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/cvs/libev/ev.c
Revision: 1.10
Committed: Wed Oct 31 07:36:03 2007 UTC (16 years, 6 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.9: +48 -34 lines
Log Message:
introduce MUCH needed internal typedefs, better autoconfiguration

File Contents

# User Rev Content
1 root 1.1 #include <math.h>
2     #include <stdlib.h>
3 root 1.7 #include <unistd.h>
4     #include <fcntl.h>
5     #include <signal.h>
6 root 1.1
7     #include <stdio.h>
8    
9 root 1.4 #include <assert.h>
10 root 1.1 #include <errno.h>
11     #include <sys/time.h>
12     #include <time.h>
13    
14 root 1.10 #ifndef HAVE_MONOTONIC
15     # ifdef CLOCK_MONOTONIC
16     # define HAVE_MONOTONIC 1
17     # endif
18 root 1.1 #endif
19    
20 root 1.10 #ifndef HAVE_SELECT
21     # define HAVE_SELECT 1
22     #endif
23    
24     #ifndef HAVE_EPOLL
25     # define HAVE_EPOLL 0
26     #endif
27    
28     #ifndef HAVE_REALTIME
29     # define HAVE_REALTIME 1 /* posix requirement, but might be slower */
30     #endif
31 root 1.1
32 root 1.4 #define MIN_TIMEJUMP 1. /* minimum timejump that gets detected (if monotonic clock available) */
33 root 1.1 #define MAX_BLOCKTIME 60.
34    
35     #include "ev.h"
36    
37     struct ev_watcher {
38     EV_WATCHER (ev_watcher);
39     };
40    
41     struct ev_watcher_list {
42     EV_WATCHER_LIST (ev_watcher_list);
43     };
44    
45 root 1.10 typedef struct ev_watcher *W;
46     typedef struct ev_watcher_list *WL;
47    
48 root 1.4 static ev_tstamp now, diff; /* monotonic clock */
49 root 1.1 ev_tstamp ev_now;
50     int ev_method;
51    
52     static int have_monotonic; /* runtime */
53    
54     static ev_tstamp method_fudge; /* stupid epoll-returns-early bug */
55 root 1.5 static void (*method_modify)(int fd, int oev, int nev);
56 root 1.1 static void (*method_poll)(ev_tstamp timeout);
57    
58 root 1.8 /*****************************************************************************/
59    
60 root 1.1 ev_tstamp
61     ev_time (void)
62     {
63     #if HAVE_REALTIME
64     struct timespec ts;
65     clock_gettime (CLOCK_REALTIME, &ts);
66     return ts.tv_sec + ts.tv_nsec * 1e-9;
67     #else
68     struct timeval tv;
69     gettimeofday (&tv, 0);
70     return tv.tv_sec + tv.tv_usec * 1e-6;
71     #endif
72     }
73    
74     static ev_tstamp
75     get_clock (void)
76     {
77     #if HAVE_MONOTONIC
78     if (have_monotonic)
79     {
80     struct timespec ts;
81     clock_gettime (CLOCK_MONOTONIC, &ts);
82     return ts.tv_sec + ts.tv_nsec * 1e-9;
83     }
84     #endif
85    
86     return ev_time ();
87     }
88    
89     #define array_needsize(base,cur,cnt,init) \
90     if ((cnt) > cur) \
91     { \
92 root 1.2 int newcnt = cur ? cur << 1 : 16; \
93 root 1.1 fprintf (stderr, "resize(" # base ") from %d to %d\n", cur, newcnt);\
94     base = realloc (base, sizeof (*base) * (newcnt)); \
95     init (base + cur, newcnt - cur); \
96     cur = newcnt; \
97     }
98    
99 root 1.8 /*****************************************************************************/
100    
101 root 1.1 typedef struct
102     {
103     struct ev_io *head;
104     unsigned char wev, rev; /* want, received event set */
105     } ANFD;
106    
107     static ANFD *anfds;
108     static int anfdmax;
109    
110     static int *fdchanges;
111     static int fdchangemax, fdchangecnt;
112    
113     static void
114     anfds_init (ANFD *base, int count)
115     {
116     while (count--)
117     {
118     base->head = 0;
