xref: /freebsd/sys/sys/eventhandler.h (revision 4570e665)
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  * $FreeBSD$
27  */
28 
29 #ifndef _SYS_EVENTHANDLER_H_
30 #define _SYS_EVENTHANDLER_H_
31 
32 #include <sys/lock.h>
33 #include <sys/ktr.h>
34 #include <sys/mutex.h>
35 #include <sys/queue.h>
36 
37 struct eventhandler_entry {
38 	TAILQ_ENTRY(eventhandler_entry)	ee_link;
39 	int				ee_priority;
40 #define	EHE_DEAD_PRIORITY	(-1)
41 	void				*ee_arg;
42 };
43 
44 #ifdef VIMAGE
45 struct eventhandler_entry_vimage {
46 	void	(* func)(void);		/* Original function registered. */
47 	void	*ee_arg;		/* Original argument registered. */
48 	void	*sparep[2];
49 };
50 #endif
51 
52 struct eventhandler_list {
53 	char				*el_name;
54 	int				el_flags;
55 #define EHL_INITTED	(1<<0)
56 	u_int				el_runcount;
57 	struct mtx			el_lock;
58 	TAILQ_ENTRY(eventhandler_list)	el_link;
59 	TAILQ_HEAD(,eventhandler_entry)	el_entries;
60 };
61 
62 typedef struct eventhandler_entry	*eventhandler_tag;
63 
64 #define	EHL_LOCK(p)		mtx_lock(&(p)->el_lock)
65 #define	EHL_UNLOCK(p)		mtx_unlock(&(p)->el_lock)
66 #define	EHL_LOCK_ASSERT(p, x)	mtx_assert(&(p)->el_lock, x)
67 
68 /*
69  * Macro to invoke the handlers for a given event.
70  */
71 #define _EVENTHANDLER_INVOKE(name, list, ...) do {			\
72 	struct eventhandler_entry *_ep;					\
73 	struct eventhandler_entry_ ## name *_t;				\
74 									\
75 	KASSERT((list)->el_flags & EHL_INITTED,				\
76  	   ("eventhandler_invoke: running non-inited list"));		\
77 	EHL_LOCK_ASSERT((list), MA_OWNED);				\
78 	(list)->el_runcount++;						\
79 	KASSERT((list)->el_runcount > 0,				\
80 	    ("eventhandler_invoke: runcount overflow"));		\
81 	CTR0(KTR_EVH, "eventhandler_invoke(\"" __STRING(name) "\")");	\
82 	TAILQ_FOREACH(_ep, &((list)->el_entries), ee_link) {		\
83 		if (_ep->ee_priority != EHE_DEAD_PRIORITY) {		\
84 			EHL_UNLOCK((list));				\
85 			_t = (struct eventhandler_entry_ ## name *)_ep;	\
86 			CTR1(KTR_EVH, "eventhandler_invoke: executing %p", \
87  			    (void *)_t->eh_func);			\
88 			_t->eh_func(_ep->ee_arg , ## __VA_ARGS__);	\
89 			EHL_LOCK((list));				\
90 		}							\
91 	}								\
92 	KASSERT((list)->el_runcount > 0,				\
93 	    ("eventhandler_invoke: runcount underflow"));		\
94 	(list)->el_runcount--;						\
95 	if ((list)->el_runcount == 0)					\
96 		eventhandler_prune_list(list);				\
97 	EHL_UNLOCK((list));						\
98 } while (0)
99 
100 /*
101  * Slow handlers are entirely dynamic; lists are created
102  * when entries are added to them, and thus have no concept of "owner",
103  *
104  * Slow handlers need to be declared, but do not need to be defined. The
105  * declaration must be in scope wherever the handler is to be invoked.
