| /* |
| * Copyright (C) 2014 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. |
| */ |
| |
| #ifndef Sizes_h |
| #define Sizes_h |
| |
| #include "Algorithm.h" |
| #include "BPlatform.h" |
| #include <algorithm> |
| #include <cstdint> |
| #include <cstddef> |
| #include <limits> |
| #include <type_traits> |
| #include <chrono> |
| |
| namespace bmalloc { |
| |
| // Repository for malloc sizing constants and calculations. |
| |
| namespace Sizes { |
| static const size_t kB = 1024; |
| static const size_t MB = kB * kB; |
| |
| static const size_t alignment = 8; |
| static const size_t alignmentMask = alignment - 1ul; |
| |
| static const size_t chunkSize = 1 * MB; |
| static const size_t chunkMask = ~(chunkSize - 1ul); |
| |
| static const size_t smallLineSize = 256; |
| static const size_t smallPageSize = 4 * kB; |
| static const size_t smallPageLineCount = smallPageSize / smallLineSize; |
| |
| static const size_t maskSizeClassMax = 512; |
| static const size_t smallMax = 32 * kB; |
| |
| static const size_t pageSizeMax = smallMax * 2; |
| static const size_t pageClassCount = pageSizeMax / smallPageSize; |
| |
| static const size_t pageSizeWasteFactor = 8; |
| static const size_t logWasteFactor = 8; |
| |
| static const size_t largeAlignment = smallMax / pageSizeWasteFactor; |
| static const size_t largeAlignmentMask = largeAlignment - 1; |
| |
| static const size_t deallocatorLogCapacity = 512; |
| static const size_t bumpRangeCacheCapacity = 3; |
| |
| static const size_t scavengerBytesPerMemoryPressureCheck = 16 * MB; |
| static const double memoryPressureThreshold = 0.75; |
| |
| static const std::chrono::milliseconds asyncTaskSleepDuration = std::chrono::milliseconds(2000); |
| |
| static const size_t maskSizeClassCount = maskSizeClassMax / alignment; |
| |
| inline constexpr size_t maskSizeClass(size_t size) |
| { |
| // We mask to accommodate zero. |
| return mask((size - 1) / alignment, maskSizeClassCount - 1); |
| } |
| |
| inline size_t maskObjectSize(size_t maskSizeClass) |
| { |
| return (maskSizeClass + 1) * alignment; |
| } |
| |
| static const size_t logAlignmentMin = maskSizeClassMax / logWasteFactor; |
| |
| static const size_t logSizeClassCount = (log2(smallMax) - log2(maskSizeClassMax)) * logWasteFactor; |
| |
| inline size_t logSizeClass(size_t size) |
| { |
| size_t base = log2(size - 1) - log2(maskSizeClassMax); |
| size_t offset = (size - 1 - (maskSizeClassMax << base)); |
| return base * logWasteFactor + offset / (logAlignmentMin << base); |
| } |
| |
| inline size_t logObjectSize(size_t logSizeClass) |
| { |
| size_t base = logSizeClass / logWasteFactor; |
| size_t offset = logSizeClass % logWasteFactor; |
| return (maskSizeClassMax << base) + (offset + 1) * (logAlignmentMin << base); |
| } |
| |
| static const size_t sizeClassCount = maskSizeClassCount + logSizeClassCount; |
| |
| inline size_t sizeClass(size_t size) |
| { |
| if (size <= maskSizeClassMax) |
| return maskSizeClass(size); |
| return maskSizeClassCount + logSizeClass(size); |
| } |
| |
| inline size_t objectSize(size_t sizeClass) |
| { |
| if (sizeClass < maskSizeClassCount) |
| return maskObjectSize(sizeClass); |
| return logObjectSize(sizeClass - maskSizeClassCount); |
| } |
| |
| inline size_t pageSize(size_t pageClass) |
| { |
| return (pageClass + 1) * smallPageSize; |
| } |
| } |
| |
| using namespace Sizes; |
| |
| } // namespace bmalloc |
| |
| #endif // Sizes_h |