/*
* CDDL HEADER START
*
* 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]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2002-2003, Network Appliance, Inc. All rights reserved.
*/
/*
* Copyright 2003 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
*
* MODULE: dapl_cno_wait.c
*
* PURPOSE: Wait for a consumer notification event
* Description: Interfaces in this file are completely described in
* the DAPL 1.1 API, Chapter 6, section 3.2.3
*
* $Id: dapl_cno_wait.c,v 1.6 2003/06/16 17:53:32 sjs2 Exp $
*/
#include "dapl.h"
#include "dapl_adapter_util.h"
#include "dapl_ring_buffer_util.h"
/*
* dapl_cno_wait
*
* DAPL Requirements Version xxx, 6.3.2.3
*
* Wait for a consumer notification event
*
* Input:
* cno_handle
* timeout
* evd_handle
*
* Output:
* evd_handle
*
* Returns:
* DAT_SUCCESS
* DAT_INVALID_HANDLE
* DAT_QUEUE_EMPTY
* DAT_INVALID_PARAMETER
*/
DAT_RETURN
dapl_cno_wait(
IN DAT_CNO_HANDLE cno_handle, /* cno_handle */
IN DAT_TIMEOUT timeout, /* agent */
OUT DAT_EVD_HANDLE *evd_handle) /* evd_handle */
{
DAPL_CNO *cno_ptr;
DAPL_EVD *evd_ptr, *head_evd_ptr;
DAT_RETURN dat_status;
int nevents;
if (DAPL_BAD_HANDLE(cno_handle, DAPL_MAGIC_CNO)) {
dat_status = DAT_INVALID_HANDLE | DAT_INVALID_HANDLE_CNO;
goto bail;
}
dat_status = DAT_SUCCESS;
cno_ptr = (DAPL_CNO *) cno_handle;
if (cno_ptr->cno_state == DAPL_CNO_STATE_DEAD) {
dat_status = DAT_ERROR(DAT_INVALID_STATE,
DAT_INVALID_STATE_CNO_DEAD);
goto bail;
}
dapl_os_lock(&cno_ptr->header.lock);
if (dapl_llist_is_empty(&cno_ptr->evd_list_head)) {
dapl_os_unlock(&cno_ptr->header.lock);
return (DAT_ERROR(DAT_QUEUE_EMPTY, 0));
}
/* scan evd list */
evd_ptr = (DAPL_EVD *)
dapl_llist_next_entry(&cno_ptr->evd_list_head, NULL);
for (;;) {
/*
* Check the evd ring buffer for events, if nothing is found
* peek into the CQ to see if there are events
*/
if (dapls_rbuf_count(&evd_ptr->pending_event_queue) > 0) {
break;
}
nevents = 0;
dapls_ib_cq_peek(evd_ptr, &nevents);
if (nevents > 0) {
break;
}
evd_ptr = (DAPL_EVD *)
dapl_llist_next_entry(&cno_ptr->evd_list_head,
&evd_ptr->cno_list_entry);
if (evd_ptr == NULL) {
break;
}
}
/* shift list by one to simulate round-robin */
head_evd_ptr = (DAPL_EVD *)
dapl_llist_remove_head(&cno_ptr->evd_list_head);
dapl_os_assert(head_evd_ptr != NULL);
dapl_llist_add_tail(&cno_ptr->evd_list_head,
&head_evd_ptr->cno_list_entry, head_evd_ptr);
if (evd_ptr != NULL) {
*evd_handle = evd_ptr;
dapl_os_unlock(&cno_ptr->header.lock);
return (DAT_SUCCESS);
}
cno_ptr->cno_waiters++;
dapl_os_unlock(&cno_ptr->header.lock);
dat_status = dapls_ib_cno_wait(cno_ptr, timeout, &evd_ptr);
dapl_os_lock(&cno_ptr->header.lock);
cno_ptr->cno_waiters--;
/* verify that evd_ptr is still in the list */
head_evd_ptr = dapl_llist_next_entry(&cno_ptr->evd_list_head, NULL);
for (;;) {
if (head_evd_ptr == NULL || head_evd_ptr == evd_ptr) {
break;
}
head_evd_ptr = (DAPL_EVD *)
dapl_llist_next_entry(&cno_ptr->evd_list_head,
&head_evd_ptr->cno_list_entry);
}
if (cno_ptr->cno_state == DAPL_CNO_STATE_DEAD) {
dat_status = DAT_ERROR(DAT_INVALID_STATE,
DAT_INVALID_STATE_CNO_DEAD);
} else if (dat_status == DAT_SUCCESS) {
/*
* After the first triggering, this will be a valid handle.
* If we're racing with wakeups of other CNO waiters,
* that's ok.
*/
if (head_evd_ptr == evd_ptr && evd_ptr != NULL) {
*evd_handle = evd_ptr;
} else {
dat_status = DAT_ERROR(DAT_QUEUE_EMPTY, 0);
}
}
/*
* The only other reason we could have made it out of
* the loop is a timeout.
*/
dapl_os_unlock(&cno_ptr->header.lock);
bail:
return (dat_status);
}