106  */
107 #define EVENTHANDLER_DECLARE(name, type)				\
108 struct eventhandler_entry_ ## name 					\
109 {									\
110 	struct eventhandler_entry	ee;				\
111 	type				eh_func;			\
112 };									\
113 struct __hack
114 
115 #define EVENTHANDLER_DEFINE(name, func, arg, priority)			\
116 	static eventhandler_tag name ## _tag;				\
117 	static void name ## _evh_init(void *ctx)			\
118 	{								\
119 		name ## _tag = EVENTHANDLER_REGISTER(name, func, ctx,	\
120 		    priority);						\
121 	}								\
122 	SYSINIT(name ## _evh_init, SI_SUB_CONFIGURE, SI_ORDER_ANY,	\
123 	    name ## _evh_init, arg);					\
124 	struct __hack
125 
126 #define EVENTHANDLER_INVOKE(name, ...)					\
127 do {									\
128 	struct eventhandler_list *_el;					\
129 									\
130 	if ((_el = eventhandler_find_list(#name)) != NULL) 		\
131 		_EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__);	\
132 } while (0)
133 
134 #define EVENTHANDLER_REGISTER(name, func, arg, priority)		\
135 	eventhandler_register(NULL, #name, func, arg, priority)
136 
137 #define EVENTHANDLER_DEREGISTER(name, tag) 				\
138 do {									\
139 	struct eventhandler_list *_el;					\
140 									\
141 	if ((_el = eventhandler_find_list(#name)) != NULL)		\
142 		eventhandler_deregister(_el, tag);			\
143 } while(0)
144 
145 
146 eventhandler_tag eventhandler_register(struct eventhandler_list *list,
147 	    const char *name, void *func, void *arg, int priority);
148 void	eventhandler_deregister(struct eventhandler_list *list,
149 	    eventhandler_tag tag);
150 struct eventhandler_list *eventhandler_find_list(const char *name);
151 void	eventhandler_prune_list(struct eventhandler_list *list);
152 
153 #ifdef VIMAGE
154 typedef	void (*vimage_iterator_func_t)(void *, ...);
155 
156 eventhandler_tag vimage_eventhandler_register(struct eventhandler_list *list,
157 	    const char *name, void *func, void *arg, int priority,
158 	    vimage_iterator_func_t);
159 #endif
160 
161 /*
162  * Standard system event queues.
163  */
164 
165 /* Generic priority levels */
166 #define	EVENTHANDLER_PRI_FIRST	0
167 #define	EVENTHANDLER_PRI_ANY	10000
168 #define	EVENTHANDLER_PRI_LAST	20000
169 
170 /* Shutdown events */
171 typedef void (*shutdown_fn)(void *, int);
172 
173 #define	SHUTDOWN_PRI_FIRST	EVENTHANDLER_PRI_FIRST
174 #define	SHUTDOWN_PRI_DEFAULT	EVENTHANDLER_PRI_ANY
175 #define	SHUTDOWN_PRI_LAST	EVENTHANDLER_PRI_LAST
176 
177 EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn);	/* before fs sync */
178 EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn);	/* after fs sync */
179 EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
180 
181 /* Power state change events */
182 typedef void (*power_change_fn)(void *);
183 EVENTHANDLER_DECLARE(power_resume, power_change_fn);
184 EVENTHANDLER_DECLARE(power_suspend, power_change_fn);
185 
186 /* Low memory event */
187 typedef void (*vm_lowmem_handler_t)(void *, int);
188 #define	LOWMEM_PRI_DEFAULT	EVENTHANDLER_PRI_FIRST
189 EVENTHANDLER_DECLARE(vm_lowmem, vm_lowmem_handler_t);
190 
191 /* Root mounted event */
192 typedef void (*mountroot_handler_t)(void *);
193 EVENTHANDLER_DECLARE(mountroot, mountroot_handler_t);
194 
195 /* File system mount events */
196 struct mount;
197 struct vnode;
198 struct thread;
199 typedef void (*vfs_mounted_notify_fn)(void *, struct mount *, struct vnode *,
200     struct thread *);
201 typedef void (*vfs_unmounted_notify_fn)(void *, struct mount *,
202     struct thread *);
203 EVENTHANDLER_DECLARE(vfs_mounted, vfs_mounted_notify_fn);
204 EVENTHANDLER_DECLARE(vfs_unmounted, vfs_unmounted_notify_fn);
205 
206 /*
207  * Process events
208  * process_fork and exit handlers are called without Giant.
