SetIOAllowed when stopping worker audio threads

chrome/browser/chromeos/audio_mixer_alsa.cc

 // Copyright (c) 2010 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 "chrome/browser/chromeos/audio_mixer_alsa.h"
 
 #include <alsa/asoundlib.h>
 
 #include "base/logging.h"
 #include "base/task.h"
+#include "base/threading/thread_restrictions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/common/pref_names.h"
 
 namespace chromeos {
 
 // Connect to the ALSA mixer using their simple element API.  Init is performed
 // asynchronously on the worker thread.
 //
@@ skipping 23 matching lines @@
       save_volume_(0),
       mixer_state_(UNINITIALIZED),
       alsa_mixer_(NULL),
       elem_master_(NULL),
       elem_pcm_(NULL) {
 }
 
 AudioMixerAlsa::~AudioMixerAlsa() {
   FreeAlsaMixer();
   if (thread_ != NULL) {
+    // A ScopedAllowIO object is required to join the thread when calling Stop.
+    // The worker thread should be idle at this time.
+    // See http://crosbug.com/11110 for discussion.
+    base::ThreadRestrictions::ScopedAllowIO allow_io_for_thread_join;
+
     thread_->Stop();
     thread_.reset();
   }
 }
 
 void AudioMixerAlsa::Init(InitDoneCallback* callback) {
   DCHECK(callback);
   if (!InitThread()) {
     callback->Run(false);
     delete callback;
@@ skipping 230 matching lines @@
     mute = GetElementMuted_Locked(elem_master_);
   else
     mute = (pref_mute == kPrefMuteOn) ? true : false;
 
   VLOG(1) << "Setting volume to " << pref_volume << " and mute to " << mute;
 
   if (mute) {
     save_volume_ = pref_volume;
     DoSetVolumeDb_Locked(min_volume_);
   } else {
-      DoSetVolumeDb_Locked(pref_volume);
+    DoSetVolumeDb_Locked(pref_volume);
   }
 
   SetElementMuted_Locked(elem_master_, mute);
   if (elem_pcm_)
     SetElementMuted_Locked(elem_pcm_, mute);
 }
 
 void AudioMixerAlsa::RestoreVolumeMuteOnUIThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // This happens during init, so set the volume off the UI thread.
@@ skipping 117 matching lines @@
 void AudioMixerAlsa::SetElementMuted_Locked(snd_mixer_elem_t* elem, bool mute) {
   int enabled = mute ? 0 : 1;
   snd_mixer_selem_set_playback_switch_all(elem, enabled);
 
   VLOG(1) << "Set playback switch " << snd_mixer_selem_get_name(elem)
           << " to " << enabled;
 }
 
 }  // namespace chromeos