subr_callback.c revision 1.2.6.2
1 1.2.6.2 chap /* $NetBSD: subr_callback.c,v 1.2.6.2 2006/06/19 04:07:16 chap Exp $ */ 2 1.2.6.2 chap 3 1.2.6.2 chap /*- 4 1.2.6.2 chap * Copyright (c)2006 YAMAMOTO Takashi, 5 1.2.6.2 chap * All rights reserved. 6 1.2.6.2 chap * 7 1.2.6.2 chap * Redistribution and use in source and binary forms, with or without 8 1.2.6.2 chap * modification, are permitted provided that the following conditions 9 1.2.6.2 chap * are met: 10 1.2.6.2 chap * 1. Redistributions of source code must retain the above copyright 11 1.2.6.2 chap * notice, this list of conditions and the following disclaimer. 12 1.2.6.2 chap * 2. Redistributions in binary form must reproduce the above copyright 13 1.2.6.2 chap * notice, this list of conditions and the following disclaimer in the 14 1.2.6.2 chap * documentation and/or other materials provided with the distribution. 15 1.2.6.2 chap * 16 1.2.6.2 chap * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 1.2.6.2 chap * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 1.2.6.2 chap * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 1.2.6.2 chap * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 1.2.6.2 chap * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 1.2.6.2 chap * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 1.2.6.2 chap * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 1.2.6.2 chap * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 1.2.6.2 chap * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 1.2.6.2 chap * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 1.2.6.2 chap * SUCH DAMAGE. 27 1.2.6.2 chap */ 28 1.2.6.2 chap 29 1.2.6.2 chap #include <sys/cdefs.h> 30 1.2.6.2 chap __KERNEL_RCSID(0, "$NetBSD: subr_callback.c,v 1.2.6.2 2006/06/19 04:07:16 chap Exp $"); 31 1.2.6.2 chap 32 1.2.6.2 chap #include <sys/param.h> 33 1.2.6.2 chap #include <sys/systm.h> 34 1.2.6.2 chap #include <sys/proc.h> 35 1.2.6.2 chap #include <sys/callback.h> 36 1.2.6.2 chap 37 1.2.6.2 chap #define CH_WANT 1 38 1.2.6.2 chap 39 1.2.6.2 chap void 40 1.2.6.2 chap callback_head_init(struct callback_head *ch) 41 1.2.6.2 chap { 42 1.2.6.2 chap 43 1.2.6.2 chap simple_lock_init(&ch->ch_lock); 44 1.2.6.2 chap TAILQ_INIT(&ch->ch_q); 45 1.2.6.2 chap ch->ch_next = NULL; 46 1.2.6.2 chap ch->ch_nentries = 0; 47 1.2.6.2 chap ch->ch_running = 0; 48 1.2.6.2 chap ch->ch_flags = 0; 49 1.2.6.2 chap } 50 1.2.6.2 chap 51 1.2.6.2 chap void 52 1.2.6.2 chap callback_register(struct callback_head *ch, struct callback_entry *ce, 53 1.2.6.2 chap void *obj, int (*fn)(struct callback_entry *, void *, void *)) 54 1.2.6.2 chap { 55 1.2.6.2 chap 56 1.2.6.2 chap ce->ce_func = fn; 57 1.2.6.2 chap ce->ce_obj = obj; 58 1.2.6.2 chap simple_lock(&ch->ch_lock); 59 1.2.6.2 chap TAILQ_INSERT_TAIL(&ch->ch_q, ce, ce_q); 60 1.2.6.2 chap ch->ch_nentries++; 61 1.2.6.2 chap