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 Sizes_h 27#define Sizes_h 28 29#include "Algorithm.h" 30#include <algorithm> 31#include <cstdint> 32#include <cstddef> 33#include <limits> 34#include <type_traits> 35#include <chrono> 36 37namespace bmalloc { 38 39// Repository for malloc sizing constants and calculations. 40 41namespace Sizes { 42 static const size_t kB = 1024; 43 static const size_t MB = kB * kB; 44 45 static const size_t alignment = 8; 46 static const size_t alignmentMask = alignment - 1ul; 47 48 static const size_t superChunkSize = 32 * MB; 49 50 static const size_t smallMax = 256; 51 static const size_t smallLineSize = 512; 52 static const size_t smallLineMask = ~(smallLineSize - 1ul); 53 54 static const size_t smallChunkSize = superChunkSize / 4; 55 static const size_t smallChunkOffset = superChunkSize * 3 / 4; 56 static const size_t smallChunkMask = ~(smallChunkSize - 1ul); 57 58 static const size_t mediumMax = 1024; 59 static const size_t mediumLineSize = 2048; 60 static const size_t mediumLineMask = ~(mediumLineSize - 1ul); 61 62 static const size_t mediumChunkSize = superChunkSize / 4; 63 static const size_t mediumChunkOffset = superChunkSize * 2 / 4; 64 static const size_t mediumChunkMask = ~(mediumChunkSize - 1ul); 65 66 static const size_t largeChunkSize = superChunkSize / 2; 67 static const size_t largeChunkOffset = 0; 68 static const size_t largeChunkMask = ~(largeChunkSize - 1ul); 69 70 static const size_t largeAlignment = 64; 71 static const size_t largeMax = largeChunkSize * 99 / 100; // Plenty of room for metadata. 72 static const size_t largeMin = 1024; 73 74 static const size_t segregatedFreeListSearchDepth = 16; 75 76 static const uintptr_t typeMask = (superChunkSize - 1) & ~((superChunkSize / 4) - 1); // 4 taggable chunks 77 static const uintptr_t smallType = (superChunkSize + smallChunkOffset) & typeMask; 78 static const uintptr_t mediumType = (superChunkSize + mediumChunkOffset) & typeMask; 79 static const uintptr_t largeTypeMask = ~(mediumType & smallType); 80 static const uintptr_t smallOrMediumTypeMask = mediumType & smallType; 81 static const uintptr_t smallOrMediumSmallTypeMask = smallType ^ mediumType; // Only valid if object is known to be small or medium. 82 83 static const size_t deallocatorLogCapacity = 256; 84 85 static const size_t smallLineCacheCapacity = 16; 86 static const size_t mediumLineCacheCapacity = 8; 87 88 static const size_t smallAllocatorLogCapacity = 16; 89 static const size_t mediumAllocatorLogCapacity = 8; 90 91 static const std::chrono::milliseconds scavengeSleepDuration = std::chrono::milliseconds(512); 92 93 inline size_t smallSizeClassFor(size_t size) 94 { 95 static const size_t smallSizeClassMask = (smallMax / alignment) - 1; 96 return mask((size - 1ul) / alignment, smallSizeClassMask); 97 } 98}; 99 100using namespace Sizes; 101 102} // namespace bmalloc 103 104#endif // Sizes_h 105