media/audio/audio_manager.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/audio/audio_manager.h"
   6
   7 #include "base/bind.h"
   8 #include "base/bind_helpers.h"
   9 #include "base/command_line.h"
  10 #include "base/debug/alias.h"
  11 #include "base/lazy_instance.h"
  12 #include "base/logging.h"
  13 #include "base/message_loop/message_loop.h"
  14 #include "base/power_monitor/power_monitor.h"
  15 #include "build/build_config.h"
  16 #include "media/audio/audio_manager_factory.h"
  17 #include "media/audio/fake_audio_log_factory.h"
  18 #include "media/base/media_switches.h"
  19
  20 #if defined(OS_WIN)
  21 #include "base/win/scoped_com_initializer.h"
  22 #endif
  23
  24 namespace media {
  25 namespace {
  26
  27 // The singleton instance of AudioManager. This is set when Create() is called.
  28 AudioManager* g_last_created = NULL;
  29
  30 // The singleton instance of AudioManagerFactory. This is only set if
  31 // SetFactory() is called. If it is set when Create() is called, its
  32 // CreateInstance() function is used to set |g_last_created|. Otherwise, the
  33 // linked implementation of media::CreateAudioManager is used to set
  34 // |g_last_created|.
  35 AudioManagerFactory* g_audio_manager_factory = NULL;
  36
  37 // Maximum number of failed pings to the audio thread allowed. A crash will be
  38 // issued once this count is reached.  We require at least two pings before
  39 // crashing to ensure unobservable power events aren't mistakenly caught (e.g.,
  40 // the system suspends before a OnSuspend() event can be fired.).
  41 const int kMaxHangFailureCount = 2;
  42
  43 // Helper class for managing global AudioManager data and hang timers. If the
  44 // audio thread is unresponsive for more than two minutes we want to crash the
  45 // process so we can catch offenders quickly in the field.
  46 class AudioManagerHelper : public base::PowerObserver {
  47  public:
  48   AudioManagerHelper()
  49       : max_hung_task_time_(base::TimeDelta::FromMinutes(1)),
  50         hang_detection_enabled_(true),
  51         io_task_running_(false),
  52         audio_task_running_(false) {}
  53   ~AudioManagerHelper() override {}
  54
  55   void StartHangTimer(
  56       const scoped_refptr<base::SingleThreadTaskRunner>& monitor_task_runner) {
  57     CHECK(!monitor_task_runner_);
  58     monitor_task_runner_ = monitor_task_runner;
  59     base::PowerMonitor::Get()->AddObserver(this);
  60     hang_failures_ = 0;
  61     io_task_running_ = audio_task_running_ = true;
  62     UpdateLastAudioThreadTimeTick();
  63     CrashOnAudioThreadHang();
  64   }
  65
  66   // Disable hang detection when the system goes into the suspend state.
  67   void OnSuspend() override {
  68     base::AutoLock lock(hang_lock_);
  69     hang_detection_enabled_ = false;
  70     hang_failures_ = 0;
  71   }
  72
  73   // Reenable hang detection once the system comes out of the suspend state.
  74   void OnResume() override {
  75     base::AutoLock lock(hang_lock_);
  76     hang_detection_enabled_ = true;
  77     last_audio_thread_timer_tick_ = base::TimeTicks::Now();
  78     hang_failures_ = 0;
  79
  80     // If either of the tasks were stopped during suspend, start them now.
  81     if (!audio_task_running_) {
  82       audio_task_running_ = true;
  83
  84       base::AutoUnlock unlock(hang_lock_);
  85       UpdateLastAudioThreadTimeTick();
  86     }
  87
  88     if (!io_task_running_) {
  89       io_task_running_ = true;
  90
  91       base::AutoUnlock unlock(hang_lock_);
  92       CrashOnAudioThreadHang();
  93     }
  94   }
  95
  96   // Runs on |monitor_task_runner| typically, but may be started on any thread.
  97   void CrashOnAudioThreadHang() {
  98     {
  99       base::AutoLock lock(hang_lock_);
 100
 101       // Don't attempt to verify the tick time or post our task if the system is
 102       // in the process of suspending or resuming.
 103       if (!hang_detection_enabled_) {
 104         io_task_running_ = false;
 105         return;
 106       }
 107
 108       DCHECK(io_task_running_);
 109       const base::TimeTicks now = base::TimeTicks::Now();
 110       const base::TimeDelta tick_delta = now - last_audio_thread_timer_tick_;
 111       if (tick_delta > max_hung_task_time_) {
 112         CHECK_LT(++hang_failures_, kMaxHangFailureCount);
 113       } else {
 114         hang_failures_ = 0;
 115       }
 116     }
 117
 118     // Don't hold the lock while posting the next task.
 119     monitor_task_runner_->PostDelayedTask(
 120         FROM_HERE, base::Bind(&AudioManagerHelper::CrashOnAudioThreadHang,
 121                               base::Unretained(this)),
 122         max_hung_task_time_);
 123   }
 124
 125   // Runs on the audio thread typically, but may be started on any thread.