119     base->wev = base->rev = EV_NONE;
120     ++base;
121     }
122     }
123    
124     typedef struct
125     {
126 root 1.10 W w;
127 root 1.1 int events;
128     } ANPENDING;
129    
130     static ANPENDING *pendings;
131     static int pendingmax, pendingcnt;
132    
133     static void
134 root 1.10 event (W w, int events)
135 root 1.1 {
136     w->pending = ++pendingcnt;
137     array_needsize (pendings, pendingmax, pendingcnt, );
138     pendings [pendingcnt - 1].w = w;
139     pendings [pendingcnt - 1].events = events;
140     }
141    
142     static void
143     fd_event (int fd, int events)
144     {
145     ANFD *anfd = anfds + fd;
146     struct ev_io *w;
147    
148     for (w = anfd->head; w; w = w->next)
149     {
150     int ev = w->events & events;
151    
152     if (ev)
153 root 1.10 event ((W)w, ev);
154 root 1.1 }
155     }
156    
157 root 1.9 static void
158 root 1.10 queue_events (W *events, int eventcnt, int type)
159 root 1.9 {
160     int i;
161    
162     for (i = 0; i < eventcnt; ++i)
163     event (events [i], type);
164     }
165    
166 root 1.8 /*****************************************************************************/
167    
168 root 1.4 static struct ev_timer **atimers;
169     static int atimermax, atimercnt;
170    
171     static struct ev_timer **rtimers;
172     static int rtimermax, rtimercnt;
173 root 1.1
174     static void
175 root 1.4 upheap (struct ev_timer **timers, int k)
176 root 1.1 {
177     struct ev_timer *w = timers [k];
178    
179     while (k && timers [k >> 1]->at > w->at)
180     {
181     timers [k] = timers [k >> 1];
182     timers [k]->active = k + 1;
183     k >>= 1;
184     }
185    
186     timers [k] = w;
187     timers [k]->active = k + 1;
188    
189     }
190    
191     static void
192 root 1.4 downheap (struct ev_timer **timers, int N, int k)
193 root 1.1 {
194     struct ev_timer *w = timers [k];
195    
196 root 1.4 while (k < (N >> 1))
197 root 1.1 {
198     int j = k << 1;
199    
200 root 1.4 if (j + 1 < N && timers [j]->at > timers [j + 1]->at)
201 root 1.1 ++j;
202    
203     if (w->at <= timers [j]->at)
204     break;
205    
206     timers [k] = timers [j];
207 root 1.2 timers [k]->active = k + 1;
208 root 1.1 k = j;
209     }
210    
211     timers [k] = w;
212     timers [k]->active = k + 1;
213     }
214    
215 root 1.8 /*****************************************************************************/
216    
217 root 1.7 typedef struct
218     {
219     struct ev_signal *head;
220     sig_atomic_t gotsig;
221     } ANSIG;
222    
223     static ANSIG *signals;
224 root 1.4 static int signalmax;
225 root 1.1
226 root 1.7 static int sigpipe [2];
227     static sig_atomic_t gotsig;
228     static struct ev_io sigev;
229    
230 root 1.1 static void
231 root 1.7 signals_init (ANSIG *base, int count)
232 root 1.1 {
233     while (count--)
234 root 1.7 {
235     base->head = 0;
236     base->gotsig = 0;
237     ++base;
238     }
239     }
240    
241     static void
242     sighandler (int signum)
243     {
244     signals [signum - 1].gotsig = 1;
245    
246     if (!gotsig)
247     {
248     gotsig = 1;
249     write (sigpipe [1], &gotsig, 1);
250     }
251     }
252    
253     static void
254     sigcb (struct ev_io *iow, int revents)
255     {
256     struct ev_signal *w;
257     int sig;
258    
259     gotsig = 0;
260     read (sigpipe [0], &revents, 1);
261    
262     for (sig = signalmax; sig--; )
263     if (signals [sig].gotsig)
264     {
265     signals [sig].gotsig = 0;
