text: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include "base/message_loop/message_loop.h"
  #include "base/strings/stringprintf.h"
  #include "media/audio/linux/alsa_output.h"
  #include "media/audio/linux/alsa_wrapper.h"
  #include "media/audio/linux/audio_manager_linux.h"
  #include "media/base/data_buffer.h"
  #include "media/base/seekable_buffer.h"
  #include "testing/gmock/include/gmock/gmock.h"
  #include "testing/gtest/include/gtest/gtest.h"
  
  using testing::_;
  using testing::AllOf;
  using testing::AtLeast;
  using testing::DoAll;
  using testing::Field;
  using testing::InSequence;
  using testing::Invoke;
  using testing::InvokeWithoutArgs;
  using testing::Mock;
  using testing::MockFunction;
  using testing::Return;
  using testing::SetArgumentPointee;
  using testing::StrictMock;
  using testing::StrEq;
  using testing::Unused;
  
  namespace media {
  
  class MockAlsaWrapper : public AlsaWrapper {
   public:
    MOCK_METHOD3(DeviceNameHint, int(int card,
                                     const char* iface,
                                     void*** hints));
    MOCK_METHOD2(DeviceNameGetHint, char*(const void* hint, const char* id));
    MOCK_METHOD1(DeviceNameFreeHint, int(void** hints));
  
    MOCK_METHOD4(PcmOpen, int(snd_pcm_t** handle, const char* name,
                              snd_pcm_stream_t stream, int mode));
    MOCK_METHOD1(PcmClose, int(snd_pcm_t* handle));
    MOCK_METHOD1(PcmPrepare, int(snd_pcm_t* handle));
    MOCK_METHOD1(PcmDrop, int(snd_pcm_t* handle));
    MOCK_METHOD2(PcmDelay, int(snd_pcm_t* handle, snd_pcm_sframes_t* delay));
    MOCK_METHOD3(PcmWritei, snd_pcm_sframes_t(snd_pcm_t* handle,
                                              const void* buffer,
                                              snd_pcm_uframes_t size));
    MOCK_METHOD3(PcmReadi, snd_pcm_sframes_t(snd_pcm_t* handle,
                                             void* buffer,
                                             snd_pcm_uframes_t size));
    MOCK_METHOD3(PcmRecover, int(snd_pcm_t* handle, int err, int silent));
    MOCK_METHOD7(PcmSetParams, int(snd_pcm_t* handle, snd_pcm_format_t format,
                                   snd_pcm_access_t access, unsigned int channels,
                                   unsigned int rate, int soft_resample,
                                   unsigned int latency));
    MOCK_METHOD3(PcmGetParams, int(snd_pcm_t* handle,
                                   snd_pcm_uframes_t* buffer_size,
                                   snd_pcm_uframes_t* period_size));
    MOCK_METHOD1(PcmName, const char*(snd_pcm_t* handle));
    MOCK_METHOD1(PcmAvailUpdate, snd_pcm_sframes_t(snd_pcm_t* handle));
    MOCK_METHOD1(PcmState, snd_pcm_state_t(snd_pcm_t* handle));
    MOCK_METHOD1(PcmStart, int(snd_pcm_t* handle));
  
    MOCK_METHOD1(StrError, const char*(int errnum));
  };
  
  class MockAudioSourceCallback : public AudioOutputStream::AudioSourceCallback {
   public:
    MOCK_METHOD2(OnMoreData, int(AudioBus* audio_bus,
                                 AudioBuffersState buffers_state));
    MOCK_METHOD3(OnMoreIOData, int(AudioBus* source,
                                   AudioBus* dest,
                                   AudioBuffersState buffers_state));
    MOCK_METHOD1(OnError, void(AudioOutputStream* stream));
  };
  
  class MockAudioManagerLinux : public AudioManagerLinux {
   public:
    MOCK_METHOD0(Init, void());
    MOCK_METHOD0(HasAudioOutputDevices, bool());
    MOCK_METHOD0(HasAudioInputDevices, bool());
    MOCK_METHOD1(MakeLinearOutputStream, AudioOutputStream*(
        const AudioParameters& params));
    MOCK_METHOD3(MakeLowLatencyOutputStream, AudioOutputStream*(
        const AudioParameters& params,
        const std::string& device_id,
        const std::string& input_device_id));
    MOCK_METHOD2(MakeLowLatencyInputStream, AudioInputStream*(
        const AudioParameters& params, const std::string& device_id));
  
    // We need to override this function in order to skip the checking the number
    // of active output streams. It is because the number of active streams
    // is managed inside MakeAudioOutputStream, and we don't use
    // MakeAudioOutputStream to create the stream in the tests.
    virtual void ReleaseOutputStream(AudioOutputStream* stream) OVERRIDE {
      DCHECK(stream);
      delete stream;
    }
  
    // We don't mock this method since all tests will do the same thing
    // and use the current message loop.
    virtual scoped_refptr<base::MessageLoopProxy> GetMessageLoop() OVERRIDE {
      return base::MessageLoop::current()->message_loop_proxy();
    }
  };
  
  class AlsaPcmOutputStreamTest : public testing::Test {
   protected:
    AlsaPcmOutputStreamTest() {
      mock_manager_.reset(new StrictMock<MockAudioManagerLinux>());
    }
  
    virtual ~AlsaPcmOutputStreamTest() {
    }
  
    AlsaPcmOutputStream* CreateStream(ChannelLayout layout) {
      return CreateStream(layout, kTestFramesPerPacket);
    }
  
