2 * Copyright (c) 1999 Michael Smith <msmith@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/sys/sys/eventhandler.h,v 1.5 2000/01/16 06:11:33 bde Exp $
27 * $DragonFly: src/sys/sys/eventhandler.h,v 1.6 2004/12/30 07:01:52 cpressey Exp $
30 #include <sys/queue.h>
32 #ifndef SYS_EVENTHANDLER_H
33 #define SYS_EVENTHANDLER_H
35 #if !defined(_KERNEL) && !defined(_KERNEL_STRUCTURES)
36 #error "This file should not be included by userland programs."
39 struct eventhandler_entry
41 TAILQ_ENTRY(eventhandler_entry) ee_link;
46 struct eventhandler_list
48 TAILQ_ENTRY(eventhandler_list) el_link;
51 #define EHE_INITTED (1<<0)
52 TAILQ_HEAD(,eventhandler_entry) el_entries;
55 typedef struct eventhandler_entry *eventhandler_tag;
58 * Fast handler lists require the eventhandler list be present
59 * at link time. They don't allow addition of entries to
60 * unknown eventhandler lists, ie. each list must have an
63 * Fast handler lists must be defined once by the owner
64 * of the eventhandler list, and the declaration must be in
65 * scope at any point the list is manipulated.
67 #define EVENTHANDLER_FAST_DECLARE(name, type) \
68 extern struct eventhandler_list Xeventhandler_list_ ## name ; \
69 struct eventhandler_entry_ ## name \
71 struct eventhandler_entry ee; \
76 #define EVENTHANDLER_FAST_DEFINE(name, type) \
77 struct eventhandler_list Xeventhandler_list_ ## name = { #name }; \
80 #define EVENTHANDLER_FAST_INVOKE(name, args...) \
82 struct eventhandler_list *_el = &Xeventhandler_list_ ## name ; \
83 struct eventhandler_entry *_ep = TAILQ_FIRST(&(_el->el_entries)); \
85 while (_ep != NULL) { \
86 ((struct eventhandler_entry_ ## name *)_ep)->eh_func(_ep->ee_arg , ## args); \
87 _ep = TAILQ_NEXT(_ep, ee_link); \
91 #define EVENTHANDLER_FAST_REGISTER(name, func, arg, priority) \
92 eventhandler_register(Xeventhandler_list_ ## name, #name, func, arg, priority)
94 #define EVENTHANDLER_FAST_DEREGISTER(name, tag) \
95 eventhandler_deregister(Xeventhandler_list ## name, tag)
99 * Slow handlers are entirely dynamic; lists are created
100 * when entries are added to them, and thus have no concept of "owner".
102 * Slow handlers need to be declared, but do not need to be defined. The
103 * declaration must be in scope wherever the handler is to be invoked.
105 #define EVENTHANDLER_DECLARE(name, type) \
106 struct eventhandler_entry_ ## name \
108 struct eventhandler_entry ee; \
113 #define EVENTHANDLER_INVOKE(name, args...) \
115 struct eventhandler_list *_el; \
116 struct eventhandler_entry *_ep; \
118 if ((_el = eventhandler_find_list(#name)) != NULL) { \
119 for (_ep = TAILQ_FIRST(&(_el->el_entries)); \
121 _ep = TAILQ_NEXT(_ep, ee_link)) { \
122 ((struct eventhandler_entry_ ## name *)_ep)->eh_func(_ep->ee_arg , ## args); \
127 #define EVENTHANDLER_REGISTER(name, func, arg, priority) \
128 eventhandler_register(NULL, #name, func, arg, priority)
130 #define EVENTHANDLER_DEREGISTER(name, tag) \
132 struct eventhandler_list *_el; \
134 if ((_el = eventhandler_find_list(#name)) != NULL) \
135 eventhandler_deregister(_el, tag); \
140 extern eventhandler_tag eventhandler_register(struct eventhandler_list *list,
145 extern void eventhandler_deregister(struct eventhandler_list *list,
146 eventhandler_tag tag);
147 extern struct eventhandler_list *eventhandler_find_list(char *name);
151 * Standard system event queues.
154 /* Generic priority levels */
155 #define EVENTHANDLER_PRI_FIRST 0
156 #define EVENTHANDLER_PRI_ANY 10000
157 #define EVENTHANDLER_PRI_LAST 20000
159 /* Shutdown events */
160 typedef void (*shutdown_fn) (void *, int);
162 #define SHUTDOWN_PRI_FIRST EVENTHANDLER_PRI_FIRST
163 #define SHUTDOWN_PRI_DEFAULT EVENTHANDLER_PRI_ANY
164 #define SHUTDOWN_PRI_LAST EVENTHANDLER_PRI_LAST
166 EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn); /* before fs sync */
167 EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn); /* after fs sync */
168 EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
170 #endif /* SYS_EVENTHANDLER_H */