266    
267     for (w = signals [sig].head; w; w = w->next)
268 root 1.10 event ((W)w, EV_SIGNAL);
269 root 1.7 }
270     }
271    
272     static void
273     siginit (void)
274     {
275     fcntl (sigpipe [0], F_SETFD, FD_CLOEXEC);
276     fcntl (sigpipe [1], F_SETFD, FD_CLOEXEC);
277    
278     /* rather than sort out wether we really need nb, set it */
279     fcntl (sigpipe [0], F_SETFL, O_NONBLOCK);
280     fcntl (sigpipe [1], F_SETFL, O_NONBLOCK);
281    
282     evio_set (&sigev, sigpipe [0], EV_READ);
283     evio_start (&sigev);
284 root 1.1 }
285    
286 root 1.8 /*****************************************************************************/
287    
288 root 1.9 static struct ev_idle **idles;
289     static int idlemax, idlecnt;
290    
291     static struct ev_check **checks;
292     static int checkmax, checkcnt;
293    
294     /*****************************************************************************/
295    
296 root 1.1 #if HAVE_EPOLL
297     # include "ev_epoll.c"
298     #endif
299     #if HAVE_SELECT
300     # include "ev_select.c"
301     #endif
302    
303     int ev_init (int flags)
304     {
305     #if HAVE_MONOTONIC
306     {
307     struct timespec ts;
308     if (!clock_gettime (CLOCK_MONOTONIC, &ts))
309     have_monotonic = 1;
310     }
311     #endif
312    
313     ev_now = ev_time ();
314 root 1.4 now = get_clock ();
315     diff = ev_now - now;
316 root 1.1
317 root 1.7 if (pipe (sigpipe))
318     return 0;
319    
320     ev_method = EVMETHOD_NONE;
321 root 1.1 #if HAVE_EPOLL
322 root 1.7 if (ev_method == EVMETHOD_NONE) epoll_init (flags);
323 root 1.1 #endif
324     #if HAVE_SELECT
325 root 1.7 if (ev_method == EVMETHOD_NONE) select_init (flags);
326 root 1.1 #endif
327    
328 root 1.7 if (ev_method)
329     {
330     evw_init (&sigev, sigcb, 0);
331     siginit ();
332     }
333    
334 root 1.1 return ev_method;
335     }
336    
337 root 1.8 /*****************************************************************************/
338    
339 root 1.1 void ev_prefork (void)
340     {
341     }
342    
343     void ev_postfork_parent (void)
344     {
345     }
346    
347     void ev_postfork_child (void)
348     {
349     #if HAVE_EPOLL
350 root 1.5 if (ev_method == EVMETHOD_EPOLL)
351     epoll_postfork_child ();
352 root 1.1 #endif
353 root 1.7
354     evio_stop (&sigev);
355     close (sigpipe [0]);
356     close (sigpipe [1]);
357     pipe (sigpipe);
358     siginit ();
359 root 1.1 }
360    
361 root 1.8 /*****************************************************************************/
362    
363 root 1.1 static void
364 root 1.5 fd_reify (void)
365     {
366     int i;
367    
368     for (i = 0; i < fdchangecnt; ++i)
369     {
370     int fd = fdchanges [i];
371     ANFD *anfd = anfds + fd;
372     struct ev_io *w;
373    
374     int wev = 0;
375    
376     for (w = anfd->head; w; w = w->next)
377     wev |= w->events;
378    
379     if (anfd->wev != wev)
380     {
381     method_modify (fd, anfd->wev, wev);
382     anfd->wev = wev;
383     }
384     }
385    
386     fdchangecnt = 0;
387     }
388    
389     static void
390 root 1.1 call_pending ()
391     {
392     int i;
393    
394     for (i = 0; i < pendingcnt; ++i)
395     {
396     ANPENDING *p = pendings + i;
397    
398     if (p->w)
399     {
400     p->w->pending = 0;
401     p->w->cb (p->w, p->events);
402     }
403     }
404    
405     pendingcnt = 0;
406     }
407    
408     static void
409 root 1.4 timers_reify (struct ev_timer **timers, int timercnt, ev_tstamp now)
