1.\" $OpenBSD: pthread_cond_wait.3,v 1.9 2007/05/31 19:19:36 jmc Exp $ 2.\" 3.\" Copyright (c) 1997 Brian Cully <shmit@kublai.com> 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the author nor the names of any co-contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" $FreeBSD: pthread_cond_wait.3,v 1.6 1999/08/28 00:03:04 peter Exp $ 31.\" 32.Dd $Mdocdate: May 31 2007 $ 33.Dt PTHREAD_COND_WAIT 3 34.Os 35.Sh NAME 36.Nm pthread_cond_wait 37.Nd wait on a condition variable 38.Sh SYNOPSIS 39.Fd #include <pthread.h> 40.Ft int 41.Fn pthread_cond_wait "pthread_cond_t *cond" "pthread_mutex_t *mutex" 42.Sh DESCRIPTION 43The 44.Fn pthread_cond_wait 45function atomically blocks the current thread waiting on the condition 46variable specified by 47.Fa cond , 48and unblocks the mutex specified by 49.Fa mutex . 50The waiting thread unblocks only after another thread calls 51.Xr pthread_cond_signal 3 , 52or 53.Xr pthread_cond_broadcast 3 54with the same condition variable, and the current thread reacquires the lock 55on 56.Fa mutex . 57.Sh RETURN VALUES 58If successful, the 59.Fn pthread_cond_wait 60function will return zero. 61Otherwise an error number will be returned to indicate the error. 62.Sh ERRORS 63.Fn pthread_cond_wait 64will fail if: 65.Bl -tag -width Er 66.It Bq Er EINVAL 67The value specified by 68.Fa cond 69or the value specified by 70.Fa mutex 71is invalid. 72.El 73.Sh SEE ALSO 74.Xr pthread_cond_broadcast 3 , 75.Xr pthread_cond_destroy 3 , 76.Xr pthread_cond_init 3 , 77.Xr pthread_cond_signal 3 , 78.Xr pthread_cond_timedwait 3 79.Sh STANDARDS 80.Fn pthread_cond_wait 81conforms to 82.St -p1003.1-96 . 83