NAME pthread_rwlock_wrlock, pthread_rwlock_trywrlock - acquire a read/write lock for writing CONTENTS Library Synopsis Description Implementation Notes Return Values Errors See Also Standards History LIBRARY .Lb libc_r .Lb libpthread .Lb libthr SYNOPSIS .In pthread.h int pthread_rwlock_wrlock "pthread_rwlock_t *lock" int pthread_rwlock_trywrlock "pthread_rwlock_t *lock" DESCRIPTION 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. IMPLEMENTATION NOTES To prevent writer starvation, writers are favored over readers. RETURN VALUES 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. ERRORS The pthread_rwlock_trywrlock function will fail if:
The results are undefined if the calling thread already holds the lock at the time the call is made. IMPLEMENTATION NOTES To prevent writer starvation, writers are favored over readers. RETURN VALUES 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. ERRORS The pthread_rwlock_trywrlock function will fail if:
The pthread_rwlock_wrlock and pthread_rwlock_trywrlock functions may fail if:
