/* * Copyright (C) 2018 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 "FreeList.h" #include "MarkedBlock.h" #include <wtf/Noncopyable.h> namespace JSC { class BlockDirectory; class GCDeferralContext; class LocalAllocator : public BasicRawSentinelNode<LocalAllocator> { WTF_MAKE_NONCOPYABLE(LocalAllocator); public: LocalAllocator(BlockDirectory*); ~LocalAllocator(); void* allocate(GCDeferralContext*, AllocationFailureMode); unsigned cellSize() const { return m_cellSize; } void stopAllocating(); void prepareForAllocation(); void resumeAllocating(); void stopAllocatingForGood(); static ptrdiff_t offsetOfFreeList(); static ptrdiff_t offsetOfCellSize(); bool isFreeListedCell(const void*) const; private: friend class BlockDirectory; void reset(); JS_EXPORT_PRIVATE void* allocateSlowCase(GCDeferralContext*, AllocationFailureMode failureMode); void didConsumeFreeList(); void* tryAllocateWithoutCollecting(); void* tryAllocateIn(MarkedBlock::Handle*); void* allocateIn(MarkedBlock::Handle*); ALWAYS_INLINE void doTestCollectionsIfNeeded(GCDeferralContext*); BlockDirectory* m_directory; unsigned m_cellSize; 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. size_t m_allocationCursor { 0 }; // Points to the next block that is a candidate for allocation. }; inline ptrdiff_t LocalAllocator::offsetOfFreeList() { return OBJECT_OFFSETOF(LocalAllocator, m_freeList); } inline ptrdiff_t LocalAllocator::offsetOfCellSize() { return OBJECT_OFFSETOF(LocalAllocator, m_cellSize); } } // namespace JSC