Change sendfile() to use the new m_ext callback scheme for cleaning up after
[dragonfly.git] / sys / sys / eventhandler.h
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1/*-
2 * Copyright (c) 1999 Michael Smith <msmith@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 *
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
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/sys/sys/eventhandler.h,v 1.5 2000/01/16 06:11:33 bde Exp $
3b58be24 27 * $DragonFly: src/sys/sys/eventhandler.h,v 1.4 2004/04/21 02:17:13 cpressey Exp $
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28 */
29
30#include <sys/queue.h>
31
32#ifndef SYS_EVENTHANDLER_H
33#define SYS_EVENTHANDLER_H
34
35struct eventhandler_entry
36{
37 TAILQ_ENTRY(eventhandler_entry) ee_link;
38 int ee_priority;
39 void *ee_arg;
40};
41
42struct eventhandler_list
43{
44 TAILQ_ENTRY(eventhandler_list) el_link;
45 char *el_name;
46 int el_flags;
47#define EHE_INITTED (1<<0)
48 TAILQ_HEAD(,eventhandler_entry) el_entries;
49};
50
51typedef struct eventhandler_entry *eventhandler_tag;
52
53/*
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
57 * "owner".
58 *
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.
62 */
63#define EVENTHANDLER_FAST_DECLARE(name, type) \
64extern struct eventhandler_list Xeventhandler_list_ ## name ; \
65struct eventhandler_entry_ ## name \
66{ \
67 struct eventhandler_entry ee; \
68 type eh_func; \
69}; \
70struct __hack
71
72#define EVENTHANDLER_FAST_DEFINE(name, type) \
73struct eventhandler_list Xeventhandler_list_ ## name = { #name }; \
74struct __hack
75
76#define EVENTHANDLER_FAST_INVOKE(name, args...) \
77do { \
78 struct eventhandler_list *_el = &Xeventhandler_list_ ## name ; \
79 struct eventhandler_entry *_ep = TAILQ_FIRST(&(_el->el_entries)); \
80 \
81 while (_ep != NULL) { \
82 ((struct eventhandler_entry_ ## name *)_ep)->eh_func(_ep->ee_arg , ## args); \
83 _ep = TAILQ_NEXT(_ep, ee_link); \
84 } \
85} while (0)
86
87#define EVENTHANDLER_FAST_REGISTER(name, func, arg, priority) \
88 eventhandler_register(Xeventhandler_list_ ## name, #name, func, arg, priority)
89
90#define EVENTHANDLER_FAST_DEREGISTER(name, tag) \
91 eventhandler_deregister(Xeventhandler_list ## name, tag)
92
93
94/*
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95 * Slow handlers are entirely dynamic; lists are created
96 * when entries are added to them, and thus have no concept of "owner".
984263bc 97 *
3b58be24 98 * Slow handlers need to be declared, but do not need to be defined. The
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99 * declaration must be in scope wherever the handler is to be invoked.
100 */
101#define EVENTHANDLER_DECLARE(name, type) \
102struct eventhandler_entry_ ## name \
103{ \
104 struct eventhandler_entry ee; \
105 type eh_func; \
106}; \
107struct __hack
108
109#define EVENTHANDLER_INVOKE(name, args...) \
110do { \
111 struct eventhandler_list *_el; \
112 struct eventhandler_entry *_ep; \
113 \
114 if ((_el = eventhandler_find_list(#name)) != NULL) { \
115 for (_ep = TAILQ_FIRST(&(_el->el_entries)); \
116 _ep != NULL; \
117 _ep = TAILQ_NEXT(_ep, ee_link)) { \
118 ((struct eventhandler_entry_ ## name *)_ep)->eh_func(_ep->ee_arg , ## args); \
119 } \
120 } \
121} while (0)
122
123#define EVENTHANDLER_REGISTER(name, func, arg, priority) \
124 eventhandler_register(NULL, #name, func, arg, priority)
125
126#define EVENTHANDLER_DEREGISTER(name, tag) \
127do { \
128 struct eventhandler_list *_el; \
129 \
130 if ((_el = eventhandler_find_list(#name)) != NULL) \
131 eventhandler_deregister(_el, tag); \
132} while(0)
3b58be24 133
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134
135extern eventhandler_tag eventhandler_register(struct eventhandler_list *list,
136 char *name,
137 void *func,
138 void *arg,
139 int priority);
140extern void eventhandler_deregister(struct eventhandler_list *list,
141 eventhandler_tag tag);
142extern struct eventhandler_list *eventhandler_find_list(char *name);
143
144/*
145 * Standard system event queues.
146 */
147
148/* Shutdown events */
b153f746 149typedef void (*shutdown_fn) (void *, int);
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150
151#define SHUTDOWN_PRI_FIRST 0
152#define SHUTDOWN_PRI_DEFAULT 10000
153#define SHUTDOWN_PRI_LAST 20000
154
155EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn); /* before fs sync */
156EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn); /* after fs sync */
157EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
158
159#endif /* SYS_EVENTHANDLER_H */