Skip to main content

Browse the archive

Revision 0b06af91463d5b6068ad794ac7307075440f8e4b authored by Peter Dillinger on 01 December 2020, 18:15:36 UTC, committed by Facebook GitHub Bot on 01 December 2020, 18:17:56 UTC 
Warn about practically unfixable TSAN warnings in stack trace (#7723)
 
Summary:
TSAN reports that our stack trace handler makes unsafe calls
during a signal handler. I just tried fixing some of them and I don't
think it's fixable unless we can get away from using FILE stdio. Even if
we can use lower level functions only, I'm not sure it's fixed.

I also tried suppressing the reports with function and file level TSAN
suppression, but that doesn't seem to work, perhaps because the
violation is reported on the callee, not the caller.

So I added a warning to be printed whenever these violations would be
reported that they are practically ignorable.

Internal ref: T77844138

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7723

Test Plan:
run external_sst_file_test with seeded abort(), with TSAN
(TSAN warnings + new warning) and without TSAN (no warning, just stack
trace).

Reviewed By: akankshamahajan15

Differential Revision: D25228011

Pulled By: pdillinger

fbshipit-source-id: 3eda1d6e7ca3cdc64076cf99ae954168837d2818
1 parent eb65d67
Raw File
read_write_util.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).
//
// 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.

#include "file/read_write_util.h"

#include <sstream>
#include "test_util/sync_point.h"

namespace ROCKSDB_NAMESPACE {

IOStatus NewWritableFile(FileSystem* fs, const std::string& fname,
                         std::unique_ptr<FSWritableFile>* result,
                         const FileOptions& options) {
  IOStatus s = fs->NewWritableFile(fname, options, result, nullptr);
  TEST_KILL_RANDOM("NewWritableFile:0", rocksdb_kill_odds * REDUCE_ODDS2);
  return s;
}

bool ReadOneLine(std::istringstream* iss, SequentialFileReader* seq_file_reader,
                 std::string* output, bool* has_data, Status* result) {
  const int kBufferSize = 8192;
  char buffer[kBufferSize + 1];
  Slice input_slice;

  std::string line;
  bool has_complete_line = false;
  while (!has_complete_line) {
    if (std::getline(*iss, line)) {
      has_complete_line = !iss->eof();
    } else {
      has_complete_line = false;
    }
    if (!has_complete_line) {
      // if we're not sure whether we have a complete line,
      // further read from the file.
      if (*has_data) {
        *result = seq_file_reader->Read(kBufferSize, &input_slice, buffer);
      }
      if (input_slice.size() == 0) {
        // meaning we have read all the data
        *has_data = false;
        break;
      } else {
        iss->str(line + input_slice.ToString());
        // reset the internal state of iss so that we can keep reading it.
        iss->clear();
        *has_data = (input_slice.size() == kBufferSize);
        continue;
      }
    }
  }
  *output = line;
  return *has_data || has_complete_line;
}

#ifndef NDEBUG
bool IsFileSectorAligned(const size_t off, size_t sector_size) {
  return off % sector_size == 0;
}
#endif  // NDEBUG
}  // namespace ROCKSDB_NAMESPACE
back to top