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/*
* Copyright (C) 2009, 2011 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 "GCThreadSharedData.h"
#include "CopyVisitor.h"
#include "CopyVisitorInlines.h"
#include "GCThread.h"
#include "VM.h"
#include "MarkStack.h"
#include "SlotVisitor.h"
#include "SlotVisitorInlines.h"
namespace JSC {
#if ENABLE(PARALLEL_GC)
void GCThreadSharedData::resetChildren()
{
for (size_t i = 0; i < m_gcThreads.size(); ++i)
m_gcThreads[i]->slotVisitor()->reset();
}
size_t GCThreadSharedData::childVisitCount()
{
unsigned long result = 0;
for (unsigned i = 0; i < m_gcThreads.size(); ++i)
result += m_gcThreads[i]->slotVisitor()->visitCount();
return result;
}
#endif
GCThreadSharedData::GCThreadSharedData(VM* vm)
: m_vm(vm)
, m_copiedSpace(&vm->heap.m_storageSpace)
, m_shouldHashCons(false)
, m_sharedMarkStack(vm->heap.blockAllocator())
, m_numberOfActiveParallelMarkers(0)
, m_parallelMarkersShouldExit(false)
, m_copyIndex(0)
, m_numberOfActiveGCThreads(0)
, m_gcThreadsShouldWait(false)
, m_currentPhase(NoPhase)
{
m_copyLock.Init();
#if ENABLE(PARALLEL_GC)
// Grab the lock so the new GC threads can be properly initialized before they start running.
MutexLocker locker(m_phaseLock);
for (unsigned i = 1; i < Options::numberOfGCMarkers(); ++i) {
m_numberOfActiveGCThreads++;
SlotVisitor* slotVisitor = new SlotVisitor(*this);
CopyVisitor* copyVisitor = new CopyVisitor(*this);
GCThread* newThread = new GCThread(*this, slotVisitor, copyVisitor);
ThreadIdentifier threadID = createThread(GCThread::gcThreadStartFunc, newThread, "JavaScriptCore::Marking");
newThread->initializeThreadID(threadID);
m_gcThreads.append(newThread);
}
// Wait for all the GCThreads to get to the right place.
while (m_numberOfActiveGCThreads)
m_activityCondition.wait(m_phaseLock);
#endif
}
GCThreadSharedData::~GCThreadSharedData()
{
#if ENABLE(PARALLEL_GC)
// Destroy our marking threads.
{
MutexLocker markingLocker(m_markingLock);
MutexLocker phaseLocker(m_phaseLock);
ASSERT(m_currentPhase == NoPhase);
m_parallelMarkersShouldExit = true;
m_gcThreadsShouldWait = false;
m_currentPhase = Exit;
m_phaseCondition.broadcast();
}
for (unsigned i = 0; i < m_gcThreads.size(); ++i) {
waitForThreadCompletion(m_gcThreads[i]->threadID());
delete m_gcThreads[i];
}
#endif
}
void GCThreadSharedData::reset()
{
ASSERT(m_sharedMarkStack.isEmpty());
#if ENABLE(PARALLEL_GC)
m_opaqueRoots.clear();
#else
ASSERT(m_opaqueRoots.isEmpty());
#endif
m_weakReferenceHarvesters.removeAll();
if (m_shouldHashCons) {
m_vm->resetNewStringsSinceLastHashCons();
m_shouldHashCons = false;
}
}
void GCThreadSharedData::startNextPhase(GCPhase phase)
{
MutexLocker phaseLocker(m_phaseLock);
ASSERT(!m_gcThreadsShouldWait);
ASSERT(m_currentPhase == NoPhase);
m_gcThreadsShouldWait = true;
m_currentPhase = phase;
m_phaseCondition.broadcast();
}
void GCThreadSharedData::endCurrentPhase()
{
ASSERT(m_gcThreadsShouldWait);
MutexLocker locker(m_phaseLock);
m_currentPhase = NoPhase;
m_gcThreadsShouldWait = false;
m_phaseCondition.broadcast();
while (m_numberOfActiveGCThreads)
m_activityCondition.wait(m_phaseLock);
}
void GCThreadSharedData::didStartMarking()
{
MutexLocker markingLocker(m_markingLock);
m_parallelMarkersShouldExit = false;
startNextPhase(Mark);
}
void GCThreadSharedData::didFinishMarking()
{
{
MutexLocker markingLocker(m_markingLock);
m_parallelMarkersShouldExit = true;
m_markingCondition.broadcast();
}
ASSERT(m_currentPhase == Mark);
endCurrentPhase();
}
void GCThreadSharedData::didStartCopying()
{
{
SpinLockHolder locker(&m_copyLock);
WTF::copyToVector(m_copiedSpace->m_blockSet, m_blocksToCopy);
m_copyIndex = 0;
}
// We do this here so that we avoid a race condition where the main thread can
// blow through all of the copying work before the GCThreads fully wake up.
// The GCThreads then request a block from the CopiedSpace when the copying phase
// has completed, which isn't allowed.
for (size_t i = 0; i < m_gcThreads.size(); i++)
m_gcThreads[i]->copyVisitor()->startCopying();
startNextPhase(Copy);
}
void GCThreadSharedData::didFinishCopying()
{
ASSERT(m_currentPhase == Copy);
endCurrentPhase();
}
} // namespace JSC
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