    AlsaPcmOutputStream* CreateStream(ChannelLayout layout,
                                      int32 samples_per_packet) {
      AudioParameters params(kTestFormat, layout, kTestSampleRate,
                             kTestBitsPerSample, samples_per_packet);
      return new AlsaPcmOutputStream(kTestDeviceName,
                                     params,
                                     &mock_alsa_wrapper_,
                                     mock_manager_.get());
    }
  
    // Helper function to malloc the string returned by DeviceNameHint for NAME.
    static char* EchoHint(const void* name, Unused) {
      return strdup(static_cast<const char*>(name));
    }
  
    // Helper function to malloc the string returned by DeviceNameHint for IOID.
    static char* OutputHint(Unused, Unused) {
      return strdup("Output");
    }
  
    // Helper function to initialize |test_stream->buffer_|. Must be called
    // in all tests that use buffer_ without opening the stream.
    void InitBuffer(AlsaPcmOutputStream* test_stream) {
      DCHECK(test_stream);
      packet_ = new media::DataBuffer(kTestPacketSize);
      packet_->set_data_size(kTestPacketSize);
      test_stream->buffer_.reset(new media::SeekableBuffer(0, kTestPacketSize));
      test_stream->buffer_->Append(packet_.get());
    }
  
    static const ChannelLayout kTestChannelLayout;
    static const int kTestSampleRate;
    static const int kTestBitsPerSample;
    static const int kTestBytesPerFrame;
    static const AudioParameters::Format kTestFormat;
    static const char kTestDeviceName[];
    static const char kDummyMessage[];
    static const uint32 kTestFramesPerPacket;
    static const int kTestPacketSize;
    static const int kTestFailedErrno;
    static snd_pcm_t* const kFakeHandle;
  
    // Used to simulate DeviceNameHint.
    static char kSurround40[];
    static char kSurround41[];
    static char kSurround50[];
    static char kSurround51[];
    static char kSurround70[];
    static char kSurround71[];
    static void* kFakeHints[];
  
    StrictMock<MockAlsaWrapper> mock_alsa_wrapper_;
    scoped_ptr<StrictMock<MockAudioManagerLinux> > mock_manager_;
    base::MessageLoop message_loop_;
    scoped_refptr<media::DataBuffer> packet_;
  
   private:
    DISALLOW_COPY_AND_ASSIGN(AlsaPcmOutputStreamTest);
  };
  
  const ChannelLayout AlsaPcmOutputStreamTest::kTestChannelLayout =
      CHANNEL_LAYOUT_STEREO;
  const int AlsaPcmOutputStreamTest::kTestSampleRate =
      AudioParameters::kAudioCDSampleRate;
  const int AlsaPcmOutputStreamTest::kTestBitsPerSample = 8;
  const int AlsaPcmOutputStreamTest::kTestBytesPerFrame =
      AlsaPcmOutputStreamTest::kTestBitsPerSample / 8 *
      ChannelLayoutToChannelCount(AlsaPcmOutputStreamTest::kTestChannelLayout);
  const AudioParameters::Format AlsaPcmOutputStreamTest::kTestFormat =
      AudioParameters::AUDIO_PCM_LINEAR;
  const char AlsaPcmOutputStreamTest::kTestDeviceName[] = "TestDevice";
  const char AlsaPcmOutputStreamTest::kDummyMessage[] = "dummy";
  const uint32 AlsaPcmOutputStreamTest::kTestFramesPerPacket = 1000;
  const int AlsaPcmOutputStreamTest::kTestPacketSize =
      AlsaPcmOutputStreamTest::kTestFramesPerPacket *
      AlsaPcmOutputStreamTest::kTestBytesPerFrame;
  const int AlsaPcmOutputStreamTest::kTestFailedErrno = -EACCES;
  snd_pcm_t* const AlsaPcmOutputStreamTest::kFakeHandle =
      reinterpret_cast<snd_pcm_t*>(1);
  
  char AlsaPcmOutputStreamTest::kSurround40[] = "surround40:CARD=foo,DEV=0";
  char AlsaPcmOutputStreamTest::kSurround41[] = "surround41:CARD=foo,DEV=0";
  char AlsaPcmOutputStreamTest::kSurround50[] = "surround50:CARD=foo,DEV=0";
  char AlsaPcmOutputStreamTest::kSurround51[] = "surround51:CARD=foo,DEV=0";
  char AlsaPcmOutputStreamTest::kSurround70[] = "surround70:CARD=foo,DEV=0";
  char AlsaPcmOutputStreamTest::kSurround71[] = "surround71:CARD=foo,DEV=0";
  void* AlsaPcmOutputStreamTest::kFakeHints[] = {
      kSurround40, kSurround41, kSurround50, kSurround51,
      kSurround70, kSurround71, NULL };
  
