dapl_cno_wait.c revision 9517:b4839b0aa7a4
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 2003 Sun Microsystems, Inc. All rights reserved. 28 * Use is subject to license terms. 29 */ 30 31/* 32 * 33 * MODULE: dapl_cno_wait.c 34 * 35 * PURPOSE: Wait for a consumer notification event 36 * Description: Interfaces in this file are completely described in 37 * the DAPL 1.1 API, Chapter 6, section 3.2.3 38 * 39 * $Id: dapl_cno_wait.c,v 1.6 2003/06/16 17:53:32 sjs2 Exp $ 40 */ 41 42#include "dapl.h" 43#include "dapl_adapter_util.h" 44#include "dapl_ring_buffer_util.h" 45 46/* 47 * dapl_cno_wait 48 * 49 * DAPL Requirements Version xxx, 6.3.2.3 50 * 51 * Wait for a consumer notification event 52 * 53 * Input: 54 * cno_handle 55 * timeout 56 * evd_handle 57 * 58 * Output: 59 * evd_handle 60 * 61 * Returns: 62 * DAT_SUCCESS 63 * DAT_INVALID_HANDLE 64 * DAT_QUEUE_EMPTY 65 * DAT_INVALID_PARAMETER 66 */ 67DAT_RETURN 68dapl_cno_wait( 69 IN DAT_CNO_HANDLE cno_handle, /* cno_handle */ 70 IN DAT_TIMEOUT timeout, /* agent */ 71 OUT DAT_EVD_HANDLE *evd_handle) /* evd_handle */ 72{ 73 DAPL_CNO *cno_ptr; 74 DAPL_EVD *evd_ptr, *head_evd_ptr; 75 DAT_RETURN dat_status; 76 int nevents; 77 78 if (DAPL_BAD_HANDLE(cno_handle, DAPL_MAGIC_CNO)) { 79 dat_status = DAT_INVALID_HANDLE | DAT_INVALID_HANDLE_CNO; 80 goto bail; 81 } 82 83 dat_status = DAT_SUCCESS; 84 cno_ptr = (DAPL_CNO *) cno_handle; 85 86 if (cno_ptr->cno_state == DAPL_CNO_STATE_DEAD) { 87 dat_status = DAT_ERROR(DAT_INVALID_STATE, 88 DAT_INVALID_STATE_CNO_DEAD); 89 goto bail; 90 } 91 92 dapl_os_lock(&cno_ptr->header.lock); 93 if (dapl_llist_is_empty(&cno_ptr->evd_list_head)) { 94 dapl_os_unlock(&cno_ptr->header.lock); 95 return (DAT_ERROR(DAT_QUEUE_EMPTY, 0)); 96 } 97 98 /* scan evd list */ 99 evd_ptr = (DAPL_EVD *) 100 dapl_llist_next_entry(&cno_ptr->evd_list_head, NULL); 101 102 for (;;) { 103 /* 104 * Check the evd ring buffer for events, if nothing is found 105 * peek into the CQ to see if there are events 106 */ 107 if (dapls_rbuf_count(&evd_ptr->pending_event_queue) > 0) { 108 break; 109 } 110 111 nevents = 0; 112 dapls_ib_cq_peek(evd_ptr, &nevents); 113 if (nevents > 0) { 114 break; 115 } 116 117 evd_ptr = (DAPL_EVD *) 118 dapl_llist_next_entry(&cno_ptr->evd_list_head, 119 &evd_ptr->cno_list_entry); 120 if (evd_ptr == NULL) { 121 break; 122 } 123 } 124 125 /* shift list by one to simulate round-robin */ 126 head_evd_ptr = (DAPL_EVD *) 127 dapl_llist_remove_head(&cno_ptr->evd_list_head); 128 dapl_os_assert(head_evd_ptr != NULL); 129 dapl_llist_add_tail(&cno_ptr->evd_list_head, 130 &head_evd_ptr->cno_list_entry, head_evd_ptr); 131 132 if (evd_ptr != NULL) { 133 *evd_handle = evd_ptr; 134 dapl_os_unlock(&cno_ptr->header.lock); 135 return (DAT_SUCCESS); 136 } 137 138 cno_ptr->cno_waiters++; 139 dapl_os_unlock(&cno_ptr->header.lock); 140 141 dat_status = dapls_ib_cno_wait(cno_ptr, timeout, &evd_ptr); 142 143 dapl_os_lock(&cno_ptr->header.lock); 144 cno_ptr->cno_waiters--; 145 146 /* verify that evd_ptr is still in the list */ 147 head_evd_ptr = dapl_llist_next_entry(&cno_ptr->evd_list_head, NULL); 148 for (;;) { 149 if (head_evd_ptr == NULL || head_evd_ptr == evd_ptr) { 150 break; 151 } 152 head_evd_ptr = (DAPL_EVD *) 153 dapl_llist_next_entry(&cno_ptr->evd_list_head, 154 &head_evd_ptr->cno_list_entry); 155 } 156 157 if (cno_ptr->cno_state == DAPL_CNO_STATE_DEAD) { 158 dat_status = DAT_ERROR(DAT_INVALID_STATE, 159 DAT_INVALID_STATE_CNO_DEAD); 160 } else if (dat_status == DAT_SUCCESS) { 161 /* 162 * After the first triggering, this will be a valid handle. 163 * If we're racing with wakeups of other CNO waiters, 164 * that's ok. 165 */ 166 if (head_evd_ptr == evd_ptr && evd_ptr != NULL) { 167 *evd_handle = evd_ptr; 168 } else { 169 dat_status = DAT_ERROR(DAT_QUEUE_EMPTY, 0); 170 } 171 } 172 /* 173 * The only other reason we could have made it out of 174 * the loop is a timeout. 175 */ 176 dapl_os_unlock(&cno_ptr->header.lock); 177bail: 178 return (dat_status); 179} 180