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/*
* Copyright (C) 2010 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.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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 "GCActivityCallback.h"
#include "APIShims.h"
#include "Heap.h"
#include "JSGlobalData.h"
#include "JSLock.h"
#include "JSObject.h"
#include <wtf/RetainPtr.h>
#include <wtf/WTFThreadData.h>
namespace JSC {
#if USE(CF)
const double gcTimeSlicePerMB = 0.01; // Percentage of CPU time we will spend to reclaim 1 MB
const double maxGCTimeSlice = 0.05; // The maximum amount of CPU time we want to use for opportunistic timer-triggered collections.
const double timerSlop = 2.0; // Fudge factor to avoid performance cost of resetting timer.
const double pagingTimeOut = 0.1; // Time in seconds to allow opportunistic timer to iterate over all blocks to see if the Heap is paged out.
const CFTimeInterval hour = 60 * 60;
DefaultGCActivityCallback::DefaultGCActivityCallback(Heap* heap)
: GCActivityCallback(heap->globalData(), CFRunLoopGetCurrent())
, m_delay(s_decade)
{
}
DefaultGCActivityCallback::DefaultGCActivityCallback(Heap* heap, CFRunLoopRef runLoop)
: GCActivityCallback(heap->globalData(), runLoop)
, m_delay(s_decade)
{
}
void DefaultGCActivityCallback::doWork()
{
Heap* heap = &m_globalData->heap;
if (!isEnabled())
return;
APIEntryShim shim(m_globalData);
#if !PLATFORM(IOS)
double startTime = WTF::monotonicallyIncreasingTime();
if (heap->isPagedOut(startTime + pagingTimeOut)) {
heap->activityCallback()->cancel();
heap->increaseLastGCLength(pagingTimeOut);
return;
}
#endif
heap->collect(Heap::DoNotSweep);
}
void DefaultGCActivityCallback::scheduleTimer(double newDelay)
{
if (newDelay * timerSlop > m_delay)
return;
double delta = m_delay - newDelay;
m_delay = newDelay;
CFRunLoopTimerSetNextFireDate(m_timer.get(), CFRunLoopTimerGetNextFireDate(m_timer.get()) - delta);
}
void DefaultGCActivityCallback::cancelTimer()
{
m_delay = s_decade;
CFRunLoopTimerSetNextFireDate(m_timer.get(), CFAbsoluteTimeGetCurrent() + s_decade);
}
void DefaultGCActivityCallback::didAllocate(size_t bytes)
{
// The first byte allocated in an allocation cycle will report 0 bytes to didAllocate.
// We pretend it's one byte so that we don't ignore this allocation entirely.
if (!bytes)
bytes = 1;
Heap* heap = static_cast<Heap*>(&m_globalData->heap);
double gcTimeSlice = std::min((static_cast<double>(bytes) / MB) * gcTimeSlicePerMB, maxGCTimeSlice);
double newDelay = heap->lastGCLength() / gcTimeSlice;
scheduleTimer(newDelay);
}
void DefaultGCActivityCallback::willCollect()
{
cancelTimer();
}
void DefaultGCActivityCallback::cancel()
{
cancelTimer();
}
#else
DefaultGCActivityCallback::DefaultGCActivityCallback(Heap* heap)
: GCActivityCallback(heap->globalData())
{
}
void DefaultGCActivityCallback::doWork()
{
}
void DefaultGCActivityCallback::didAllocate(size_t)
{
}
void DefaultGCActivityCallback::willCollect()
{
}
void DefaultGCActivityCallback::cancel()
{
}
#endif
}