DAT_CNO_WAIT(3DAT) Direct Access Transport Library Functions

NAME

dat_cno_wait - wait for notification events

SYNOPSIS

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

DAT_RETURN
dat_cno_wait (
IN DAT_CNO_HANDLE cno_handle,
IN DAT_TIMEOUT timeout,
OUT DAT_EVD_HANDLE *evd_handle
)

PARAMETERS

cno_handle
Handle for an instance of CNO


timeout
The duration to wait for a notification. The value
DAT_TIMEOUT_INFINITE can be used to wait indefinitely.


evd_handle
Handle for an instance of EVD

DESCRIPTION

The dat_cno_wait() function allows the Consumer to wait for
notification events from a set of Event Dispatchers all from the same
Interface Adapter. The Consumer blocks until notified or the timeout
period expires.


An Event Dispatcher that is disabled or in the "Waited" state does
not deliver notifications. A uDAPL Consumer waiting directly upon an
Event Dispatcher preempts the CNO.


The consumer can optionally specify a timeout, after which it is
unblocked even if there are no notification events. On a timeout,
evd_handle is explicitly set to a null handle.


The returned evd_handle is only a hint. Another Consumer can reap the
Event before this Consumer can get around to checking the Event
Dispatcher. Additionally, other Event Dispatchers feeding this CNO
might have been notified. The Consumer is responsible for ensuring
that all EVDs feeding this CNO are polled regardless of whether they
are identified as the immediate cause of the CNO unblocking.


All the waiters on the CNO, including the OS Wait Proxy Agent if it
is associated with the CNO, are unblocked with the NULL handle
returns for an unblocking EVD evd_handle when the IA instance is
destroyed or when all EVDs the CNO is associated with are freed.

RETURN VALUES

DAT_SUCCESS
The operation was successful.


DAT_INVALID_HANDLE
The cno_handle parameter is invalid.


DAT_QUEUE_EMPTY
The operation timed out without a
notification.


DAT_INVALID_PARAMETER
One of the parameters was invalid or out of
range, a combination of parameters was
invalid, or the timeout parameter is
invalid.


DAT_INTERRUPTED_CALL
The operation was interrupted by a signal.

ATTRIBUTES

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


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

SEE ALSO

libdat(3LIB), attributes(7)

July 16, 2004 DAT_CNO_WAIT(3DAT)