// Copyright (c) 2006-2008 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 "base/message_pump_default.h" | |
#include "base/logging.h" | |
namespace base { | |
MessagePumpDefault::MessagePumpDefault() | |
: keep_running_(true), | |
event_(false, false) { | |
} | |
void MessagePumpDefault::Run(Delegate* delegate) { | |
DCHECK(keep_running_) << "Quit must have been called outside of Run!"; | |
for (;;) { | |
bool did_work = delegate->DoWork(); | |
if (!keep_running_) | |
break; | |
if (did_work) | |
continue; | |
// TODO(darin): Delayed work will be starved if DoWork continues to return | |
// true. We should devise a better strategy. | |
// | |
// It is tempting to call DoWork followed by DoDelayedWork before checking | |
// did_work, but we need to make sure that any tasks that were dispatched | |
// prior to a timer actually run before the timer. Getting that right may | |
// require some additional changes. | |
did_work = delegate->DoDelayedWork(&delayed_work_time_); | |
if (!keep_running_) | |
break; | |
if (did_work) | |
continue; | |
did_work = delegate->DoIdleWork(); | |
if (!keep_running_) | |
break; | |
if (did_work) | |
continue; | |
if (delayed_work_time_.is_null()) { | |
event_.Wait(); | |
} else { | |
TimeDelta delay = delayed_work_time_ - Time::Now(); | |
if (delay > TimeDelta()) { | |
event_.TimedWait(delay); | |
} else { | |
// It looks like delayed_work_time_ indicates a time in the past, so we | |
// need to call DoDelayedWork now. | |
delayed_work_time_ = Time(); | |
} | |
} | |
// Since event_ is auto-reset, we don't need to do anything special here | |
// other than service each delegate method. | |
} | |
keep_running_ = true; | |
} | |
void MessagePumpDefault::Quit() { | |
keep_running_ = false; | |
} | |
void MessagePumpDefault::ScheduleWork() { | |
// Since this can be called on any thread, we need to ensure that our Run | |
// loop wakes up. | |
event_.Signal(); | |
} | |
void MessagePumpDefault::ScheduleDelayedWork(const Time& delayed_work_time) { | |
// We know that we can't be blocked on Wait right now since this method can | |
// only be called on the same thread as Run, so we only need to update our | |
// record of how long to sleep when we do sleep. | |
delayed_work_time_ = delayed_work_time; | |
} | |
} // namespace base | |