410 root 1.1 {
411 root 1.4 while (timercnt && timers [0]->at <= now)
412 root 1.1 {
413     struct ev_timer *w = timers [0];
414    
415 root 1.4 /* first reschedule or stop timer */
416 root 1.1 if (w->repeat)
417     {
418     if (w->is_abs)
419 root 1.4 w->at += floor ((now - w->at) / w->repeat + 1.) * w->repeat;
420 root 1.1 else
421 root 1.4 w->at = now + w->repeat;
422    
423     assert (w->at > now);
424 root 1.1
425 root 1.4 downheap (timers, timercnt, 0);
426 root 1.1 }
427     else
428 root 1.4 {
429     evtimer_stop (w); /* nonrepeating: stop timer */
430     --timercnt; /* maybe pass by reference instead? */
431     }
432 root 1.1
433 root 1.10 event ((W)w, EV_TIMEOUT);
434 root 1.1 }
435     }
436    
437 root 1.4 static void
438     time_update ()
439     {
440     int i;
441     ev_now = ev_time ();
442    
443     if (have_monotonic)
444     {
445     ev_tstamp odiff = diff;
446    
447     /* detecting time jumps is much more difficult */
448     for (i = 2; --i; ) /* loop a few times, before making important decisions */
449     {
450     now = get_clock ();
451     diff = ev_now - now;
452    
453     if (fabs (odiff - diff) < MIN_TIMEJUMP)
454     return; /* all is well */
455    
456     ev_now = ev_time ();
457     }
458    
459     /* time jump detected, reschedule atimers */
460     for (i = 0; i < atimercnt; ++i)
461     {
462     struct ev_timer *w = atimers [i];
463     w->at += ceil ((ev_now - w->at) / w->repeat + 1.) * w->repeat;
464     }
465     }
466     else
467     {
468     if (now > ev_now || now < ev_now - MAX_BLOCKTIME - MIN_TIMEJUMP)
469     /* time jump detected, adjust rtimers */
470     for (i = 0; i < rtimercnt; ++i)
471     rtimers [i]->at += ev_now - now;
472    
473     now = ev_now;
474     }
475     }
476    
477 root 1.1 int ev_loop_done;
478    
479 root 1.4 void ev_loop (int flags)
480 root 1.1 {
481     double block;
482     ev_loop_done = flags & EVLOOP_ONESHOT;
483    
484 root 1.9 if (checkcnt)
485     {
486 root 1.10 queue_events ((W *)checks, checkcnt, EV_CHECK);
487 root 1.9 call_pending ();
488     }
489    
490 root 1.1 do
491     {
492     /* update fd-related kernel structures */
493 root 1.5 fd_reify ();
494 root 1.1
495     /* calculate blocking time */
496 root 1.9 if (flags & EVLOOP_NONBLOCK || idlecnt)
497 root 1.1 block = 0.;
498     else
499     {
500 root 1.4 block = MAX_BLOCKTIME;
501    
502     if (rtimercnt)
503     {
504     ev_tstamp to = rtimers [0]->at - get_clock () + method_fudge;
505     if (block > to) block = to;
506     }
507    
508     if (atimercnt)
509     {
510     ev_tstamp to = atimers [0]->at - ev_time () + method_fudge;
511     if (block > to) block = to;
512     }
513    
514 root 1.1 if (block < 0.) block = 0.;
515     }
516    
517     method_poll (block);
518    
519 root 1.4 /* update ev_now, do magic */
520     time_update ();
521    
522 root 1.9 /* queue pending timers and reschedule them */
523 root 1.4 /* absolute timers first */
524     timers_reify (atimers, atimercnt, ev_now);
525     /* relative timers second */
526     timers_reify (rtimers, rtimercnt, now);
527 root 1.1
528 root 1.9 /* queue idle watchers unless io or timers are pending */
529     if (!pendingcnt)
530 root 1.10 queue_events ((W *)idles, idlecnt, EV_IDLE);
531 root 1.9
532     /* queue check and possibly idle watchers */
533 root 1.10 queue_events ((W *)checks, checkcnt, EV_CHECK);
534 root 1.9
535 root 1.1 call_pending ();
536     }
537     while (!ev_loop_done);
538     }
