908100399c
Summary:
When a child thread that uses ThreadLocalPtr, ThreadLocalPtr::OnThreadExit
will be called when that child thread is destroyed. However,
OnThreadExit will try to access a static singleton of ThreadLocalPtr,
which will be destroyed when the main thread exit. As a result,
when a child thread that uses ThreadLocalPtr exits AFTER the main thread
exits, illegal memory access will occur.
This diff includes a test that reproduce this legacy bug.
==2095206==ERROR: AddressSanitizer: heap-use-after-free on address
0x608000007fa0 at pc 0x959b79 bp 0x7f5fa7426b60 sp 0x7f5fa7426b58
READ of size 8 at 0x608000007fa0 thread T1
This patch fix this issue by having the thread local mutex never be deleted
(but will leak small piece of memory at the end.) The patch also describe
a better solution (thread_local) in the comment that requires gcc 4.8.1 and
in latest clang as a future work once we agree to move toward gcc 4.8.
Test Plan:
COMPILE_WITH_ASAN=1 make thread_local_test -j32
./thread_local_test --gtest_filter="*MainThreadDiesFirst"
Reviewers: anthony, hermanlee4, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D53013
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 specially 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 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/