Ensures that audio tasks cannot run after AudioManager is deleted.

content/browser/browser_main_loop.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/browser_main_loop.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 33 matching lines @@
 #include "base/timer/hi_res_timer_manager.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/trace_event.h"
 #include "build/build_config.h"
 #include "components/discardable_memory/service/discardable_shared_memory_manager.h"
 #include "components/display_compositor/host_shared_bitmap_manager.h"
 #include "components/tracing/common/process_metrics_memory_dump_provider.h"
 #include "components/tracing/common/trace_config_file.h"
 #include "components/tracing/common/trace_to_console.h"
 #include "components/tracing/common/tracing_switches.h"
-#include "content/browser/audio_manager_thread.h"
 #include "content/browser/browser_thread_impl.h"
 #include "content/browser/dom_storage/dom_storage_area.h"
 #include "content/browser/download/download_resource_handler.h"
 #include "content/browser/download/save_file_manager.h"
 #include "content/browser/gpu/browser_gpu_channel_host_factory.h"
 #include "content/browser/gpu/browser_gpu_memory_buffer_manager.h"
 #include "content/browser/gpu/compositor_util.h"
 #include "content/browser/gpu/gpu_data_manager_impl.h"
 #include "content/browser/gpu/gpu_process_host.h"
 #include "content/browser/gpu/shader_cache_factory.h"
@@ skipping 19 matching lines @@
 #include "content/public/browser/gpu_data_manager_observer.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/tracing_controller.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_features.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/main_function_params.h"
 #include "content/public/common/result_codes.h"
 #include "device/gamepad/gamepad_service.h"
 #include "gpu/vulkan/features.h"
+#include "media/audio/audio_manager.h"
 #include "media/audio/audio_system_impl.h"
+#include "media/audio/audio_thread_impl.h"
 #include "media/base/media.h"
 #include "media/base/user_input_monitor.h"
 #include "media/midi/midi_service.h"
 #include "mojo/edk/embedder/embedder.h"
 #include "mojo/edk/embedder/scoped_ipc_support.h"
 #include "net/base/network_change_notifier.h"
 #include "net/socket/client_socket_factory.h"
 #include "net/ssl/ssl_config_service.h"
 #include "ppapi/features/features.h"
 #include "services/resource_coordinator/memory/coordinator/coordinator_impl.h"
@@ skipping 1242 matching lines @@
   // Must happen after the I/O thread is shutdown since this class lives on the
   // I/O thread and isn't threadsafe.
   {
     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:GamepadService");
     device::GamepadService::GetInstance()->Terminate();
   }
   {
     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:DeleteDataSources");
     URLDataManager::DeleteDataSources();
   }
+  {
+    TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:AudioMan");
+    DestroyAudioManager();
+  }
 
   if (parts_) {
     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:PostDestroyThreads");
     parts_->PostDestroyThreads();
   }
 }
 
 void BrowserMainLoop::StopStartupTracingTimer() {
   startup_trace_timer_.Stop();
 }
@@ skipping 370 matching lines @@
   DCHECK(is_tracing_startup_for_duration_);
 
   is_tracing_startup_for_duration_ = false;
   TracingController::GetInstance()->StopTracing(
       TracingController::CreateFileSink(
           startup_trace_file_,
           base::Bind(OnStoppedStartupTracing, startup_trace_file_)));
 }
 
 void BrowserMainLoop::CreateAudioManager() {
-  DCHECK(!audio_thread_);
   DCHECK(!audio_manager_);
 
   audio_manager_ = GetContentClient()->browser()->CreateAudioManager(
       MediaInternals::GetInstance());
   if (!audio_manager_) {
-    audio_thread_ = base::MakeUnique<AudioManagerThread>();
     audio_manager_ = media::AudioManager::Create(
-        audio_thread_->task_runner(), audio_thread_->worker_task_runner(),
+        base::MakeUnique<media::AudioThreadImpl>(),
         BrowserThread::GetTaskRunnerForThread(BrowserThread::FILE),
         MediaInternals::GetInstance());
   }
   CHECK(audio_manager_);
 
   audio_system_ = media::AudioSystemImpl::Create(audio_manager_.get());
   CHECK(audio_system_);
 }
 
+void BrowserMainLoop::DestroyAudioManager() {
+  DCHECK(audio_manager_);
+
+  audio_system_.reset();

[o1ka, 2017/04/28 13:24:19]

Audio thread can have AudioSystem operations posted to it, and now they refer to
an invalid pointer.

Should we fix it according to the decision in the mail thread?

1. AudioManager::Shutdown(): This shuts down the AudioManager and stops the
audio thread.
2. delete AudioSystem
3. delete AudioThread
4. delete AudioManager

[alokp, 2017/04/28 17:31:12]

Good catch. IMO we should just shutdown the AM here and let ~BML destroy
AudioSystem and AudioManager in correct order. WDYT?

[o1ka, 2017/05/02 16:16:00]

sgtm

[alokp, 2017/05/09 19:06:15]

Done.

+
+  audio_manager_->Shutdown();
+  audio_manager_.reset();
+}
+
 }  // namespace content