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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 "core/frame/DOMTimer.h"
#include "core/dom/ExecutionContext.h"
#include "core/inspector/InspectorInstrumentation.h"
#include "core/inspector/InspectorTraceEvents.h"
#include "platform/TraceEvent.h"
#include "wtf/CurrentTime.h"
namespace WebCore {
static const int maxIntervalForUserGestureForwarding = 1000; // One second matches Gecko.
static const int maxTimerNestingLevel = 5;
static const double oneMillisecond = 0.001;
// Chromium uses a minimum timer interval of 4ms. We'd like to go
// lower; however, there are poorly coded websites out there which do
// create CPU-spinning loops. Using 4ms prevents the CPU from
// spinning too busily and provides a balance between CPU spinning and
// the smallest possible interval timer.
static const double minimumInterval = 0.004;
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.
}
double DOMTimer::hiddenPageAlignmentInterval()
{
// Timers on hidden pages are aligned so that they fire once per
// second at most.
return 1.0;
}
double DOMTimer::visiblePageAlignmentInterval()
{
// Alignment does not apply to timers on visible pages.
return 0;
}
int DOMTimer::install(ExecutionContext* context, PassOwnPtr<ScheduledAction> action, int timeout, bool singleShot)
{
int timeoutID = context->installNewTimeout(action, timeout, singleShot);
TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "TimerInstall", "data", InspectorTimerInstallEvent::data(context, timeoutID, timeout, singleShot));
TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline.stack"), "CallStack", "stack", InspectorCallStackEvent::currentCallStack());
// FIXME(361045): remove InspectorInstrumentation calls once DevTools Timeline migrates to tracing.
InspectorInstrumentation::didInstallTimer(context, timeoutID, timeout, singleShot);
return timeoutID;
}
void DOMTimer::removeByID(ExecutionContext* context, int timeoutID)
{
context->removeTimeoutByID(timeoutID);
TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "TimerRemove", "data", InspectorTimerRemoveEvent::data(context, timeoutID));
TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline.stack"), "CallStack", "stack", InspectorCallStackEvent::currentCallStack());
// FIXME(361045): remove InspectorInstrumentation calls once DevTools Timeline migrates to tracing.
InspectorInstrumentation::didRemoveTimer(context, timeoutID);
}
DOMTimer::DOMTimer(ExecutionContext* context, PassOwnPtr<ScheduledAction> action, int interval, bool singleShot, int timeoutID)
: SuspendableTimer(context)
, m_timeoutID(timeoutID)
, m_nestingLevel(timerNestingLevel + 1)
, m_action(action)
{
ASSERT(timeoutID > 0);
if (shouldForwardUserGesture(interval, m_nestingLevel))
m_userGestureToken = UserGestureIndicator::currentToken();
double intervalMilliseconds = std::max(oneMillisecond, interval * oneMillisecond);
if (intervalMilliseconds < minimumInterval && m_nestingLevel >= maxTimerNestingLevel)
intervalMilliseconds = minimumInterval;
if (singleShot)
startOneShot(intervalMilliseconds, FROM_HERE);
else
startRepeating(intervalMilliseconds, FROM_HERE);
}
DOMTimer::~DOMTimer()
{
}
int DOMTimer::timeoutID() const
{
return m_timeoutID;
}
void DOMTimer::fired()
{
ExecutionContext* context = executionContext();
timerNestingLevel = m_nestingLevel;
ASSERT(!context->activeDOMObjectsAreSuspended());
// Only the first execution of a multi-shot timer should get an affirmative user gesture indicator.
UserGestureIndicator gestureIndicator(m_userGestureToken.release());
TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "TimerFire", "data", InspectorTimerFireEvent::data(context, m_timeoutID));
// FIXME(361045): remove InspectorInstrumentation calls once DevTools Timeline migrates to tracing.
InspectorInstrumentationCookie cookie = InspectorInstrumentation::willFireTimer(context, m_timeoutID);
// Simple case for non-one-shot timers.
if (isActive()) {
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();
// This timer is being deleted; no access to member variables allowed after this point.
context->removeTimeoutByID(m_timeoutID);
action->execute(context);
InspectorInstrumentation::didFireTimer(cookie);
TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "UpdateCounters", "data", InspectorUpdateCountersEvent::data());
timerNestingLevel = 0;
}
void DOMTimer::contextDestroyed()
{
SuspendableTimer::contextDestroyed();
}
void DOMTimer::stop()
{
SuspendableTimer::stop();
// Need to release JS objects potentially protected by ScheduledAction
// because they can form circular references back to the ExecutionContext
// which will cause a memory leak.
m_action.clear();
}
double DOMTimer::alignedFireTime(double fireTime) const
{
double alignmentInterval = executionContext()->timerAlignmentInterval();
if (alignmentInterval) {
double currentTime = monotonicallyIncreasingTime();
if (fireTime <= currentTime)
return fireTime;
// When a repeating timer is scheduled for exactly the
// background page alignment interval, because it's impossible
// for the timer to be rescheduled instantaneously, it misses
// every other fire time. Avoid this by looking at the next
// fire time rounded both down and up.
double alignedTimeRoundedDown = floor(fireTime / alignmentInterval) * alignmentInterval;
double alignedTimeRoundedUp = ceil(fireTime / alignmentInterval) * alignmentInterval;
// If the version rounded down is in the past, discard it
// immediately.
if (alignedTimeRoundedDown <= currentTime)
return alignedTimeRoundedUp;
// Only use the rounded-down time if it's within a certain
// tolerance of the fire time. This avoids speeding up timers
// on background pages in the common case.
if (fireTime - alignedTimeRoundedDown < minimumInterval)
return alignedTimeRoundedDown;
return alignedTimeRoundedUp;
}
return fireTime;
}
} // namespace WebCore
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