Remove the AudioManager singleton.

media/audio/audio_output_dispatcher.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/audio_output_dispatcher.h"
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/message_loop.h"
 #include "base/time.h"
 #include "media/audio/audio_io.h"
 
 AudioOutputDispatcher::AudioOutputDispatcher(
     AudioManager* audio_manager, const AudioParameters& params,
     int close_delay_ms)
     : audio_manager_(audio_manager),
       message_loop_(audio_manager->GetMessageLoop()),
       params_(params),
       pause_delay_milliseconds_(2 * params.samples_per_packet *
           base::Time::kMillisecondsPerSecond / params.sample_rate),
       paused_proxies_(0),
-      ALLOW_THIS_IN_INITIALIZER_LIST(close_timer_(FROM_HERE,
+      ALLOW_THIS_IN_INITIALIZER_LIST(weak_this_(this)),
+      close_timer_(FROM_HERE,
           base::TimeDelta::FromMilliseconds(close_delay_ms),
-          this, &AudioOutputDispatcher::ClosePendingStreams)) {
+          weak_this_.GetWeakPtr(),
+          &AudioOutputDispatcher::ClosePendingStreams) {
+  DCHECK_EQ(MessageLoop::current(), message_loop_);
 }
 
 AudioOutputDispatcher::~AudioOutputDispatcher() {
+  DCHECK_EQ(MessageLoop::current(), message_loop_);
 }
 
 bool AudioOutputDispatcher::StreamOpened() {
   DCHECK_EQ(MessageLoop::current(), message_loop_);
   paused_proxies_++;
 
   // Ensure that there is at least one open stream.
   if (idle_streams_.empty() && !CreateAndOpenStream()) {
     return false;
   }
@@ skipping 13 matching lines @@
   AudioOutputStream* stream = idle_streams_.back();
   idle_streams_.pop_back();
 
   DCHECK_GT(paused_proxies_, 0u);
   paused_proxies_--;
 
   close_timer_.Reset();
 
   // Schedule task to allocate streams for other proxies if we need to.
   message_loop_->PostTask(FROM_HERE, base::Bind(
-      &AudioOutputDispatcher::OpenTask, this));
+      &AudioOutputDispatcher::OpenTask, weak_this_.GetWeakPtr()));
 
   return stream;
 }
 
 void AudioOutputDispatcher::StreamStopped(AudioOutputStream* stream) {
   DCHECK_EQ(MessageLoop::current(), message_loop_);
 
   paused_proxies_++;
 
   pausing_streams_.push_front(stream);
 
   // Don't recycle stream until two buffers worth of time has elapsed.
   message_loop_->PostDelayedTask(
       FROM_HERE,
-      base::Bind(&AudioOutputDispatcher::StopStreamTask, this),
+      base::Bind(&AudioOutputDispatcher::StopStreamTask,
+                 weak_this_.GetWeakPtr()),
       pause_delay_milliseconds_);
 }
 
 void AudioOutputDispatcher::StopStreamTask() {
+  DCHECK_EQ(MessageLoop::current(), message_loop_);
+
   if (pausing_streams_.empty())
     return;
+
   AudioOutputStream* stream = pausing_streams_.back();
   pausing_streams_.pop_back();
   idle_streams_.push_back(stream);
   close_timer_.Reset();
 }
 
 void AudioOutputDispatcher::StreamClosed() {
   DCHECK_EQ(MessageLoop::current(), message_loop_);
 
   while (!pausing_streams_.empty()) {
     idle_streams_.push_back(pausing_streams_.back());
     pausing_streams_.pop_back();
   }
 
   DCHECK_GT(paused_proxies_, 0u);
   paused_proxies_--;
 
   while (idle_streams_.size() > paused_proxies_) {
     idle_streams_.back()->Close();
     idle_streams_.pop_back();
   }
 }
 
+void AudioOutputDispatcher::Shutdown() {
+  DCHECK_EQ(MessageLoop::current(), message_loop_);
+
+  // Cancel any pending tasks to close paused streams or create new ones.
+  weak_this_.InvalidateWeakPtrs();
+
+  // No AudioOutputProxy objects should hold a reference to us when we get
+  // to this stage.
+  DCHECK(HasOneRef()) << "Only the AudioManager should hold a reference";
+
+  AudioOutputStreamList::iterator it = idle_streams_.begin();
+  for (; it != idle_streams_.end(); ++it)
+    (*it)->Close();
+  idle_streams_.clear();
+
+  it = pausing_streams_.begin();
+  for (; it != pausing_streams_.end(); ++it)
+    (*it)->Close();
+  pausing_streams_.clear();
+}
+
 MessageLoop* AudioOutputDispatcher::message_loop() {
   return message_loop_;
 }
 
 bool AudioOutputDispatcher::CreateAndOpenStream() {
-  AudioOutputStream* stream =
-      audio_manager_->MakeAudioOutputStream(params_);
-  if (!stream) {
+  AudioOutputStream* stream = audio_manager_->MakeAudioOutputStream(params_);
+  if (!stream)
     return false;
-  }
+
   if (!stream->Open()) {
     stream->Close();
     return false;
   }
   idle_streams_.push_back(stream);
   return true;
 }
 
 void AudioOutputDispatcher::OpenTask() {
   // Make sure that we have at least one stream allocated if there
   // are paused streams.
   if (paused_proxies_ > 0 && idle_streams_.empty() &&
       pausing_streams_.empty()) {
     CreateAndOpenStream();
   }
 
   close_timer_.Reset();
 }
 
 // This method is called by |close_timer_|.
 void AudioOutputDispatcher::ClosePendingStreams() {
+  DCHECK_EQ(MessageLoop::current(), message_loop_);
+
   while (!idle_streams_.empty()) {
     idle_streams_.back()->Close();
     idle_streams_.pop_back();
   }
 }