pthread_rwlock_wrlock(3) - NetBSD Manual Pages

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PTHREAD_RWLOCK_WRLOC... NetBSD Library Functions ManualPTHREAD_RWLOCK_WRLOC...


NAME

     pthread_rwlock_wrlock, pthread_rwlock_timedwrlock,
     pthread_rwlock_trywrlock -- acquire a read/write lock for writing


LIBRARY

     POSIX Threads Library (libpthread, -lpthread)


SYNOPSIS

     #include <pthread.h>

     int
     pthread_rwlock_wrlock(pthread_rwlock_t *lock);

     int
     pthread_rwlock_timedwrlock(pthread_rwlock_t * restrict lock,
         const struct timespec * restrict abstime);

     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_timedwrlock() performs the same action, but will not
     wait beyond abstime to obtain the lock before returning.

     The pthread_rwlock_trywrlock() function performs the same action as
     pthread_rwlock_wrlock(), but does not block if the lock cannot be immedi-
     ately obtained.

     The results are undefined if the calling thread already holds the lock at
     the time the call is made.


RETURN VALUES

     If successful, the pthread_rwlock_wrlock(), pthread_rwlock_timedwrlock(),
     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 shall fail if:

     [EBUSY]            The calling thread is not able to acquire the lock
                        without blocking.

     The pthread_rwlock_timedrdlock() function shall fail if:

     [ETIMEDOUT]        The time specified by abstime was reached before the
                        lock could be obtained.

     The pthread_rwlock_wrlock(), pthread_rwlock_timedwrlock(), and
     pthread_rwlock_trywrlock() functions may fail if:

     [EDEADLK]          The calling thread already owns the read/write lock
                        (for reading or writing).

     [EINVAL]           The value specified by lock is invalid.


SEE ALSO

     pthread_rwlock_destroy(3), pthread_rwlock_init(3),
     pthread_rwlock_rdlock(3), pthread_rwlock_unlock(3)


STANDARDS

     pthread_rwlock_wrlock(), pthread_rwlock_timedwrlock(),
      and pthread_rwlock_trywrlock() conform to ISO/IEC 9945-1:1996
     (``POSIX.1'').

NetBSD 5.1                     January 30, 2003                     NetBSD 5.1