DAT_SRQ_SET_LW(3DAT) Direct Access Transport Library Functions


NAME


dat_srq_set_lw - set low watermark on shared receive queue

SYNOPSIS


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

DAT_RETURN
dat_srq_set_lw (
IN DAT_SRQ_HANDLE srq_handle,
IN DAT_COUNT low_watermark
)


PARAMETERS


srq_handle
A handle for an instance of a Shared Receive Queue.


low_watermark
The low watermark for the number of Recv buffers on SRQ.


DESCRIPTION


The dat_srq_set_lw() function sets the low watermark value for the SRQ
and arms the SRQ for generating an asynchronous event for the low
watermark. An asynchronous event will be generated when the number of
buffers on the SRQ is below the low watermark for the first time. This
can occur during the current call or when an associated EP takes a buffer
from the SRQ.


The asynchronous event will be generated only once per setting of the low
watermark. Once an event is generated, no new asynchronous events for the
number of buffers inthe SRQ below the specified value will be generated
until the SRQ is again set for the Low Watermark. If the Consumer is
again interested in the event, the Consumer should set the low watermark
again.

RETURN VALUES


DAT_SUCCESS
The operation was successful.


DAT_INVALID_HANDLE
The srq_handle argument is an invalid DAT
handle.


DAT_INVALID_PARAMETER
Invalid parameter; the value of low_watermark
is exceeds the value of max_recv_dtos.


DAT_MODEL_NOT_SUPPORTED
The requested Model was not supported by the
Provider. The Provider does not support SRQ
Low Watermark.


USAGE


Upon receiving the asynchronous event for the SRQ low watermark, the
Consumer can replenish Recv buffers on the SRQ or take any other action
that is appropriate.


Regardless of whether an asynchronous event for the low watermark has
been generated, this operation will set the generation of an asynchronous
event with the Consumer-provided low watermark value. If the new low
watermark value is below the current number of free Receive DTOs posted
to the SRQ, an asynchronous event will be generated immediately.
Otherwise the old low watermark value is simply replaced with the new
one.

ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


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

SEE ALSO


dat_srq_create(3DAT), dat_srq_free(3DAT), dat_srq_post_recv(3DAT),
dat_srq_query(3DAT), dat_srq_resize(3DAT), libdat(3LIB), attributes(5)


July 16, 2004 DAT_SRQ_SET_LW(3DAT)