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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 "InspectorInstrumentation.h"
#include "ScheduledAction.h"
#include "ScriptExecutionContext.h"
#include "UserGestureIndicator.h"
#include <wtf/CurrentTime.h>
#include <wtf/HashSet.h>
#include <wtf/StdLibExtras.h>
using namespace std;
namespace WebCore {
static const int maxIntervalForUserGestureForwarding = 1000; // One second matches Gecko.
static const int maxTimerNestingLevel = 5;
static const double oneMillisecond = 0.001;
static int timerNestingLevel = 0;
static inline bool shouldForwardUserGesture(int interval, int nestingLevel)
{
return UserGestureIndicator::processingUserGesture()
&& interval <= maxIntervalForUserGestureForwarding
&& nestingLevel == 1; // Gestures should not be forwarded to nested timers.
}
DOMTimer::DOMTimer(ScriptExecutionContext* context, PassOwnPtr<ScheduledAction> action, int interval, bool singleShot)
: SuspendableTimer(context)
, m_nestingLevel(timerNestingLevel + 1)
, m_action(action)
, m_originalInterval(interval)
, m_shouldForwardUserGesture(shouldForwardUserGesture(interval, m_nestingLevel))
{
// Keep asking for the next id until we're given one that we don't already have.
do {
m_timeoutId = context->circularSequentialID();
} while (!context->addTimeout(m_timeoutId, this));
double intervalMilliseconds = intervalClampedToMinimum(interval, context->minimumTimerInterval());
if (singleShot)
startOneShot(intervalMilliseconds);
else
startRepeating(intervalMilliseconds);
}
DOMTimer::~DOMTimer()
{
if (scriptExecutionContext())
scriptExecutionContext()->removeTimeout(m_timeoutId);
}
int DOMTimer::install(ScriptExecutionContext* context, PassOwnPtr<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);
timer->suspendIfNeeded();
InspectorInstrumentation::didInstallTimer(context, timer->m_timeoutId, 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;
InspectorInstrumentation::didRemoveTimer(context, timeoutId);
delete context->findTimeout(timeoutId);
}
void DOMTimer::fired()
{
ScriptExecutionContext* context = scriptExecutionContext();
timerNestingLevel = m_nestingLevel;
ASSERT(!context->activeDOMObjectsAreSuspended());
UserGestureIndicator gestureIndicator(m_shouldForwardUserGesture ? DefinitelyProcessingUserGesture : PossiblyProcessingUserGesture);
// Only the first execution of a multi-shot timer should get an affirmative user gesture indicator.
m_shouldForwardUserGesture = false;
InspectorInstrumentationCookie cookie = InspectorInstrumentation::willFireTimer(context, m_timeoutId);
// Simple case for non-one-shot timers.
if (isActive()) {
double minimumInterval = context->minimumTimerInterval();
if (repeatInterval() && repeatInterval() < minimumInterval) {
m_nestingLevel++;
if (m_nestingLevel >= maxTimerNestingLevel)
augmentRepeatInterval(minimumInterval - repeatInterval());
}
// No access to member variables after this point, it can delete the timer.
m_action->execute(context);
InspectorInstrumentation::didFireTimer(cookie);
return;
}
// Delete timer before executing the action for one-shot timers.
OwnPtr<ScheduledAction> action = m_action.release();
// No access to member variables after this point.
delete this;
action->execute(context);
InspectorInstrumentation::didFireTimer(cookie);
timerNestingLevel = 0;
}
void DOMTimer::contextDestroyed()
{
SuspendableTimer::contextDestroyed();
delete this;
}
void DOMTimer::stop()
{
SuspendableTimer::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::adjustMinimumTimerInterval(double oldMinimumTimerInterval)
{
if (m_nestingLevel < maxTimerNestingLevel)
return;
double newMinimumInterval = scriptExecutionContext()->minimumTimerInterval();
double newClampedInterval = intervalClampedToMinimum(m_originalInterval, newMinimumInterval);
if (repeatInterval()) {
augmentRepeatInterval(newClampedInterval - repeatInterval());
return;
}
double previousClampedInterval = intervalClampedToMinimum(m_originalInterval, oldMinimumTimerInterval);
augmentFireInterval(newClampedInterval - previousClampedInterval);
}
double DOMTimer::intervalClampedToMinimum(int timeout, double minimumTimerInterval) const
{
double intervalMilliseconds = max(oneMillisecond, timeout * oneMillisecond);
if (intervalMilliseconds < minimumTimerInterval && m_nestingLevel >= maxTimerNestingLevel)
intervalMilliseconds = minimumTimerInterval;
return intervalMilliseconds;
}
double DOMTimer::alignedFireTime(double fireTime) const
{
double alignmentInterval = scriptExecutionContext()->timerAlignmentInterval();
if (alignmentInterval) {
double currentTime = monotonicallyIncreasingTime();
if (fireTime <= currentTime)
return fireTime;
double alignedTime = ceil(fireTime / alignmentInterval) * alignmentInterval;
return alignedTime;
}
return fireTime;
}
} // namespace WebCore
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