.\" $OpenBSD: pthread_mutex_init.3,v 1.6 1999/11/24 05:35:32 d Exp $
.\" Copyright (c) 1997 Brian Cully <shmit@kublai.com>
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.\" $FreeBSD: pthread_mutex_init.3,v 1.6 1999/08/28 00:03:07 peter Exp $
.\"
.Dd July 29, 1998
.Dt PTHREAD_MUTEX_INIT 3
.Os
.Sh NAME
.Nm pthread_mutex_init
.Nd create a mutex
.Sh SYNOPSIS
.Fd #include <pthread.h>
.Ft int
.Fn pthread_mutex_init "pthread_mutex_t *mutex" "const pthread_mutexattr_t *attr"
.Sh DESCRIPTION
The
.Fn pthread_mutex_init
function creates a new mutex, with attributes specified with
.Fa attr .
If
.Fa attr
is
.Dv NULL
the default attributes are used.
.Sh RETURN VALUES
If successful,
.Fn pthread_mutex_init
will return zero and put the new mutex ID into
.Fa mutex ,
otherwise an error number will be returned to indicate the error.
.Sh ERRORS
.Fn pthread_mutex_init
will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa attr
is invalid.
.It Bq Er ENOMEM
The process cannot allocate enough memory to create another mutex.
.It Bq Er EAGAIN
The temporarily lacks the resources to create another mutex.
.El
.Sh SEE ALSO
.Xr pthread_mutex_destroy 3 ,
.Xr pthread_mutex_lock 3 ,
.Xr pthread_mutex_trylock 3 ,
.Xr pthread_mutex_unlock 3
.Sh STANDARDS
.Fn pthread_mutex_init
conforms to ISO/IEC 9945-1 ANSI/IEEE
.Pq Dq Tn POSIX
Std 1003.1 Second Edition 1996-07-12.