PTHREAD_RWLOCK_WRLOCK(3) | Library Functions Manual | PTHREAD_RWLOCK_WRLOCK(3) |
pthread_rwlock_wrlock
,
pthread_rwlock_trywrlock
—
acquire a read/write lock for writing
#include
<pthread.h>
int
pthread_rwlock_wrlock
(pthread_rwlock_t
*lock);
int
pthread_rwlock_trywrlock
(pthread_rwlock_t
*lock);
The
pthread_rwlock_wrlock
()
function blocks until a write lock can be acquired against
lock. The
pthread_rwlock_trywrlock
()
function performs the same action, but does not block if the lock cannot be
immediately obtained.
The results are undefined if the calling thread already holds the lock at the time the call is made.
To prevent writer starvation, writers are favored over readers.
If successful, the pthread_rwlock_wrlock
()
and pthread_rwlock_trywrlock
() functions will return
zero. Otherwise an error number will be returned to indicate the error.
The pthread_rwlock_trywrlock
() function
will fail if:
EBUSY
]The pthread_rwlock_wrlock
() and
pthread_rwlock_trywrlock
() functions may fail
if:
pthread_rwlock_init(3), pthread_rwlock_rdlock(3), pthread_rwlock_tryrdlock(3), pthread_rwlock_unlock(3)
The pthread_rwlock_wrlock
() and
pthread_rwlock_trywrlock
() functions are expected to
conform to Version 2 of the Single UNIX
Specification (“SUSv2”).
The pthread_rwlock_wrlock
() function first
appeared in FreeBSD 3.0.
August 4, 1998 | macOS 14.6 |