Add thread safety to AudioManagerBase to protect access to the audio thread member variable.

media/audio/linux/audio_manager_linux.cc

 // Copyright (c) 2011 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/command_line.h"
 #include "base/environment.h"
 #include "base/logging.h"
 #include "base/nix/xdg_util.h"
@@ skipping 31 matching lines @@
 bool AudioManagerLinux::HasAudioOutputDevices() {
   return HasAnyAlsaAudioDevice(kStreamPlayback);
 }
 
 bool AudioManagerLinux::HasAudioInputDevices() {
   return HasAnyAlsaAudioDevice(kStreamCapture);
 }
 
 AudioOutputStream* AudioManagerLinux::MakeAudioOutputStream(
     const AudioParameters& params) {
-  // Early return for testing hook.  Do this before checking for
-  // |initialized_|.
-  if (params.format == AudioParameters::AUDIO_MOCK) {
+  // Early return for testing hook.
+  if (params.format == AudioParameters::AUDIO_MOCK)
     return FakeAudioOutputStream::MakeFakeStream(params);
-  }
-
-  if (!initialized()) {
-    // We should never get here since this method is called on the audio thread.
-    NOTREACHED();
-    return NULL;
-  }
 
   // Don't allow opening more than |kMaxOutputStreams| streams.
   if (active_output_stream_count_ >= kMaxOutputStreams)
     return NULL;
 
   AudioOutputStream* stream = NULL;
 #if defined(USE_PULSEAUDIO)
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kUsePulseAudio)) {
     stream = new PulseAudioOutputStream(params, this);
   } else {
@@ skipping 17 matching lines @@
     const AudioParameters& params, const std::string& device_id) {
   if (!params.IsValid() || params.channels > kMaxInputChannels ||
       device_id.empty()) {
     return NULL;
   }
 
   if (params.format == AudioParameters::AUDIO_MOCK) {
     return FakeAudioInputStream::MakeFakeStream(params);
   }
 
-  if (!initialized())
-    return NULL;
-
   std::string device_name = (device_id == AudioManagerBase::kDefaultDeviceId) ?
       AlsaPcmInputStream::kAutoSelectDevice : device_id;
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kAlsaInputDevice)) {
     device_name = CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
         switches::kAlsaInputDevice);
   }
 
   AlsaPcmInputStream* stream = new AlsaPcmInputStream(this,
       device_name, params, wrapper_.get());
 
@@ skipping 197 matching lines @@
                     << wrapper_->StrError(error);
     }
   }
 
   return has_device;
 }
 
 AudioManager* CreateAudioManager() {
   return new AudioManagerLinux();
 }