1.\" Copyright (c) 1998 Alex Nash 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd August 4, 1998 28.Dt PTHREAD_RWLOCK_UNLOCK 3 29.Os 30.Sh NAME 31.Nm pthread_rwlock_unlock 32.Nd release a read/write lock 33.Sh SYNOPSIS 34.Fd #include <pthread.h> 35.Ft int 36.Fn pthread_rwlock_unlock "pthread_rwlock_t *lock" 37.Sh DESCRIPTION 38The 39.Fn pthread_rwlock_unlock 40function is used to release the read/write lock previously obtained by 41.Fn pthread_rwlock_rdlock , 42.Fn pthread_rwlock_wrlock , 43.Fn pthread_rwlock_tryrdlock , 44or 45.Fn pthread_rwlock_trywrlock . 46.Sh RETURN VALUES 47If successful, the 48.Fn pthread_rwlock_unlock 49function will return zero. Otherwise an error number will be returned 50to indicate the error. 51.Pp 52The results are undefined if 53.Fa lock 54is not held by the calling thread. 55.Sh SEE ALSO 56.Xr pthread_rwlock_rdlock 3 , 57.Xr pthread_rwlock_wrlock 3 58.Sh STANDARDS 59The 60.Fn pthread_rwlock_unlock 61function is expected to conform to 62.St -susv2 . 63.Sh ERRORS 64The 65.Fn pthread_rwlock_unlock 66function may fail if: 67.Bl -tag -width Er 68.It Bq Er EINVAL 69The value specified by 70.Fa lock 71is invalid. 72.It Bq Er EPERM 73The current thread does not own the read/write lock. 74.El 75.Sh HISTORY 76The 77.Fn pthread_rwlock_unlock 78function first appeared in 79.Fx 3.0 . 80