pthread_rwlock_unlock() — Unlock a read or write lock object

Standards

Format

#define _OPEN_THREADS
#include <pthread.h>

int pthread_rwlock_unlock(pthread_rwlock_t *rwlock);

#define _UNIX03_THREADS
#include <pthread.h>

int pthread_rwlock_unlock(pthread_rwlock_t *rwlock);

General description

The pthread_rwlock_unlock() function releases a read or write lock object. If one or more threads are waiting to lock the rwlock, pthread_rwlock_unlock() causes one or more of these threads to return from the pthread_rwlock_rdlock() or the pthread_rwlock_wrlock() call with the read or write lock object acquired. If there are multiple threads blocked on rwlock for both read locks and write locks, z/OS® UNIX will give the read or write lock to the next waiting call whether it is a read or a write request even when there is a writer blocked waiting for the lock. If no threads are waiting for the rwlock, the rwlock unlocks with no current owner.

Returned value

If successful, pthread_rwlock_unlock() returns 0.

Special behavior for Single UNIX Specification, Version 3: If unsuccessful, pthread_rwlock_unlock() returns an error number to indicate the error.

Related information

• pthread.h
• pthread_rwlock_destroy() — Destroy a read or write lock object
• pthread_rwlock_init() — Initialize a read or write lock object
• pthread_rwlock_rdlock() — Wait for a lock on a read or write lock object
• pthread_rwlock_tryrdlock() — Attempt to lock a read or write lock object for reading
• pthread_rwlock_trywrlock() — Attempt to lock a read or write lock object for writing
• pthread_rwlock_wrlock() — Wait for a lock on a read or write lock object for writing