Abort expensive AudioManager methods once shutdown starts.

media/audio/audio_manager_base.cc

 // Copyright (c) 2012 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/audio_manager_base.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 63 matching lines @@
 AudioManagerBase::AudioManagerBase(AudioLogFactory* audio_log_factory)
     : max_num_output_streams_(kDefaultMaxOutputStreams),
       max_num_input_streams_(kDefaultMaxInputStreams),
       num_output_streams_(0),
       num_input_streams_(0),
       // TODO(dalecurtis): Switch this to an ObserverListThreadSafe, so we don't
       // block the UI thread when swapping devices.
       output_listeners_(
           ObserverList<AudioDeviceListener>::NOTIFY_EXISTING_ONLY),
       audio_thread_("AudioThread"),
-      audio_log_factory_(audio_log_factory) {
+      audio_log_factory_(audio_log_factory),
+      in_shutdown_(0) {
 #if defined(OS_WIN)
   audio_thread_.init_com_with_mta(true);
 #elif defined(OS_MACOSX)
   // CoreAudio calls must occur on the main thread of the process, which in our
   // case is sadly the browser UI thread.  Failure to execute calls on the right
   // thread leads to crashes and odd behavior.  See http://crbug.com/158170.
   // TODO(dalecurtis): We should require the message loop to be passed in.
   const CommandLine* cmd_line = CommandLine::ForCurrentProcess();
   if (!cmd_line->HasSwitch(switches::kDisableMainThreadAudio) &&
       base::MessageLoopProxy::current().get() &&
@@ skipping 36 matching lines @@
 
   return audio_thread_.message_loop_proxy();
 }
 
 AudioOutputStream* AudioManagerBase::MakeAudioOutputStream(
     const AudioParameters& params,
     const std::string& device_id) {
   // TODO(miu): Fix ~50 call points across several unit test modules to call
   // this method on the audio thread, then uncomment the following:
   // DCHECK(task_runner_->BelongsToCurrentThread());
+  if (base::AtomicRefCountIsOne(&in_shutdown_))
+    return NULL;
 
   if (!params.IsValid()) {
     DLOG(ERROR) << "Audio parameters are invalid";
     return NULL;
   }
 
   // Limit the number of audio streams opened. This is to prevent using
   // excessive resources for a large number of audio streams. More
   // importantly it prevents instability on certain systems.
   // See bug: http://crbug.com/30242.
@@ skipping 29 matching lines @@
 
   return stream;
 }
 
 AudioInputStream* AudioManagerBase::MakeAudioInputStream(
     const AudioParameters& params,
     const std::string& device_id) {
   // TODO(miu): Fix ~20 call points across several unit test modules to call
   // this method on the audio thread, then uncomment the following:
   // DCHECK(task_runner_->BelongsToCurrentThread());
+  if (base::AtomicRefCountIsOne(&in_shutdown_))
+    return NULL;
 
   if (!params.IsValid() || (params.channels() > kMaxInputChannels) ||
       device_id.empty()) {
     DLOG(ERROR) << "Audio parameters are invalid for device " << device_id;
     return NULL;
   }
 
   if (num_input_streams_ >= max_num_input_streams_) {
     DLOG(ERROR) << "Number of opened input audio streams "
                 << num_input_streams_
@@ skipping 21 matching lines @@
     ++num_input_streams_;
   }
 
   return stream;
 }
 
 AudioOutputStream* AudioManagerBase::MakeAudioOutputStreamProxy(
     const AudioParameters& params,
     const std::string& device_id) {
   DCHECK(task_runner_->BelongsToCurrentThread());
+  if (base::AtomicRefCountIsOne(&in_shutdown_))
+    return NULL;
 
   // If the caller supplied an empty device id to select the default device,
   // we fetch the actual device id of the default device so that the lookup
   // will find the correct device regardless of whether it was opened as
   // "default" or via the specific id.
   // NOTE: Implementations that don't yet support opening non-default output
   // devices may return an empty string from GetDefaultOutputDeviceID().
   std::string output_device_id = device_id.empty() ?
       GetDefaultOutputDeviceID() : device_id;
 
@@ skipping 74 matching lines @@
 }
 
 void AudioManagerBase::ReleaseInputStream(AudioInputStream* stream) {
   DCHECK(stream);
   // TODO(xians) : Have a clearer destruction path for the AudioInputStream.
   --num_input_streams_;
   delete stream;
 }
 
 void AudioManagerBase::Shutdown() {
+  DCHECK(base::AtomicRefCountIsZero(&in_shutdown_));
+  base::AtomicRefCountInc(&in_shutdown_);
+
   // Only true when we're sharing the UI message loop with the browser.  The UI
   // loop is no longer running at this time and browser destruction is imminent.
   if (task_runner_->BelongsToCurrentThread()) {
     ShutdownOnAudioThread();
   } else {
     task_runner_->PostTask(FROM_HERE, base::Bind(
         &AudioManagerBase::ShutdownOnAudioThread, base::Unretained(this)));
   }
 
   // Stop() will wait for any posted messages to be processed first.
   audio_thread_.Stop();
 }
 
 void AudioManagerBase::ShutdownOnAudioThread() {
   DCHECK(task_runner_->BelongsToCurrentThread());
+  DCHECK(base::AtomicRefCountIsOne(&in_shutdown_));
 
   AudioOutputDispatchers::iterator it = output_dispatchers_.begin();
   for (; it != output_dispatchers_.end(); ++it) {
     scoped_refptr<AudioOutputDispatcher>& dispatcher = (*it)->dispatcher;
     dispatcher->Shutdown();
 
     // All AudioOutputProxies must have been freed before Shutdown is called.
     // If they still exist, things will go bad.  They have direct pointers to
     // both physical audio stream objects that belong to the dispatcher as
     // well as the message loop of the audio thread that will soon go away.
@@ skipping 12 matching lines @@
 }
 
 void AudioManagerBase::RemoveOutputDeviceChangeListener(
     AudioDeviceListener* listener) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   output_listeners_.RemoveObserver(listener);
 }
 
 void AudioManagerBase::NotifyAllOutputDeviceChangeListeners() {
   DCHECK(task_runner_->BelongsToCurrentThread());
+  if (base::AtomicRefCountIsOne(&in_shutdown_))
+    return;
   DVLOG(1) << "Firing OnDeviceChange() notifications.";
   FOR_EACH_OBSERVER(AudioDeviceListener, output_listeners_, OnDeviceChange());
 }
 
 AudioParameters AudioManagerBase::GetDefaultOutputStreamParameters() {
   return GetPreferredOutputStreamParameters(GetDefaultOutputDeviceID(),
       AudioParameters());
 }
 
 AudioParameters AudioManagerBase::GetOutputStreamParameters(
@@ skipping 55 matching lines @@
     (*it)->dispatcher->CloseStreamsForWedgeFix();
   }
   for (AudioOutputDispatchers::iterator it = output_dispatchers_.begin();
        it != output_dispatchers_.end(); ++it) {
     (*it)->dispatcher->RestartStreamsForWedgeFix();
   }
 #endif
 }
 
 }  // namespace media