8b2cfef9e0
Summary: Although ColumnFamilySet comments say that DB mutex can be freed during iteration, as long as you hold a ref while releasing DB mutex, this is not quite true because UnrefAndTryDelete might delete cfd right before it is needed to get ->next_ for the next iteration of the loop. This change solves the problem by making a wrapper class that makes such iteration easier while handling the tricky details of UnrefAndTryDelete on the previous cfd only after getting next_ in operator++. FreeDeadColumnFamilies should already have been obsolete; this removes it for good. Similarly, ColumnFamilySet::iterator doesn't need to check for cfd with 0 refs, because those are immediately deleted. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9730 Test Plan: was reported with ASAN on unit tests like DBLogicalBlockSizeCacheTest.CreateColumnFamily (very rare); keep watching Reviewed By: ltamasi Differential Revision: D35038143 Pulled By: pdillinger fbshipit-source-id: 0a5478d5be96c135343a00603711b7df43ae19c9
RocksDB: A Persistent Key-Value Store for Flash and RAM Storage
RocksDB is developed and maintained by Facebook Database Engineering Team. It is built on earlier work on 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/main/examples
See the github 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.
Questions and discussions are welcome on the RocksDB Developers Public Facebook group and email list on Google Groups.
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.