'\" te
.\" This manual page is derived from the DAT/uDAPL 1.2 specification.
.\" Portions Copyright (c) 2007, Sun Microsystems, Inc. All Rights Reserved.
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
.\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
.TH DAT_EVD_MODIFY_CNO 3DAT "Jul 16, 2004"
.SH NAME
dat_evd_modify_cno \- change the associated CNO for the Event Dispatcher
.SH SYNOPSIS
.LP
.nf
cc [ \fIflag\fR\&.\|.\|. ] \fIfile\fR\&.\|.\|. \fB-ldat\fR [ \fIlibrary\fR\&.\|.\|. ]
#include <\fBdat/udat.h\fR>

DAT_RETURN
    dat_evd_modify_cno (
    IN    DAT_EVD_HANDLE    \fIevd_handle\fR,
    IN    DAT_CNO_HANDLE    \fIcno_handle\fR
    )
.fi

.SH PARAMETERS
.sp
.ne 2
.na
\fB\fIevd_handle\fR\fR
.ad
.RS 14n
Handle for an instance of the Event Dispatcher.
.RE

.sp
.ne 2
.na
\fB\fIcno_handle\fR\fR
.ad
.RS 14n
Handle for a CNO. The value of \fBDAT_NULL_HANDLE\fR specifies no CNO.
.RE

.SH DESCRIPTION
.sp
.LP
The \fBdat_evd_modify_cno()\fR function changes the associated CNO for the
Event Dispatcher.
.sp
.LP
A Consumer can specify the value of \fBDAT_HANDLE_NULL\fR for \fIcno_handle\fR
to associate not CNO with the Event Dispatcher instance.
.sp
.LP
Upon completion of the \fBdat_evd_modify_cno()\fR operation, the passed IN new
CNO is used for notification. During the operation, an event arrival can be
delivered to the old or new CNO. If Notification is generated by EVD, it is
delivered to the new or old CNO.
.sp
.LP
If the EVD is enabled at the time \fBdat_evd_modify_cno()\fR is called, the
Consumer must be prepared to collect a notification event on the EVD's old CNO
as well as the new one. Checking immediately prior to calling
\fBdat_evd_modify_cno()\fR is not adequate. A notification could have been
generated after the prior check and before the completion of the change.
.sp
.LP
The Consumer can avoid the risk of missed notifications either by temporarily
disabling the EVD, or by checking the prior CNO after invoking this operation.
The Consumer can disable EVD before a \fBdat_evd_modify_cno()\fR call and
enable it afterwards. This ensures that any notifications from the EVD are
delivered to the new CNO only.
.sp
.LP
If this function is used to disassociate a CNO from the EVD, events arriving on
this EVD might cause waiters on that CNO to awaken after returning from this
routine because of unblocking a CNO waiter already "in progress" at the time
this routine is called. If this is the case, the events causing that unblocking
are present on the EVD upon return from the \fBdat_evd_modify_cno()\fR call and
can be dequeued at that time
.SH RETURN VALUES
.sp
.ne 2
.na
\fB\fBDAT_SUCCESS\fR\fR
.ad
.RS 22n
The operation was successful.
.RE

.sp
.ne 2
.na
\fB\fBDAT_INVALID_HANDLE\fR\fR
.ad
.RS 22n
Invalid DAT handle.
.RE

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(7) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Standard: uDAPL, 1.1, 1.2
_
MT-Level	Unsafe
.TE

.SH SEE ALSO
.sp
.LP
.BR libdat (3LIB),
.BR attributes (7)