simple_unlock(&ch->ch_lock); 62 1.2.6.2 chap } 63 1.2.6.2 chap 64 1.2.6.2 chap void 65 1.2.6.2 chap callback_unregister(struct callback_head *ch, struct callback_entry *ce) 66 1.2.6.2 chap { 67 1.2.6.2 chap 68 1.2.6.2 chap simple_lock(&ch->ch_lock); 69 1.2.6.2 chap while (ch->ch_running > 0) { 70 1.2.6.2 chap ch->ch_flags |= CH_WANT; 71 1.2.6.2 chap ltsleep(&ch->ch_running, PVM, "recunreg", 0, &ch->ch_lock); 72 1.2.6.2 chap } 73 1.2.6.2 chap if (__predict_false(ch->ch_next == ce)) { 74 1.2.6.2 chap ch->ch_next = TAILQ_NEXT(ce, ce_q); 75 1.2.6.2 chap } 76 1.2.6.2 chap TAILQ_REMOVE(&ch->ch_q, ce, ce_q); 77 1.2.6.2 chap ch->ch_nentries--; 78 1.2.6.2 chap simple_unlock(&ch->ch_lock); 79 1.2.6.2 chap } 80 1.2.6.2 chap 81 1.2.6.2 chap static int 82 1.2.6.2 chap callback_runone(struct callback_head *ch, void *arg) 83 1.2.6.2 chap { 84 1.2.6.2 chap struct callback_entry *ce; 85 1.2.6.2 chap int result; 86 1.2.6.2 chap 87 1.2.6.2 chap KASSERT(ch->ch_nentries > 0); 88 1.2.6.2 chap KASSERT(ch->ch_running > 0); 89 1.2.6.2 chap 90 1.2.6.2 chap ce = ch->ch_next; 91 1.2.6.2 chap if (ce == NULL) { 92 1.2.6.2 chap ce = TAILQ_FIRST(&ch->ch_q); 93 1.2.6.2 chap } 94 1.2.6.2 chap KASSERT(ce != NULL); 95 1.2.6.2 chap result = (*ce->ce_func)(ce, ce->ce_obj, arg); 96 1.2.6.2 chap ch->ch_next = TAILQ_NEXT(ce, ce_q); 97 1.2.6.2 chap return result; 98 1.2.6.2 chap } 99 1.2.6.2 chap 100 1.2.6.2 chap static void 101 1.2.6.2 chap callback_run_enter(struct callback_head *ch) 102 1.2.6.2 chap { 103 1.2.6.2 chap 104 1.2.6.2 chap simple_lock(&ch->ch_lock); 105 1.2.6.2 chap ch->ch_running++; 106 1.2.6.2 chap simple_unlock(&ch->ch_lock); 107 1.2.6.2 chap } 108 1.2.6.2 chap 109 1.2.6.2 chap static void 110 1.2.6.2 chap callback_run_leave(struct callback_head *ch) 111 1.2.6.2 chap { 112 1.2.6.2 chap 113 1.2.6.2 chap simple_lock(&ch->ch_lock); 114 1.2.6.2 chap KASSERT(ch->ch_running > 0); 115 1.2.6.2 chap ch->ch_running--; 116 1.2.6.2 chap if (ch->ch_running == 0 && (ch->ch_flags & CH_WANT) != 0) { 117 1.2.6.2 chap ch->ch_flags &= ~CH_WANT; 118 1.2.6.2 chap wakeup(&ch->ch_running); 119 1.2.6.2 chap } 120 1.2.6.2 chap simple_unlock(&ch->ch_lock); 121 1.2.6.2 chap } 122 1.2.6.2 chap 123 1.2.6.2 chap int 124 1.2.6.2 chap callback_run_roundrobin(struct callback_head *ch, void *arg) 125 1.2.6.2 chap { 126 1.2.6.2 chap int i; 127 1.2.6.2 chap int n; 128 1.2.6.2 chap int result = 0; 129 1.2.6.2 chap 130 1.2.6.2 chap callback_run_enter(ch); 131 1.2.6.2 chap n = ch->ch_nentries; 132 1.2.6.2 chap for (i = 0; i < n; i++) { 133 1.2.6.2 chap result = callback_runone(ch, arg); 134 1.2.6.2 chap if (result != CALLBACK_CHAIN_CONTINUE) { 135 1.2.6.2 chap break; 136 1.2.6.2 chap } 137 1.2.6.2 chap } 138 1.2.6.2 chap callback_run_leave(ch); 139 1.2.6.2 chap 140 1.2.6.2 chap return result; 141 1.2.6.2 chap } 142
Indexes created Thu Sep 25 16:09:42 GMT 2025