.\" $OpenBSD: pthread_rwlockattr_setpshared.3,v 1.5 2000/04/12 21:48:03 aaron Exp $
.\" Copyright (c) 1998 Alex Nash
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.\" $FreeBSD: pthread_rwlockattr_setpshared.3,v 1.2 1999/08/28 00:03:11 peter Exp $
.\"
.Dd August 4, 1998
.Dt PTHREAD_RWLOCKATTR_SETPSHARED 3
.Os
.Sh NAME
.Nm pthread_rwlockattr_setpshared
.Nd set the process shared attribute
.Sh SYNOPSIS
.Fd #include <pthread.h>
.Ft int
.Fn pthread_rwlockattr_setpshared "pthread_rwlockattr_t *attr" "int pshared"
.Sh DESCRIPTION
The
.Fn pthread_rwlockattr_setpshared
function sets the process shared attribute of
.Fa attr
to the value referenced by
.Fa pshared .
.Fa pshared
may be one of two values:
.Bl -hang -offset flag -width 123456789012345678901234
.It Ar PTHREAD_PROCESS_SHARED
Any thread of any process that has access to the memory where the
read/write lock resides can manipulate the lock.
.It Ar PTHREAD_PROCESS_PRIVATE
Only threads created within the same process as the thread that
initialized the read/write lock can manipulate the lock.  This is
the default value.
.El
.Sh RETURN VALUES
If successful, the
.Fn pthread_rwlockattr_setpshared
function will return zero.  Otherwise an error number will be returned
to indicate the error.
.Sh SEE ALSO
.Xr pthread_rwlock_init 3 ,
.Xr pthread_rwlockattr_init 3 ,
.Xr pthread_rwlockattr_setpshared 3
.Sh STANDARDS
The
.Fn pthread_rwlockattr_setpshared
function is expected to conform to
.St -susv2 .
.Sh ERRORS
.Fn pthread_rwlockattr_setpshared
will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa attr
or
.Fa pshared
is invalid.
.El
.Sh HISTORY
The
.Fn pthread_rwlockattr_setpshared
function first appeared in
.Fx 3.0
and
.Ox 2.5 .
.Sh BUGS
The PTHREAD_PROCESS_SHARED attribute is not supported.