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 BSD 4 33.Sh NAME 34.Nm pthread_cond_wait 35.Nd wait on a condition variable 36.Sh LIBRARY 37.Lb libc_r 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 , or 52.Xr pthread_cond_broadcast 3 53with the same condition variable, and the current thread requires the lock 54on 55.Fa mutex . 56.Sh RETURN VALUES 57If successful, the 58.Fn pthread_cond_wait 59function will return zero. 60Otherwise an error number will be returned to 61indicate 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.Pp 74.Sh SEE ALSO 75.Xr pthread_cond_broadcast 3 , 76.Xr pthread_cond_destroy 3 , 77.Xr pthread_cond_init 3 , 78.Xr pthread_cond_signal 3 , 79.Xr pthread_cond_timedwait 3 80.Sh STANDARDS 81.Fn pthread_cond_wait 82conforms to ISO/IEC 9945-1 ANSI/IEEE 83.Pq Dq Tn POSIX 84Std 1003.1 Second Edition 1996-07-12. 85