Reimplement the AlsaPcmOutputStream and fix the threading issues.

media/audio/linux/audio_manager_linux.cc

 // Copyright (c) 2006-2009 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/logging.h"
 #include "media/audio/fake_audio_output_stream.h"
 #include "media/audio/linux/alsa_output.h"
+#include "media/audio/linux/alsa_wrapper.h"
 
 namespace {
 AudioManagerLinux* g_audio_manager = NULL;
 }  // namespace
 
 // Implementation of AudioManager.
 bool AudioManagerLinux::HasAudioDevices() {
   // TODO(ajwong): Make this actually query audio devices.
   return true;
 }
 
 AudioOutputStream* AudioManagerLinux::MakeAudioStream(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_) {
+    return NULL;
+  }
+
   // TODO(ajwong): Do we want to be able to configure the device? default
   // should work correctly for all mono/stereo, but not surround, which needs
   // surround40, surround51, etc.
   //
   // http://0pointer.de/blog/projects/guide-to-sound-apis.html
-  if (format == AudioManager::AUDIO_MOCK) {
-    return FakeAudioOutputStream::MakeFakeStream();
-  } else {
-    AlsaPCMOutputStream* stream =
-        new AlsaPCMOutputStream(AlsaPCMOutputStream::kDefaultDevice,
-                                100 /* 100ms minimal buffer */,
-                                format, channels, sample_rate, bits_per_sample);
-    return stream;
-  }
+  AlsaPcmOutputStream* stream =
+      new AlsaPcmOutputStream(AlsaPcmOutputStream::kDefaultDevice,
+                              format, channels, sample_rate, bits_per_sample,
+                              wrapper_.get(), audio_thread_.message_loop());
+
+  // TODO(ajwong): Set up this to clear itself when the stream closes.
+  active_streams_[stream] = scoped_refptr<AlsaPcmOutputStream>(stream);
+  return stream;
 }
 
-AudioManagerLinux::AudioManagerLinux() {
+AudioManagerLinux::AudioManagerLinux()
+    : audio_thread_("AudioThread"),
+      initialized_(false) {
 }
 
 AudioManagerLinux::~AudioManagerLinux() {
 }
 
+void AudioManagerLinux::Init() {
+  initialized_ = audio_thread_.Start();
+  wrapper_.reset(new AlsaWrapper());
+}
+
 void AudioManagerLinux::MuteAll() {
   // TODO(ajwong): Implement.
   NOTIMPLEMENTED();
 }
 
 void AudioManagerLinux::UnMuteAll() {
   // TODO(ajwong): Implement.
   NOTIMPLEMENTED();
 }
 
 // TODO(ajwong): Collapse this with the windows version.
 void DestroyAudioManagerLinux(void* not_used) {
   delete g_audio_manager;
   g_audio_manager = NULL;
 }
 
 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;
 }