 126   void UpdateLastAudioThreadTimeTick() {
 127     {
 128       base::AutoLock lock(hang_lock_);
 129       last_audio_thread_timer_tick_ = base::TimeTicks::Now();
 130       hang_failures_ = 0;
 131
 132       // Don't post our task if the system is or will be suspended.
 133       if (!hang_detection_enabled_) {
 134         audio_task_running_ = false;
 135         return;
 136       }
 137
 138       DCHECK(audio_task_running_);
 139     }
 140
 141     // Don't hold the lock while posting the next task.
 142     g_last_created->GetTaskRunner()->PostDelayedTask(
 143         FROM_HERE,
 144         base::Bind(&AudioManagerHelper::UpdateLastAudioThreadTimeTick,
 145                    base::Unretained(this)),
 146         max_hung_task_time_ / 5);
 147   }
 148
 149   AudioLogFactory* fake_log_factory() { return &fake_log_factory_; }
 150
 151 #if defined(OS_WIN)
 152   // This should be called before creating an AudioManager in tests to ensure
 153   // that the creating thread is COM initialized.
 154   void InitializeCOMForTesting() {
 155     com_initializer_for_testing_.reset(new base::win::ScopedCOMInitializer());
 156   }
 157 #endif
 158
 159  private:
 160   FakeAudioLogFactory fake_log_factory_;
 161
 162   const base::TimeDelta max_hung_task_time_;
 163   scoped_refptr<base::SingleThreadTaskRunner> monitor_task_runner_;
 164
 165   base::Lock hang_lock_;
 166   bool hang_detection_enabled_;
 167   base::TimeTicks last_audio_thread_timer_tick_;
 168   int hang_failures_;
 169   bool io_task_running_;
 170   bool audio_task_running_;
 171
 172 #if defined(OS_WIN)
 173   scoped_ptr<base::win::ScopedCOMInitializer> com_initializer_for_testing_;
 174 #endif
 175
 176   DISALLOW_COPY_AND_ASSIGN(AudioManagerHelper);
 177 };
 178
 179 static bool g_hang_monitor_enabled = false;
 180
 181 static base::LazyInstance<AudioManagerHelper>::Leaky g_helper =
 182     LAZY_INSTANCE_INITIALIZER;
 183 }  // namespace
 184
 185 // Forward declaration of the platform specific AudioManager factory function.
 186 AudioManager* CreateAudioManager(AudioLogFactory* audio_log_factory);
 187
 188 AudioManager::AudioManager() {}
 189
 190 AudioManager::~AudioManager() {
 191   CHECK(!g_last_created || g_last_created == this);
 192   g_last_created = NULL;
 193 }
 194
 195 // static
 196 void AudioManager::SetFactory(AudioManagerFactory* factory) {
 197   CHECK(factory);
 198   CHECK(!g_last_created);
 199   CHECK(!g_audio_manager_factory);
 200   g_audio_manager_factory = factory;
 201 }
 202
 203 // static
 204 void AudioManager::ResetFactoryForTesting() {
 205   if (g_audio_manager_factory) {
 206     delete g_audio_manager_factory;
 207     g_audio_manager_factory = nullptr;
 208   }
 209 }
 210
 211 // static
 212 AudioManager* AudioManager::Create(AudioLogFactory* audio_log_factory) {
 213   CHECK(!g_last_created);
 214   if (g_audio_manager_factory)
 215     g_last_created = g_audio_manager_factory->CreateInstance(audio_log_factory);
 216   else
 217     g_last_created = CreateAudioManager(audio_log_factory);
 218
 219   return g_last_created;
 220 }
 221
 222 // static
 223 AudioManager* AudioManager::CreateWithHangTimer(
 224     AudioLogFactory* audio_log_factory,
 225     const scoped_refptr<base::SingleThreadTaskRunner>& monitor_task_runner) {
 226   AudioManager* manager = Create(audio_log_factory);
 227   if (g_hang_monitor_enabled ||
 228       base::CommandLine::ForCurrentProcess()->HasSwitch(
 229           switches::kEnableAudioHangMonitor)) {
 230     g_helper.Pointer()->StartHangTimer(monitor_task_runner);
 231   }
 232   return manager;
 233 }
 234
 235 // static
 236 AudioManager* AudioManager::CreateForTesting() {
 237 #if defined(OS_WIN)
 238   g_helper.Pointer()->InitializeCOMForTesting();
 239 #endif
 240   return Create(g_helper.Pointer()->fake_log_factory());
 241 }
 242
 243 // static
 244 void AudioManager::EnableHangMonitor() {
 245   CHECK(!g_last_created);
 246 // On OSX the audio thread is the UI thread, for which a hang monitor is not
 247 // necessary or recommended.  If it's manually requested, we should allow it
 248 // to start though.
 249 #if !defined(OS_MACOSX)
 250   g_hang_monitor_enabled = true;
 251 #endif
 252 }
 253
 254 // static
 255 AudioManager* AudioManager::Get() {
 256   return g_last_created;
 257 }
 258
 259 }  // namespace media