| Bug #39024 | Crash in DeferredIndex::detachTransaction | ||
|---|---|---|---|
| Submitted: | 25 Aug 2008 21:40 | Modified: | 9 Jan 2009 13:43 |
| Reporter: | Vladislav Vaintroub | Email Updates: | |
| Status: | Closed | Impact on me: | |
| Category: | MySQL Server: Falcon storage engine | Severity: | S3 (Non-critical) |
| Version: | OS: | Any | |
| Assigned to: | Vladislav Vaintroub | CPU Architecture: | Any |
[25 Aug 2008 21:46]
Vladislav Vaintroub
Hmm, not sure analysis is correct. Seems like sync.unlock() is always called, and eventually Index::detachDeferredIndex() locks and unlocks it again.
[27 Aug 2008 21:53]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/52787 2805 Vladislav Vaintroub 2008-08-27 Bug#39024 Crash in DeferredIndex::detachTransaction DeferredIndex::syncObject is accessed even after "this" object is destroyed in releaseRef(). I put a block at the start of function and before releaseRef() to force the destructor of sync before the object itself is destroyed.
[6 Nov 2008 5:19]
Kevin Lewis
The original fix for this bug stopped the assert, but introduced the following bugs. See Bug#39711 for the final patch which fixed these also. Bug#39711 "Running falcon_bug_34351_C shows increasing memory usage" Bug#39795 "Falcon: Online add index does not support index with non-null columns" Bug#39796 "Falcon: Reference count decrement not atomic"
[9 Jan 2009 13:43]
MC Brown
Internal only. No documentation needed.
Description: During SystemQA tests, including DDL , falcon crashes at drop table with following callstack. The assertion checks the state of the SyncObject to be None. Error::debugBreak()+0x12 Error::error(char const*, ...)+0x7a Error::assertionFailed(char const*, char const*, int) SyncObject::~SyncObject()+0x2f DeferredIndex::~DeferredIndex()+0x73 DeferredIndex::releaseRef()+0x34 DeferredIndex::detachTransaction()+0x90 Transaction::releaseDeferredIndexes(Table*)+0x41 Transaction::dropTable(Table*)+0x19 TransactionManager::dropTable(Table*, Transaction*)+0x59 Database::dropTable(Table*, Transaction*)+0xf6 DeferredIndex::detachTransaction() looks like this void DeferredIndex::detachTransaction(void) { Sync sync(&syncObject, "DeferredIndex::detachTransaction"); sync.lock(Exclusive); ..code.. releaseRef(); } it release reference to itself which eventually ends up in delete this; while lock to this::SyncObject can still be held (it can be released as well, but not in all cases). How to repeat: Run systemQA tests on system QA machines. Suggested fix: sync.unlock() unconditionally before doing releaseRef()