  // Custom action to clear a memory buffer.
  ACTION(ClearBuffer) {
    arg0->Zero();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, ConstructedState) {
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    EXPECT_EQ(AlsaPcmOutputStream::kCreated, test_stream->state());
    test_stream->Close();
  
    // Should support mono.
    test_stream = CreateStream(CHANNEL_LAYOUT_MONO);
    EXPECT_EQ(AlsaPcmOutputStream::kCreated, test_stream->state());
    test_stream->Close();
  
    // Should support multi-channel.
    test_stream = CreateStream(CHANNEL_LAYOUT_SURROUND);
    EXPECT_EQ(AlsaPcmOutputStream::kCreated, test_stream->state());
    test_stream->Close();
  
    // Bad bits per sample.
    AudioParameters bad_bps_params(kTestFormat, kTestChannelLayout,
                                   kTestSampleRate, kTestBitsPerSample - 1,
                                   kTestFramesPerPacket);
    test_stream = new AlsaPcmOutputStream(kTestDeviceName,
                                          bad_bps_params,
                                          &mock_alsa_wrapper_,
                                          mock_manager_.get());
    EXPECT_EQ(AlsaPcmOutputStream::kInError, test_stream->state());
    test_stream->Close();
  
    // Bad format.
    AudioParameters bad_format_params(
        AudioParameters::AUDIO_LAST_FORMAT, kTestChannelLayout, kTestSampleRate,
        kTestBitsPerSample, kTestFramesPerPacket);
    test_stream = new AlsaPcmOutputStream(kTestDeviceName,
                                          bad_format_params,
                                          &mock_alsa_wrapper_,
                                          mock_manager_.get());
    EXPECT_EQ(AlsaPcmOutputStream::kInError, test_stream->state());
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, LatencyFloor) {
    const double kMicrosPerFrame =
        static_cast<double>(1000000) / kTestSampleRate;
    const double kPacketFramesInMinLatency =
        AlsaPcmOutputStream::kMinLatencyMicros / kMicrosPerFrame / 2.0;
  
    // Test that packets which would cause a latency under less than
    // AlsaPcmOutputStream::kMinLatencyMicros will get clipped to
    // AlsaPcmOutputStream::kMinLatencyMicros,
    EXPECT_CALL(mock_alsa_wrapper_, PcmOpen(_, _, _, _))
        .WillOnce(DoAll(SetArgumentPointee<0>(kFakeHandle),
                        Return(0)));
    EXPECT_CALL(mock_alsa_wrapper_,
                PcmSetParams(_, _, _, _, _, _,
                             AlsaPcmOutputStream::kMinLatencyMicros))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmGetParams(_, _, _))
        .WillOnce(DoAll(SetArgumentPointee<1>(kTestFramesPerPacket),
                        SetArgumentPointee<2>(kTestFramesPerPacket / 2),
                        Return(0)));
  
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout,
                                                    kPacketFramesInMinLatency);
    ASSERT_TRUE(test_stream->Open());
  
    // Now close it and test that everything was released.
    EXPECT_CALL(mock_alsa_wrapper_, PcmClose(kFakeHandle)).WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmName(kFakeHandle))
        .WillOnce(Return(kTestDeviceName));
    test_stream->Close();
  
    Mock::VerifyAndClear(&mock_alsa_wrapper_);
    Mock::VerifyAndClear(mock_manager_.get());
  
    // Test that having more packets ends up with a latency based on packet size.
    const int kOverMinLatencyPacketSize = kPacketFramesInMinLatency + 1;
    int64 expected_micros = AlsaPcmOutputStream::FramesToTimeDelta(
        kOverMinLatencyPacketSize * 2, kTestSampleRate).InMicroseconds();
  
    EXPECT_CALL(mock_alsa_wrapper_, PcmOpen(_, _, _, _))
        .WillOnce(DoAll(SetArgumentPointee<0>(kFakeHandle), Return(0)));
    EXPECT_CALL(mock_alsa_wrapper_,
                PcmSetParams(_, _, _, _, _, _, expected_micros))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmGetParams(_, _, _))
        .WillOnce(DoAll(SetArgumentPointee<1>(kTestFramesPerPacket),
                        SetArgumentPointee<2>(kTestFramesPerPacket / 2),
                        Return(0)));
  
    test_stream = CreateStream(kTestChannelLayout,
                               kOverMinLatencyPacketSize);
    ASSERT_TRUE(test_stream->Open());
  
    // Now close it and test that everything was released.
    EXPECT_CALL(mock_alsa_wrapper_, PcmClose(kFakeHandle))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmName(kFakeHandle))
        .WillOnce(Return(kTestDeviceName));
    test_stream->Close();
  
    Mock::VerifyAndClear(&mock_alsa_wrapper_);
    Mock::VerifyAndClear(mock_manager_.get());
  }
  
  TEST_F(AlsaPcmOutputStreamTest, OpenClose) {
    int64 expected_micros = AlsaPcmOutputStream::FramesToTimeDelta(
        2 * kTestFramesPerPacket, kTestSampleRate).InMicroseconds();
  
