libev/ev.c

#include <math.h>
#include <stdlib.h>

#include <stdio.h>

#include <errno.h>
#include <sys/time.h>
#include <time.h>

#ifdef CLOCK_MONOTONIC
# define HAVE_MONOTONIC 1
#endif

#define HAVE_EPOLL 1
#define HAVE_REALTIME 1
#define HAVE_SELECT 0

#define MAX_BLOCKTIME 60.

#include "ev.h"

struct ev_watcher {
  EV_WATCHER (ev_watcher);
};

struct ev_watcher_list {
  EV_WATCHER_LIST (ev_watcher_list);
};

ev_tstamp ev_now;
int ev_method;

static int have_monotonic; /* runtime */

static ev_tstamp method_fudge; /* stupid epoll-returns-early bug */
static void (*method_reify)(void);
static void (*method_poll)(ev_tstamp timeout);

ev_tstamp
ev_time (void)
{
#if HAVE_REALTIME
  struct timespec ts;
  clock_gettime (CLOCK_REALTIME, &ts);
  return ts.tv_sec + ts.tv_nsec * 1e-9;
#else
  struct timeval tv;
  gettimeofday (&tv, 0);
  return tv.tv_sec + tv.tv_usec * 1e-6;
#endif
}

static ev_tstamp
get_clock (void)
{
#if HAVE_MONOTONIC
  if (have_monotonic)
    {
      struct timespec ts;
      clock_gettime (CLOCK_MONOTONIC, &ts);
      return ts.tv_sec + ts.tv_nsec * 1e-9;
    }
#endif

  return ev_time ();
}

#define array_needsize(base,cur,cnt,init)               \
  if ((cnt) > cur)                                      \
    {                                                   \
      int newcnt = cur ? cur << 1 : 16;                 \
      fprintf (stderr, "resize(" # base ") from %d to %d\n", cur, newcnt);\
      base = realloc (base, sizeof (*base) * (newcnt)); \
      init (base + cur, newcnt - cur);                  \
      cur = newcnt;                                     \
    }

typedef struct
{
  struct ev_io *head;
  unsigned char wev, rev; /* want, received event set */
} ANFD;

static ANFD *anfds;
static int anfdmax;

static int *fdchanges;
static int fdchangemax, fdchangecnt;

static void
anfds_init (ANFD *base, int count)
{
  while (count--)
    {
      base->head = 0;
      base->wev = base->rev = EV_NONE;
      ++base;
    }
}

typedef struct
{
  struct ev_watcher *w;
  int events;
} ANPENDING;

static ANPENDING *pendings;
static int pendingmax, pendingcnt;

static void
event (struct ev_watcher *w, int events)
{
  w->pending = ++pendingcnt;
  array_needsize (pendings, pendingmax, pendingcnt, );
  pendings [pendingcnt - 1].w      = w;
  pendings [pendingcnt - 1].events = events;
}

static void
fd_event (int fd, int events)
{
  ANFD *anfd = anfds + fd;
  struct ev_io *w;

  for (w = anfd->head; w; w = w->next)
    {
      int ev = w->events & events;

      if (ev)
        event ((struct ev_watcher *)w, ev);
    }
}

static struct ev_timer **timers;
static int timermax, timercnt;

static void
upheap (int k)
{
  struct ev_timer *w = timers [k];

  while (k && timers [k >> 1]->at > w->at)
    {
      timers [k] = timers [k >> 1];
      timers [k]->active = k + 1;
      k >>= 1;
    }

  timers [k] = w;
  timers [k]->active = k + 1;

}

static void
downheap (int k)
{
  struct ev_timer *w = timers [k];

  while (k < (timercnt >> 1))
    {
      int j = k << 1;

      if (j + 1 < timercnt && timers [j]->at > timers [j + 1]->at)
        ++j;

      if (w->at <= timers [j]->at)
        break;

      timers [k] = timers [j];
      timers [k]->active = k + 1;
      k = j;
    }

  timers [k] = w;
  timers [k]->active = k + 1;
}

static struct ev_signal **signals;
static int signalmax, signalcnt;

static void
signals_init (struct ev_signal **base, int count)
{
  while (count--)
    *base++ = 0;
}

#if HAVE_EPOLL
# include "ev_epoll.c"
#endif
#if HAVE_SELECT
# include "ev_select.c"
#endif

int ev_init (int flags)
{
#if HAVE_MONOTONIC
  {
    struct timespec ts;
    if (!clock_gettime (CLOCK_MONOTONIC, &ts))
      have_monotonic = 1;
  }
#endif

  ev_now = ev_time ();

