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/*
* Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
* Copyright (C) 2009 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "ThreadTimers.h"
#include "SharedTimer.h"
#include "ThreadGlobalData.h"
#include "Timer.h"
#include <wtf/CurrentTime.h>
namespace WebCore {
// Timers are created, started and fired on the same thread, and each thread has its own ThreadTimers
// copy to keep the heap and a set of currently firing timers.
static MainThreadSharedTimer* mainThreadSharedTimer()
{
static MainThreadSharedTimer* timer = new MainThreadSharedTimer;
return timer;
}
ThreadTimers::ThreadTimers()
: m_sharedTimer(0)
, m_firingTimers(false)
{
if (isMainThread())
setSharedTimer(mainThreadSharedTimer());
}
// A worker thread may initialize SharedTimer after some timers are created.
// Also, SharedTimer can be replaced with 0 before all timers are destroyed.
void ThreadTimers::setSharedTimer(SharedTimer* sharedTimer)
{
if (m_sharedTimer) {
m_sharedTimer->setFiredFunction(0);
m_sharedTimer->stop();
}
m_sharedTimer = sharedTimer;
if (sharedTimer) {
m_sharedTimer->setFiredFunction(ThreadTimers::sharedTimerFired);
updateSharedTimer();
}
}
void ThreadTimers::updateSharedTimer()
{
if (!m_sharedTimer)
return;
if (m_firingTimers || m_timerHeap.isEmpty())
m_sharedTimer->stop();
else
m_sharedTimer->setFireTime(m_timerHeap.first()->m_nextFireTime);
}
void ThreadTimers::collectFiringTimers(double fireTime, Vector<TimerBase*>& firingTimers)
{
while (!m_timerHeap.isEmpty() && m_timerHeap.first()->m_nextFireTime <= fireTime) {
TimerBase* timer = m_timerHeap.first();
firingTimers.append(timer);
m_timersReadyToFire.add(timer);
timer->m_nextFireTime = 0;
timer->heapDeleteMin();
}
}
void ThreadTimers::fireTimers(double fireTime, const Vector<TimerBase*>& firingTimers)
{
size_t size = firingTimers.size();
for (size_t i = 0; i != size; ++i) {
TimerBase* timer = firingTimers[i];
// If not in the set, this timer has been deleted or re-scheduled in another timer's fired function.
// So either we don't want to fire it at all or we will fire it next time the shared timer goes off.
// It might even have been deleted; that's OK because we won't do anything else with the pointer.
if (!m_timersReadyToFire.contains(timer))
continue;
// Setting the next fire time has a side effect of removing the timer from the firing timers set.
double interval = timer->repeatInterval();
timer->setNextFireTime(interval ? fireTime + interval : 0);
// Once the timer has been fired, it may be deleted, so do nothing else with it after this point.
timer->fired();
// Catch the case where the timer asked timers to fire in a nested event loop.
if (!m_firingTimers)
break;
}
}
void ThreadTimers::sharedTimerFired()
{
// Redirect to non-static method.
threadGlobalData().threadTimers().sharedTimerFiredInternal();
}
void ThreadTimers::sharedTimerFiredInternal()
{
// Do a re-entrancy check.
if (m_firingTimers)
return;
m_firingTimers = true;
double fireTime = currentTime();
Vector<TimerBase*> firingTimers;
// m_timersReadyToFire will initially contain the same set as firingTimers, but
// as timers fire some mat become re-scheduled or deleted. They get removed from
// m_timersReadyToFire so we can avoid firing them.
ASSERT(m_timersReadyToFire.isEmpty());
collectFiringTimers(fireTime, firingTimers);
fireTimers(fireTime, firingTimers);
m_timersReadyToFire.clear();
m_firingTimers = false;
updateSharedTimer();
}
void ThreadTimers::fireTimersInNestedEventLoop()
{
// Reset the reentrancy guard so the timers can fire again.
m_firingTimers = false;
m_timersReadyToFire.clear();
updateSharedTimer();
}
} // namespace WebCore
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