    // Open() call opens the playback device, sets the parameters, posts a task
    // with the resulting configuration data, and transitions the object state to
    // kIsOpened.
    EXPECT_CALL(mock_alsa_wrapper_,
                PcmOpen(_, StrEq(kTestDeviceName),
                        SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK))
        .WillOnce(DoAll(SetArgumentPointee<0>(kFakeHandle),
                        Return(0)));
    EXPECT_CALL(mock_alsa_wrapper_,
                PcmSetParams(kFakeHandle,
                             SND_PCM_FORMAT_U8,
                             SND_PCM_ACCESS_RW_INTERLEAVED,
                             ChannelLayoutToChannelCount(kTestChannelLayout),
                             kTestSampleRate,
                             1,
                             expected_micros))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmGetParams(kFakeHandle, _, _))
        .WillOnce(DoAll(SetArgumentPointee<1>(kTestFramesPerPacket),
                        SetArgumentPointee<2>(kTestFramesPerPacket / 2),
                        Return(0)));
  
    // Open the stream.
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    ASSERT_TRUE(test_stream->Open());
  
    EXPECT_EQ(AlsaPcmOutputStream::kIsOpened, test_stream->state());
    EXPECT_EQ(kFakeHandle, test_stream->playback_handle_);
    EXPECT_EQ(kTestFramesPerPacket, test_stream->frames_per_packet_);
    EXPECT_TRUE(test_stream->buffer_.get());
    EXPECT_FALSE(test_stream->stop_stream_);
  
    // Now close it and test that everything was released.
    EXPECT_CALL(mock_alsa_wrapper_, PcmClose(kFakeHandle))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmName(kFakeHandle))
        .WillOnce(Return(kTestDeviceName));
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, PcmOpenFailed) {
    EXPECT_CALL(mock_alsa_wrapper_, PcmOpen(_, _, _, _))
        .WillOnce(Return(kTestFailedErrno));
    EXPECT_CALL(mock_alsa_wrapper_, StrError(kTestFailedErrno))
        .WillOnce(Return(kDummyMessage));
  
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    ASSERT_FALSE(test_stream->Open());
    ASSERT_EQ(AlsaPcmOutputStream::kInError, test_stream->state());
  
    // Ensure internal state is set for a no-op stream if PcmOpen() failes.
    EXPECT_TRUE(test_stream->stop_stream_);
    EXPECT_TRUE(test_stream->playback_handle_ == NULL);
    EXPECT_FALSE(test_stream->buffer_.get());
  
    // Close the stream since we opened it to make destruction happy.
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, PcmSetParamsFailed) {
    EXPECT_CALL(mock_alsa_wrapper_, PcmOpen(_, _, _, _))
        .WillOnce(DoAll(SetArgumentPointee<0>(kFakeHandle),
                        Return(0)));
    EXPECT_CALL(mock_alsa_wrapper_, PcmSetParams(_, _, _, _, _, _, _))
        .WillOnce(Return(kTestFailedErrno));
    EXPECT_CALL(mock_alsa_wrapper_, PcmClose(kFakeHandle))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmName(kFakeHandle))
        .WillOnce(Return(kTestDeviceName));
    EXPECT_CALL(mock_alsa_wrapper_, StrError(kTestFailedErrno))
        .WillOnce(Return(kDummyMessage));
  
    // If open fails, the stream stays in kCreated because it has effectively had
    // no changes.
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    ASSERT_FALSE(test_stream->Open());
    EXPECT_EQ(AlsaPcmOutputStream::kInError, test_stream->state());
  
    // Ensure internal state is set for a no-op stream if PcmSetParams() failes.
    EXPECT_TRUE(test_stream->stop_stream_);
    EXPECT_TRUE(test_stream->playback_handle_ == NULL);
    EXPECT_FALSE(test_stream->buffer_.get());
  
    // Close the stream since we opened it to make destruction happy.
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, StartStop) {
    // Open() call opens the playback device, sets the parameters, posts a task
    // with the resulting configuration data, and transitions the object state to
    // kIsOpened.
    EXPECT_CALL(mock_alsa_wrapper_, PcmOpen(_, _, _, _))
        .WillOnce(DoAll(SetArgumentPointee<0>(kFakeHandle),
                        Return(0)));
    EXPECT_CALL(mock_alsa_wrapper_, PcmSetParams(_, _, _, _, _, _, _))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmGetParams(_, _, _))
        .WillOnce(DoAll(SetArgumentPointee<1>(kTestFramesPerPacket),
                        SetArgumentPointee<2>(kTestFramesPerPacket / 2),
                        Return(0)));
  
    // Open the stream.
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    ASSERT_TRUE(test_stream->Open());
  
    // Expect Device setup.
    EXPECT_CALL(mock_alsa_wrapper_, PcmDrop(kFakeHandle))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmPrepare(kFakeHandle))
        .WillOnce(Return(0));
  
    // Expect the pre-roll.
    MockAudioSourceCallback mock_callback;
    EXPECT_CALL(mock_alsa_wrapper_, PcmState(kFakeHandle))
        .WillRepeatedly(Return(SND_PCM_STATE_RUNNING));
    EXPECT_CALL(mock_alsa_wrapper_, PcmDelay(kFakeHandle, _))
        .WillRepeatedly(DoAll(SetArgumentPointee<1>(0), Return(0)));
    EXPECT_CALL(mock_callback, OnMoreData(_, _))
        .WillRepeatedly(DoAll(ClearBuffer(), Return(kTestFramesPerPacket)));
    EXPECT_CALL(mock_alsa_wrapper_, PcmWritei(kFakeHandle, _, _))
        .WillRepeatedly(Return(kTestFramesPerPacket));
  
