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// 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/waitable_event.h"
namespace base {
WaitableEvent::WaitableEvent(bool manual_reset, bool signaled)
: lock_(),
cvar_(&lock_),
signaled_(signaled),
manual_reset_(manual_reset) {
}
WaitableEvent::~WaitableEvent() {
// Members are destroyed in the reverse of their initialization order, so we
// should not have to worry about lock_ being destroyed before cvar_.
}
void WaitableEvent::Reset() {
AutoLock locked(lock_);
signaled_ = false;
}
void WaitableEvent::Signal() {
AutoLock locked(lock_);
if (!signaled_) {
signaled_ = true;
if (manual_reset_) {
cvar_.Broadcast();
} else {
cvar_.Signal();
}
}
}
bool WaitableEvent::IsSignaled() {
return TimedWait(TimeDelta::FromMilliseconds(0));
}
bool WaitableEvent::Wait() {
AutoLock locked(lock_);
while (!signaled_)
cvar_.Wait();
if (!manual_reset_)
signaled_ = false;
return true;
}
bool WaitableEvent::TimedWait(const TimeDelta& max_time) {
AutoLock locked(lock_);
// In case of spurious wake-ups, we need to adjust the amount of time that we
// spend sleeping.
TimeDelta total_time;
for (;;) {
TimeTicks start = TimeTicks::Now();
cvar_.TimedWait(max_time - total_time);
if (signaled_)
break;
total_time += TimeTicks::Now() - start;
if (total_time >= max_time)
break;
}
bool result = signaled_;
if (!manual_reset_)
signaled_ = false;
return result;
}
} // namespace base
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