1.\" Copyright (c) 1997 Brian Cully <shmit@kublai.com> 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.\" 3. Neither the name of the author nor the names of any co-contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" $FreeBSD$ 29.\" 30.Dd July 28, 1998 31.Dt PTHREAD_COND_WAIT 3 32.Os 33.Sh NAME 34.Nm pthread_cond_wait 35.Nd wait on a condition variable 36.Sh LIBRARY 37.Lb libc_r 38.Lb libpthread 39.Lb libthr 40.Sh SYNOPSIS 41.In pthread.h 42.Ft int 43.Fn pthread_cond_wait "pthread_cond_t *cond" "pthread_mutex_t *mutex" 44.Sh DESCRIPTION 45The 46.Fn pthread_cond_wait 47function atomically blocks the current thread waiting on the condition 48variable specified by 49.Fa cond , 50and unblocks the mutex specified by 51.Fa mutex . 52The waiting thread unblocks only after another thread calls 53.Xr pthread_cond_signal 3 , 54or 55.Xr pthread_cond_broadcast 3 56with the same condition variable, and the current thread reacquires the lock 57on 58.Fa mutex . 59.Sh RETURN VALUES 60If successful, the 61.Fn pthread_cond_wait 62function will return zero. 63Otherwise an error number will be returned to 64indicate the error. 65.Sh ERRORS 66The 67.Fn pthread_cond_wait 68function will fail if: 69.Bl -tag -width Er 70.It Bq Er EINVAL 71The value specified by 72.Fa cond 73or the value specified by 74.Fa mutex 75is invalid. 76.El 77.Sh SEE ALSO 78.Xr pthread_cond_broadcast 3 , 79.Xr pthread_cond_destroy 3 , 80.Xr pthread_cond_init 3 , 81.Xr pthread_cond_signal 3 , 82.Xr pthread_cond_timedwait 3 83.Sh STANDARDS 84The 85.Fn pthread_cond_wait 86function conforms to 87.St -p1003.1-96 . 88