1.\" $OpenBSD: pthread_cond_wait.3,v 1.10 2013/06/05 03:44:50 tedu 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: June 5 2013 $
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.In 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