1.\" $OpenBSD: pthread_cond_wait.3,v 1.5 1999/11/24 05:35:31 d Exp $ 2.\" Copyright (c) 1997 Brian Cully <shmit@kublai.com> 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. Neither the name of the author nor the names of any co-contributors 14.\" may be used to endorse or promote products derived from this software 15.\" without specific prior written permission. 16.\" 17.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 18.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27.\" SUCH DAMAGE. 28.\" 29.\" $FreeBSD: pthread_cond_wait.3,v 1.6 1999/08/28 00:03:04 peter Exp $ 30.\" 31.Dd July 28, 1998 32.Dt PTHREAD_COND_WAIT 3 33.Os 34.Sh NAME 35.Nm pthread_cond_wait 36.Nd wait on a condition variable 37.Sh SYNOPSIS 38.Fd #include <pthread.h> 39.Ft int 40.Fn pthread_cond_wait "pthread_cond_t *cond" "pthread_mutex_t *mutex" 41.Sh DESCRIPTION 42The 43.Fn pthread_cond_wait 44function atomically blocks the current thread waiting on the condition 45variable specified by 46.Fa cond , 47and unblocks the mutex specified by 48.Fa mutex . 49The waiting thread unblocks only after another thread calls 50.Xr pthread_cond_signal 3 , or 51.Xr pthread_cond_broadcast 3 52with the same condition variable, and the current thread reaquires the lock 53on 54.Fa mutex . 55.Sh RETURN VALUES 56If successful, the 57.Fn pthread_cond_wait 58function will return zero. Otherwise an error number will be returned to 59indicate the error. 60.Sh ERRORS 61.Fn pthread_cond_wait 62will fail if: 63.Bl -tag -width Er 64.It Bq Er EINVAL 65The value specified by 66.Fa cond 67or the value specified by 68.Fa mutex 69is invalid. 70.El 71.Sh SEE ALSO 72.Xr pthread_cond_broadcast 3 , 73.Xr pthread_cond_destroy 3 , 74.Xr pthread_cond_init 3 , 75.Xr pthread_cond_signal 3 , 76.Xr pthread_cond_timedwait 3 77.Sh STANDARDS 78.Fn pthread_cond_wait 79conforms to ISO/IEC 9945-1 ANSI/IEEE 80.Pq Dq Tn POSIX 81Std 1003.1 Second Edition 1996-07-12. 82