Method ThreadMain

src/butil/threading/watchdog.cc:119–168

// Internal private methods that the watchdog thread uses.

void Watchdog::ThreadDelegate::ThreadMain() {
  SetThreadName();
  TimeDelta remaining_duration;
  StaticData* static_data = g_static_data.Pointer();
  while (1) {
    AutoLock lock(watchdog_->lock_);
    while (DISARMED == watchdog_->state_)
      watchdog_->condition_variable_.Wait();
    if (SHUTDOWN == watchdog_->state_) {
      watchdog_->state_ = JOINABLE;
      return;
    }
    DCHECK(ARMED == watchdog_->state_);
    remaining_duration = watchdog_->duration_ -
        (TimeTicks::Now() - watchdog_->start_time_);
    if (remaining_duration.InMilliseconds() > 0) {
      // Spurios wake?  Timer drifts?  Go back to sleep for remaining time.
      watchdog_->condition_variable_.TimedWait(remaining_duration);
      continue;
    }
    // We overslept, so this seems like a real alarm.
    // Watch out for a user that stopped the debugger on a different alarm!
    {
      AutoLock static_lock(static_data->lock);
      if (static_data->last_debugged_alarm_time > watchdog_->start_time_) {
        // False alarm: we started our clock before the debugger break (last
        // alarm time).
        watchdog_->start_time_ += static_data->last_debugged_alarm_delay;
        if (static_data->last_debugged_alarm_time > watchdog_->start_time_)
          // Too many alarms must have taken place.
          watchdog_->state_ = DISARMED;
        continue;
      }
    }
    watchdog_->state_ = DISARMED;  // Only alarm at most once.
    TimeTicks last_alarm_time = TimeTicks::Now();
    {
      AutoUnlock lock(watchdog_->lock_);
      watchdog_->Alarm();  // Set a break point here to debug on alarms.
    }
    TimeDelta last_alarm_delay = TimeTicks::Now() - last_alarm_time;
    if (last_alarm_delay <= TimeDelta::FromMilliseconds(2))
      continue;
    // Ignore race of two alarms/breaks going off at roughly the same time.
    AutoLock static_lock(static_data->lock);
    // This was a real debugger break.
    static_data->last_debugged_alarm_time = last_alarm_time;
    static_data->last_debugged_alarm_delay = last_alarm_delay;
  }
}

void Watchdog::ThreadDelegate::SetThreadName() const {
  std::string name = watchdog_->thread_watched_name_ + " Watchdog";