Fix AudioManager shutdown

This patch makes sure the audio thread is stopped before
the AudioManager is destroyed. Under heavy load it is
possible to have tasks still on the audio thread's message
loop when the audio manager is destroyed. These were
getting called when the Thread object is destroyed which
happens after all of the AudioManager destructors are
called. The new Cleanup() method stops the thread before
any destruction occurs.

BUG=67804
TEST=none

Review URL: http://codereview.chromium.org/6026011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@70034 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 30 insertions, 2 deletions

diff --git a/media/audio/audio_manager.cc b/media/audio/audio_manager.cc
index 3abd010..bc91c63 100644
--- a/media/audio/audio_manager.cc
+++ b/media/audio/audio_manager.cc
@@ -9,6 +9,7 @@
 
 namespace {
 
+bool g_destroy_called = false;
 AudioManager* g_audio_manager = NULL;
 
 // NullAudioManager is the audio manager used on the systems that have no
@@ -40,13 +41,18 @@ class NullAudioManager : public AudioManager {
 
 // static
 void AudioManager::Destroy(void* not_used) {
-  delete g_audio_manager;
+  g_destroy_called = true;
+
+  g_audio_manager->Cleanup();
+
+  AudioManager* audio_manager = g_audio_manager;
   g_audio_manager = NULL;
+  delete audio_manager;
 }
 
 // static
 AudioManager* AudioManager::GetAudioManager() {
-  if (!g_audio_manager) {
+  if (!g_audio_manager && !g_destroy_called) {
     g_audio_manager = CreateAudioManager();
     g_audio_manager->Init();
     base::AtExitManager::RegisterCallback(&AudioManager::Destroy, NULL);
diff --git a/media/audio/audio_manager.h b/media/audio/audio_manager.h
index aa7f018..2afc789 100644
--- a/media/audio/audio_manager.h
+++ b/media/audio/audio_manager.h
@@ -93,6 +93,9 @@ class AudioManager {
   // Called from GetAudioManager() to initialiaze the instance.
   virtual void Init() = 0;
 
+  // Called by Destroy() to cleanup the instance before destruction.
+  virtual void Cleanup() = 0;
+
  private:
   static void Destroy(void*);
 
diff --git a/media/audio/audio_manager_base.cc b/media/audio/audio_manager_base.cc
index e522240..73a97ba 100644
--- a/media/audio/audio_manager_base.cc
+++ b/media/audio/audio_manager_base.cc
@@ -16,12 +16,20 @@ AudioManagerBase::AudioManagerBase()
 }
 
 AudioManagerBase::~AudioManagerBase() {
+  DCHECK(!audio_thread_.IsRunning());
 }
 
 void AudioManagerBase::Init() {
   initialized_ = audio_thread_.Start();
 }
 
+void AudioManagerBase::Cleanup() {
+  if (initialized_) {
+    initialized_ = false;
+    audio_thread_.Stop();
+  }
+}
+
 string16 AudioManagerBase::GetAudioInputDeviceModel() {
   return string16();
 }
diff --git a/media/audio/audio_manager_base.h b/media/audio/audio_manager_base.h
index aa664f4..370a20c 100644
--- a/media/audio/audio_manager_base.h
+++ b/media/audio/audio_manager_base.h
@@ -18,6 +18,7 @@ class AudioManagerBase : public AudioManager {
   AudioManagerBase();
 
   virtual void Init();
+  virtual void Cleanup();
 
   virtual MessageLoop* GetMessageLoop();
 
diff --git a/media/audio/audio_output_controller.cc b/media/audio/audio_output_controller.cc
index ee2614e..1d84638 100644
--- a/media/audio/audio_output_controller.cc
+++ b/media/audio/audio_output_controller.cc
@@ -48,6 +48,9 @@ scoped_refptr<AudioOutputController> AudioOutputController::Create(
   if (!CheckParameters(params))
     return NULL;
 
+  if (!AudioManager::GetAudioManager())
+    return NULL;
+
   // Starts the audio controller thread.
   scoped_refptr<AudioOutputController> controller(new AudioOutputController(
       event_handler, buffer_capacity, NULL));
@@ -72,6 +75,9 @@ scoped_refptr<AudioOutputController> AudioOutputController::CreateLowLatency(
   if (!CheckParameters(params))
     return NULL;
 
+  if (!AudioManager::GetAudioManager())
+    return NULL;
+
   // Starts the audio controller thread.
   scoped_refptr<AudioOutputController> controller(new AudioOutputController(
       event_handler, 0, sync_reader));
@@ -142,6 +148,9 @@ void AudioOutputController::DoCreate(AudioParameters params) {
     return;
   DCHECK(state_ == kEmpty);
 
+  if (!AudioManager::GetAudioManager())
+    return;
+
   stream_ = AudioManager::GetAudioManager()->MakeAudioOutputStreamProxy(params);
   if (!stream_) {
     // TODO(hclam): Define error types.
diff --git a/media/audio/audio_output_proxy_unittest.cc b/media/audio/audio_output_proxy_unittest.cc
index efc164c..0e531dd 100644
--- a/media/audio/audio_output_proxy_unittest.cc
+++ b/media/audio/audio_output_proxy_unittest.cc
@@ -38,6 +38,7 @@ class MockAudioManager : public AudioManager {
   MockAudioManager() { };
 
   MOCK_METHOD0(Init, void());
+  MOCK_METHOD0(Cleanup, void());
   MOCK_METHOD0(HasAudioOutputDevices, bool());
   MOCK_METHOD0(HasAudioInputDevices, bool());
   MOCK_METHOD0(GetAudioInputDeviceModel, string16());