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(7) 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(7)

July 16, 2004 DAT_SRQ_SET_LW(3DAT)