test
    // flow. I.e. if the caller that gets blocked on the TakeN task is WaitFor
    // below, we will deadlock, because the graph must be iterated to unblock
    // the TakeN task.
    EXPECT_EQ(nativeStream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::Yes);
    ProcessEventQueue();
    EXPECT_EQ(nativeStream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::Yes);
  });

  std::tie(nonNativeStream) = WaitFor(initPromise).unwrap()[0];
  EXPECT_TRUE(nonNativeStream->mHasInput);
  EXPECT_FALSE(nonNativeStream->mHasOutput);
  EXPECT_EQ(nonNativeStream->InputChannels(), 1U);
  EXPECT_EQ(nonNativeStream->GetInputDeviceID(), secondDevice);

  while (
      nonNativeStream->State()
          .map([](cubeb_state aState) { return aState != CUBEB_STATE_STARTED; })
          .valueOr(true)) {
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Wait for the first result after non-native device input creation.
  waitForResult(4);

  // Disconnect native input. First non-native input should be promoted to
  // native, and processing param generation should increase monotonically
  // through the switch.
  DispatchFunction([&] {
    firstTrack->RemoveListener(fallbackListener);
    secondTrack->AddListener(fallbackListener);
    firstTrack->DisconnectDeviceInput();
  });
  ProcessEventQueue();
  initPromise = TakeN(cubeb->StreamInitEvent(), 1);
  // Process the disconnect message, and check that the second device is now
  // used with the new graph driver.
  EXPECT_EQ(nativeStream->ManualDataCallback(0),
            MockCubebStream::KeepProcessing::Yes);
  // Perform the switch.
  EXPECT_EQ(nativeStream->ManualDataCallback(0),
            MockCubebStream::KeepProcessing::No);
  std::tie(nativeStream) = WaitFor(initPromise).unwrap()[0];
  EXPECT_TRUE(nativeStream->mHasInput);
  EXPECT_TRUE(nativeStream->mHasOutput);
  EXPECT_EQ(nativeStream->InputChannels(), 1U);
  EXPECT_EQ(nativeStream->GetInputDeviceID(), secondDevice);

  while (
      nativeStream->State()
          .map([](cubeb_state aState) { return aState != CUBEB_STATE_STARTED; })
          .valueOr(true)) {
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // Wait for the new AudioCallbackDriver to come into effect.
  fallbackListener->Reset();
  while (fallbackListener->OnFallback()) {
    EXPECT_EQ(nativeStream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::Yes);
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }

  // So that waitForResult doesn't make callbacks to it anymore.
  nonNativeStream = nullptr;

  // Wait for the first result after driver creation.
  waitForResult(5);

  // Request new processing params.
  EXPECT_CALL(*secondListener, RequestedInputProcessingParams)
      .WillRepeatedly(Return(CUBEB_INPUT_PROCESSING_PARAM_NOISE_SUPPRESSION));
  waitForResult(6);

  // Clean up.
  DispatchFunction([&] {
    firstTrack->Destroy();
    secondTrack->RemoveListener(fallbackListener);
    secondTrack->Destroy();
  });
  auto destroyPromise = TakeN(cubeb->StreamDestroyEvent(), 1);
  DispatchFunction([&] {
    ProcessEventQueue();
    // Process the destroy message.
    EXPECT_EQ(nativeStream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::Yes);
    // Shut down native.
    EXPECT_EQ(nativeStream->ManualDataCallback(0),
              MockCubebStream::KeepProcessing::No);
  });
  RefPtr<SmartMockCubebStream> destroyedStream;
  std::tie(destroyedStream) = WaitFor(destroyPromise).unwrap()[0];
  EXPECT_EQ(destroyedStream, nativeStream);
  {
    NativeInputTrack* native = graph->GetNativeInputTrackMainThread();
    ASSERT_TRUE(!native);
  }
}

class MockProcessedMediaTrack : public ProcessedMediaTrack {
 public:
  explicit MockProcessedMediaTrack(TrackRate aRate)
      : ProcessedMediaTrack(aRate, MediaSegment::AUDIO, new AudioSegment()) {
    ON_CALL(*this, ProcessInput)
        .WillByDefault([segment = GetData<AudioSegment>()](
                           GraphTime aFrom, GraphTime aTo, uint32_t aFlags) {
          segment->AppendNullData(aTo - aFrom);
        });
  }

