223b5ee13d
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/14930 Fix a TSAN-detected data race on the vptr between `MultiOpsTxnsStressTest::VerifyPkSkFast` making virtual calls through `db_` and `WritePreparedTxnDB::~WritePreparedTxnDB` updating the vptr during destruction. The race occurs because `VerifyPkSkFast` (called from a compaction notification callback on a background thread) accesses `db_` which is a non-atomic raw pointer. Meanwhile, the main thread destroys the TransactionDB wrapper via `db_owner_.reset()` in `StressTest::CleanUp()`. The previous fix (commit 768838ddcd99, `OnDBShutdownBegin`) reduced the race window by adding a `shutting_down_` check in the listener, but did not fully eliminate it because a background thread can pass the check before shutdown begins and then proceed to use `db_` while the destructor runs. This fix addresses the root cause in two ways: 1. In `VerifyPkSkFast`: Use the atomically loaded `db` local variable (from `db_aptr_.load(memory_order_acquire)`) for ALL virtual calls instead of the non-atomic `db_` member. This ensures the pointer used for virtual dispatch was safely acquired before any shutdown signaling. 2. In `StressTest::CleanUp()`: Store nullptr to `db_aptr_` before calling `Close()`. This prevents any NEW entries into `VerifyPkSkFast` from background threads that have not yet loaded the pointer. `Close()` then waits for all in-flight background work (including any `VerifyPkSkFast` that already loaded a non-null pointer) to complete before proceeding to destroy the DB. Together, these changes ensure that no background thread performs a virtual call through the TransactionDB pointer while the destructor is modifying the vptr. Reviewed By: xingbowang Differential Revision: D111480308 fbshipit-source-id: 0c998888d07712236c28eee60d04c6f169949a80
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.