.\"	$OpenBSD: pthread_barrier_init.3,v 1.3 2013/06/05 03:44:50 tedu Exp $
.\"
.\" Copyright (c) 2012 Paul Irofti <pirofti@openbsd.org>
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.Dd $Mdocdate: June 5 2013 $
.Dt PTHREAD_BARRIER_INIT 3
.Os
.Sh NAME
.Nm pthread_barrier_init ,
.Nm pthread_barrier_destroy
.Nd initialize and destroy a barrier object
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_barrier_init "pthread_barrier_t *barrier" "pthread_barrierattr_t *attr" "unsigned int count"
.Ft int
.Fn pthread_barrier_destroy "pthread_barrier_t *barrier"
.Sh DESCRIPTION
The
.Fn pthread_barrier_init
function creates a new barrier object, with attributes specified with
.Fa attr
and with a threshold specified with
.Fa count .
If
.Fa attr
is
.Dv NULL
the default attributes are used.
The
.Fa count
argument is later used by the
.Fn pthread_barrier_wait
function to check if the required number of threads reached the barrier.
.Pp
The
.Fn pthread_barrier_destroy
function frees the resources allocated for
.Fa barrier .
.Sh RETURN VALUES
If successful,
.Fn pthread_barrier_init
and
.Fn pthread_barrier_destroy
return zero;
otherwise an error number is returned to indicate the error.
.Sh ERRORS
.Fn pthread_barrier_init
will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa barrier
or
.Fa attr
is invalid.
.It Bq Er ENOMEM
The process cannot allocate enough memory to create another barrier object.
.It Bq Er ENOTSUP
The attributes specified by
.Fa attr
are not supported by the current implementation.
.El
.Pp
.Fn pthread_barrier_destroy
will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa barrier
is invalid.
.It Bq Er EBUSY
There are still threads waiting on the barrier.
.El
.Sh SEE ALSO
.Xr pthread_barrier_wait 3 ,
.Xr pthread_barrierattr_getpshared 3 ,
.Xr pthread_barrierattr_init 3
.Sh STANDARDS
.Fn pthread_barrier_init
and
.Fn pthread_barrier_destroy
conform to
.St -p1003.1-2008 .
.Sh BUGS
Currently only private barriers are supported and the pshared attribute is
always set that way.
Any attempts to change that value will trigger
.Er ENOTSUP .