209  * exec handlers are called with Giant, but that is by accident.
210  */
211 struct proc;
212 struct image_params;
213 
214 typedef void (*exitlist_fn)(void *, struct proc *);
215 typedef void (*forklist_fn)(void *, struct proc *, struct proc *, int);
216 typedef void (*execlist_fn)(void *, struct proc *, struct image_params *);
217 typedef void (*proc_ctor_fn)(void *, struct proc *);
218 typedef void (*proc_dtor_fn)(void *, struct proc *);
219 typedef void (*proc_init_fn)(void *, struct proc *);
220 typedef void (*proc_fini_fn)(void *, struct proc *);
221 EVENTHANDLER_DECLARE(process_ctor, proc_ctor_fn);
222 EVENTHANDLER_DECLARE(process_dtor, proc_dtor_fn);
223 EVENTHANDLER_DECLARE(process_init, proc_init_fn);
224 EVENTHANDLER_DECLARE(process_fini, proc_fini_fn);
225 EVENTHANDLER_DECLARE(process_exit, exitlist_fn);
226 EVENTHANDLER_DECLARE(process_fork, forklist_fn);
227 EVENTHANDLER_DECLARE(process_exec, execlist_fn);
228 
229 /*
230  * application dump event
231  */
232 typedef void (*app_coredump_start_fn)(void *, struct thread *, char *name);
233 typedef void (*app_coredump_progress_fn)(void *, struct thread *td, int byte_count);
234 typedef void (*app_coredump_finish_fn)(void *, struct thread *td);
235 typedef void (*app_coredump_error_fn)(void *, struct thread *td, char *msg, ...);
236 
237 EVENTHANDLER_DECLARE(app_coredump_start, app_coredump_start_fn);
238 EVENTHANDLER_DECLARE(app_coredump_progress, app_coredump_progress_fn);
239 EVENTHANDLER_DECLARE(app_coredump_finish, app_coredump_finish_fn);
240 EVENTHANDLER_DECLARE(app_coredump_error, app_coredump_error_fn);
241 
242 typedef void (*thread_ctor_fn)(void *, struct thread *);
243 typedef void (*thread_dtor_fn)(void *, struct thread *);
244 typedef void (*thread_fini_fn)(void *, struct thread *);
245 typedef void (*thread_init_fn)(void *, struct thread *);
246 EVENTHANDLER_DECLARE(thread_ctor, thread_ctor_fn);
247 EVENTHANDLER_DECLARE(thread_dtor, thread_dtor_fn);
248 EVENTHANDLER_DECLARE(thread_init, thread_init_fn);
249 EVENTHANDLER_DECLARE(thread_fini, thread_fini_fn);
250 
251 typedef void (*uma_zone_chfn)(void *);
252 EVENTHANDLER_DECLARE(nmbclusters_change, uma_zone_chfn);
253 EVENTHANDLER_DECLARE(nmbufs_change, uma_zone_chfn);
254 EVENTHANDLER_DECLARE(maxsockets_change, uma_zone_chfn);
255 
256 /* Kernel linker file load and unload events */
257 struct linker_file;
258 typedef void (*kld_load_fn)(void *, struct linker_file *);
259 typedef void (*kld_unload_fn)(void *, const char *, caddr_t, size_t);
260 typedef void (*kld_unload_try_fn)(void *, struct linker_file *, int *);
261 EVENTHANDLER_DECLARE(kld_load, kld_load_fn);
262 EVENTHANDLER_DECLARE(kld_unload, kld_unload_fn);
263 EVENTHANDLER_DECLARE(kld_unload_try, kld_unload_try_fn);
264 
265 /* Generic graphics framebuffer interface */
266 struct fb_info;
267 typedef void (*register_framebuffer_fn)(void *, struct fb_info *);
268 typedef void (*unregister_framebuffer_fn)(void *, struct fb_info *);
269 EVENTHANDLER_DECLARE(register_framebuffer, register_framebuffer_fn);
270 EVENTHANDLER_DECLARE(unregister_framebuffer, unregister_framebuffer_fn);
271 
272 #endif /* _SYS_EVENTHANDLER_H_ */
273