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/*
* Copyright (C) 2018-2022 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.
*/
#pragma once
#include "AllocationFailureMode.h"
#include "FreeList.h"
#include "MarkedBlock.h"
#include <wtf/Noncopyable.h>
namespace JSC {
class BlockDirectory;
class GCDeferralContext;
class Heap;
class LocalAllocator : public BasicRawSentinelNode<LocalAllocator> {
WTF_MAKE_NONCOPYABLE(LocalAllocator);
public:
LocalAllocator(BlockDirectory*);
JS_EXPORT_PRIVATE ~LocalAllocator();
void* allocate(Heap&, size_t cellSize, GCDeferralContext*, AllocationFailureMode);
unsigned cellSize() const { return m_freeList.cellSize(); }
void stopAllocating();
void prepareForAllocation();
void resumeAllocating();
void stopAllocatingForGood();
static constexpr ptrdiff_t offsetOfFreeList();
static constexpr ptrdiff_t offsetOfCellSize();
BlockDirectory& directory() const { return *m_directory; }
private:
friend class BlockDirectory;
void reset();
JS_EXPORT_PRIVATE void* allocateSlowCase(Heap&, size_t, GCDeferralContext*, AllocationFailureMode);
void didConsumeFreeList();
void* tryAllocateWithoutCollecting(size_t);
void* tryAllocateIn(MarkedBlock::Handle*, size_t);
void* allocateIn(MarkedBlock::Handle*, size_t cellSize);
ALWAYS_INLINE void doTestCollectionsIfNeeded(Heap&, GCDeferralContext*);
BlockDirectory* m_directory;
FreeList m_freeList;
MarkedBlock::Handle* m_currentBlock { nullptr };
MarkedBlock::Handle* m_lastActiveBlock { nullptr };
// After you do something to a block based on one of these cursors, you clear the bit in the
// corresponding bitvector and leave the cursor where it was.
unsigned m_allocationCursor { 0 }; // Points to the next block that is a candidate for allocation.
};
inline constexpr ptrdiff_t LocalAllocator::offsetOfFreeList()
{
return OBJECT_OFFSETOF(LocalAllocator, m_freeList);
}
inline constexpr ptrdiff_t LocalAllocator::offsetOfCellSize()
{
return OBJECT_OFFSETOF(LocalAllocator, m_freeList) + FreeList::offsetOfCellSize();
}
} // namespace JSC
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