Share one thread between all AudioOutputControllers instead of creating one per stream.

media/audio/linux/audio_manager_linux.cc

 // Copyright (c) 2010 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 "media/audio/linux/audio_manager_linux.h"
 
-#include "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "media/audio/fake_audio_input_stream.h"
 #include "media/audio/fake_audio_output_stream.h"
 #include "media/audio/linux/alsa_output.h"
 #include "media/audio/linux/alsa_wrapper.h"
 #include "media/base/media_switches.h"
 
-
-namespace {
-
-AudioManagerLinux* g_audio_manager = NULL;
-}  // namespace
-
 // Implementation of AudioManager.
 bool AudioManagerLinux::HasAudioOutputDevices() {
   // TODO(ajwong): Make this actually query audio devices.
   return true;
 }
 
 bool AudioManagerLinux::HasAudioInputDevices() {
   // TODO(satish): implement.
   return false;
 }
@@ skipping 17 matching lines @@
     Format format,
     int channels,
     int sample_rate,
     char bits_per_sample) {
   // Early return for testing hook.  Do this before checking for
   // |initialized_|.
   if (format == AudioManager::AUDIO_MOCK) {
     return FakeAudioOutputStream::MakeFakeStream();
   }
 
-  if (!initialized_) {
+  if (!initialized()) {
     return NULL;
   }
 
   std::string device_name = AlsaPcmOutputStream::kAutoSelectDevice;
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kAlsaDevice)) {
     device_name = CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
         switches::kAlsaDevice);
   }
   AlsaPcmOutputStream* stream =
       new AlsaPcmOutputStream(device_name, format, channels, sample_rate,
                               bits_per_sample, wrapper_.get(), this,
-                              audio_thread_.message_loop());
+                              GetMessageLoop());
 
   AutoLock l(lock_);
   active_streams_[stream] = scoped_refptr<AlsaPcmOutputStream>(stream);
   return stream;
 }
 
-AudioManagerLinux::AudioManagerLinux()
-    : audio_thread_("AudioThread"),
-      initialized_(false) {
+AudioManagerLinux::AudioManagerLinux() {
 }
 
 AudioManagerLinux::~AudioManagerLinux() {
   // Make sure we stop the thread first. If we let the default destructor to
   // destruct the members, we may destroy audio streams before stopping the
   // thread, resulting an unexpected behavior.
   // This way we make sure activities of the audio streams are all stopped
   // before we destroy them.
   audio_thread_.Stop();
   active_streams_.clear();
 }
 
 void AudioManagerLinux::Init() {
-  initialized_ = audio_thread_.Start();
+  AudioManagerBase::Init();
   wrapper_.reset(new AlsaWrapper());
 }
 
 void AudioManagerLinux::MuteAll() {
   NOTIMPLEMENTED();
 }
 
 void AudioManagerLinux::UnMuteAll() {
   NOTIMPLEMENTED();
 }
 
 void AudioManagerLinux::ReleaseOutputStream(AlsaPcmOutputStream* stream) {
   if (stream) {
     AutoLock l(lock_);
     active_streams_.erase(stream);
   }
 }
 
-// TODO(ajwong): Collapse this with the windows version.
-void DestroyAudioManagerLinux(void* not_used) {
-  delete g_audio_manager;
-  g_audio_manager = NULL;
+// static
+AudioManager* AudioManager::CreateAudioManager() {
+  return new AudioManagerLinux();
 }
-
-AudioManager* AudioManager::GetAudioManager() {
-  if (!g_audio_manager) {
-    g_audio_manager = new AudioManagerLinux();
-    g_audio_manager->Init();
-    base::AtExitManager::RegisterCallback(&DestroyAudioManagerLinux, NULL);
-  }
-  return g_audio_manager;
-}