xref: /dragonfly/sys/sys/eventhandler.h (revision 8af44722)
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 $
27  */
28 
29 #ifndef _SYS_EVENTHANDLER_H_
30 #define _SYS_EVENTHANDLER_H_
31 
32 #if !defined(_KERNEL) && !defined(_KERNEL_STRUCTURES)
33 
34 #error "This file should not be included by userland programs."
35 
36 #else
37 
38 #include <sys/queue.h>
39 
40 struct eventhandler_entry
41 {
42     TAILQ_ENTRY(eventhandler_entry)	ee_link;
43     int					ee_priority;
44     void				*ee_arg;
45 };
46 
47 struct eventhandler_list
48 {
49     TAILQ_ENTRY(eventhandler_list)	el_link;
50     char				*el_name;
51     int					el_flags;
52 #define EHE_INITTED	(1<<0)
53     TAILQ_HEAD(,eventhandler_entry)	el_entries;
54 };
55 
56 typedef struct eventhandler_entry	*eventhandler_tag;
57 
58 /*
59  * Fast handler lists require the eventhandler list be present
60  * at link time.  They don't allow addition of entries to
61  * unknown eventhandler lists, ie. each list must have an
62  * "owner".
63  *
64  * Fast handler lists must be defined once by the owner
65  * of the eventhandler list, and the declaration must be in
66  * scope at any point the list is manipulated.
67  */
68 #define EVENTHANDLER_FAST_DECLARE(name, type)			\
69 extern struct eventhandler_list Xeventhandler_list_ ## name ;	\
70 struct eventhandler_entry_ ## name 				\
71 {								\
72     struct eventhandler_entry	ee;				\
73     type		eh_func;				\
74 };								\
75 struct __hack
76 
77 #define EVENTHANDLER_FAST_DEFINE(name, type)				\
78 struct eventhandler_list Xeventhandler_list_ ## name = { #name };	\
79 struct __hack
80 
81 #define EVENTHANDLER_FAST_INVOKE(name, args...)				\
82 do {									\
83     struct eventhandler_list *_el = &Xeventhandler_list_ ## name ;	\
84     struct eventhandler_entry *_ep = TAILQ_FIRST(&(_el->el_entries));	\
85 									\
86     while (_ep != NULL) {						\
87 	((struct eventhandler_entry_ ## name *)_ep)->eh_func(_ep->ee_arg , ## args); \
88 	_ep = TAILQ_NEXT(_ep, ee_link);					\
89     }									\
90 } while (0)
91 
92 #define EVENTHANDLER_FAST_REGISTER(name, func, arg, priority) \
93     eventhandler_register(Xeventhandler_list_ ## name, #name, func, arg, priority)
94 
95 #define EVENTHANDLER_FAST_DEREGISTER(name, tag) \
96     eventhandler_deregister(Xeventhandler_list ## name, tag)
97 
98 
99 /*
100  * Slow handlers are entirely dynamic; lists are created
101  * when entries are added to them, and thus have no concept of "owner".
102  *
103  * Slow handlers need to be declared, but do not need to be defined. The
104  * declaration must be in scope wherever the handler is to be invoked.
105  */
106 #define EVENTHANDLER_DECLARE(name, type)	\
107 struct eventhandler_entry_ ## name 		\
108 {						\
109     struct eventhandler_entry	ee;		\
110     type		eh_func;		\
111 };						\
112 struct __hack
113 
114 #define EVENTHANDLER_INVOKE(name, args...)				\
115 do {									\
116     struct eventhandler_list *_el;					\
117     struct eventhandler_entry *_ep;					\
118 									\
119     if ((_el = eventhandler_find_list(#name)) != NULL) {		\
120 	for (_ep = TAILQ_FIRST(&(_el->el_entries));			\
121 	     _ep != NULL;						\
122 	     _ep = TAILQ_NEXT(_ep, ee_link)) {				\
123 	    ((struct eventhandler_entry_ ## name *)_ep)->eh_func(_ep->ee_arg , ## args); \
124 	}								\
125     }									\
126 } while (0)
127 
128 #define EVENTHANDLER_REGISTER(name, func, arg, priority) \
129     eventhandler_register(NULL, #name, func, arg, priority)
130 
131 #define EVENTHANDLER_DEREGISTER(name, tag) 		\
132 do {							\
133     struct eventhandler_list *_el;			\
134 							\
135     if ((_el = eventhandler_find_list(#name)) != NULL)	\
136 	eventhandler_deregister(_el, tag);		\
137 } while(0)
138 
139 
140 #ifdef _KERNEL
141 eventhandler_tag	eventhandler_register(struct eventhandler_list *,
142 					      const char *, void *, void *,
143 					      int);
144 void			eventhandler_deregister(struct eventhandler_list *,
145 						eventhandler_tag);
146 struct eventhandler_list *eventhandler_find_list(const char *);
147 #endif /* _KERNEL */
148 
149 /*
150  * Standard system event queues.
151  */
152 
153 /* Generic priority levels */
154 #define	EVENTHANDLER_PRI_FIRST	0
155 #define	EVENTHANDLER_PRI_ANY	10000
156 #define	EVENTHANDLER_PRI_LAST	20000
157 
158 struct image_params;
159 struct proc;
160 
161 /* Shutdown events */
162 typedef void (*shutdown_fn) (void *, int);
163 
164 #define	SHUTDOWN_PRI_FIRST	EVENTHANDLER_PRI_FIRST
165 #define	SHUTDOWN_PRI_SECOND	(EVENTHANDLER_PRI_FIRST + 1)
166 #define	SHUTDOWN_PRI_THIRD	(EVENTHANDLER_PRI_FIRST + 2)
167 #define	SHUTDOWN_PRI_DEFAULT	EVENTHANDLER_PRI_ANY
168 #define	SHUTDOWN_PRI_DRIVER	(EVENTHANDLER_PRI_ANY + 5000)
169 #define	SHUTDOWN_PRI_LAST	EVENTHANDLER_PRI_LAST
170 typedef void (*execlist_fn)(void *, struct image_params *);
171 typedef void (*exit_list_fn)(void *, struct proc *);
172 
173 EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn);	/* before fs sync */
174 EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn);	/* after fs sync */
175 EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
176 
177 #endif	/* _KERNEL || _KERNEL_STRUCTURES */
178 #endif	/* !_SYS_EVENTHANDLER_H_ */
179