dat_ep_set_watermark(3DAT) Direct Access Transport Library Functions dat_ep_set_watermark(3DAT)
NAME
dat_ep_set_watermark - set high watermark on Endpoint
SYNOPSIS
cc [ flag... ] file... -ldat [ library... ]
#include <dat/udat.h>
DAT_RETURN
dat_ep_set_watermark (
IN DAT_EP_HANDLE ep_handle,
IN DAT_COUNT soft_high_watermark,
IN DAT_COUNT hard_high_watermark
)
PARAMETERS
ep_handle The handle for an instance of an Endpoint.
soft_high_watermark The soft high watermark for the number of Recv buffers consumed by the Endpoint.
hard_high_watermark The hard high watermark for the number of Recv buffers consumed by the Endpoint.
DESCRIPTION
The dat_ep_set_watermark() function sets the soft and hard high watermark values for EP and arms EP for generating asynchronous events for
high watermarks. An asynchronous event will be generated for IA async_evd when the number of Recv buffers at EP exceeds the soft high
watermark for the first time. A connection broken event will be generated for EP connect_evd when the number of Recv buffers at EP exceeds
the hard high watermark. These can occur during this call or when EP takes a buffer from the SRQ or EP RQ. The soft and hard high watermark
asynchronous event generation and setting are independent of each other.
The asynchronous event for a soft high watermark is generated only once per setting. Once an event is generated, no new asynchronous events
for the soft high watermark is generated until the EP is again set for the soft high watermark. If the Consumer is once again interested in
the event, the Consumer should again set the soft high watermark.
If the Consumer is not interested in a soft or hard high watermark, the value of DAT_WATERMARK_INFINITE can be specified for the case that
is the default value. This value specifies that a non-asynchronous event will be generated for a high watermark EP attribute for which this
value is set. It does not prevent generation of a connection broken event for EP when no Recv buffer is available for a message arrived on
the EP connection.
The operation is supported for all states of Endpoint.
RETURN VALUES
DAT_SUCCESS
The operation was successful.
DAT_INVALID_HANDLE
The ep_handle argument is an invalid DAT handle.
DAT_INVALID_PARAMETER
One of the parameters is invalid.
DAT_MODEL_NOT_SUPPORTED
The requested Model was not supported by the Provider. The Provider does not support EP Soft or Hard High Watermarks.
USAGE
For a hard high watermark, the Provider is ready to generate a connection broken event as soon as the connection is established.
If the asynchronous event for a soft or hard high watermark has not yet been generated, this call simply modifies the values for these
attributes. The Provider remains armed for generation of these asynchronous events.
Regardless of whether an asynchronous event for the soft and hard high watermark has been generated, this operation will set the generation
of an asynchronous event with the Consumer-provided high watermark values. If the new high watermark values are below the current number of
Receive DTOs at EP, an asynchronous event will be generated immediately. Otherwise the old soft or hard (or both) high watermark values are
simply replaced with the new ones.
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_ep_create(3DAT), dat_ep_recv_query(3DAT), dat_srq_create(3DAT), dat_srq_free(3DAT), dat_srq_post_recv(3DAT), dat_srq_query(3DAT),
dat_srq_resize(3DAT), dat_srq_set_lw(3DAT), libdat(3LIB), attributes(5)
SunOS 5.10 16 Jul 2004 dat_ep_set_watermark(3DAT)