    // Expect scheduling.
    EXPECT_CALL(mock_alsa_wrapper_, PcmAvailUpdate(kFakeHandle))
        .Times(AtLeast(2))
        .WillRepeatedly(Return(kTestFramesPerPacket));
  
    test_stream->Start(&mock_callback);
    // Start() will issue a WriteTask() directly and then schedule the next one,
    // call Stop() immediately after to ensure we don't run the message loop
    // forever.
    test_stream->Stop();
    message_loop_.RunUntilIdle();
  
    EXPECT_CALL(mock_alsa_wrapper_, PcmClose(kFakeHandle))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmName(kFakeHandle))
        .WillOnce(Return(kTestDeviceName));
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, WritePacket_FinishedPacket) {
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    InitBuffer(test_stream);
    test_stream->TransitionTo(AlsaPcmOutputStream::kIsOpened);
    test_stream->TransitionTo(AlsaPcmOutputStream::kIsPlaying);
  
    // Nothing should happen.  Don't set any expectations and Our strict mocks
    // should verify most of this.
  
    // Test empty buffer.
    test_stream->buffer_->Clear();
    test_stream->WritePacket();
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, WritePacket_NormalPacket) {
    // We need to open the stream before writing data to ALSA.
    EXPECT_CALL(mock_alsa_wrapper_, PcmOpen(_, _, _, _))
        .WillOnce(DoAll(SetArgumentPointee<0>(kFakeHandle),
                        Return(0)));
    EXPECT_CALL(mock_alsa_wrapper_, PcmSetParams(_, _, _, _, _, _, _))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmGetParams(_, _, _))
        .WillOnce(DoAll(SetArgumentPointee<1>(kTestFramesPerPacket),
                        SetArgumentPointee<2>(kTestFramesPerPacket / 2),
                        Return(0)));
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    ASSERT_TRUE(test_stream->Open());
    InitBuffer(test_stream);
    test_stream->TransitionTo(AlsaPcmOutputStream::kIsPlaying);
  
    // Write a little less than half the data.
    int written = packet_->data_size() / kTestBytesPerFrame / 2 - 1;
    EXPECT_CALL(mock_alsa_wrapper_, PcmAvailUpdate(kFakeHandle))
          .WillOnce(Return(written));
    EXPECT_CALL(mock_alsa_wrapper_, PcmWritei(kFakeHandle, packet_->data(), _))
        .WillOnce(Return(written));
  
    test_stream->WritePacket();
  
    ASSERT_EQ(test_stream->buffer_->forward_bytes(),
              packet_->data_size() - written * kTestBytesPerFrame);
  
    // Write the rest.
    EXPECT_CALL(mock_alsa_wrapper_, PcmAvailUpdate(kFakeHandle))
        .WillOnce(Return(kTestFramesPerPacket - written));
    EXPECT_CALL(mock_alsa_wrapper_,
                PcmWritei(kFakeHandle,
                          packet_->data() + written * kTestBytesPerFrame,
                          _))
        .WillOnce(Return(packet_->data_size() / kTestBytesPerFrame - written));
    test_stream->WritePacket();
    EXPECT_EQ(0, test_stream->buffer_->forward_bytes());
  
    // Now close it and test that everything was released.
    EXPECT_CALL(mock_alsa_wrapper_, PcmClose(kFakeHandle))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmName(kFakeHandle))
        .WillOnce(Return(kTestDeviceName));
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, WritePacket_WriteFails) {
    // We need to open the stream before writing data to ALSA.
    EXPECT_CALL(mock_alsa_wrapper_, PcmOpen(_, _, _, _))
        .WillOnce(DoAll(SetArgumentPointee<0>(kFakeHandle),
                        Return(0)));
    EXPECT_CALL(mock_alsa_wrapper_, PcmSetParams(_, _, _, _, _, _, _))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmGetParams(_, _, _))
        .WillOnce(DoAll(SetArgumentPointee<1>(kTestFramesPerPacket),
                        SetArgumentPointee<2>(kTestFramesPerPacket / 2),
                        Return(0)));
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    ASSERT_TRUE(test_stream->Open());
    InitBuffer(test_stream);
    test_stream->TransitionTo(AlsaPcmOutputStream::kIsPlaying);
  
    // Fail due to a recoverable error and see that PcmRecover code path
    // continues normally.
    EXPECT_CALL(mock_alsa_wrapper_, PcmAvailUpdate(kFakeHandle))
        .WillOnce(Return(kTestFramesPerPacket));
    EXPECT_CALL(mock_alsa_wrapper_, PcmWritei(kFakeHandle, _, _))
        .WillOnce(Return(-EINTR));
    EXPECT_CALL(mock_alsa_wrapper_, PcmRecover(kFakeHandle, _, _))
        .WillOnce(Return(0));
  
    test_stream->WritePacket();
  
    ASSERT_EQ(test_stream->buffer_->forward_bytes(), packet_->data_size());
  
