xref: /illumos-gate/usr/src/man/man3dat/dat_srq_resize.3dat (revision 533affcbc7fc4d0c8132976ea454aaa715fe2307)
te
This manual page is derived from the DAT/uDAPL 1.2 specification.
Portions Copyright (c) 2007, Sun Microsystems, Inc. All Rights Reserved.
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
DAT_SRQ_RESIZE 3DAT "Jul 16, 2004"
NAME
dat_srq_resize - modify the size of the shared receive queue
SYNOPSIS

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

DAT_RETURN
 dat_srq_resize (
 IN DAT_SRQ_HANDLE srq_handle,
 IN DAT_COUNT srq_max_recv_dto
 )
PARAMETERS
srq_handle

A handle for an instance of the SRQ.

srq_max_recv_dto

The new maximum number of Recv DTOs that Shared Receive Queue must hold.

DESCRIPTION

The dat_srq_resize() function modifies the size of the queue of SRQ.

Resizing of Shared Receive Queue should not cause any incoming messages on any of the EPs that use the SRQ to be lost. If the number of outstanding Recv buffers on the SRQ is larger then the requested srq_max_recv_dto, the operation returns DAT_INVALID_STATE and do not change SRQ. This includes not just the buffers on the SRQ but all outstanding Receive buffers that had been posted to the SRQ and whose completions have not reaped yet. Thus, the outstanding buffers include the buffers on SRQ, the buffers posted to SRQ at are at SRQ associated EPs, and the buffers posted to SRQ for which completions have been generated but not yet reaped by Consumer from recv_evds of the EPs that use the SRQ.

If the requested srq_max_recv_dto is below the SRQ low watermark, the operation returns DAT_INVALID_STATE and does not change SRQ.

RETURN VALUES
DAT_SUCCESS

The operation was successful.

DAT_INVALID_HANDLE

The srq_handle argument is an invalid DAT handle.

DAT_INVALID_PARAMETER

The srq_max_recv_dto argument is invalid.

DAT_INSUFFICIENT_RESOURCES

The operation failed due to resource limitations.

DAT_INVALID_STATE

Invalid state. Either the number of entries on the SRQ exceeds the requested SRQ queue length or the requested SRQ queue length is smaller than the SRQ low watermark.

USAGE

The dat_srq_resize() function is required not to lose any buffers. Thus, it cannot shrink below the outstanding number of Recv buffers on SRQ. There is no requirement to shrink the SRQ to return DAT_SUCCESS.

The quality of the implementation determines how closely to the Consumer-requested value the Provider shrinks the SRQ. For example, the Provider can shrink the SRQ to the Consumer-requested value and if the requested value is smaller than the outstanding buffers on SRQ, return DAT_INVALID_STATE; or the Provider can shrink to some value larger than that requested by the Consumer but below current SRQ size; or the Provider does not change the SRQ size and still returns DAT_SUCCESS.

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_set_lw (3DAT), libdat (3LIB), attributes (7)