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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 
Avoid blob db call Sync() while writing
 
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
Raw File
dynamic_bloom.cc 
// 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).

#include "dynamic_bloom.h"

#include <algorithm>

#include "port/port.h"
#include "rocksdb/slice.h"
#include "util/allocator.h"
#include "util/hash.h"

namespace rocksdb {

namespace {

uint32_t GetTotalBitsForLocality(uint32_t total_bits) {
  uint32_t num_blocks =
      (total_bits + CACHE_LINE_SIZE * 8 - 1) / (CACHE_LINE_SIZE * 8);

  // Make num_blocks an odd number to make sure more bits are involved
  // when determining which block.
  if (num_blocks % 2 == 0) {
    num_blocks++;
  }

  return num_blocks * (CACHE_LINE_SIZE * 8);
}
}

DynamicBloom::DynamicBloom(Allocator* allocator, uint32_t total_bits,
                           uint32_t locality, uint32_t num_probes,
                           uint32_t (*hash_func)(const Slice& key),
                           size_t huge_page_tlb_size,
                           Logger* logger)
    : DynamicBloom(num_probes, hash_func) {
  SetTotalBits(allocator, total_bits, locality, huge_page_tlb_size, logger);
}

DynamicBloom::DynamicBloom(uint32_t num_probes,
                           uint32_t (*hash_func)(const Slice& key))
    : kTotalBits(0),
      kNumBlocks(0),
      kNumProbes(num_probes),
      hash_func_(hash_func == nullptr ? &BloomHash : hash_func) {}

void DynamicBloom::SetRawData(unsigned char* raw_data, uint32_t total_bits,
                              uint32_t num_blocks) {
  data_ = reinterpret_cast<std::atomic<uint8_t>*>(raw_data);
  kTotalBits = total_bits;
  kNumBlocks = num_blocks;
}

void DynamicBloom::SetTotalBits(Allocator* allocator,
                                uint32_t total_bits, uint32_t locality,
                                size_t huge_page_tlb_size,
                                Logger* logger) {
  kTotalBits = (locality > 0) ? GetTotalBitsForLocality(total_bits)
                              : (total_bits + 7) / 8 * 8;
  kNumBlocks = (locality > 0) ? (kTotalBits / (CACHE_LINE_SIZE * 8)) : 0;

  assert(kNumBlocks > 0 || kTotalBits > 0);
  assert(kNumProbes > 0);

  uint32_t sz = kTotalBits / 8;
  if (kNumBlocks > 0) {
    sz += CACHE_LINE_SIZE - 1;
  }
  assert(allocator);

  char* raw = allocator->AllocateAligned(sz, huge_page_tlb_size, logger);
  memset(raw, 0, sz);
  auto cache_line_offset = reinterpret_cast<uintptr_t>(raw) % CACHE_LINE_SIZE;
  if (kNumBlocks > 0 && cache_line_offset > 0) {
    raw += CACHE_LINE_SIZE - cache_line_offset;
  }
  data_ = reinterpret_cast<std::atomic<uint8_t>*>(raw);
}

}  // rocksdb
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