1/* 2 * Copyright (C) 2014 Apple Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#ifndef XLargeChunk_h 27#define XLargeChunk_h 28 29#include "Sizes.h" 30 31namespace bmalloc { 32 33class XLargeChunk { 34public: 35 static XLargeChunk* create(size_t); 36 static void destroy(XLargeChunk*); 37 38 static XLargeChunk* get(void* object) { return reinterpret_cast<XLargeChunk*>(LargeChunk::get(object)); } 39 40 char* begin() { return m_largeChunk.begin(); } 41 size_t& size(); 42 43private: 44 XLargeChunk(const Range&, size_t); 45 Range& range(); 46 47 LargeChunk m_largeChunk; 48}; 49 50inline XLargeChunk::XLargeChunk(const Range& range, size_t size) 51{ 52 this->range() = range; 53 this->size() = size; 54} 55 56inline XLargeChunk* XLargeChunk::create(size_t size) 57{ 58 size_t vmSize = bmalloc::vmSize(sizeof(XLargeChunk) + size); 59 std::pair<void*, Range> result = vmAllocate(vmSize, superChunkSize, largeChunkOffset); 60 return new (result.first) XLargeChunk(result.second, size); 61} 62 63inline void XLargeChunk::destroy(XLargeChunk* chunk) 64{ 65 const Range& range = chunk->range(); 66 vmDeallocate(range.begin(), range.size()); 67} 68 69inline Range& XLargeChunk::range() 70{ 71 // Since we hold only one object, we only use our first BoundaryTag. So, we 72 // can stuff our range into the remaining metadata. 73 Range& result = *reinterpret_cast<Range*>(roundUpToMultipleOf<alignment>(LargeChunk::beginTag(begin()) + 1)); 74 BASSERT(static_cast<void*>(&result) < static_cast<void*>(begin())); 75 return result; 76} 77 78inline size_t& XLargeChunk::size() 79{ 80 // Since we hold only one object, we only use our first BoundaryTag. So, we 81 // can stuff our size into the remaining metadata. 82 size_t& result = *reinterpret_cast<size_t*>(roundUpToMultipleOf<alignment>(&range() + 1)); 83 BASSERT(static_cast<void*>(&result) < static_cast<void*>(begin())); 84 return result; 85} 86 87}; // namespace bmalloc 88 89#endif // XLargeChunk 90