    // Fail the next write, and see that stop_stream_ is set.
    EXPECT_CALL(mock_alsa_wrapper_, PcmAvailUpdate(kFakeHandle))
          .WillOnce(Return(kTestFramesPerPacket));
    EXPECT_CALL(mock_alsa_wrapper_, PcmWritei(kFakeHandle, _, _))
        .WillOnce(Return(kTestFailedErrno));
    EXPECT_CALL(mock_alsa_wrapper_, PcmRecover(kFakeHandle, _, _))
        .WillOnce(Return(kTestFailedErrno));
    EXPECT_CALL(mock_alsa_wrapper_, StrError(kTestFailedErrno))
        .WillOnce(Return(kDummyMessage));
    test_stream->WritePacket();
    EXPECT_EQ(test_stream->buffer_->forward_bytes(), packet_->data_size());
    EXPECT_TRUE(test_stream->stop_stream_);
  
    // Now close it and test that everything was released.
    EXPECT_CALL(mock_alsa_wrapper_, PcmClose(kFakeHandle))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, PcmName(kFakeHandle))
        .WillOnce(Return(kTestDeviceName));
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, WritePacket_StopStream) {
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    InitBuffer(test_stream);
    test_stream->TransitionTo(AlsaPcmOutputStream::kIsOpened);
    test_stream->TransitionTo(AlsaPcmOutputStream::kIsPlaying);
  
    // No expectations set on the strict mock because nothing should be called.
    test_stream->stop_stream_ = true;
    test_stream->WritePacket();
    EXPECT_EQ(0, test_stream->buffer_->forward_bytes());
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, BufferPacket) {
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    InitBuffer(test_stream);
    test_stream->buffer_->Clear();
  
    MockAudioSourceCallback mock_callback;
    EXPECT_CALL(mock_alsa_wrapper_, PcmState(_))
        .WillOnce(Return(SND_PCM_STATE_RUNNING));
    EXPECT_CALL(mock_alsa_wrapper_, PcmDelay(_, _))
        .WillOnce(DoAll(SetArgumentPointee<1>(1), Return(0)));
    EXPECT_CALL(mock_alsa_wrapper_, PcmAvailUpdate(_))
        .WillRepeatedly(Return(0));  // Buffer is full.
  
    // Return a partially filled packet.
    EXPECT_CALL(mock_callback, OnMoreData(_, _))
        .WillOnce(DoAll(ClearBuffer(), Return(kTestFramesPerPacket / 2)));
  
    bool source_exhausted;
    test_stream->set_source_callback(&mock_callback);
    test_stream->packet_size_ = kTestPacketSize;
    test_stream->BufferPacket(&source_exhausted);
  
    EXPECT_EQ(kTestPacketSize / 2, test_stream->buffer_->forward_bytes());
    EXPECT_FALSE(source_exhausted);
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, BufferPacket_Negative) {
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    InitBuffer(test_stream);
    test_stream->buffer_->Clear();
  
    // Simulate where the underrun has occurred right after checking the delay.
    MockAudioSourceCallback mock_callback;
    EXPECT_CALL(mock_alsa_wrapper_, PcmState(_))
        .WillOnce(Return(SND_PCM_STATE_RUNNING));
    EXPECT_CALL(mock_alsa_wrapper_, PcmDelay(_, _))
        .WillOnce(DoAll(SetArgumentPointee<1>(-1), Return(0)));
    EXPECT_CALL(mock_alsa_wrapper_, PcmAvailUpdate(_))
        .WillRepeatedly(Return(0));  // Buffer is full.
    EXPECT_CALL(mock_callback, OnMoreData(_, _))
        .WillOnce(DoAll(ClearBuffer(), Return(kTestFramesPerPacket / 2)));
  
    bool source_exhausted;
    test_stream->set_source_callback(&mock_callback);
    test_stream->packet_size_ = kTestPacketSize;
    test_stream->BufferPacket(&source_exhausted);
  
    EXPECT_EQ(kTestPacketSize / 2, test_stream->buffer_->forward_bytes());
    EXPECT_FALSE(source_exhausted);
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, BufferPacket_Underrun) {
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    InitBuffer(test_stream);
    test_stream->buffer_->Clear();
  
    // If ALSA has underrun then we should assume a delay of zero.
    MockAudioSourceCallback mock_callback;
    EXPECT_CALL(mock_alsa_wrapper_, PcmState(_))
        .WillOnce(Return(SND_PCM_STATE_XRUN));
    EXPECT_CALL(mock_alsa_wrapper_, PcmAvailUpdate(_))
        .WillRepeatedly(Return(0));  // Buffer is full.
    EXPECT_CALL(mock_callback,
                OnMoreData(_, AllOf(
                    Field(&AudioBuffersState::pending_bytes, 0),
                    Field(&AudioBuffersState::hardware_delay_bytes, 0))))
        .WillOnce(DoAll(ClearBuffer(), Return(kTestFramesPerPacket / 2)));
  
    bool source_exhausted;
    test_stream->set_source_callback(&mock_callback);
    test_stream->packet_size_ = kTestPacketSize;
    test_stream->BufferPacket(&source_exhausted);
  
    EXPECT_EQ(kTestPacketSize / 2, test_stream->buffer_->forward_bytes());
    EXPECT_FALSE(source_exhausted);
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, BufferPacket_FullBuffer) {
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    InitBuffer(test_stream);
    // No expectations set on the strict mock because nothing should be called.
    bool source_exhausted;
    test_stream->packet_size_ = kTestPacketSize;
    test_stream->BufferPacket(&source_exhausted);
    EXPECT_EQ(kTestPacketSize, test_stream->buffer_->forward_bytes());
    EXPECT_FALSE(source_exhausted);
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, AutoSelectDevice_DeviceSelect) {
    // Try channels from 1 -> 9. and see that we get the more specific surroundXX
    // device opened for channels 4-8.  For all other channels, the device should
    // default to |AlsaPcmOutputStream::kDefaultDevice|.  We should also not
    // downmix any channel in this case because downmixing is only defined for
    // channels 4-8, which we are guaranteeing to work.
    //
    // Note that the loop starts at "1", so the first parameter is ignored in
    // these arrays.
    const char* kExpectedDeviceName[] = { NULL,
                                          AlsaPcmOutputStream::kDefaultDevice,
                                          AlsaPcmOutputStream::kDefaultDevice,
                                          AlsaPcmOutputStream::kDefaultDevice,
                                          kSurround40, kSurround50, kSurround51,
                                          kSurround70, kSurround71,
                                          AlsaPcmOutputStream::kDefaultDevice };
    bool kExpectedDownmix[] = { false, false, false, false, false, true,
                                false, false, false, false };
    ChannelLayout kExpectedLayouts[] = { CHANNEL_LAYOUT_NONE,
                                         CHANNEL_LAYOUT_MONO,
                                         CHANNEL_LAYOUT_STEREO,
                                         CHANNEL_LAYOUT_SURROUND,
                                         CHANNEL_LAYOUT_4_0,
                                         CHANNEL_LAYOUT_5_0,
                                         CHANNEL_LAYOUT_5_1,
                                         CHANNEL_LAYOUT_7_0,
                                         CHANNEL_LAYOUT_7_1 };
  
  
    for (int i = 1; i < 9; ++i) {
      if (i == 3 || i == 4 || i == 5)  // invalid number of channels
        continue;
      SCOPED_TRACE(base::StringPrintf("Attempting %d Channel", i));
  
      // Hints will only be grabbed for channel numbers that have non-default
      // devices associated with them.
      if (kExpectedDeviceName[i] != AlsaPcmOutputStream::kDefaultDevice) {
        // The DeviceNameHint and DeviceNameFreeHint need to be paired to avoid a
        // memory leak.
        EXPECT_CALL(mock_alsa_wrapper_, DeviceNameHint(_, _, _))
            .WillOnce(DoAll(SetArgumentPointee<2>(&kFakeHints[0]), Return(0)));
        EXPECT_CALL(mock_alsa_wrapper_, DeviceNameFreeHint(&kFakeHints[0]))
            .Times(1);
      }
  
      EXPECT_CALL(mock_alsa_wrapper_,
                  PcmOpen(_, StrEq(kExpectedDeviceName[i]), _, _))
          .WillOnce(DoAll(SetArgumentPointee<0>(kFakeHandle), Return(0)));
      EXPECT_CALL(mock_alsa_wrapper_,
                  PcmSetParams(kFakeHandle, _, _, i, _, _, _))
          .WillOnce(Return(0));
  
      // The parameters are specified by ALSA documentation, and are in constants
      // in the implementation files.
      EXPECT_CALL(mock_alsa_wrapper_, DeviceNameGetHint(_, StrEq("IOID")))
          .WillRepeatedly(Invoke(OutputHint));
      EXPECT_CALL(mock_alsa_wrapper_, DeviceNameGetHint(_, StrEq("NAME")))
          .WillRepeatedly(Invoke(EchoHint));
  
      AlsaPcmOutputStream* test_stream = CreateStream(kExpectedLayouts[i]);
      EXPECT_TRUE(test_stream->AutoSelectDevice(i));
      EXPECT_EQ(kExpectedDownmix[i],
                static_cast<bool>(test_stream->channel_mixer_));
  
      Mock::VerifyAndClearExpectations(&mock_alsa_wrapper_);
      Mock::VerifyAndClearExpectations(mock_manager_.get());
      test_stream->Close();
    }
  }
  
  TEST_F(AlsaPcmOutputStreamTest, AutoSelectDevice_FallbackDevices) {
    using std::string;
  
    // If there are problems opening a multi-channel device, it the fallbacks
    // operations should be as follows.  Assume the multi-channel device name is
    // surround50:
    //
    //   1) Try open "surround50"
    //   2) Try open "plug:surround50".
    //   3) Try open "default".
    //   4) Try open "plug:default".
    //   5) Give up trying to open.
    //
    const string first_try = kSurround50;
    const string second_try = string(AlsaPcmOutputStream::kPlugPrefix) +
                              kSurround50;
    const string third_try = AlsaPcmOutputStream::kDefaultDevice;
    const string fourth_try = string(AlsaPcmOutputStream::kPlugPrefix) +
                              AlsaPcmOutputStream::kDefaultDevice;
  
