From 19fcec84d8d7d21e796c7624e521b60d28ee21ed Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:45:59 +0200 Subject: Adding upstream version 16.2.11+ds. Signed-off-by: Daniel Baumann --- src/rocksdb/memory/arena.h | 141 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 141 insertions(+) create mode 100644 src/rocksdb/memory/arena.h (limited to 'src/rocksdb/memory/arena.h') diff --git a/src/rocksdb/memory/arena.h b/src/rocksdb/memory/arena.h new file mode 100644 index 000000000..a7ee4c6ab --- /dev/null +++ b/src/rocksdb/memory/arena.h @@ -0,0 +1,141 @@ +// Copyright (c) 2011-present, Facebook, Inc. All rights reserved. +// This source code is licensed under both the GPLv2 (found in the +// COPYING file in the root directory) and Apache 2.0 License +// (found in the LICENSE.Apache file in the root directory). +// +// Copyright (c) 2011 The LevelDB Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. See the AUTHORS file for names of contributors. + +// Arena is an implementation of Allocator class. For a request of small size, +// it allocates a block with pre-defined block size. For a request of big +// size, it uses malloc to directly get the requested size. + +#pragma once +#ifndef OS_WIN +#include +#endif +#include +#include +#include +#include +#include +#include "memory/allocator.h" +#include "util/mutexlock.h" + +namespace ROCKSDB_NAMESPACE { + +class Arena : public Allocator { + public: + // No copying allowed + Arena(const Arena&) = delete; + void operator=(const Arena&) = delete; + + static const size_t kInlineSize = 2048; + static const size_t kMinBlockSize; + static const size_t kMaxBlockSize; + + // huge_page_size: if 0, don't use huge page TLB. If > 0 (should set to the + // supported hugepage size of the system), block allocation will try huge + // page TLB first. If allocation fails, will fall back to normal case. + explicit Arena(size_t block_size = kMinBlockSize, + AllocTracker* tracker = nullptr, size_t huge_page_size = 0); + ~Arena(); + + char* Allocate(size_t bytes) override; + + // huge_page_size: if >0, will try to allocate from huage page TLB. + // The argument will be the size of the page size for huge page TLB. Bytes + // will be rounded up to multiple of the page size to allocate through mmap + // anonymous option with huge page on. The extra space allocated will be + // wasted. If allocation fails, will fall back to normal case. To enable it, + // need to reserve huge pages for it to be allocated, like: + // sysctl -w vm.nr_hugepages=20 + // See linux doc Documentation/vm/hugetlbpage.txt for details. + // huge page allocation can fail. In this case it will fail back to + // normal cases. The messages will be logged to logger. So when calling with + // huge_page_tlb_size > 0, we highly recommend a logger is passed in. + // Otherwise, the error message will be printed out to stderr directly. + char* AllocateAligned(size_t bytes, size_t huge_page_size = 0, + Logger* logger = nullptr) override; + + // Returns an estimate of the total memory usage of data allocated + // by the arena (exclude the space allocated but not yet used for future + // allocations). + size_t ApproximateMemoryUsage() const { + return blocks_memory_ + blocks_.capacity() * sizeof(char*) - + alloc_bytes_remaining_; + } + + size_t MemoryAllocatedBytes() const { return blocks_memory_; } + + size_t AllocatedAndUnused() const { return alloc_bytes_remaining_; } + + // If an allocation is too big, we'll allocate an irregular block with the + // same size of that allocation. + size_t IrregularBlockNum() const { return irregular_block_num; } + + size_t BlockSize() const override { return kBlockSize; } + + bool IsInInlineBlock() const { + return blocks_.empty(); + } + + private: + char inline_block_[kInlineSize] __attribute__((__aligned__(alignof(max_align_t)))); + // Number of bytes allocated in one block + const size_t kBlockSize; + // Array of new[] allocated memory blocks + typedef std::vector Blocks; + Blocks blocks_; + + struct MmapInfo { + void* addr_; + size_t length_; + + MmapInfo(void* addr, size_t length) : addr_(addr), length_(length) {} + }; + std::vector huge_blocks_; + size_t irregular_block_num = 0; + + // Stats for current active block. + // For each block, we allocate aligned memory chucks from one end and + // allocate unaligned memory chucks from the other end. Otherwise the + // memory waste for alignment will be higher if we allocate both types of + // memory from one direction. + char* unaligned_alloc_ptr_ = nullptr; + char* aligned_alloc_ptr_ = nullptr; + // How many bytes left in currently active block? + size_t alloc_bytes_remaining_ = 0; + +#ifdef MAP_HUGETLB + size_t hugetlb_size_ = 0; +#endif // MAP_HUGETLB + char* AllocateFromHugePage(size_t bytes); + char* AllocateFallback(size_t bytes, bool aligned); + char* AllocateNewBlock(size_t block_bytes); + + // Bytes of memory in blocks allocated so far + size_t blocks_memory_ = 0; + AllocTracker* tracker_; +}; + +inline char* Arena::Allocate(size_t bytes) { + // The semantics of what to return are a bit messy if we allow + // 0-byte allocations, so we disallow them here (we don't need + // them for our internal use). + assert(bytes > 0); + if (bytes <= alloc_bytes_remaining_) { + unaligned_alloc_ptr_ -= bytes; + alloc_bytes_remaining_ -= bytes; + return unaligned_alloc_ptr_; + } + return AllocateFallback(bytes, false /* unaligned */); +} + +// check and adjust the block_size so that the return value is +// 1. in the range of [kMinBlockSize, kMaxBlockSize]. +// 2. the multiple of align unit. +extern size_t OptimizeBlockSize(size_t block_size); + +} // namespace ROCKSDB_NAMESPACE -- cgit v1.2.3