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| author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2016-04-20 06:15:07 +0200 |
|---|---|---|
| committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2016-04-22 09:25:08 +0200 |
| commit | b5a21bf139168285a009c8da65e63ea99bc064ba (patch) | |
| tree | c2817f7cd6c2f50aaa90367139267f9767da1123 | |
| parent | score: Rename _CORE_RWLock_Obtain() (diff) | |
| download | rtems-b5a21bf139168285a009c8da65e63ea99bc064ba.tar.bz2 | |
posix: Avoid Giant lock in sem_getvalue()
Update #2555.
| -rw-r--r-- | cpukit/posix/src/semgetvalue.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/cpukit/posix/src/semgetvalue.c b/cpukit/posix/src/semgetvalue.c index ed49c09d38..f89526610f 100644 --- a/cpukit/posix/src/semgetvalue.c +++ b/cpukit/posix/src/semgetvalue.c @@ -37,13 +37,22 @@ int sem_getvalue( { POSIX_Semaphore_Control *the_semaphore; Objects_Locations location; + ISR_lock_Context lock_context; - the_semaphore = _POSIX_Semaphore_Get( sem, &location ); + the_semaphore = _POSIX_Semaphore_Get_interrupt_disable( + sem, + &location, + &lock_context + ); switch ( location ) { case OBJECTS_LOCAL: + /* + * Assume a relaxed atomic load of the value on SMP configurations. + * Thus, there is no need to acquire a lock. + */ *sval = _CORE_semaphore_Get_count( &the_semaphore->Semaphore ); - _Objects_Put( &the_semaphore->Object ); + _ISR_lock_ISR_enable( &lock_context ); return 0; #if defined(RTEMS_MULTIPROCESSING) |