| Bug #40899 | Mutex not unlocked in ndb_util_thread_func | ||
|---|---|---|---|
| Submitted: | 20 Nov 2008 19:16 | Modified: | 28 Jan 2009 17:33 |
| Reporter: | Marc ALFF | Email Updates: | |
| Status: | Verified | Impact on me: | |
| Category: | MySQL Cluster: Cluster (NDB) storage engine | Severity: | S2 (Serious) |
| Version: | mysql-5.1 | OS: | Any |
| Assigned to: | CPU Architecture: | Any | |
| Tags: | 5.1 and up | ||
[16 Apr 2009 13:51]
Jonathan Miller
Should be an unlock when exiting, but not during run time/per martin
Description: In 5.1, in ha_ndb_cluster.cc, in ndb_util_thread_func(), the code contain at the beginning: pthread_mutex_lock(&LOCK_ndb_util_thread); thd= new THD; /* note that contructor of THD uses DBUG_ */ if (thd == NULL) { my_errno= HA_ERR_OUT_OF_MEM; DBUG_RETURN(NULL); } If the server is out of memory (which might happen under normal operations if we implement per thread memory quotas), this function returns while holding a lock on the LOCK_ndb_util_thread mutex. Note that fix bug exist in 5.1 and 6.0, but not in 5.0, so technically this is a risk of regression with a dead lock. How to repeat: Code review Suggested fix: Fix the indentation Fix the comments typos Allocate THD before locking the mutex, which will make the critical section smaller as well.