Yanqin Jin 0ce0edbe12 Fix a data race between GetColumnFamilyMetaData and MarkFilesBeingCompacted (#6056)
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
2019-11-20 16:36:29 -08:00
..
2019-09-18 20:26:04 -07:00
2017-07-15 16:11:23 -07:00
2019-05-31 15:24:43 -07:00
2018-10-04 20:46:50 -07:00
2017-07-15 16:11:23 -07:00
2018-08-24 18:13:20 -07:00
2017-07-15 16:11:23 -07:00
2017-07-15 16:11:23 -07:00
2019-05-31 15:24:43 -07:00
2019-05-31 11:57:01 -07:00
2019-05-31 11:57:01 -07:00
2017-07-15 16:11:23 -07:00
2017-07-15 16:11:23 -07:00
2017-07-15 16:11:23 -07:00
2017-07-15 16:11:23 -07:00
2017-07-15 16:11:23 -07:00