xref: /freebsd-11-stable/sys/sys/event.h (revision b1f418a6e62276640a02e569d987b5ec6b7766d9)
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_SYSCOUNT		12
47 
48 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
49 #define	EV_SET(kevp_, a, b, c, d, e, f) do {	\
50 	*(kevp_) = (struct kevent){		\
51 	    .ident = (a),			\
52 	    .filter = (b),			\
53 	    .flags = (c),			\
54 	    .fflags = (d),			\
55 	    .data = (e),			\
56 	    .udata = (f),			\
57 	};					\
58 } while(0)
59 #else /* Pre-C99 or not STDC (e.g., C++) */
60 /* The definition of the local variable kevp could possibly conflict
61  * with a user-defined value passed in parameters a-f.
62  */
63 #define EV_SET(kevp_, a, b, c, d, e, f) do {	\
64 	struct kevent *kevp = (kevp_);		\
65 	(kevp)->ident = (a);			\
66 	(kevp)->filter = (b);			\
67 	(kevp)->flags = (c);			\
68 	(kevp)->fflags = (d);			\
69 	(kevp)->data = (e);			\
70 	(kevp)->udata = (f);			\
71 } while(0)
72 #endif
73 
74 struct kevent {
75 	uintptr_t	ident;		/* identifier for this event */
76 	short		filter;		/* filter for event */
77 	u_short		flags;		/* action flags for kqueue */
78 	u_int		fflags;		/* filter flag value */
79 	intptr_t	data;		/* filter data value */
80 	void		*udata;		/* opaque user data identifier */
81 };
82 
83 #if defined(_WANT_KEVENT32) || (defined(_KERNEL) && defined(__LP64__))
84 struct kevent32 {
85 	u_int32_t	ident;		/* identifier for this event */
86 	short		filter;		/* filter for event */
87 	u_short		flags;
88 	u_int		fflags;
89 	int32_t		data;
90 	u_int32_t	udata;		/* opaque user data identifier */
91 };
92 #endif
93 
94 /* actions */
95 #define EV_ADD		0x0001		/* add event to kq (implies enable) */
96 #define EV_DELETE	0x0002		/* delete event from kq */
97 #define EV_ENABLE	0x0004		/* enable event */
98 #define EV_DISABLE	0x0008		/* disable event (not reported) */
99 #define EV_FORCEONESHOT	0x0100		/* enable _ONESHOT and force trigger */
100 
101 /* flags */
102 #define EV_ONESHOT	0x0010		/* only report one occurrence */
103 #define EV_CLEAR	0x0020		/* clear event state after reporting */
104 #define EV_RECEIPT	0x0040		/* force EV_ERROR on success, data=0 */
105 #define EV_DISPATCH	0x0080		/* disable event after reporting */
106 
107 #define EV_SYSFLAGS	0xF000		/* reserved by system */
108 #define	EV_DROP		0x1000		/* note should be dropped */
109 #define EV_FLAG1	0x2000		/* filter-specific flag */
110 #define EV_FLAG2	0x4000		/* filter-specific flag */
111 
112 /* returned values */
113 #define EV_EOF		0x8000		/* EOF detected */
114 #define EV_ERROR	0x4000		/* error, data contains errno */
115 
116  /*
117   * data/hint flags/masks for EVFILT_USER, shared with userspace
118   *
119   * On input, the top two bits of fflags specifies how the lower twenty four
120   * bits should be applied to the stored value of fflags.
121   *
122   * On output, the top two bits will always be set to NOTE_FFNOP and the
123   * remaining twenty four bits will contain the stored fflags value.
