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/*
* Copyright (C) 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. 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 INC. 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 "HandleSet.h"
#include "HandleBlock.h"
#include "HandleBlockInlines.h"
#include "HeapRootVisitor.h"
#include "JSObject.h"
#include "Operations.h"
#include <wtf/DataLog.h>
namespace JSC {
HandleSet::HandleSet(VM* vm)
: m_vm(vm)
, m_nextToFinalize(0)
{
grow();
}
HandleSet::~HandleSet()
{
while (!m_blockList.isEmpty())
m_vm->heap.blockAllocator().deallocate(HandleBlock::destroy(m_blockList.removeHead()));
}
void HandleSet::grow()
{
HandleBlock* newBlock = HandleBlock::create(m_vm->heap.blockAllocator().allocate<HandleBlock>(), this);
m_blockList.append(newBlock);
for (int i = newBlock->nodeCapacity() - 1; i >= 0; --i) {
Node* node = newBlock->nodeAtIndex(i);
new (NotNull, node) Node;
m_freeList.push(node);
}
}
void HandleSet::visitStrongHandles(HeapRootVisitor& heapRootVisitor)
{
Node* end = m_strongList.end();
for (Node* node = m_strongList.begin(); node != end; node = node->next()) {
#if ENABLE(GC_VALIDATION)
RELEASE_ASSERT(isLiveNode(node));
#endif
heapRootVisitor.visit(node->slot());
}
}
void HandleSet::writeBarrier(HandleSlot slot, const JSValue& value)
{
// Forbid assignment to handles during the finalization phase, since it would violate many GC invariants.
// File a bug with stack trace if you hit this.
RELEASE_ASSERT(!m_nextToFinalize);
if (!value == !*slot && slot->isCell() == value.isCell())
return;
Node* node = toNode(slot);
#if ENABLE(GC_VALIDATION)
RELEASE_ASSERT(isLiveNode(node));
#endif
SentinelLinkedList<Node>::remove(node);
if (!value || !value.isCell()) {
m_immediateList.push(node);
return;
}
m_strongList.push(node);
#if ENABLE(GC_VALIDATION)
RELEASE_ASSERT(isLiveNode(node));
#endif
}
unsigned HandleSet::protectedGlobalObjectCount()
{
unsigned count = 0;
Node* end = m_strongList.end();
for (Node* node = m_strongList.begin(); node != end; node = node->next()) {
JSValue value = *node->slot();
if (value.isObject() && asObject(value.asCell())->isGlobalObject())
count++;
}
return count;
}
#if ENABLE(GC_VALIDATION) || !ASSERT_DISABLED
bool HandleSet::isLiveNode(Node* node)
{
if (node->prev()->next() != node)
return false;
if (node->next()->prev() != node)
return false;
return true;
}
#endif
} // namespace JSC
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