xref: /NextBSD/sys/sys/event.h (revision c21ffb8d6aca32c9584cfa072f309a5890a21aea)
1 /*-
2  * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@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_EVENT_H_
30 #define _SYS_EVENT_H_
31 
32 #include <sys/queue.h>
33 
34 #define EVFILT_READ		(-1)
35 #define EVFILT_WRITE	(-2)
36 #define EVFILT_AIO		(-3)	/* attached to aio requests */
37 #define EVFILT_VNODE	(-4)	/* attached to vnodes */
38 #define EVFILT_PROC		(-5)	/* attached to struct proc */
39 #define EVFILT_SIGNAL	(-6)	/* attached to struct proc */
40 #define EVFILT_TIMER	(-7)	/* timers */
41 #define EVFILT_PROCDESC	(-8)	/* attached to process descriptors */
42 #define EVFILT_FS		(-9)	/* filesystem events */
43 #define EVFILT_LIO		(-10)	/* attached to lio requests */
44 #define EVFILT_USER		(-11)	/* User events */
45 #define EVFILT_SENDFILE	(-12)	/* attached to sendfile requests */
46 #define	EVFILT_MACHPORT	(-13)	/* Mach portsets */
47 #define EVFILT_VM		(-14)	/* Virtual Memory events */
48 #define EVFILT_SYSCOUNT	14
49 
50 #define EV_SET(kevp_, a, b, c, d, e, f) do {	\
51 	struct kevent *kevp = (kevp_);		\
52 	(kevp)->ident = (a);			\
53 	(kevp)->filter = (b);			\
54 	(kevp)->flags = (c);			\
55 	(kevp)->fflags = (d);			\
56 	(kevp)->data = (e);			\
57 	(kevp)->udata = (f);			\
58 } while(0)
59 
60 #define EV_SET64(kevp, a, b, c, d, e, f, g, h) do {	\
61 	struct kevent64_s *__kevp__ = (kevp);		\
62 	__kevp__->ident = (a);				\
63 	__kevp__->filter = (b);				\
64 	__kevp__->flags = (c);				\
65 	__kevp__->fflags = (d);				\
66 	__kevp__->data = (e);				\
67 	__kevp__->udata = (f);				\
68 	__kevp__->ext[0] = (g);				\
69 	__kevp__->ext[1] = (h);				\
70 } while(0)
71 
72 struct kevent {
73 	uintptr_t	ident;		/* identifier for this event */
74 	short		filter;		/* filter for event */
75 	u_short		flags;
76 	u_int		fflags;
77 	intptr_t	data;
78 	void		*udata;		/* opaque user data identifier */
79 };
80 
81 struct kevent64_s {
82 	uint64_t	ident;		/* identifier for this event */
83 	int16_t		filter;		/* filter for event */
84 	uint16_t	flags;		/* general flags */
85 	uint32_t	fflags;		/* filter-specific flags */
86 	int64_t		data;		/* filter-specific data */
87 	uint64_t	udata;		/* opaque user data identifier */
88 	uint64_t	ext[2];		/* filter-specific extensions */
89 };
90 
91 /* actions */
92 #define EV_ADD		0x0001		/* add event to kq (implies enable) */
93 #define EV_DELETE	0x0002		/* delete event from kq */
94 #define EV_ENABLE	0x0004		/* enable event */
95 #define EV_DISABLE	0x0008		/* disable event (not reported) */
96 #define EV_FORCEONESHOT	0x0100		/* enable _ONESHOT and force trigger */
97 
98 /* flags */
99 #define EV_ONESHOT	0x0010		/* only report one occurrence */
100 #define EV_CLEAR	0x0020		/* clear event state after reporting */
101 #define EV_RECEIPT	0x0040		/* force EV_ERROR on success, data=0 */
102 #define EV_DISPATCH	0x0080		/* disable event after reporting */
103 
104 #define EV_SYSFLAGS	0xF000		/* reserved by system */
105 #define	EV_DROP		0x1000		/* note should be dropped */
106 #define EV_FLAG1	0x2000		/* filter-specific flag */
107 
108 /* returned values */
109 #define EV_EOF		0x8000		/* EOF detected */
110 #define EV_ERROR	0x4000		/* error, data contains errno */
111 
112  /*
113   * data/hint flags/masks for EVFILT_USER, shared with userspace
114   *
115   * On input, the top two bits of fflags specifies how the lower twenty four
116   * bits should be applied to the stored value of fflags.
