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/*
* Copyright (C) 2008 Apple 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 "DOMTimer.h"
#include "ScheduledAction.h"
#include "ScriptExecutionContext.h"
#include <wtf/HashSet.h>
#include <wtf/StdLibExtras.h>
using namespace std;
namespace WebCore {
static const int maxTimerNestingLevel = 5;
static const double oneMillisecond = 0.001;
double DOMTimer::s_minTimerInterval = 0.010; // 10 milliseconds
static int timerNestingLevel = 0;
DOMTimer::DOMTimer(ScriptExecutionContext* context, ScheduledAction* action, int timeout, bool singleShot)
: ActiveDOMObject(context, this)
, m_action(action)
, m_nextFireInterval(0)
, m_repeatInterval(0)
{
static int lastUsedTimeoutId = 0;
++lastUsedTimeoutId;
// Avoid wraparound going negative on us.
if (lastUsedTimeoutId <= 0)
lastUsedTimeoutId = 1;
m_timeoutId = lastUsedTimeoutId;
m_nestingLevel = timerNestingLevel + 1;
scriptExecutionContext()->addTimeout(m_timeoutId, this);
double intervalMilliseconds = max(oneMillisecond, timeout * oneMillisecond);
// Use a minimum interval of 10 ms to match other browsers, but only once we've
// nested enough to notice that we're repeating.
// Faster timers might be "better", but they're incompatible.
if (intervalMilliseconds < s_minTimerInterval && m_nestingLevel >= maxTimerNestingLevel)
intervalMilliseconds = s_minTimerInterval;
if (singleShot)
startOneShot(intervalMilliseconds);
else
startRepeating(intervalMilliseconds);
}
DOMTimer::~DOMTimer()
{
if (scriptExecutionContext())
scriptExecutionContext()->removeTimeout(m_timeoutId);
}
int DOMTimer::install(ScriptExecutionContext* context, ScheduledAction* action, int timeout, bool singleShot)
{
// DOMTimer constructor links the new timer into a list of ActiveDOMObjects held by the 'context'.
// The timer is deleted when context is deleted (DOMTimer::contextDestroyed) or explicitly via DOMTimer::removeById(),
// or if it is a one-time timer and it has fired (DOMTimer::fired).
DOMTimer* timer = new DOMTimer(context, action, timeout, singleShot);
return timer->m_timeoutId;
}
void DOMTimer::removeById(ScriptExecutionContext* context, int timeoutId)
{
// timeout IDs have to be positive, and 0 and -1 are unsafe to
// even look up since they are the empty and deleted value
// respectively
if (timeoutId <= 0)
return;
delete context->findTimeout(timeoutId);
}
void DOMTimer::fired()
{
ScriptExecutionContext* context = scriptExecutionContext();
timerNestingLevel = m_nestingLevel;
// Simple case for non-one-shot timers.
if (isActive()) {
if (repeatInterval() && repeatInterval() < s_minTimerInterval) {
m_nestingLevel++;
if (m_nestingLevel >= maxTimerNestingLevel)
augmentRepeatInterval(s_minTimerInterval - repeatInterval());
}
// No access to member variables after this point, it can delete the timer.
m_action->execute(context);
return;
}
// Delete timer before executing the action for one-shot timers.
ScheduledAction* action = m_action.release();
// No access to member variables after this point.
delete this;
action->execute(context);
delete action;
timerNestingLevel = 0;
}
bool DOMTimer::hasPendingActivity() const
{
return isActive();
}
void DOMTimer::contextDestroyed()
{
ActiveDOMObject::contextDestroyed();
delete this;
}
void DOMTimer::stop()
{
TimerBase::stop();
// Need to release JS objects potentially protected by ScheduledAction
// because they can form circular references back to the ScriptExecutionContext
// which will cause a memory leak.
m_action.clear();
}
void DOMTimer::suspend()
{
ASSERT(!m_nextFireInterval && !m_repeatInterval);
m_nextFireInterval = nextFireInterval();
m_repeatInterval = repeatInterval();
TimerBase::stop();
}
void DOMTimer::resume()
{
start(m_nextFireInterval, m_repeatInterval);
m_nextFireInterval = 0;
m_repeatInterval = 0;
}
bool DOMTimer::canSuspend() const
{
return true;
}
} // namespace WebCore
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