Revision 0d4a2b733070a1bd52f981313f9e17f126701407 authored by Yi Wu on 04 August 2017, 20:09:56 UTC, committed by Facebook Github Bot on 04 August 2017, 20:12:07 UTC
Summary: The FsyncFiles background job call Fsync() periodically for blob files. However it can access WritableFileWriter concurrently with a Put() or Write(). And WritableFileWriter does not support concurrent access. It will lead to WritableFileWriter buffer being flush with same content twice, and blob file end up corrupted. Fixing by simply let FsyncFiles hold write_mutex_. Closes https://github.com/facebook/rocksdb/pull/2685 Differential Revision: D5561908 Pulled By: yiwu-arbug fbshipit-source-id: f0bb5bcab0e05694e053b8c49eab43640721e872
1 parent 627c9f1
arena.h
// 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 <sys/mman.h>
#endif
#include <cstddef>
#include <cerrno>
#include <vector>
#include <assert.h>
#include <stdint.h>
#include "util/allocator.h"
#include "util/mutexlock.h"
namespace rocksdb {
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__(sizeof(void*))));
// Number of bytes allocated in one block
const size_t kBlockSize;
// Array of new[] allocated memory blocks
typedef std::vector<char*> Blocks;
Blocks blocks_;
struct MmapInfo {
void* addr_;
size_t length_;
MmapInfo(void* addr, size_t length) : addr_(addr), length_(length) {}
};
std::vector<MmapInfo> 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
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