124   */
125 #define NOTE_FFNOP	0x00000000		/* ignore input fflags */
126 #define NOTE_FFAND	0x40000000		/* AND fflags */
127 #define NOTE_FFOR	0x80000000		/* OR fflags */
128 #define NOTE_FFCOPY	0xc0000000		/* copy fflags */
129 #define NOTE_FFCTRLMASK	0xc0000000		/* masks for operations */
130 #define NOTE_FFLAGSMASK	0x00ffffff
131 
132 #define NOTE_TRIGGER	0x01000000		/* Cause the event to be
133 						   triggered for output. */
134 
135 /*
136  * data/hint flags for EVFILT_{READ|WRITE}, shared with userspace
137  */
138 #define NOTE_LOWAT	0x0001			/* low water mark */
139 #define NOTE_FILE_POLL	0x0002			/* behave like poll() */
140 
141 /*
142  * data/hint flags for EVFILT_VNODE, shared with userspace
143  */
144 #define	NOTE_DELETE	0x0001			/* vnode was removed */
145 #define	NOTE_WRITE	0x0002			/* data contents changed */
146 #define	NOTE_EXTEND	0x0004			/* size increased */
147 #define	NOTE_ATTRIB	0x0008			/* attributes changed */
148 #define	NOTE_LINK	0x0010			/* link count changed */
149 #define	NOTE_RENAME	0x0020			/* vnode was renamed */
150 #define	NOTE_REVOKE	0x0040			/* vnode access was revoked */
151 #define	NOTE_OPEN	0x0080			/* vnode was opened */
152 #define	NOTE_CLOSE	0x0100			/* file closed, fd did not
153 						   allowed write */
154 #define	NOTE_CLOSE_WRITE 0x0200			/* file closed, fd did allowed
155 						   write */
156 #define	NOTE_READ	0x0400			/* file was read */
157 
158 /*
159  * data/hint flags for EVFILT_PROC and EVFILT_PROCDESC, shared with userspace
160  */
161 #define	NOTE_EXIT	0x80000000		/* process exited */
162 #define	NOTE_FORK	0x40000000		/* process forked */
163 #define	NOTE_EXEC	0x20000000		/* process exec'd */
164 #define	NOTE_PCTRLMASK	0xf0000000		/* mask for hint bits */
165 #define	NOTE_PDATAMASK	0x000fffff		/* mask for pid */
166 
167 /* additional flags for EVFILT_PROC */
168 #define	NOTE_TRACK	0x00000001		/* follow across forks */
169 #define	NOTE_TRACKERR	0x00000002		/* could not track child */
170 #define	NOTE_CHILD	0x00000004		/* am a child process */
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 
178 struct knote;
179 SLIST_HEAD(klist, knote);
180 struct kqueue;
181 TAILQ_HEAD(kqlist, kqueue);
182 struct knlist {
183 	struct	klist	kl_list;
184 	void    (*kl_lock)(void *);	/* lock function */
185 	void    (*kl_unlock)(void *);
186 	void	(*kl_assert_locked)(void *);
187 	void	(*kl_assert_unlocked)(void *);
188 	void	*kl_lockarg;		/* argument passed to lock functions */
189 	int	kl_autodestroy;
190 };
191 
192 
193 #ifdef _KERNEL
194 
195 /*
196  * Flags for knote call
197  */
198 #define	KNF_LISTLOCKED	0x0001			/* knlist is locked */
199 #define	KNF_NOKQLOCK	0x0002			/* do not keep KQ_LOCK */
200 
201 #define KNOTE(list, hint, flags)	knote(list, hint, flags)
202 #define KNOTE_LOCKED(list, hint)	knote(list, hint, KNF_LISTLOCKED)
203 #define KNOTE_UNLOCKED(list, hint)	knote(list, hint, 0)
204 
205 #define	KNLIST_EMPTY(list)		SLIST_EMPTY(&(list)->kl_list)
206 
207 /*
208  * Flag indicating hint is a signal.  Used by EVFILT_SIGNAL, and also
209  * shared by EVFILT_PROC  (all knotes attached to p->p_klist)
210  */
211 #define NOTE_SIGNAL	0x08000000
212 
213 /*
214  * Hint values for the optional f_touch event filter.  If f_touch is not set
215  * to NULL and f_isfd is zero the f_touch filter will be called with the type
216  * argument set to EVENT_REGISTER during a kevent() system call.  It is also
217  * called under the same conditions with the type argument set to EVENT_PROCESS
218  * when the event has been triggered.
219  */
220 #define EVENT_REGISTER	1
221 #define EVENT_PROCESS	2
222 
223 struct filterops {
224 	int	f_isfd;		/* true if ident == filedescriptor */
225 	int	(*f_attach)(struct knote *kn);
226 	void	(*f_detach)(struct knote *kn);
227 	int	(*f_event)(struct knote *kn, long hint);
228 	void	(*f_touch)(struct knote *kn, struct kevent *kev, u_long type);
229 };
230 
231 /*
232  * Setting the KN_INFLUX flag enables you to unlock the kq that this knote
233  * is on, and modify kn_status as if you had the KQ lock.
234  *
235  * kn_sfflags, kn_sdata, and kn_kevent are protected by the knlist lock.
