xref: /freebsd/contrib/pf/libevent/event.c (revision 0957b409)
1 /*
2  * Copyright (c) 2000-2004 Niels Provos <provos@citi.umich.edu>
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  * 3. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 #ifdef HAVE_CONFIG_H
28 #include "config.h"
29 #endif
30 
31 #ifdef WIN32
32 #define WIN32_LEAN_AND_MEAN
33 #include <windows.h>
34 #undef WIN32_LEAN_AND_MEAN
35 #include "misc.h"
36 #endif
37 #include <sys/types.h>
38 #include <sys/tree.h>
39 #ifdef HAVE_SYS_TIME_H
40 #include <sys/time.h>
41 #else
42 #include <sys/_time.h>
43 #endif
44 #include <sys/queue.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #ifndef WIN32
48 #include <unistd.h>
49 #endif
50 #include <errno.h>
51 #include <signal.h>
52 #include <string.h>
53 #include <assert.h>
54 
55 #include "event.h"
56 #include "event-internal.h"
57 #include "log.h"
58 
59 #ifdef HAVE_EVENT_PORTS
60 extern const struct eventop evportops;
61 #endif
62 #ifdef HAVE_SELECT
63 extern const struct eventop selectops;
64 #endif
65 #ifdef HAVE_POLL
66 extern const struct eventop pollops;
67 #endif
68 #ifdef HAVE_RTSIG
69 extern const struct eventop rtsigops;
70 #endif
71 #ifdef HAVE_EPOLL
72 extern const struct eventop epollops;
73 #endif
74 #ifdef HAVE_WORKING_KQUEUE
75 extern const struct eventop kqops;
76 #endif
77 #ifdef HAVE_DEVPOLL
78 extern const struct eventop devpollops;
79 #endif
80 #ifdef WIN32
81 extern const struct eventop win32ops;
82 #endif
83 
84 /* In order of preference */
85 const struct eventop *eventops[] = {
86 #ifdef HAVE_EVENT_PORTS
87 	&evportops,
88 #endif
89 #ifdef HAVE_WORKING_KQUEUE
90 	&kqops,
91 #endif
92 #ifdef HAVE_EPOLL
93 	&epollops,
94 #endif
95 #ifdef HAVE_DEVPOLL
96 	&devpollops,
97 #endif
98 #ifdef HAVE_RTSIG
99 	&rtsigops,
100 #endif
101 #ifdef HAVE_POLL
102 	&pollops,
103 #endif
104 #ifdef HAVE_SELECT
105 	&selectops,
106 #endif
107 #ifdef WIN32
108 	&win32ops,
109 #endif
110 	NULL
111 };
112 
113 /* Global state */
114 struct event_list signalqueue;
115 
116 struct event_base *current_base = NULL;
117 
118 /* Handle signals - This is a deprecated interface */
119 int (*event_sigcb)(void);		/* Signal callback when gotsig is set */
120 volatile sig_atomic_t event_gotsig;	/* Set in signal handler */
121 
122 /* Prototypes */
123 static void	event_queue_insert(struct event_base *, struct event *, int);
124 static void	event_queue_remove(struct event_base *, struct event *, int);
125 static int	event_haveevents(struct event_base *);
126 
127 static void	event_process_active(struct event_base *);
128 
129 static int	timeout_next(struct event_base *, struct timeval *);
130 static void	timeout_process(struct event_base *);
131 static void	timeout_correct(struct event_base *, struct timeval *);
132 
133 static int
134 compare(struct event *a, struct event *b)
135 {
136 	if (timercmp(&a->ev_timeout, &b->ev_timeout, <))
137 		return (-1);
138 	else if (timercmp(&a->ev_timeout, &b->ev_timeout, >))
139 		return (1);
140 	if (a < b)
141 		return (-1);
142 	else if (a > b)
143 		return (1);
144 	return (0);
145 }
146 
147 static int
148 gettime(struct timeval *tp)
149 {
150 #ifdef HAVE_CLOCK_GETTIME
151 	struct timespec	ts;
152 
153 #ifdef HAVE_CLOCK_MONOTONIC
154 	if (clock_gettime(CLOCK_MONOTONIC, &ts) == -1)
155 #else
156 	if (clock_gettime(CLOCK_REALTIME, &ts) == -1)
