media/audio/audio_output_dispatcher_impl.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/audio/audio_output_dispatcher_impl.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/bind.h"
  10 #include "base/compiler_specific.h"
  11 #include "base/message_loop/message_loop.h"
  12 #include "base/time/time.h"
  13 #include "media/audio/audio_io.h"
  14 #include "media/audio/audio_output_proxy.h"
  15
  16 namespace media {
  17
  18 AudioOutputDispatcherImpl::AudioOutputDispatcherImpl(
  19     AudioManager* audio_manager,
  20     const AudioParameters& params,
  21     const std::string& output_device_id,
  22     const std::string& input_device_id,
  23     const base::TimeDelta& close_delay)
  24     : AudioOutputDispatcher(audio_manager, params, output_device_id,
  25           input_device_id),
  26       pause_delay_(base::TimeDelta::FromMicroseconds(
  27           2 * params.frames_per_buffer() * base::Time::kMicrosecondsPerSecond /
  28           static_cast<float>(params.sample_rate()))),
  29       paused_proxies_(0),
  30       weak_this_(this),
  31       close_timer_(FROM_HERE,
  32                    close_delay,
  33                    this,
  34                    &AudioOutputDispatcherImpl::ClosePendingStreams) {
  35 }
  36
  37 AudioOutputDispatcherImpl::~AudioOutputDispatcherImpl() {
  38   DCHECK(proxy_to_physical_map_.empty());
  39   DCHECK(idle_streams_.empty());
  40   DCHECK(pausing_streams_.empty());
  41 }
  42
  43 bool AudioOutputDispatcherImpl::OpenStream() {
  44   DCHECK(message_loop_->BelongsToCurrentThread());
  45
  46   paused_proxies_++;
  47
  48   // Ensure that there is at least one open stream.
  49   if (idle_streams_.empty() && !CreateAndOpenStream()) {
  50     paused_proxies_--;
  51     return false;
  52   }
  53
  54   close_timer_.Reset();
  55   return true;
  56 }
  57
  58 bool AudioOutputDispatcherImpl::StartStream(
  59     AudioOutputStream::AudioSourceCallback* callback,
  60     AudioOutputProxy* stream_proxy) {
  61   DCHECK(message_loop_->BelongsToCurrentThread());
  62
  63   if (idle_streams_.empty() && !CreateAndOpenStream())
  64     return false;
  65
  66   AudioOutputStream* physical_stream = idle_streams_.back();
  67   DCHECK(physical_stream);
  68   idle_streams_.pop_back();
  69
  70   DCHECK_GT(paused_proxies_, 0u);
  71   --paused_proxies_;
  72
  73   close_timer_.Reset();
  74
  75   // Schedule task to allocate streams for other proxies if we need to.
  76   message_loop_->PostTask(FROM_HERE, base::Bind(
  77       &AudioOutputDispatcherImpl::OpenTask, weak_this_.GetWeakPtr()));
  78
  79   double volume = 0;
  80   stream_proxy->GetVolume(&volume);
  81   physical_stream->SetVolume(volume);
  82   physical_stream->Start(callback);
  83   proxy_to_physical_map_[stream_proxy] = physical_stream;
  84   return true;
  85 }
  86
  87 void AudioOutputDispatcherImpl::StopStream(AudioOutputProxy* stream_proxy) {
  88   DCHECK(message_loop_->BelongsToCurrentThread());
  89
  90   AudioStreamMap::iterator it = proxy_to_physical_map_.find(stream_proxy);
  91   DCHECK(it != proxy_to_physical_map_.end());
  92   AudioOutputStream* physical_stream = it->second;
  93   proxy_to_physical_map_.erase(it);
  94
  95   physical_stream->Stop();
  96
  97   ++paused_proxies_;
  98
  99   pausing_streams_.push_front(physical_stream);
 100
 101   // Don't recycle stream until two buffers worth of time has elapsed.
