Move the device enumerate/open/close work to device thread from IO thread

content/browser/renderer_host/media/audio_input_device_manager.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 "content/browser/renderer_host/media/audio_input_device_manager.h"
 
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
+#include "content/browser/browser_main_loop.h"
 #include "content/browser/renderer_host/media/audio_input_device_manager_event_handler.h"
 #include "content/public/browser/browser_thread.h"
 #include "media/audio/audio_manager_base.h"
 
+using content::BrowserMainLoop;
 using content::BrowserThread;
 
 namespace media_stream {
 
 const int AudioInputDeviceManager::kFakeOpenSessionId = 1;
 const int AudioInputDeviceManager::kInvalidSessionId = 0;
 const char AudioInputDeviceManager::kInvalidDeviceId[] = "";
 
 // Starting id for the first capture session.
 const int kFirstSessionId = AudioInputDeviceManager::kFakeOpenSessionId + 1;
 
 AudioInputDeviceManager::AudioInputDeviceManager(
-    media::AudioManager* audio_manager)
+    scoped_refptr<base::MessageLoopProxy> message_loop)
     : listener_(NULL),
       next_capture_session_id_(kFirstSessionId),
-      audio_manager_(audio_manager) {
+      message_loop_(message_loop) {
 }
 
 AudioInputDeviceManager::~AudioInputDeviceManager() {
 }
 
 void AudioInputDeviceManager::Register(MediaStreamProviderListener* listener) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK(!listener_);
   listener_ = listener;
 }
 
 void AudioInputDeviceManager::Unregister() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK(listener_);
   listener_ = NULL;
 }
 
 void AudioInputDeviceManager::EnumerateDevices() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK(listener_);
 
+  message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&AudioInputDeviceManager::EnumerateOnDeviceThread, this));
+}
+
+int AudioInputDeviceManager::Open(const StreamDeviceInfo& device) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  // Generates a new id for this device.
+  int session_id = next_capture_session_id_++;
+  message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&AudioInputDeviceManager::OpenOnDeviceThread,
+                 this, session_id, device));
+
+  return session_id;
+}
+
+void AudioInputDeviceManager::Close(int session_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  DCHECK(listener_);
+  message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&AudioInputDeviceManager::CloseOnDeviceThread,
+                 this, session_id));
+}
+
+void AudioInputDeviceManager::EnumerateOnDeviceThread() {
+  DCHECK(IsOnDeviceThread());
+  // TODO(xians): Ensure AudioManager outlives MediaStreamManager.

[tommi (sloooow) - chröme, 2012/07/02 13:36:36]

Is the device thread guaranteed to have terminated before any of the "known"
Chrome thread such as the IO thread or the main browser loop?

If so, then you can safely call GetAudioManager() here without worrying if it's
valid or not since if the device thread is running, you're guaranteed that
BrowserLoop is valid.

If not, then I think we should fix that and here is not where we need to fix it.
 It should be a property of the device thread itself that it does never outlive
the browser loop and/or IO thread.

[no longer working on chromium, 2012/07/04 12:35:25]

Done.

   media::AudioDeviceNames device_names;
-  audio_manager_->GetAudioInputDeviceNames(&device_names);
+  BrowserMainLoop::GetAudioManager()->GetAudioInputDeviceNames(&device_names);
 
   StreamDeviceInfoArray* devices = new StreamDeviceInfoArray;
   for (media::AudioDeviceNames::iterator it = device_names.begin();
        it != device_names.end();
        ++it) {
          devices->push_back(StreamDeviceInfo(
             content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE, it->device_name,
             it->unique_id, false));
   }
 
   // Returns the device list through the listener by posting a task on
   // IO thread since MediaStreamManager handles the callback asynchronously.
   BrowserThread::PostTask(
       BrowserThread::IO,
       FROM_HERE,
       base::Bind(&AudioInputDeviceManager::DevicesEnumeratedOnIOThread,
                  this,
                  devices));
 }
 
-int AudioInputDeviceManager::Open(const StreamDeviceInfo& device) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-
-  // Generates a new id for this device.
-  int session_id = next_capture_session_id_++;
+void AudioInputDeviceManager::OpenOnDeviceThread(
+    int session_id, const StreamDeviceInfo& device) {
+  DCHECK(IsOnDeviceThread());
   DCHECK(devices_.find(session_id) == devices_.end());
 
-  media::AudioDeviceName audio_input_device_name;
-  audio_input_device_name.device_name = device.name;
-  audio_input_device_name.unique_id = device.device_id;
-
   // Adds the session_id and device to the list.
-  devices_[session_id] = audio_input_device_name;
+  media::AudioDeviceName target_device(device.name, device.device_id);
+  devices_[session_id] = target_device;
 
   // Returns the |session_id| through the listener by posting a task on
   // IO thread since MediaStreamManager handles the callback asynchronously.
   BrowserThread::PostTask(BrowserThread::IO,
                           FROM_HERE,
                           base::Bind(&AudioInputDeviceManager::OpenedOnIOThread,
                                      this,
                                      session_id));
-
-  return session_id;
 }
 
-void AudioInputDeviceManager::Close(int session_id) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  DCHECK(listener_);
+void AudioInputDeviceManager::CloseOnDeviceThread(int session_id) {
+  DCHECK(IsOnDeviceThread());
 
   if (devices_.find(session_id) != devices_.end())
     devices_.erase(session_id);
 
   // Checks if the device has been stopped, if not, send stop signal.
   EventHandlerMap::iterator it = event_handlers_.find(session_id);
   if (it != event_handlers_.end()) {
     it->second->OnDeviceStopped(session_id);
     event_handlers_.erase(session_id);
   }
@@ skipping 64 matching lines @@
                       session_id);
 }
 
 void AudioInputDeviceManager::ClosedOnIOThread(int session_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   if (listener_)
     listener_->Closed(content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE,
                       session_id);
 }
 
+bool AudioInputDeviceManager::IsOnDeviceThread() const {
+  return message_loop_->BelongsToCurrentThread();
+}
+
 }  // namespace media_stream