539    
540 root 1.8 /*****************************************************************************/
541    
542 root 1.1 static void
543 root 1.10 wlist_add (WL *head, WL elem)
544 root 1.1 {
545     elem->next = *head;
546     *head = elem;
547     }
548    
549     static void
550 root 1.10 wlist_del (WL *head, WL elem)
551 root 1.1 {
552     while (*head)
553     {
554     if (*head == elem)
555     {
556     *head = elem->next;
557     return;
558     }
559    
560     head = &(*head)->next;
561     }
562     }
563    
564     static void
565 root 1.10 ev_start (W w, int active)
566 root 1.1 {
567     w->pending = 0;
568     w->active = active;
569     }
570    
571     static void
572 root 1.10 ev_stop (W w)
573 root 1.1 {
574     if (w->pending)
575     pendings [w->pending - 1].w = 0;
576    
577     w->active = 0;
578     /* nop */
579     }
580    
581 root 1.8 /*****************************************************************************/
582    
583 root 1.1 void
584     evio_start (struct ev_io *w)
585     {
586     if (ev_is_active (w))
587     return;
588    
589     int fd = w->fd;
590    
591 root 1.10 ev_start ((W)w, 1);
592 root 1.1 array_needsize (anfds, anfdmax, fd + 1, anfds_init);
593 root 1.10 wlist_add ((WL *)&anfds[fd].head, (WL)w);
594 root 1.1
595     ++fdchangecnt;
596     array_needsize (fdchanges, fdchangemax, fdchangecnt, );
597     fdchanges [fdchangecnt - 1] = fd;
598     }
599    
600     void
601     evio_stop (struct ev_io *w)
602     {
603     if (!ev_is_active (w))
604     return;
605    
606 root 1.10 wlist_del ((WL *)&anfds[w->fd].head, (WL)w);
607     ev_stop ((W)w);
608 root 1.1
609     ++fdchangecnt;
610     array_needsize (fdchanges, fdchangemax, fdchangecnt, );
611     fdchanges [fdchangecnt - 1] = w->fd;
612     }
613    
614     void
615     evtimer_start (struct ev_timer *w)
616     {
617     if (ev_is_active (w))
618     return;
619    
620     if (w->is_abs)
621     {
622 root 1.2 /* this formula differs from the one in timer_reify becuse we do not round up */
623 root 1.1 if (w->repeat)
624     w->at += ceil ((ev_now - w->at) / w->repeat) * w->repeat;
625 root 1.4
626 root 1.10 ev_start ((W)w, ++atimercnt);
627 root 1.4 array_needsize (atimers, atimermax, atimercnt, );
628     atimers [atimercnt - 1] = w;
629     upheap (atimers, atimercnt - 1);
630 root 1.1 }
631     else
632 root 1.4 {
633     w->at += now;
634    
635 root 1.10 ev_start ((W)w, ++rtimercnt);
636 root 1.4 array_needsize (rtimers, rtimermax, rtimercnt, );
637     rtimers [rtimercnt - 1] = w;
638     upheap (rtimers, rtimercnt - 1);
639     }
640 root 1.1
641     }
642    
643     void
644     evtimer_stop (struct ev_timer *w)
645     {
646     if (!ev_is_active (w))
647     return;
648    
649 root 1.4 if (w->is_abs)
650 root 1.2 {
651 root 1.4 if (w->active < atimercnt--)
652     {
653     atimers [w->active - 1] = atimers [atimercnt];
654     downheap (atimers, atimercnt, w->active - 1);
655     }
656     }
657     else
658     {
659     if (w->active < rtimercnt--)
660     {
661     rtimers [w->active - 1] = rtimers [rtimercnt];
662     downheap (rtimers, rtimercnt, w->active - 1);
663     }
664 root 1.2 }
665    
666 root 1.10 ev_stop ((W)w);
667 root 1.1 }
668    
669     void
670     evsignal_start (struct ev_signal *w)
671     {
672     if (ev_is_active (w))
673     return;
674    
675 root 1.10 ev_start ((W)w, 1);
676 root 1.1 array_needsize (signals, signalmax, w->signum, signals_init);
677 root 1.10 wlist_add ((WL *)&signals [w->signum - 1].head, (WL)w);
