pthread_rwlock_unlock(3c) [sunos man page]

pthread_rwlock_unlock(3C)												 pthread_rwlock_unlock(3C)

NAME

       pthread_rwlock_unlock - unlock read-write lock object

SYNOPSIS

       cc -mt [ flag... ] file... -lpthread [ library... ]
       #include <pthread.h>

       int pthread_rwlock_unlock(pthread_rwlock_t *rwlock);

       The pthread_rwlock_unlock() function is called to release a lock held on the read-write lock object referenced by rwlock. Results are unde-
       fined if the read-write lock rwlock is not held by the calling thread.

       If this function is called to release a read lock from the read-write lock object and there are other read locks  currently  held  on  this
       read-write  lock  object,  the read-write lock object remains in the read locked state. If this function releases the calling thread's last
       read lock on this read-write lock object, then the calling thread is no longer one of the owners of the object. If this	function  releases
       the last read lock for this read-write lock object, the read-write lock object will be put in the unlocked state with no owners.

       If  this function is called to release a write lock for this read-write lock object, the read-write lock object will be put in the unlocked
       state with no owners.

       If the call to the pthread_rwlock_unlock() function results in the read-write lock object becoming unlocked and there are multiple  threads
       waiting	to acquire the read-write lock object for writing, the scheduling policy is used to determine which thread acquires the read-write
       lock object for writing. If there are multiple threads waiting to acquire the read-write lock object for reading, the scheduling policy	is
       used  to  determine  the  order in which the waiting threads acquire the read-write lock object for reading.  If there are multiple threads
       blocked on rwlock for both read locks and write locks, it is unspecified whether the readers acquire the lock first  or	whether  a  writer
       acquires the lock first.

       Results are undefined if any of these functions are called with an uninitialized read-write lock.

       If successful, the pthread_rwlock_unlock() function returns 0. Otherwise, an error number is returned to indicate the error.

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

       pthread_rwlock_init(3C), pthread_rwlock_rdlock(3C), pthread_rwlock_wrlock(3C), pthread_rwlockattr_init(3C), attributes(5), standards(5)

								    23 Mar 2005 					 pthread_rwlock_unlock(3C)

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pthread_rwlock_wrlock(3C)												 pthread_rwlock_wrlock(3C)

NAME

       pthread_rwlock_wrlock, pthread_rwlock_trywrlock - lock or attempt to lock read-write lock object for writing

SYNOPSIS

       cc -mt [ flag... ] file... -lpthread [ library... ]
       #include <pthread.h>

       int pthread_rwlock_wrlock(pthread_rwlock_t *rwlock);

       int pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock);

       The  pthread_rwlock_wrlock()  function  applies	a  write lock to the read-write lock referenced by rwlock. The calling thread acquires the
       write lock if no other thread (reader or writer) holds the read-write lock rwlock. Otherwise, the thread blocks until it  can  acquire  the
       lock.

       The  pthread_rwlock_trywrlock()	function applies a write lock like the pthread_rwlock_wrlock() function, with the exception that the func-
       tion fails if any thread currently holds rwlock (for reading or writing).

       Writers are favored over readers of the same priority to avoid writer starvation. See pthread_rwlock_rdlock(3C).

       Results are undefined if any of these functions are called with an uninitialized read-write lock.

       If a signal is delivered to a thread waiting for a read-write lock for writing, upon return from the  signal  handler  the  thread  resumes
       waiting for the read-write lock for writing as if it was not interrupted.

       If successful, the pthread_rwlock_wrlock() function returns 0. Otherwise, an error number is returned to indicate the error.

       The  pthread_rwlock_trywrlock()	function returns 0 if the lock for writing on the read-write lock object referenced by rwlock is acquired.
       Otherwise an error number is returned to indicate the error.

       The pthread_rwlock_wrlock() function will fail if:

       EDEADLK	       The current thread already owns the read-write lock for writing or reading.

       The pthread_rwlock_trywrlock() function will fail if:

       EBUSY	       The read-write lock could not be acquired for writing because it was already locked for reading or writing.

       See  attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

       pthread_rwlock_init(3C), pthread_rwlock_unlock(3C), pthread_rwlockattr_init(3C), pthread_rwlock_rdlock(3C), attributes(5), standards(5)

								    23 Mar 2005 					 pthread_rwlock_wrlock(3C)

Linux and UNIX Man Pages

pthread_rwlock_unlock(3c) [sunos man page]

Check Out this Related Man Page