 102   message_loop_->PostDelayedTask(
 103       FROM_HERE,
 104       base::Bind(&AudioOutputDispatcherImpl::StopStreamTask,
 105                  weak_this_.GetWeakPtr()),
 106       pause_delay_);
 107 }
 108
 109 void AudioOutputDispatcherImpl::StreamVolumeSet(AudioOutputProxy* stream_proxy,
 110                                                 double volume) {
 111   DCHECK(message_loop_->BelongsToCurrentThread());
 112   AudioStreamMap::iterator it = proxy_to_physical_map_.find(stream_proxy);
 113   if (it != proxy_to_physical_map_.end()) {
 114     AudioOutputStream* physical_stream = it->second;
 115     physical_stream->SetVolume(volume);
 116   }
 117 }
 118
 119 void AudioOutputDispatcherImpl::StopStreamTask() {
 120   DCHECK(message_loop_->BelongsToCurrentThread());
 121
 122   if (pausing_streams_.empty())
 123     return;
 124
 125   AudioOutputStream* stream = pausing_streams_.back();
 126   pausing_streams_.pop_back();
 127   idle_streams_.push_back(stream);
 128   close_timer_.Reset();
 129 }
 130
 131 void AudioOutputDispatcherImpl::CloseStream(AudioOutputProxy* stream_proxy) {
 132   DCHECK(message_loop_->BelongsToCurrentThread());
 133
 134   while (!pausing_streams_.empty()) {
 135     idle_streams_.push_back(pausing_streams_.back());
 136     pausing_streams_.pop_back();
 137   }
 138
 139   DCHECK_GT(paused_proxies_, 0u);
 140   paused_proxies_--;
 141
 142   while (idle_streams_.size() > paused_proxies_) {
 143     idle_streams_.back()->Close();
 144     idle_streams_.pop_back();
 145   }
 146 }
 147
 148 void AudioOutputDispatcherImpl::Shutdown() {
 149   DCHECK(message_loop_->BelongsToCurrentThread());
 150
 151   // Cancel any pending tasks to close paused streams or create new ones.
 152   weak_this_.InvalidateWeakPtrs();
 153
 154   // No AudioOutputProxy objects should hold a reference to us when we get
 155   // to this stage.
 156   DCHECK(HasOneRef()) << "Only the AudioManager should hold a reference";
 157
 158   AudioOutputStreamList::iterator it = idle_streams_.begin();
 159   for (; it != idle_streams_.end(); ++it)
 160     (*it)->Close();
 161   idle_streams_.clear();
 162
 163   it = pausing_streams_.begin();
 164   for (; it != pausing_streams_.end(); ++it)
 165     (*it)->Close();
 166   pausing_streams_.clear();
 167 }
 168
 169 bool AudioOutputDispatcherImpl::CreateAndOpenStream() {
 170   DCHECK(message_loop_->BelongsToCurrentThread());
 171   AudioOutputStream* stream = audio_manager_->MakeAudioOutputStream(
 172       params_, output_device_id_, input_device_id_);
 173   if (!stream)
 174     return false;
 175
 176   if (!stream->Open()) {
 177     stream->Close();
 178     return false;
 179   }
 180   idle_streams_.push_back(stream);
 181   return true;
 182 }
 183
 184 void AudioOutputDispatcherImpl::OpenTask() {
 185   DCHECK(message_loop_->BelongsToCurrentThread());
 186   // Make sure that we have at least one stream allocated if there
 187   // are paused streams.
 188   if (paused_proxies_ > 0 && idle_streams_.empty() &&
 189       pausing_streams_.empty()) {
 190     CreateAndOpenStream();
 191   }
 192
 193   close_timer_.Reset();
 194 }
 195
 196 // This method is called by |close_timer_|.
 197 void AudioOutputDispatcherImpl::ClosePendingStreams() {
 198   DCHECK(message_loop_->BelongsToCurrentThread());
 199   while (!idle_streams_.empty()) {
 200     idle_streams_.back()->Close();
 201     idle_streams_.pop_back();
 202   }
 203 }
 204
 205 }  // namespace media