678 root 1.7
679     if (!w->next)
680     {
681     struct sigaction sa;
682     sa.sa_handler = sighandler;
683     sigfillset (&sa.sa_mask);
684     sa.sa_flags = 0;
685     sigaction (w->signum, &sa, 0);
686     }
687 root 1.1 }
688    
689     void
690     evsignal_stop (struct ev_signal *w)
691     {
692     if (!ev_is_active (w))
693     return;
694    
695 root 1.10 wlist_del ((WL *)&signals [w->signum - 1].head, (WL)w);
696     ev_stop ((W)w);
697 root 1.7
698     if (!signals [w->signum - 1].head)
699     signal (w->signum, SIG_DFL);
700 root 1.1 }
701    
702 root 1.9 void evidle_start (struct ev_idle *w)
703     {
704     if (ev_is_active (w))
705     return;
706    
707 root 1.10 ev_start ((W)w, ++idlecnt);
708 root 1.9 array_needsize (idles, idlemax, idlecnt, );
709     idles [idlecnt - 1] = w;
710     }
711    
712     void evidle_stop (struct ev_idle *w)
713     {
714     idles [w->active - 1] = idles [--idlecnt];
715 root 1.10 ev_stop ((W)w);
716 root 1.9 }
717    
718     void evcheck_start (struct ev_check *w)
719     {
720     if (ev_is_active (w))
721     return;
722    
723 root 1.10 ev_start ((W)w, ++checkcnt);
724 root 1.9 array_needsize (checks, checkmax, checkcnt, );
725     checks [checkcnt - 1] = w;
726     }
727    
728     void evcheck_stop (struct ev_check *w)
729     {
730     checks [w->active - 1] = checks [--checkcnt];
731 root 1.10 ev_stop ((W)w);
732 root 1.9 }
733    
734 root 1.1 /*****************************************************************************/
735 root 1.10
736     #if 0
737 root 1.1
738     static void
739     sin_cb (struct ev_io *w, int revents)
740     {
741     fprintf (stderr, "sin %d, revents %d\n", w->fd, revents);
742     }
743    
744     static void
745     ocb (struct ev_timer *w, int revents)
746     {
747 root 1.4 //fprintf (stderr, "timer %f,%f (%x) (%f) d%p\n", w->at, w->repeat, revents, w->at - ev_time (), w->data);
748     evtimer_stop (w);
749     evtimer_start (w);
750 root 1.1 }
751    
752 root 1.7 static void
753     scb (struct ev_signal *w, int revents)
754     {
755     fprintf (stderr, "signal %x,%d\n", revents, w->signum);
756     }
757    
758 root 1.9 static void
759     gcb (struct ev_signal *w, int revents)
760     {
761     fprintf (stderr, "generic %x\n", revents);
762     }
763    
764 root 1.1 int main (void)
765     {
766     struct ev_io sin;
767    
768     ev_init (0);
769    
770     evw_init (&sin, sin_cb, 55);
771     evio_set (&sin, 0, EV_READ);
772     evio_start (&sin);
773    
774 root 1.4 struct ev_timer t[10000];
775 root 1.2
776 root 1.9 #if 0
777 root 1.2 int i;
778 root 1.4 for (i = 0; i < 10000; ++i)
779 root 1.2 {
780     struct ev_timer *w = t + i;
781     evw_init (w, ocb, i);
782 root 1.4 evtimer_set_abs (w, drand48 (), 0.99775533);
783 root 1.2 evtimer_start (w);
784     if (drand48 () < 0.5)
785     evtimer_stop (w);
786     }
787 root 1.4 #endif
788    
789     struct ev_timer t1;
790     evw_init (&t1, ocb, 0);
791     evtimer_set_abs (&t1, 5, 10);
792     evtimer_start (&t1);
793 root 1.1
794 root 1.7 struct ev_signal sig;
795     evw_init (&sig, scb, 65535);
796     evsignal_set (&sig, SIGQUIT);
797     evsignal_start (&sig);
798    
799 root 1.9 struct ev_check cw;
800     evw_init (&cw, gcb, 0);
801     evcheck_start (&cw);
802    
803     struct ev_idle iw;
804     evw_init (&iw, gcb, 0);
805     evidle_start (&iw);
806    
807 root 1.1 ev_loop (0);
808    
809     return 0;
810     }
811    
812     #endif
813    
814    
815    
816