1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright (c) 2002-2003, Network Appliance, Inc. All rights reserved.
24 */
25
26 /*
27 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
28 * Use is subject to license terms.
29 */
30
31 /*
32 *
33 * MODULE: dapl_evd_dequeue.c
34 *
35 * PURPOSE: Event Management
36 *
37 * Description: Interfaces in this file are completely described in
38 * the uDAPL 1.1 API, Chapter 6, section 3
39 *
40 * $Id: dapl_evd_dequeue.c,v 1.9 2003/07/30 18:13:38 hobie16 Exp $
41 */
42
43 #include "dapl.h"
44 #include "dapl_ring_buffer_util.h"
45 #include "dapl_evd_util.h"
46
47 /*
48 * dapl_evd_dequeue
49 *
50 * DAPL Requirements Version xxx, 6.3.2.7
51 *
52 * Remove first element from an event dispatcher
53 *
54 * Input:
55 * evd_handle
56 *
57 * Output:
58 * event
59 *
60 * Returns:
61 * DAT_SUCCESS
62 * DAT_INVALID_HANDLE
63 * DAT_INVALID_PARAMETER
64 * DAT_INVALID_STATE
65 * DAT_QUEUE_EMPTY
66 */
67
dapl_evd_dequeue(IN DAT_EVD_HANDLE evd_handle,OUT DAT_EVENT * event)68 DAT_RETURN dapl_evd_dequeue(
69 IN DAT_EVD_HANDLE evd_handle,
70 OUT DAT_EVENT *event)
71 {
72 DAPL_EVD *evd_ptr;
73 DAT_EVENT *local_event;
74 DAT_RETURN dat_status;
75
76 dapl_dbg_log(DAPL_DBG_TYPE_API,
77 "dapl_evd_dequeue (%p, %p)\n",
78 evd_handle,
79 event);
80
81 evd_ptr = (DAPL_EVD *)evd_handle;
82 dat_status = DAT_SUCCESS;
83
84 if (DAPL_BAD_HANDLE(evd_handle, DAPL_MAGIC_EVD)) {
85 dat_status = DAT_ERROR(DAT_INVALID_HANDLE, 0);
86 goto bail;
87 }
88
89 if (event == NULL) {
90 dat_status = DAT_ERROR(DAT_INVALID_PARAMETER, DAT_INVALID_ARG2);
91 goto bail;
92 }
93
94 /*
95 * We need to dequeue under lock, as the IB OS Access API
96 * restricts us from having multiple threads in CQ poll, and the
97 * DAPL 1.1 API allows multiple threads in dat_evd_dequeue()
98 */
99 dapl_os_lock(&evd_ptr->header.lock);
100
101 /*
102 * Make sure there are no other waiters and the evd is active.
103 * Currently this means only the OPEN state is allowed.
104 */
105 if (evd_ptr->evd_state != DAPL_EVD_STATE_OPEN ||
106 evd_ptr->catastrophic_overflow) {
107 dapl_os_unlock(&evd_ptr->header.lock);
108 dat_status = DAT_ERROR(DAT_INVALID_STATE, 0);
109 goto bail;
110 }
111
112 /*
113 * Try the EVD rbuf first; poll from the CQ only if that's empty.
114 * This keeps events in order if dat_evd_wait() has copied events
115 * from CQ to EVD.
116 */
117 if (evd_ptr->pending_event_queue.head !=
118 evd_ptr->pending_event_queue.tail) {
119 local_event = (DAT_EVENT *)
120 dapls_rbuf_remove(&evd_ptr->pending_event_queue);
121 if (local_event != NULL) {
122 *event = *local_event;
123 dat_status = dapls_rbuf_add(&evd_ptr->free_event_queue,
124 local_event);
125 } else { /* should never happen */
126 dat_status = DAT_ERROR(DAT_INTERNAL_ERROR, 0);
127 }
128 } else if (evd_ptr->ib_cq_handle == IB_INVALID_HANDLE) {
129 dat_status = DAT_ERROR(DAT_QUEUE_EMPTY, 0);
130 } else if ((evd_ptr->evd_flags & (DAT_EVD_CONNECTION_FLAG |
131 DAT_EVD_CR_FLAG | DAT_EVD_ASYNC_FLAG)) == 0) {
132 /*
133 * No need to drop into kernel, just check the CQ.
134 */
135 dat_status = dapls_evd_cq_poll_to_event(evd_ptr, event);
136 } else {
137 /* poll for events with threshold and timeout both 0 */
138 evd_ptr->threshold = 0;
139
140 dapl_os_unlock(&evd_ptr->header.lock);
141 dat_status = dapls_evd_copy_events(evd_ptr, 0);
142 if (dat_status != DAT_SUCCESS) {
143 dat_status = DAT_ERROR(DAT_QUEUE_EMPTY, 0);
144 goto bail;
145 }
146
147 dapl_os_lock(&evd_ptr->header.lock);
148
149 local_event = (DAT_EVENT *)dapls_rbuf_remove(
150 &evd_ptr->pending_event_queue);
151 if (local_event != NULL) {
152 *event = *local_event;
153 dat_status = dapls_rbuf_add(&evd_ptr->free_event_queue,
154 local_event);
155 } else { /* still didn't find anything */
156 dat_status = DAT_ERROR(DAT_QUEUE_EMPTY, 0);
157 }
158 }
159
160 dapl_os_unlock(&evd_ptr->header.lock);
161 bail:
162 dapl_dbg_log(DAPL_DBG_TYPE_RTN,
163 "dapl_evd_dequeue () returns 0x%x\n",
164 dat_status);
165
166 return (dat_status);
167 }
168