\" $NetBSD: sem_init.3,v 1.5 2019/02/21 21:54:09 christos Exp $

\" $NetBSD: sem_init.3,v 1.5 2019/02/21 21:54:09 christos Exp $
\"
\" Copyright (C) 2000 Jason Evans <[email protected]>.
\" All rights reserved.
\"
\" Redistribution and use in source and binary forms, with or without
\" modification, are permitted provided that the following conditions
\" are met:
\" 1. Redistributions of source code must retain the above copyright
\" notice(s), this list of conditions and the following disclaimer as
\" the first lines of this file unmodified other than the possible
\" addition of one or more copyright notices.
\" 2. Redistributions in binary form must reproduce the above copyright
\" notice(s), this list of conditions and the following disclaimer in
\" the documentation and/or other materials provided with the
\" distribution.
\"
\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
\"
Dd February 21, 2019
Dt SEM_INIT 3
Os
Sh NAME
Nm sem_init
Nd initialize an unnamed semaphore
Sh LIBRARY
Lb librt
Sh SYNOPSIS
In semaphore.h
Ft int
Fn sem_init "sem_t *sem" "int pshared" "unsigned int value"
Sh DESCRIPTION
The
Fn sem_init
function initializes the unnamed semaphore pointed to by
Fa sem
to have the value
Fa value .
A non-zero value for
Fa pshared
specifies a shared semaphore that can be used by multiple processes.
Pp
Following a successful call to
Fn sem_init ,
Fa sem
can be used as an argument in subsequent calls to
Fn sem_wait ,
Fn sem_timedwait ,
Fn sem_trywait ,
Fn sem_post ,
and
Fn sem_destroy .
Fa sem
is no longer valid after a successful call to
Fa sem_destroy .
Sh RETURN VALUES
Rv -std sem_init
Sh ERRORS
Fn sem_init
will fail if:
Bl -tag -width Er
It Bq Er EINVAL
Fa value
exceeds SEM_VALUE_MAX.
It Bq Er ENOSPC
There was memory allocation error, or the limit on available semaphores
Dv ( SEM_NSEMS_MAX )
has been exceeded.
It Bq Er EPERM
Unable to initialize a shared semaphore.
El
Sh SEE ALSO
Xr sem_destroy 3 ,
Xr sem_post 3 ,
Xr sem_timedwait 3 ,
Xr sem_trywait 3 ,
Xr sem_wait 3
Sh STANDARDS
Fn sem_init
conforms to
St -p1003.1-96 .