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 August 7, 2019 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 libpthread 38.Sh SYNOPSIS 39.In pthread.h 40.Ft int 41.Fn pthread_cond_wait "pthread_cond_t *restrict cond" "pthread_mutex_t *restrict 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 releases 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 62indicate the error. 63.Sh ERRORS 64The 65.Fn pthread_cond_wait 66function will fail if: 67.Bl -tag -width Er 68.It Bq Er EINVAL 69The value specified by 70.Fa cond 71or the value specified by 72.Fa mutex 73is invalid. 74.It Bq Er EPERM 75The specified 76.Fa mutex 77was not locked by the calling thread. 78.It Bq Er EOWNERDEAD 79The argument 80.Fa mutex 81points to a robust mutex and the process containing the previous owning 82thread terminated while holding the mutex lock. 83The lock was granted to the caller and it is up to the new owner 84to make the state consistent. 85.It Bq Er ENOTRECOVERABLE 86The state protected by the 87.Fa mutex 88is not recoverable. 89.El 90.Sh SEE ALSO 91.Xr pthread_cond_broadcast 3 , 92.Xr pthread_cond_destroy 3 , 93.Xr pthread_cond_init 3 , 94.Xr pthread_cond_signal 3 , 95.Xr pthread_cond_timedwait 3 , 96.Xr pthread_mutex_consistent 3 97.Sh STANDARDS 98The 99.Fn pthread_cond_wait 100function conforms to 101.St -p1003.1-96 . 102