157 #endif
158 		return (-1);
159 	tp->tv_sec = ts.tv_sec;
160 	tp->tv_usec = ts.tv_nsec / 1000;
161 #else
162 	gettimeofday(tp, NULL);
163 #endif
164 
165 	return (0);
166 }
167 
168 RB_PROTOTYPE(event_tree, event, ev_timeout_node, compare);
169 
170 RB_GENERATE(event_tree, event, ev_timeout_node, compare);
171 
172 
173 void *
174 event_init(void)
175 {
176 	int i;
177 
178 	if ((current_base = calloc(1, sizeof(struct event_base))) == NULL)
179 		event_err(1, "%s: calloc");
180 
181 	event_sigcb = NULL;
182 	event_gotsig = 0;
183 	gettime(&current_base->event_tv);
184 
185 	RB_INIT(&current_base->timetree);
186 	TAILQ_INIT(&current_base->eventqueue);
187 	TAILQ_INIT(&signalqueue);
188 
189 	current_base->evbase = NULL;
190 	for (i = 0; eventops[i] && !current_base->evbase; i++) {
191 		current_base->evsel = eventops[i];
192 
193 		current_base->evbase = current_base->evsel->init();
194 	}
195 
196 	if (current_base->evbase == NULL)
197 		event_errx(1, "%s: no event mechanism available", __func__);
198 
199 	if (getenv("EVENT_SHOW_METHOD"))
200 		event_msgx("libevent using: %s\n",
201 			   current_base->evsel->name);
202 
203 	/* allocate a single active event queue */
204 	event_base_priority_init(current_base, 1);
205 
206 	return (current_base);
207 }
208 
209 void
210 event_base_free(struct event_base *base)
211 {
212 	int i;
213 
214 	if (base == NULL && current_base)
215 		base = current_base;
216         if (base == current_base)
217 		current_base = NULL;
218 
219 	assert(base);
220 	assert(TAILQ_EMPTY(&base->eventqueue));
221 	for (i=0; i < base->nactivequeues; ++i)
222 		assert(TAILQ_EMPTY(base->activequeues[i]));
223 
224 	assert(RB_EMPTY(&base->timetree));
225 
226 	for (i = 0; i < base->nactivequeues; ++i)
227 		free(base->activequeues[i]);
228 	free(base->activequeues);
229 
230 	if (base->evsel->dealloc != NULL)
231 		base->evsel->dealloc(base->evbase);
232 
233 	free(base);
234 }
235 
236 int
237 event_priority_init(int npriorities)
238 {
239   return event_base_priority_init(current_base, npriorities);
240 }
241 
242 int
243 event_base_priority_init(struct event_base *base, int npriorities)
244 {
245 	int i;
246 
247 	if (base->event_count_active)
248 		return (-1);
249 
250 	if (base->nactivequeues && npriorities != base->nactivequeues) {
251 		for (i = 0; i < base->nactivequeues; ++i) {
252 			free(base->activequeues[i]);
253 		}
254 		free(base->activequeues);
255 	}
256 
257 	/* Allocate our priority queues */
258 	base->nactivequeues = npriorities;
259 	base->activequeues = (struct event_list **)calloc(base->nactivequeues,
260 	    npriorities * sizeof(struct event_list *));
261 	if (base->activequeues == NULL)
262 		event_err(1, "%s: calloc", __func__);
263 
264 	for (i = 0; i < base->nactivequeues; ++i) {
265 		base->activequeues[i] = malloc(sizeof(struct event_list));
266 		if (base->activequeues[i] == NULL)
267 			event_err(1, "%s: malloc", __func__);
268 		TAILQ_INIT(base->activequeues[i]);
269 	}
270 
271 	return (0);
272 }
273 
274 int
275 event_haveevents(struct event_base *base)
276 {
277 	return (base->event_count > 0);
278 }
279 
280 /*
281  * Active events are stored in priority queues.  Lower priorities are always
282  * process before higher priorities.  Low priority events can starve high
283  * priority ones.