  MOCK_METHOD(void, ProcessInput,
              (GraphTime aFrom, GraphTime aTo, uint32_t aFlags), (override));

  uint32_t NumberOfChannels() const override { return 2; };
};

TEST(TestAudioTrackGraph, EmptyProcessingInterval)
{
  MockCubeb* cubeb = new MockCubeb(MockCubeb::RunningMode::Manual);
  CubebUtils::ForceSetCubebContext(cubeb->AsCubebContext());

  MediaTrackGraph* graph = MediaTrackGraphImpl::GetInstance(
      MediaTrackGraph::AUDIO_THREAD_DRIVER, /*Window ID*/ 1,
      CubebUtils::PreferredSampleRate(/* aShouldResistFingerprinting */ false),
      nullptr, GetMainThreadSerialEventTarget());

  RefPtr processedTrack = new MockProcessedMediaTrack(graph->GraphRate());
  RefPtr fallbackListener = new OnFallbackListener(processedTrack);
  MockFunction<void(const char* name)> checkpoint;
  {
    InSequence s;
    EXPECT_CALL(*processedTrack, ProcessInput).Times(AtLeast(1));
    EXPECT_CALL(checkpoint, Call(StrEq("before single iteration")));
    EXPECT_CALL(*processedTrack, ProcessInput).Times(1);
    EXPECT_CALL(checkpoint, Call(StrEq("before empty iteration")));
    EXPECT_CALL(checkpoint, Call(StrEq("after empty iteration")));
  }
  DispatchFunction([&] {
    graph->AddTrack(processedTrack);
    processedTrack->AddAudioOutput(reinterpret_cast<void*>(1), nullptr);
    processedTrack->AddListener(fallbackListener);
  });

  RefPtr<SmartMockCubebStream> stream = WaitFor(cubeb->StreamInitEvent());
  while (stream->State().isNothing()) {
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }
  EXPECT_EQ(*stream->State(), CUBEB_STATE_STARTED);
  // Wait for the AudioCallbackDriver to come into effect.
  while (fallbackListener->OnFallback()) {
    EXPECT_EQ(stream->ManualDataCallback(1),
              MockCubebStream::KeepProcessing::Yes);
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }
  // The graph is now run by ManualDataCallback().
  GraphTime processedUpTo0 = processedTrack->GetEnd();
  EXPECT_GT(processedUpTo0, 0u);
  checkpoint.Call("before single iteration");
  // 128 matches the block size used by MediaTrackGraph and so is expected to
  // trigger another block of processing.
  EXPECT_EQ(stream->ManualDataCallback(128),
            MockCubebStream::KeepProcessing::Yes);
  GraphTime processedUpTo1 = processedTrack->GetEnd();
  EXPECT_EQ(processedUpTo1, processedUpTo0 + 128);
  // Test that ProcessInput() is not called in a graph iteration with no
  // frames to be rendered.
  checkpoint.Call("before empty iteration");
  EXPECT_EQ(stream->ManualDataCallback(0),
            MockCubebStream::KeepProcessing::Yes);
  checkpoint.Call("after empty iteration");
  EXPECT_EQ(processedTrack->GetEnd(), processedUpTo1);

  DispatchFunction([&] { processedTrack->Destroy(); });
  ProcessEventQueue();
  // Process the destroy message and drain the stream.
  auto destroyPromise = TakeN(cubeb->StreamDestroyEvent(), 1);
  while (stream->ManualDataCallback(0) ==
         MockCubebStream::KeepProcessing::Yes) {
  }
  // Ensure the stream is no longer used by its MockCubeb before releasing our
  // reference, and before the next test might ForceSetCubebContext() to
  // destroy our cubeb.
  (void)WaitFor(destroyPromise).unwrap()[0];
}

#undef Invoke
#undef DispatchFunction
#undef DispatchMethod