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/*
* Copyright (C) 2012, 2016 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 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 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 "IncrementalSweeper.h"
#include "Heap.h"
#include "JSObject.h"
#include "JSString.h"
#include "MarkedBlock.h"
#include "JSCInlines.h"
#include <wtf/CurrentTime.h>
namespace JSC {
static const double sweepTimeSlice = .01; // seconds
static const double sweepTimeTotal = .10;
static const double sweepTimeMultiplier = 1.0 / sweepTimeTotal;
void IncrementalSweeper::scheduleTimer()
{
HeapTimer::scheduleTimer(sweepTimeSlice * sweepTimeMultiplier);
}
IncrementalSweeper::IncrementalSweeper(Heap* heap)
: HeapTimer(heap->vm())
, m_currentAllocator(nullptr)
{
}
void IncrementalSweeper::doWork()
{
doSweep(WTF::monotonicallyIncreasingTime());
}
void IncrementalSweeper::doSweep(double sweepBeginTime)
{
while (sweepNextBlock()) {
double elapsedTime = WTF::monotonicallyIncreasingTime() - sweepBeginTime;
if (elapsedTime < sweepTimeSlice)
continue;
scheduleTimer();
return;
}
cancelTimer();
}
bool IncrementalSweeper::sweepNextBlock()
{
m_vm->heap.stopIfNecessary();
MarkedBlock::Handle* block = nullptr;
for (; m_currentAllocator; m_currentAllocator = m_currentAllocator->nextAllocator()) {
block = m_currentAllocator->findBlockToSweep();
if (block)
break;
}
if (block) {
DeferGCForAWhile deferGC(m_vm->heap);
block->sweep();
m_vm->heap.objectSpace().freeOrShrinkBlock(block);
return true;
}
return m_vm->heap.sweepNextLogicallyEmptyWeakBlock();
}
void IncrementalSweeper::startSweeping()
{
scheduleTimer();
m_currentAllocator = m_vm->heap.objectSpace().firstAllocator();
}
void IncrementalSweeper::stopSweeping()
{
m_currentAllocator = nullptr;
if (m_vm)
cancelTimer();
}
} // namespace JSC
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