284  */
285 
286 static void
287 event_process_active(struct event_base *base)
288 {
289 	struct event *ev;
290 	struct event_list *activeq = NULL;
291 	int i;
292 	short ncalls;
293 
294 	if (!base->event_count_active)
295 		return;
296 
297 	for (i = 0; i < base->nactivequeues; ++i) {
298 		if (TAILQ_FIRST(base->activequeues[i]) != NULL) {
299 			activeq = base->activequeues[i];
300 			break;
301 		}
302 	}
303 
304 	assert(activeq != NULL);
305 
306 	for (ev = TAILQ_FIRST(activeq); ev; ev = TAILQ_FIRST(activeq)) {
307 		event_queue_remove(base, ev, EVLIST_ACTIVE);
308 
309 		/* Allows deletes to work */
310 		ncalls = ev->ev_ncalls;
311 		ev->ev_pncalls = &ncalls;
312 		while (ncalls) {
313 			ncalls--;
314 			ev->ev_ncalls = ncalls;
315 			(*ev->ev_callback)((int)ev->ev_fd, ev->ev_res, ev->ev_arg);
316 			if (event_gotsig)
317 				return;
318 		}
319 	}
320 }
321 
322 /*
323  * Wait continously for events.  We exit only if no events are left.
324  */
325 
326 int
327 event_dispatch(void)
328 {
329 	return (event_loop(0));
330 }
331 
332 int
333 event_base_dispatch(struct event_base *event_base)
334 {
335   return (event_base_loop(event_base, 0));
336 }
337 
338 static void
339 event_loopexit_cb(int fd, short what, void *arg)
340 {
341 	struct event_base *base = arg;
342 	base->event_gotterm = 1;
343 }
344 
345 /* not thread safe */
346 
347 int
348 event_loopexit(struct timeval *tv)
349 {
350 	return (event_once(-1, EV_TIMEOUT, event_loopexit_cb,
351 		    current_base, tv));
352 }
353 
354 int
355 event_base_loopexit(struct event_base *event_base, struct timeval *tv)
356 {
357 	return (event_once(-1, EV_TIMEOUT, event_loopexit_cb,
358 		    event_base, tv));
359 }
360 
361 /* not thread safe */
362 
363 int
364 event_loop(int flags)
365 {
366 	return event_base_loop(current_base, flags);
367 }
368 
369 int
370 event_base_loop(struct event_base *base, int flags)
371 {
372 	const struct eventop *evsel = base->evsel;
373 	void *evbase = base->evbase;
374 	struct timeval tv;
375 	int res, done;
376 
377 	done = 0;
378 	while (!done) {
379 		/* Calculate the initial events that we are waiting for */
380 		if (evsel->recalc(base, evbase, 0) == -1)
381 			return (-1);
382 
383 		/* Terminate the loop if we have been asked to */
384 		if (base->event_gotterm) {
385 			base->event_gotterm = 0;
386 			break;
387 		}
388 
389 		/* You cannot use this interface for multi-threaded apps */
390 		while (event_gotsig) {
391 			event_gotsig = 0;
392 			if (event_sigcb) {
393 				res = (*event_sigcb)();
394 				if (res == -1) {
395 					errno = EINTR;
396 					return (-1);
397 				}
398 			}
399 		}
400 
401 		/* Check if time is running backwards */
402 		gettime(&tv);
403 		if (timercmp(&tv, &base->event_tv, <)) {
404 			struct timeval off;
405 			event_debug(("%s: time is running backwards, corrected",
406 				    __func__));
407 			timersub(&base->event_tv, &tv, &off);
408 			timeout_correct(base, &off);
409 		}
410 		base->event_tv = tv;
411 
412 		if (!base->event_count_active && !(flags & EVLOOP_NONBLOCK))
413 			timeout_next(base, &tv);
414 		else
