1.\" $OpenBSD: pthread_mutex_init.3,v 1.14 2014/01/03 16:24:06 jmc 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_mutex_init.3,v 1.6 1999/08/28 00:03:07 peter Exp $ 31.\" 32.Dd $Mdocdate: January 3 2014 $ 33.Dt PTHREAD_MUTEX_INIT 3 34.Os 35.Sh NAME 36.Nm pthread_mutex_init 37.Nd create a mutex 38.Sh SYNOPSIS 39.In pthread.h 40.Ft int 41.Fn pthread_mutex_init "pthread_mutex_t *mutex" "const pthread_mutexattr_t *attr" 42.Sh DESCRIPTION 43The 44.Fn pthread_mutex_init 45function creates a new mutex, with attributes specified with 46.Fa attr . 47If 48.Fa attr 49is 50.Dv NULL 51the default attributes are used, otherwise 52.Fa attr 53should be initialized by calling 54.Xr pthread_mutexattr_init 3 . 55.Pp 56A mutex may also be initialized by assignment with the macro 57PTHREAD_MUTEX_INITIALIZER. 58.Sh RETURN VALUES 59If successful, 60.Fn pthread_mutex_init 61will return zero and put the new mutex ID into 62.Fa mutex , 63otherwise an error number will be returned to indicate the error. 64.Sh ERRORS 65.Fn pthread_mutex_init 66will fail if: 67.Bl -tag -width Er 68.It Bq Er EINVAL 69The value specified by 70.Fa attr 71is invalid. 72.It Bq Er ENOMEM 73The process cannot allocate enough memory to create another mutex. 74.El 75.Sh SEE ALSO 76.Xr pthread_mutex_destroy 3 , 77.Xr pthread_mutex_lock 3 , 78.Xr pthread_mutex_unlock 3 , 79.Xr pthread_mutexattr_init 3 80.Sh STANDARDS 81.Fn pthread_mutex_init 82conforms to 83.St -p1003.1-96 . 84