Revision 0ce0edbe120f0ec5c17b3cf7d54a09b1f911e8db authored by Yanqin Jin on 21 November 2019, 00:32:17 UTC, committed by Facebook Github Bot on 21 November 2019, 00:36:29 UTC
Summary:
Use db mutex to protect the execution of Version::GetColumnFamilyMetaData()
called in DBImpl::GetColumnFamilyMetaData().
Without mutex, GetColumnFamilyMetaData() races with MarkFilesBeingCompacted()
for access to FileMetaData::being_compacted.
Other than mutex, there are several more alternatives.

- Make FileMetaData::being_compacted an atomic variable. This will make
  FileMetaData non-copy-able.

- Separate being_compacted from FileMetaData. This requires re-organizing data
  structures that are already used in many places.

Test Plan (dev server):
```
make check
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6056

Differential Revision: D18620488

Pulled By: riversand963

fbshipit-source-id: 87f89660b5d5e2ab4ef7962b7b2a7d00e346aa3b
1 parent c0983d0
Raw File
README.md
## RocksDB: A Persistent Key-Value Store for Flash and RAM Storage

[![Linux/Mac Build Status](https://travis-ci.org/facebook/rocksdb.svg?branch=master)](https://travis-ci.org/facebook/rocksdb)
[![Windows Build status](https://ci.appveyor.com/api/projects/status/fbgfu0so3afcno78/branch/master?svg=true)](https://ci.appveyor.com/project/Facebook/rocksdb/branch/master)
[![PPC64le Build Status](http://140.211.168.68:8080/buildStatus/icon?job=Rocksdb)](http://140.211.168.68:8080/job/Rocksdb)

RocksDB is developed and maintained by Facebook Database Engineering Team.
It is built on earlier work on [LevelDB](https://github.com/google/leveldb) by Sanjay Ghemawat (sanjay@google.com)
and Jeff Dean (jeff@google.com)

This code is a library that forms the core building block for a fast
key-value server, especially suited for storing data on flash drives.
It has a Log-Structured-Merge-Database (LSM) design with flexible tradeoffs
between Write-Amplification-Factor (WAF), Read-Amplification-Factor (RAF)
and Space-Amplification-Factor (SAF). It has multi-threaded compactions,
making it especially suitable for storing multiple terabytes of data in a
single database.

Start with example usage here: https://github.com/facebook/rocksdb/tree/master/examples

See the [github wiki](https://github.com/facebook/rocksdb/wiki) for more explanation.

The public interface is in `include/`.  Callers should not include or
rely on the details of any other header files in this package.  Those
internal APIs may be changed without warning.

Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/

## License

RocksDB is dual-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).  You may select, at your option, one of the above-listed licenses.
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