415 			timerclear(&tv);
416 
417 		/* If we have no events, we just exit */
418 		if (!event_haveevents(base)) {
419 			event_debug(("%s: no events registered.", __func__));
420 			return (1);
421 		}
422 
423 		res = evsel->dispatch(base, evbase, &tv);
424 
425 		if (res == -1)
426 			return (-1);
427 
428 		timeout_process(base);
429 
430 		if (base->event_count_active) {
431 			event_process_active(base);
432 			if (!base->event_count_active && (flags & EVLOOP_ONCE))
433 				done = 1;
434 		} else if (flags & EVLOOP_NONBLOCK)
435 			done = 1;
436 	}
437 
438 	event_debug(("%s: asked to terminate loop.", __func__));
439 	return (0);
440 }
441 
442 /* Sets up an event for processing once */
443 
444 struct event_once {
445 	struct event ev;
446 
447 	void (*cb)(int, short, void *);
448 	void *arg;
449 };
450 
451 /* One-time callback, it deletes itself */
452 
453 static void
454 event_once_cb(int fd, short events, void *arg)
455 {
456 	struct event_once *eonce = arg;
457 
458 	(*eonce->cb)(fd, events, eonce->arg);
459 	free(eonce);
460 }
461 
462 /* Schedules an event once */
463 
464 int
465 event_once(int fd, short events,
466     void (*callback)(int, short, void *), void *arg, struct timeval *tv)
467 {
468 	struct event_once *eonce;
469 	struct timeval etv;
470 	int res;
471 
472 	/* We cannot support signals that just fire once */
473 	if (events & EV_SIGNAL)
474 		return (-1);
475 
476 	if ((eonce = calloc(1, sizeof(struct event_once))) == NULL)
477 		return (-1);
478 
479 	eonce->cb = callback;
480 	eonce->arg = arg;
481 
482 	if (events == EV_TIMEOUT) {
483 		if (tv == NULL) {
484 			timerclear(&etv);
485 			tv = &etv;
486 		}
487 
488 		evtimer_set(&eonce->ev, event_once_cb, eonce);
489 	} else if (events & (EV_READ|EV_WRITE)) {
490 		events &= EV_READ|EV_WRITE;
491 
492 		event_set(&eonce->ev, fd, events, event_once_cb, eonce);
493 	} else {
494 		/* Bad event combination */
495 		free(eonce);
496 		return (-1);
497 	}
498 
499 	res = event_add(&eonce->ev, tv);
500 	if (res != 0) {
501 		free(eonce);
502 		return (res);
503 	}
504 
505 	return (0);
506 }
507 
508 void
509 event_set(struct event *ev, int fd, short events,
510 	  void (*callback)(int, short, void *), void *arg)
511 {
512 	/* Take the current base - caller needs to set the real base later */
513 	ev->ev_base = current_base;
514 
515 	ev->ev_callback = callback;
516 	ev->ev_arg = arg;
517 	ev->ev_fd = fd;
518 	ev->ev_events = events;
519 	ev->ev_flags = EVLIST_INIT;
520 	ev->ev_ncalls = 0;
521 	ev->ev_pncalls = NULL;
522 
523 	/* by default, we put new events into the middle priority */
524 	ev->ev_pri = current_base->nactivequeues/2;
525 }
526 
527 int
528 event_base_set(struct event_base *base, struct event *ev)
529 {
530 	/* Only innocent events may be assigned to a different base */
531 	if (ev->ev_flags != EVLIST_INIT)
532 		return (-1);
533 
534 	ev->ev_base = base;
535 	ev->ev_pri = base->nactivequeues/2;
536 
537 	return (0);
538 }
539 
540 /*
541  * Set's the priority of an event - if an event is already scheduled
542  * changing the priority is going to fail.
