database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

Bug #28284: Test "mysqlslap" reports "out of memory"

Browse Source 
When locking a "fast" mutex a static variable cpu_count 
was used as a flag to initialize itself on the first usage 
by calling sysconf() and setting non-zero value.
This is not thread and optimization safe on some 
platforms. That's why the global initialization needs 
to be done once in a designated function.
This will also speed up the usage (by a small bit) 
because it won't have to check if it's initialized on
every call.

Fixed by moving the fast mutexes initialization out of 
my_pthread_fastmutex_lock() to fastmutex_global_init()
and call it from my_init()


include/my_pthread.h:
  Bug #28284: move the fast mutexes initialization out of 
  my_pthread_fastmutex_lock() to fastmutex_global_init()
  and call it from my_init()
mysys/my_init.c:
  Bug #28284: move the fast mutexes initialization out of 
  my_pthread_fastmutex_lock() to fastmutex_global_init()
  and call it from my_init()
mysys/thr_mutex.c:
  Bug #28284: move the fast mutexes initialization out of 
  my_pthread_fastmutex_lock() to fastmutex_global_init()
  and call it from my_init()
This commit is contained in:
unknown
2007-08-24 18:06:44 +03:00
parent 0aefd73b3d
commit 06d80f1119
3 changed files with 15 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
mysys/thr_mutex.c
View File

@ -394,15 +394,11 @@ ulong mutex_delay(ulong delayloops)
#define MY_PTHREAD_FASTMUTEX_SPINS 8
#define MY_PTHREAD_FASTMUTEX_DELAY 4
static int cpu_count= 0;
int my_pthread_fastmutex_init(my_pthread_fastmutex_t *mp,
const pthread_mutexattr_t *attr)
{
static int cpu_count= 0;
#ifdef _SC_NPROCESSORS_CONF
if (!cpu_count && (attr == MY_MUTEX_INIT_FAST))
cpu_count= sysconf(_SC_NPROCESSORS_CONF);
#endif
if ((cpu_count > 1) && (attr == MY_MUTEX_INIT_FAST))
mp->spins= MY_PTHREAD_FASTMUTEX_SPINS;
else
@ -432,4 +428,13 @@ int my_pthread_fastmutex_lock(my_pthread_fastmutex_t *mp)
}
return pthread_mutex_lock(&mp->mutex);
}
void fastmutex_global_init(void)
{
#ifdef _SC_NPROCESSORS_CONF
cpu_count= sysconf(_SC_NPROCESSORS_CONF);
#endif
}
#endif /* defined(THREAD) && defined(MY_PTHREAD_FASTMUTEX) && !defined(SAFE_MUTEX) */