    EXPECT_CALL(mock_alsa_wrapper_, DeviceNameHint(_, _, _))
        .WillOnce(DoAll(SetArgumentPointee<2>(&kFakeHints[0]), Return(0)));
    EXPECT_CALL(mock_alsa_wrapper_, DeviceNameFreeHint(&kFakeHints[0]))
        .Times(1);
    EXPECT_CALL(mock_alsa_wrapper_, DeviceNameGetHint(_, StrEq("IOID")))
        .WillRepeatedly(Invoke(OutputHint));
    EXPECT_CALL(mock_alsa_wrapper_, DeviceNameGetHint(_, StrEq("NAME")))
        .WillRepeatedly(Invoke(EchoHint));
    EXPECT_CALL(mock_alsa_wrapper_, StrError(kTestFailedErrno))
        .WillRepeatedly(Return(kDummyMessage));
  
    InSequence s;
    EXPECT_CALL(mock_alsa_wrapper_, PcmOpen(_, StrEq(first_try.c_str()), _, _))
        .WillOnce(Return(kTestFailedErrno));
    EXPECT_CALL(mock_alsa_wrapper_, PcmOpen(_, StrEq(second_try.c_str()), _, _))
        .WillOnce(Return(kTestFailedErrno));
    EXPECT_CALL(mock_alsa_wrapper_, PcmOpen(_, StrEq(third_try.c_str()), _, _))
        .WillOnce(Return(kTestFailedErrno));
    EXPECT_CALL(mock_alsa_wrapper_, PcmOpen(_, StrEq(fourth_try.c_str()), _, _))
        .WillOnce(Return(kTestFailedErrno));
  
    AlsaPcmOutputStream* test_stream = CreateStream(CHANNEL_LAYOUT_5_0);
    EXPECT_FALSE(test_stream->AutoSelectDevice(5));
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, AutoSelectDevice_HintFail) {
    // Should get |kDefaultDevice|, and force a 2-channel downmix on a failure to
    // enumerate devices.
    EXPECT_CALL(mock_alsa_wrapper_, DeviceNameHint(_, _, _))
        .WillRepeatedly(Return(kTestFailedErrno));
    EXPECT_CALL(mock_alsa_wrapper_,
                PcmOpen(_, StrEq(AlsaPcmOutputStream::kDefaultDevice), _, _))
        .WillOnce(DoAll(SetArgumentPointee<0>(kFakeHandle), Return(0)));
    EXPECT_CALL(mock_alsa_wrapper_,
                PcmSetParams(kFakeHandle, _, _, 2, _, _, _))
        .WillOnce(Return(0));
    EXPECT_CALL(mock_alsa_wrapper_, StrError(kTestFailedErrno))
        .WillOnce(Return(kDummyMessage));
  
    AlsaPcmOutputStream* test_stream = CreateStream(CHANNEL_LAYOUT_5_0);
    EXPECT_TRUE(test_stream->AutoSelectDevice(5));
    EXPECT_TRUE(test_stream->channel_mixer_);
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, BufferPacket_StopStream) {
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    InitBuffer(test_stream);
    test_stream->stop_stream_ = true;
    bool source_exhausted;
    test_stream->BufferPacket(&source_exhausted);
    EXPECT_EQ(0, test_stream->buffer_->forward_bytes());
    EXPECT_TRUE(source_exhausted);
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, ScheduleNextWrite) {
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    test_stream->TransitionTo(AlsaPcmOutputStream::kIsOpened);
    test_stream->TransitionTo(AlsaPcmOutputStream::kIsPlaying);
    InitBuffer(test_stream);
    DVLOG(1) << test_stream->state();
    EXPECT_CALL(mock_alsa_wrapper_, PcmAvailUpdate(_))
        .WillOnce(Return(10));
    test_stream->ScheduleNextWrite(false);
    DVLOG(1) << test_stream->state();
    // TODO(sergeyu): Figure out how to check that the task has been added to the
    // message loop.
  
    // Cleanup the message queue. Currently ~MessageQueue() doesn't free pending
    // tasks unless running on valgrind. The code below is needed to keep
    // heapcheck happy.
  
    test_stream->stop_stream_ = true;
    DVLOG(1) << test_stream->state();
    test_stream->TransitionTo(AlsaPcmOutputStream::kIsClosed);
    DVLOG(1) << test_stream->state();
    test_stream->Close();
  }
  
  TEST_F(AlsaPcmOutputStreamTest, ScheduleNextWrite_StopStream) {
    AlsaPcmOutputStream* test_stream = CreateStream(kTestChannelLayout);
    test_stream->TransitionTo(AlsaPcmOutputStream::kIsOpened);
    test_stream->TransitionTo(AlsaPcmOutputStream::kIsPlaying);
  
    InitBuffer(test_stream);
  
    test_stream->stop_stream_ = true;
    test_stream->ScheduleNextWrite(true);
  
    // TODO(ajwong): Find a way to test whether or not another task has been
    // posted so we can verify that the Alsa code will indeed break the task
    // posting loop.
  
    test_stream->TransitionTo(AlsaPcmOutputStream::kIsClosed);
    test_stream->Close();
  }
  
  }  // namespace media
  