543  */
544 
545 int
546 event_priority_set(struct event *ev, int pri)
547 {
548 	if (ev->ev_flags & EVLIST_ACTIVE)
549 		return (-1);
550 	if (pri < 0 || pri >= ev->ev_base->nactivequeues)
551 		return (-1);
552 
553 	ev->ev_pri = pri;
554 
555 	return (0);
556 }
557 
558 /*
559  * Checks if a specific event is pending or scheduled.
560  */
561 
562 int
563 event_pending(struct event *ev, short event, struct timeval *tv)
564 {
565 	struct timeval	now, res;
566 	int flags = 0;
567 
568 	if (ev->ev_flags & EVLIST_INSERTED)
569 		flags |= (ev->ev_events & (EV_READ|EV_WRITE));
570 	if (ev->ev_flags & EVLIST_ACTIVE)
571 		flags |= ev->ev_res;
572 	if (ev->ev_flags & EVLIST_TIMEOUT)
573 		flags |= EV_TIMEOUT;
574 	if (ev->ev_flags & EVLIST_SIGNAL)
575 		flags |= EV_SIGNAL;
576 
577 	event &= (EV_TIMEOUT|EV_READ|EV_WRITE|EV_SIGNAL);
578 
579 	/* See if there is a timeout that we should report */
580 	if (tv != NULL && (flags & event & EV_TIMEOUT)) {
581 		gettime(&now);
582 		timersub(&ev->ev_timeout, &now, &res);
583 		/* correctly remap to real time */
584 		gettimeofday(&now, NULL);
585 		timeradd(&now, &res, tv);
586 	}
587 
588 	return (flags & event);
589 }
590 
591 int
592 event_add(struct event *ev, struct timeval *tv)
593 {
594 	struct event_base *base = ev->ev_base;
595 	const struct eventop *evsel = base->evsel;
596 	void *evbase = base->evbase;
597 
598 	event_debug((
599 		 "event_add: event: %p, %s%s%scall %p",
600 		 ev,
601 		 ev->ev_events & EV_READ ? "EV_READ " : " ",
602 		 ev->ev_events & EV_WRITE ? "EV_WRITE " : " ",
603 		 tv ? "EV_TIMEOUT " : " ",
604 		 ev->ev_callback));
605 
606 	assert(!(ev->ev_flags & ~EVLIST_ALL));
607 
608 	if (tv != NULL) {
609 		struct timeval now;
610 
611 		if (ev->ev_flags & EVLIST_TIMEOUT)
612 			event_queue_remove(base, ev, EVLIST_TIMEOUT);
613 
614 		/* Check if it is active due to a timeout.  Rescheduling
615 		 * this timeout before the callback can be executed
616 		 * removes it from the active list. */
617 		if ((ev->ev_flags & EVLIST_ACTIVE) &&
618 		    (ev->ev_res & EV_TIMEOUT)) {
619 			/* See if we are just active executing this
620 			 * event in a loop
621 			 */
622 			if (ev->ev_ncalls && ev->ev_pncalls) {
623 				/* Abort loop */
624 				*ev->ev_pncalls = 0;
625 			}
626 
627 			event_queue_remove(base, ev, EVLIST_ACTIVE);
628 		}
629 
630 		gettime(&now);
631 		timeradd(&now, tv, &ev->ev_timeout);
632 
633 		event_debug((
634 			 "event_add: timeout in %d seconds, call %p",
635 			 tv->tv_sec, ev->ev_callback));
636 
637 		event_queue_insert(base, ev, EVLIST_TIMEOUT);
638 	}
639 
640 	if ((ev->ev_events & (EV_READ|EV_WRITE)) &&
641 	    !(ev->ev_flags & (EVLIST_INSERTED|EVLIST_ACTIVE))) {
