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 1.5 2004/09/10 16:40:31 joerg Exp $
30 #include <sys/queue.h>
32 #ifndef SYS_EVENTHANDLER_H
33 #define SYS_EVENTHANDLER_H
35 struct eventhandler_entry
37 TAILQ_ENTRY(eventhandler_entry) ee_link;
42 struct eventhandler_list
44 TAILQ_ENTRY(eventhandler_list) el_link;
47 #define EHE_INITTED (1<<0)
48 TAILQ_HEAD(,eventhandler_entry) el_entries;
51 typedef struct eventhandler_entry *eventhandler_tag;
54 * Fast handler lists require the eventhandler list be present
55 * at link time. They don't allow addition of entries to
56 * unknown eventhandler lists, ie. each list must have an
59 * Fast handler lists must be defined once by the owner
60 * of the eventhandler list, and the declaration must be in
61 * scope at any point the list is manipulated.
63 #define EVENTHANDLER_FAST_DECLARE(name, type) \
64 extern struct eventhandler_list Xeventhandler_list_ ## name ; \
65 struct eventhandler_entry_ ## name \
67 struct eventhandler_entry ee; \
72 #define EVENTHANDLER_FAST_DEFINE(name, type) \
73 struct eventhandler_list Xeventhandler_list_ ## name = { #name }; \
76 #define EVENTHANDLER_FAST_INVOKE(name, args...) \
78 struct eventhandler_list *_el = &Xeventhandler_list_ ## name ; \
79 struct eventhandler_entry *_ep = TAILQ_FIRST(&(_el->el_entries)); \
81 while (_ep != NULL) { \
82 ((struct eventhandler_entry_ ## name *)_ep)->eh_func(_ep->ee_arg , ## args); \
83 _ep = TAILQ_NEXT(_ep, ee_link); \
87 #define EVENTHANDLER_FAST_REGISTER(name, func, arg, priority) \
88 eventhandler_register(Xeventhandler_list_ ## name, #name, func, arg, priority)
90 #define EVENTHANDLER_FAST_DEREGISTER(name, tag) \
91 eventhandler_deregister(Xeventhandler_list ## name, tag)
95 * Slow handlers are entirely dynamic; lists are created
96 * when entries are added to them, and thus have no concept of "owner".
98 * Slow handlers need to be declared, but do not need to be defined. The
99 * declaration must be in scope wherever the handler is to be invoked.
101 #define EVENTHANDLER_DECLARE(name, type) \
102 struct eventhandler_entry_ ## name \
104 struct eventhandler_entry ee; \
109 #define EVENTHANDLER_INVOKE(name, args...) \
111 struct eventhandler_list *_el; \
112 struct eventhandler_entry *_ep; \
114 if ((_el = eventhandler_find_list(#name)) != NULL) { \
115 for (_ep = TAILQ_FIRST(&(_el->el_entries)); \
117 _ep = TAILQ_NEXT(_ep, ee_link)) { \
118 ((struct eventhandler_entry_ ## name *)_ep)->eh_func(_ep->ee_arg , ## args); \
123 #define EVENTHANDLER_REGISTER(name, func, arg, priority) \
124 eventhandler_register(NULL, #name, func, arg, priority)
126 #define EVENTHANDLER_DEREGISTER(name, tag) \
128 struct eventhandler_list *_el; \
130 if ((_el = eventhandler_find_list(#name)) != NULL) \
131 eventhandler_deregister(_el, tag); \
135 extern eventhandler_tag eventhandler_register(struct eventhandler_list *list,
140 extern void eventhandler_deregister(struct eventhandler_list *list,
141 eventhandler_tag tag);
142 extern struct eventhandler_list *eventhandler_find_list(char *name);
145 * Standard system event queues.
148 /* Generic priority levels */
149 #define EVENTHANDLER_PRI_FIRST 0
150 #define EVENTHANDLER_PRI_ANY 10000
151 #define EVENTHANDLER_PRI_LAST 20000
153 /* Shutdown events */
154 typedef void (*shutdown_fn) (void *, int);
156 #define SHUTDOWN_PRI_FIRST EVENTHANDLER_PRI_FIRST
157 #define SHUTDOWN_PRI_DEFAULT EVENTHANDLER_PRI_ANY
158 #define SHUTDOWN_PRI_LAST EVENTHANDLER_PRI_LAST
160 EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn); /* before fs sync */
161 EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn); /* after fs sync */
162 EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
164 #endif /* SYS_EVENTHANDLER_H */