DAT_EVD_MODIFY_CNO(3DAT) Direct Access Transport Library Functions

NAME

dat_evd_modify_cno - change the associated CNO for the Event
Dispatcher

SYNOPSIS

cc [ flag... ] file... -ldat [ library... ]
#include <dat/udat.h>

DAT_RETURN
dat_evd_modify_cno (
IN DAT_EVD_HANDLE evd_handle,
IN DAT_CNO_HANDLE cno_handle
)

PARAMETERS

evd_handle
Handle for an instance of the Event Dispatcher.


cno_handle
Handle for a CNO. The value of DAT_NULL_HANDLE
specifies no CNO.

DESCRIPTION

The dat_evd_modify_cno() function changes the associated CNO for the
Event Dispatcher.


A Consumer can specify the value of DAT_HANDLE_NULL for cno_handle to
associate not CNO with the Event Dispatcher instance.


Upon completion of the dat_evd_modify_cno() 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.


If the EVD is enabled at the time dat_evd_modify_cno() 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 dat_evd_modify_cno() is not adequate. A notification could
have been generated after the prior check and before the completion
of the change.


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
dat_evd_modify_cno() call and enable it afterwards. This ensures that
any notifications from the EVD are delivered to the new CNO only.


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 dat_evd_modify_cno() call and can be dequeued at
that time

RETURN VALUES

DAT_SUCCESS
The operation was successful.


DAT_INVALID_HANDLE
Invalid DAT handle.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+---------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+---------------------------+
|Interface Stability | Standard: uDAPL, 1.1, 1.2 |
+--------------------+---------------------------+
|MT-Level | Unsafe |
+--------------------+---------------------------+

SEE ALSO

libdat(3LIB), attributes(7)

July 16, 2004 DAT_EVD_MODIFY_CNO(3DAT)