642 		event_queue_insert(base, ev, EVLIST_INSERTED);
643 
644 		return (evsel->add(evbase, ev));
645 	} else if ((ev->ev_events & EV_SIGNAL) &&
646 	    !(ev->ev_flags & EVLIST_SIGNAL)) {
647 		event_queue_insert(base, ev, EVLIST_SIGNAL);
648 
649 		return (evsel->add(evbase, ev));
650 	}
651 
652 	return (0);
653 }
654 
655 int
656 event_del(struct event *ev)
657 {
658 	struct event_base *base;
659 	const struct eventop *evsel;
660 	void *evbase;
661 
662 	event_debug(("event_del: %p, callback %p",
663 		 ev, ev->ev_callback));
664 
665 	/* An event without a base has not been added */
666 	if (ev->ev_base == NULL)
667 		return (-1);
668 
669 	base = ev->ev_base;
670 	evsel = base->evsel;
671 	evbase = base->evbase;
672 
673 	assert(!(ev->ev_flags & ~EVLIST_ALL));
674 
675 	/* See if we are just active executing this event in a loop */
676 	if (ev->ev_ncalls && ev->ev_pncalls) {
677 		/* Abort loop */
678 		*ev->ev_pncalls = 0;
679 	}
680 
681 	if (ev->ev_flags & EVLIST_TIMEOUT)
682 		event_queue_remove(base, ev, EVLIST_TIMEOUT);
683 
684 	if (ev->ev_flags & EVLIST_ACTIVE)
685 		event_queue_remove(base, ev, EVLIST_ACTIVE);
686 
687 	if (ev->ev_flags & EVLIST_INSERTED) {
688 		event_queue_remove(base, ev, EVLIST_INSERTED);
689 		return (evsel->del(evbase, ev));
690 	} else if (ev->ev_flags & EVLIST_SIGNAL) {
691 		event_queue_remove(base, ev, EVLIST_SIGNAL);
692 		return (evsel->del(evbase, ev));
693 	}
694 
695 	return (0);
696 }
697 
698 void
699 event_active(struct event *ev, int res, short ncalls)
700 {
701 	/* We get different kinds of events, add them together */
702 	if (ev->ev_flags & EVLIST_ACTIVE) {
703 		ev->ev_res |= res;
704 		return;
705 	}
706 
707 	ev->ev_res = res;
708 	ev->ev_ncalls = ncalls;
709 	ev->ev_pncalls = NULL;
710 	event_queue_insert(ev->ev_base, ev, EVLIST_ACTIVE);
711 }
712 
713 int
714 timeout_next(struct event_base *base, struct timeval *tv)
715 {
716 	struct timeval dflt = TIMEOUT_DEFAULT;
717 
718 	struct timeval now;
719 	struct event *ev;
720 
721 	if ((ev = RB_MIN(event_tree, &base->timetree)) == NULL) {
722 		*tv = dflt;
723 		return (0);
724 	}
725 
726 	if (gettime(&now) == -1)
727 		return (-1);
728 
729 	if (timercmp(&ev->ev_timeout, &now, <=)) {
730 		timerclear(tv);
731 		return (0);
732 	}
733 
734 	timersub(&ev->ev_timeout, &now, tv);
735 
736 	assert(tv->tv_sec >= 0);
737 	assert(tv->tv_usec >= 0);
738 
739 	event_debug(("timeout_next: in %d seconds", tv->tv_sec));
740 	return (0);
741 }
742 
743 static void
744 timeout_correct(struct event_base *base, struct timeval *off)
745 {
746 	struct event *ev;
747 
748 	/*
749 	 * We can modify the key element of the node without destroying
750 	 * the key, beause we apply it to all in the right order.