117   *
118   * On output, the top two bits will always be set to NOTE_FFNOP and the
119   * remaining twenty four bits will contain the stored fflags value.
120   */
121 #define NOTE_FFNOP	0x00000000		/* ignore input fflags */
122 #define NOTE_FFAND	0x40000000		/* AND fflags */
123 #define NOTE_FFOR	0x80000000		/* OR fflags */
124 #define NOTE_FFCOPY	0xc0000000		/* copy fflags */
125 #define NOTE_FFCTRLMASK	0xc0000000		/* masks for operations */
126 #define NOTE_FFLAGSMASK	0x00ffffff
127 
128 #define NOTE_TRIGGER	0x01000000		/* Cause the event to be
129 						   triggered for output. */
130 
131 /*
132  * data/hint flags for EVFILT_{READ|WRITE}, shared with userspace
133  */
134 #define NOTE_LOWAT	0x0001			/* low water mark */
135 #define NOTE_FILE_POLL	0x0002			/* behave like poll() */
136 
137 /*
138  * data/hint flags for EVFILT_VNODE, shared with userspace
139  */
140 #define	NOTE_DELETE	0x0001			/* vnode was removed */
141 #define	NOTE_WRITE	0x0002			/* data contents changed */
142 #define	NOTE_EXTEND	0x0004			/* size increased */
143 #define	NOTE_ATTRIB	0x0008			/* attributes changed */
144 #define	NOTE_LINK	0x0010			/* link count changed */
145 #define	NOTE_RENAME	0x0020			/* vnode was renamed */
146 #define	NOTE_REVOKE	0x0040			/* vnode access was revoked */
147 
148 /*
149  * data/hint flags for EVFILT_PROC and EVFILT_PROCDESC, shared with userspace
150  */
151 #define	NOTE_EXIT	0x80000000		/* process exited */
152 #define	NOTE_FORK	0x40000000		/* process forked */
153 #define	NOTE_EXEC	0x20000000		/* process exec'd */
154 #define	NOTE_PCTRLMASK	0xf0000000		/* mask for hint bits */
155 #define	NOTE_PDATAMASK	0x000fffff		/* mask for pid */
156 
157 /* additional flags for EVFILT_PROC */
158 #define	NOTE_TRACK	0x00000001		/* follow across forks */
159 #define	NOTE_TRACKERR	0x00000002		/* could not track child */
160 #define	NOTE_CHILD	0x00000004		/* am a child process */
161 
162 
163 /*
164  * data/hint fflags for EVFILT_VM, shared with userspace.
165  */
166 #define NOTE_VM_PRESSURE			0x80000000              /* will react on memory pressure */
167 #define NOTE_VM_PRESSURE_TERMINATE		0x40000000              /* will quit on memory pressure, possibly after cleaning up dirty state */
168 #define NOTE_VM_PRESSURE_SUDDEN_TERMINATE	0x20000000		/* will quit immediately on memory pressure */
169 #define NOTE_VM_ERROR				0x10000000              /* there was an error */
170 
171 
172 /* additional flags for EVFILT_TIMER */
173 #define NOTE_SECONDS		0x00000001	/* data is seconds	*/
174 #define NOTE_MSECONDS		0x00000002	/* data is milliseconds */
175 #define NOTE_USECONDS		0x00000004	/* data is microseconds */
176 #define NOTE_NSECONDS		0x00000008	/* data is nanoseconds  */
177 #define NOTE_ABSOLUTE		0x00000010	/* absolute timeout     */
178 
179 
180 
181 #define	NOTE_EXITSTATUS		0x04000000	/* exit status to be returned, valid for child process only */
182 #define	NOTE_EXIT_DETAIL	0x02000000	/* provide details on reasons for exit */
183 
184 /*
185  * If NOTE_EXIT_DETAIL is present, these bits indicate specific reasons for exiting.
186  */
187 #define NOTE_EXIT_DETAIL_MASK		0x00070000
188 #define	NOTE_EXIT_DECRYPTFAIL		0x00010000
189 #define	NOTE_EXIT_MEMORY		0x00020000
190 #define NOTE_EXIT_CSERROR		0x00040000
191 
192 /*
193  * Flag indicating hint is a signal.  Used by EVFILT_SIGNAL, and also
194  * shared by EVFILT_PROC  (all knotes attached to p->p_klist)
195  */
196 #define NOTE_SIGNAL	0x08000000
197 
198 
199 struct knote;
200 SLIST_HEAD(klist, knote);
201 struct kqueue;
202 TAILQ_HEAD(kqlist, kqueue);
203 struct knlist {
204 	struct	klist	kl_list;
205 	void    (*kl_lock)(void *, char *, int);	/* lock function */
206 	void    (*kl_unlock)(void *);
207 	void	(*kl_assert_locked)(void *);
208 	void	(*kl_assert_unlocked)(void *);
209 	void *kl_lockarg;		/* argument passed to kl_lockf() */
210 };
211 
212 
213 #ifdef _KERNEL
214 /*
215  * Flags for knote call
216  */
217 #define	KNF_LISTLOCKED	0x0001			/* knlist is locked */
218 #define	KNF_NOKQLOCK	0x0002			/* do not keep KQ_LOCK */
219 
220 #define KNOTE(list, hint, flags)	knote(list, hint, flags)
221 #define KNOTE_LOCKED(list, hint)	knote(list, hint, KNF_LISTLOCKED)
222 #define KNOTE_UNLOCKED(list, hint)	knote(list, hint, 0)
223 
224 #define	KNLIST_EMPTY(list)		SLIST_EMPTY(&(list)->kl_list)
225 
226 
227 /*
228  * Hint values for the optional f_touch event filter.  If f_touch is not set
229  * to NULL and f_isfd is zero the f_touch filter will be called with the type
230  * argument set to EVENT_REGISTER during a kevent() system call.  It is also
231  * called under the same conditions with the type argument set to EVENT_PROCESS
232  * when the event has been triggered.
233  */
234 #define EVENT_REGISTER	1
235 #define EVENT_PROCESS	2
236 
237 struct filterops {
238 	int	f_isfd;		/* true if ident == filedescriptor */
239 	int	(*f_attach)(struct knote *kn);
240 	void	(*f_detach)(struct knote *kn);
241 	int	(*f_event)(struct knote *kn, long hint);
242 	void	(*f_touch)(struct knote *kn, struct kevent64_s *kev, u_long type);
243 };
244 
245 /*
246  * Setting the KN_INFLUX flag enables you to unlock the kq that this knote
247  * is on, and modify kn_status as if you had the KQ lock.
248  *
249  * kn_sfflags, kn_sdata, and kn_kevent are protected by the knlist lock.
250  */
251 struct knote {
252 	SLIST_ENTRY(knote)	kn_link;	/* for kq */
253 	SLIST_ENTRY(knote)	kn_selnext;	/* for struct selinfo */
254 	struct			knlist *kn_knlist;	/* f_attach populated */
255 	TAILQ_ENTRY(knote)	kn_tqe;
256 	struct			kqueue *kn_kq;	/* which queue we are on */
257 	struct 			kevent64_s kn_kevent;
258 	int			kn_status;	/* protected by kq lock */
259 #define KN_ACTIVE	0x01			/* event has been triggered */
260 #define KN_QUEUED	0x02			/* event is on queue */
261 #define KN_DISABLED	0x04			/* event is disabled */
262 #define KN_DETACHED	0x08			/* knote is detached */
263 #define KN_INFLUX	0x10			/* knote is in flux */
264 #define KN_MARKER	0x20			/* ignore this knote */
265 #define KN_KQUEUE	0x40			/* this knote belongs to a kq */
266 #define KN_HASKQLOCK	0x80			/* for _inevent */
267 #define	KN_SCAN		0x100			/* flux set in kqueue_scan() */
268 	int			kn_sfflags;	/* saved filter flags */
269 	intptr_t		kn_sdata;	/* saved data field */
270 	union {
271 		struct		file *p_fp;	/* file data pointer */
272 		struct		proc *p_proc;	/* proc pointer */
273 		struct		aiocblist *p_aio;	/* AIO job pointer */
274 		struct		aioliojob *p_lio;	/* LIO job pointer */
275 		sbintime_t	*p_nexttime;	/* next timer event fires at */
276 		void		*p_v;		/* generic other pointer */
277 	} kn_ptr;
278 	struct			filterops *kn_fop;
279 	void			*kn_hook;
280 	int			kn_hookid;
281 
282 #define kn_id		kn_kevent.ident
283 #define kn_filter	kn_kevent.filter
284 #define kn_flags	kn_kevent.flags
285 #define kn_fflags	kn_kevent.fflags
286 #define kn_data		kn_kevent.data
287 #define	kn_udata	kn_kevent.udata
288 #define	kn_ext		kn_kevent.ext
289 #define kn_fp		kn_ptr.p_fp
290 };
291 struct kevent_copyops {
292 	void	*arg;
293 	int	(*k_copyout)(void *arg, void *kevp, int count);
294 	int	(*k_copyin)(void *arg, void *kevp, int count);
295 };
296 
297 struct thread;
298 struct proc;
299 struct knlist;
300 struct mtx;
301 struct rwlock;
302 
303 extern void	knote(struct knlist *list, long hint, int lockflags);
304 extern void	knote_fork(struct knlist *list, int pid);
305 extern void knote_enqueue(struct knote *kn);
306 extern void	knlist_add(struct knlist *knl, struct knote *kn, int islocked);
307 extern void	knlist_remove(struct knlist *knl, struct knote *kn, int islocked);
308 extern void	knlist_remove_inevent(struct knlist *knl, struct knote *kn);
309 extern int	knlist_empty(struct knlist *knl);
310 extern void	knlist_init(struct knlist *knl, void *lock,
311 	void (*kl_lock)(void *, char *, int), void (*kl_unlock)(void *),
312     void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *));
313 extern void	knlist_init_mtx(struct knlist *knl, struct mtx *lock);
314 extern void	knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock);
315 extern void	knlist_destroy(struct knlist *knl);
316 extern void	knlist_cleardel(struct knlist *knl, struct thread *td,
317 	int islocked, int killkn);
318 #define knlist_clear(knl, islocked)				\
319 		knlist_cleardel((knl), NULL, (islocked), 0)
320 #define knlist_delete(knl, td, islocked)			\
321 		knlist_cleardel((knl), (td), (islocked), 1)
322 extern void	knote_fdclose(struct thread *p, int fd);
323 extern int 	kqfd_register(int fd, struct kevent64_s *kev, struct thread *p,
324 		    int waitok);
325 extern int	kqueue_add_filteropts(int filt, struct filterops *filtops);
326 extern int	kqueue_del_filteropts(int filt);
327 
328 #else 	/* !_KERNEL */
329 
330 #include <sys/cdefs.h>
331 struct timespec;
332 
333 __BEGIN_DECLS
334 int     kqueue(void);
335 int     kevent(int kq, const struct kevent *changelist, int nchanges,
336 	    struct kevent *eventlist, int nevents,
337 	    const struct timespec *timeout);
338 int     kevent64(int kq, const struct kevent64_s *changelist,
339 		    int nchanges, struct kevent64_s *eventlist,
340 		    int nevents, unsigned int flags,
341 		    const struct timespec *timeout);
342 __END_DECLS
343 
344 #endif /* !_KERNEL */
345 
346 #endif /* !_SYS_EVENT_H_ */
347