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/*
* Copyright (C) 2011-2013, 2015 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.
*/
#ifndef SlotVisitor_h
#define SlotVisitor_h
#include "CellState.h"
#include "CopyToken.h"
#include "HandleTypes.h"
#include "MarkStack.h"
#include "OpaqueRootSet.h"
namespace JSC {
class ConservativeRoots;
class GCThreadSharedData;
class Heap;
template<typename T> class JITWriteBarrier;
class UnconditionalFinalizer;
template<typename T> class Weak;
class WeakReferenceHarvester;
template<typename T> class WriteBarrierBase;
class SlotVisitor {
WTF_MAKE_NONCOPYABLE(SlotVisitor);
WTF_MAKE_FAST_ALLOCATED;
friend class HeapRootVisitor; // Allowed to mark a JSValue* or JSCell** directly.
friend class Heap;
public:
SlotVisitor(Heap&);
~SlotVisitor();
MarkStackArray& markStack() { return m_stack; }
const MarkStackArray& markStack() const { return m_stack; }
VM& vm();
const VM& vm() const;
Heap* heap() const;
void append(ConservativeRoots&);
template<typename T> void append(JITWriteBarrier<T>*);
template<typename T> void append(WriteBarrierBase<T>*);
template<typename Iterator> void append(Iterator begin , Iterator end);
void appendValues(WriteBarrierBase<Unknown>*, size_t count);
template<typename T>
void appendUnbarrieredPointer(T**);
void appendUnbarrieredValue(JSValue*);
template<typename T>
void appendUnbarrieredWeak(Weak<T>*);
template<typename T>
void appendUnbarrieredReadOnlyPointer(T*);
void appendUnbarrieredReadOnlyValue(JSValue);
JS_EXPORT_PRIVATE void addOpaqueRoot(void*);
JS_EXPORT_PRIVATE bool containsOpaqueRoot(void*) const;
TriState containsOpaqueRootTriState(void*) const;
int opaqueRootCount();
bool isEmpty() { return m_stack.isEmpty(); }
void didStartMarking();
void reset();
void clearMarkStack();
size_t bytesVisited() const { return m_bytesVisited; }
size_t bytesCopied() const { return m_bytesCopied; }
size_t visitCount() const { return m_visitCount; }
void donate();
void drain();
void donateAndDrain();
enum SharedDrainMode { SlaveDrain, MasterDrain };
void drainFromShared(SharedDrainMode);
void harvestWeakReferences();
void finalizeUnconditionalFinalizers();
void copyLater(JSCell*, CopyToken, void*, size_t);
void reportExtraMemoryVisited(size_t);
void addWeakReferenceHarvester(WeakReferenceHarvester*);
void addUnconditionalFinalizer(UnconditionalFinalizer*);
void dump(PrintStream&) const;
private:
friend class ParallelModeEnabler;
JS_EXPORT_PRIVATE void append(JSValue); // This is private to encourage clients to use WriteBarrier<T>.
JS_EXPORT_PRIVATE void setMarkedAndAppendToMarkStack(JSCell*);
void appendToMarkStack(JSCell*);
JS_EXPORT_PRIVATE void mergeOpaqueRoots();
void mergeOpaqueRootsIfNecessary();
void mergeOpaqueRootsIfProfitable();
void visitChildren(const JSCell*);
void donateKnownParallel();
MarkStackArray m_stack;
OpaqueRootSet m_opaqueRoots; // Handle-owning data structures not visible to the garbage collector.
size_t m_bytesVisited;
size_t m_bytesCopied;
size_t m_visitCount;
bool m_isInParallelMode;
Heap& m_heap;
CellState m_currentObjectCellStateBeforeVisiting { CellState::NewWhite };
public:
#if !ASSERT_DISABLED
bool m_isCheckingForDefaultMarkViolation;
bool m_isDraining;
#endif
};
class ParallelModeEnabler {
public:
ParallelModeEnabler(SlotVisitor& stack)
: m_stack(stack)
{
ASSERT(!m_stack.m_isInParallelMode);
m_stack.m_isInParallelMode = true;
}
~ParallelModeEnabler()
{
ASSERT(m_stack.m_isInParallelMode);
m_stack.m_isInParallelMode = false;
}
private:
SlotVisitor& m_stack;
};
} // namespace JSC
#endif // SlotVisitor_h
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