751 	 */
752 	RB_FOREACH(ev, event_tree, &base->timetree)
753 		timersub(&ev->ev_timeout, off, &ev->ev_timeout);
754 }
755 
756 void
757 timeout_process(struct event_base *base)
758 {
759 	struct timeval now;
760 	struct event *ev, *next;
761 
762 	gettime(&now);
763 
764 	for (ev = RB_MIN(event_tree, &base->timetree); ev; ev = next) {
765 		if (timercmp(&ev->ev_timeout, &now, >))
766 			break;
767 		next = RB_NEXT(event_tree, &base->timetree, ev);
768 
769 		event_queue_remove(base, ev, EVLIST_TIMEOUT);
770 
771 		/* delete this event from the I/O queues */
772 		event_del(ev);
773 
774 		event_debug(("timeout_process: call %p",
775 			 ev->ev_callback));
776 		event_active(ev, EV_TIMEOUT, 1);
777 	}
778 }
779 
780 void
781 event_queue_remove(struct event_base *base, struct event *ev, int queue)
782 {
783 	int docount = 1;
784 
785 	if (!(ev->ev_flags & queue))
786 		event_errx(1, "%s: %p(fd %d) not on queue %x", __func__,
787 			   ev, ev->ev_fd, queue);
788 
789 	if (ev->ev_flags & EVLIST_INTERNAL)
790 		docount = 0;
791 
792 	if (docount)
793 		base->event_count--;
794 
795 	ev->ev_flags &= ~queue;
796 	switch (queue) {
797 	case EVLIST_ACTIVE:
798 		if (docount)
799 			base->event_count_active--;
800 		TAILQ_REMOVE(base->activequeues[ev->ev_pri],
801 		    ev, ev_active_next);
802 		break;
803 	case EVLIST_SIGNAL:
804 		TAILQ_REMOVE(&signalqueue, ev, ev_signal_next);
805 		break;
806 	case EVLIST_TIMEOUT:
807 		RB_REMOVE(event_tree, &base->timetree, ev);
808 		break;
809 	case EVLIST_INSERTED:
810 		TAILQ_REMOVE(&base->eventqueue, ev, ev_next);
811 		break;
812 	default:
813 		event_errx(1, "%s: unknown queue %x", __func__, queue);
814 	}
815 }
816 
817 void
818 event_queue_insert(struct event_base *base, struct event *ev, int queue)
819 {
820 	int docount = 1;
821 
822 	if (ev->ev_flags & queue) {
823 		/* Double insertion is possible for active events */
824 		if (queue & EVLIST_ACTIVE)
825 			return;
826 
827 		event_errx(1, "%s: %p(fd %d) already on queue %x", __func__,
828 			   ev, ev->ev_fd, queue);
829 	}
830 
831 	if (ev->ev_flags & EVLIST_INTERNAL)
832 		docount = 0;
833 
834 	if (docount)
835 		base->event_count++;
836 
837 	ev->ev_flags |= queue;
838 	switch (queue) {
839 	case EVLIST_ACTIVE:
840 		if (docount)
841 			base->event_count_active++;
842 		TAILQ_INSERT_TAIL(base->activequeues[ev->ev_pri],
843 		    ev,ev_active_next);
844 		break;
845 	case EVLIST_SIGNAL:
846 		TAILQ_INSERT_TAIL(&signalqueue, ev, ev_signal_next);
847 		break;
848 	case EVLIST_TIMEOUT: {
849 		struct event *tmp = RB_INSERT(event_tree, &base->timetree, ev);
850 		assert(tmp == NULL);
851 		break;
852 	}
853 	case EVLIST_INSERTED:
854 		TAILQ_INSERT_TAIL(&base->eventqueue, ev, ev_next);
855 		break;
856 	default:
857 		event_errx(1, "%s: unknown queue %x", __func__, queue);
858 	}
859 }
860 
861 /* Functions for debugging */
862 
863 const char *
864 event_get_version(void)
865 {
866 	return (VERSION);
867 }
868 
869 /*
870  * No thread-safe interface needed - the information should be the same
871  * for all threads.
872  */
873 
874 const char *
875 event_get_method(void)
876 {
877 	return (current_base->evsel->name);
878 }
879