236  */
237 struct knote {
238 	SLIST_ENTRY(knote)	kn_link;	/* for kq */
239 	SLIST_ENTRY(knote)	kn_selnext;	/* for struct selinfo */
240 	struct			knlist *kn_knlist;	/* f_attach populated */
241 	TAILQ_ENTRY(knote)	kn_tqe;
242 	struct			kqueue *kn_kq;	/* which queue we are on */
243 	struct 			kevent kn_kevent;
244 	int			kn_status;	/* protected by kq lock */
245 #define KN_ACTIVE	0x01			/* event has been triggered */
246 #define KN_QUEUED	0x02			/* event is on queue */
247 #define KN_DISABLED	0x04			/* event is disabled */
248 #define KN_DETACHED	0x08			/* knote is detached */
249 #define KN_INFLUX	0x10			/* knote is in flux */
250 #define KN_MARKER	0x20			/* ignore this knote */
251 #define KN_KQUEUE	0x40			/* this knote belongs to a kq */
252 #define KN_HASKQLOCK	0x80			/* for _inevent */
253 #define	KN_SCAN		0x100			/* flux set in kqueue_scan() */
254 	int			kn_sfflags;	/* saved filter flags */
255 	intptr_t		kn_sdata;	/* saved data field */
256 	union {
257 		struct		file *p_fp;	/* file data pointer */
258 		struct		proc *p_proc;	/* proc pointer */
259 		struct		kaiocb *p_aio;	/* AIO job pointer */
260 		struct		aioliojob *p_lio;	/* LIO job pointer */
261 		sbintime_t	*p_nexttime;	/* next timer event fires at */
262 		void		*p_v;		/* generic other pointer */
263 	} kn_ptr;
264 	struct			filterops *kn_fop;
265 	void			*kn_hook;
266 	int			kn_hookid;
267 
268 #define kn_id		kn_kevent.ident
269 #define kn_filter	kn_kevent.filter
270 #define kn_flags	kn_kevent.flags
271 #define kn_fflags	kn_kevent.fflags
272 #define kn_data		kn_kevent.data
273 #define kn_fp		kn_ptr.p_fp
274 };
275 struct kevent_copyops {
276 	void	*arg;
277 	int	(*k_copyout)(void *arg, struct kevent *kevp, int count);
278 	int	(*k_copyin)(void *arg, struct kevent *kevp, int count);
279 };
280 
281 struct thread;
282 struct proc;
283 struct knlist;
284 struct mtx;
285 struct rwlock;
286 
287 void	knote(struct knlist *list, long hint, int lockflags);
288 void	knote_fork(struct knlist *list, int pid);
289 struct knlist *knlist_alloc(struct mtx *lock);
290 void	knlist_detach(struct knlist *knl);
291 void	knlist_add(struct knlist *knl, struct knote *kn, int islocked);
292 void	knlist_remove(struct knlist *knl, struct knote *kn, int islocked);
293 int	knlist_empty(struct knlist *knl);
294 void	knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *),
295 	    void (*kl_unlock)(void *), void (*kl_assert_locked)(void *),
296 	    void (*kl_assert_unlocked)(void *));
297 void	knlist_init_mtx(struct knlist *knl, struct mtx *lock);
298 void	knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock);
299 void	knlist_destroy(struct knlist *knl);
300 void	knlist_cleardel(struct knlist *knl, struct thread *td,
301 	    int islocked, int killkn);
302 #define knlist_clear(knl, islocked)				\
303 	knlist_cleardel((knl), NULL, (islocked), 0)
304 #define knlist_delete(knl, td, islocked)			\
305 	knlist_cleardel((knl), (td), (islocked), 1)
306 void	knote_fdclose(struct thread *p, int fd);
307 int 	kqfd_register(int fd, struct kevent *kev, struct thread *p,
308 	    int waitok);
309 int	kqueue_add_filteropts(int filt, struct filterops *filtops);
310 int	kqueue_del_filteropts(int filt);
311 
312 #else 	/* !_KERNEL */
313 
314 #include <sys/cdefs.h>
315 struct timespec;
316 
317 __BEGIN_DECLS
318 int     kqueue(void);
319 int     kevent(int kq, const struct kevent *changelist, int nchanges,
320 	    struct kevent *eventlist, int nevents,
321 	    const struct timespec *timeout);
322 __END_DECLS
323 
324 #endif /* !_KERNEL */
325 
326 #endif /* !_SYS_EVENT_H_ */
327