#if HAVE_EPOLL
  if (epoll_init (flags))
    return ev_method;
#endif
#if HAVE_SELECT
  if (select_init (flags))
    return ev_method;
#endif

  ev_method = EVMETHOD_NONE;
  return ev_method;
}

void ev_prefork (void)
{
}

void ev_postfork_parent (void)
{
}

void ev_postfork_child (void)
{
#if HAVE_EPOLL
  epoll_postfork_child ();
#endif
}

static void
call_pending ()
{
  int i;

  for (i = 0; i < pendingcnt; ++i)
    {
      ANPENDING *p = pendings + i;

      if (p->w)
        {
          p->w->pending = 0;
          p->w->cb (p->w, p->events);
        }
    }

  pendingcnt = 0;
}

static void
timer_reify (void)
{
  while (timercnt && timers [0]->at <= ev_now)
    {
      struct ev_timer *w = timers [0];

      /* first reschedule timer */
      if (w->repeat)
        {
          if (w->is_abs)
            w->at += ceil ((ev_now - w->at) / w->repeat + 1.) * w->repeat;
          else
            w->at = ev_now + w->repeat;

          downheap (0);
        }
      else
        evtimer_stop (w); /* nonrepeating: stop timer */

      event ((struct ev_watcher *)w, EV_TIMEOUT);
    }
}

int ev_loop_done;

int ev_loop (int flags)
{
  double block;
  ev_loop_done = flags & EVLOOP_ONESHOT;

  do
    {
      /* update fd-related kernel structures */
      method_reify (); fdchangecnt = 0;

      /* calculate blocking time */
      ev_now = ev_time ();

      if (flags & EVLOOP_NONBLOCK)
        block = 0.;
      else if (!timercnt)
        block = MAX_BLOCKTIME;
      else
        {
          block = timers [0]->at - ev_now + method_fudge;
          if (block < 0.) block = 0.;
          else if (block > MAX_BLOCKTIME) block = MAX_BLOCKTIME;
        }

      method_poll (block);

      /* put pending timers into pendign queue and reschedule them */
      timer_reify ();

      ev_now = ev_time ();
      call_pending ();
    }
  while (!ev_loop_done);
}

static void
wlist_add (struct ev_watcher_list **head, struct ev_watcher_list *elem)
{
  elem->next = *head;
  *head = elem;
}

static void
wlist_del (struct ev_watcher_list **head, struct ev_watcher_list *elem)
{
  while (*head)
    {
      if (*head == elem)
        {
          *head = elem->next;
          return;
        }

      head = &(*head)->next;
    }
}

static void
ev_start (struct ev_watcher *w, int active)
{
  w->pending = 0;
  w->active = active;
}

static void
ev_stop (struct ev_watcher *w)
{
  if (w->pending)
    pendings [w->pending - 1].w = 0;

  w->active = 0;
  /* nop */
}

void
evio_start (struct ev_io *w)
{
  if (ev_is_active (w))
    return;

  int fd = w->fd;

  ev_start ((struct ev_watcher *)w, 1);
  array_needsize (anfds, anfdmax, fd + 1, anfds_init);
  wlist_add ((struct ev_watcher_list **)&anfds[fd].head, (struct ev_watcher_list *)w);

  ++fdchangecnt;
  array_needsize (fdchanges, fdchangemax, fdchangecnt, );
  fdchanges [fdchangecnt - 1] = fd;
}

void
evio_stop (struct ev_io *w)
{
  if (!ev_is_active (w))
    return;

  wlist_del ((struct ev_watcher_list **)&anfds[w->fd].head, (struct ev_watcher_list *)w);
  ev_stop ((struct ev_watcher *)w);

  ++fdchangecnt;
  array_needsize (fdchanges, fdchangemax, fdchangecnt, );
  fdchanges [fdchangecnt - 1] = w->fd;
}

void
evtimer_start (struct ev_timer *w)
{
  if (ev_is_active (w))
    return;

  if (w->is_abs)
    {
      /* this formula differs from the one in timer_reify becuse we do not round up */
      if (w->repeat)
        w->at += ceil ((ev_now - w->at) / w->repeat) * w->repeat;
    }
  else
    w->at += ev_now;

  ev_start ((struct ev_watcher *)w, ++timercnt);
  array_needsize (timers, timermax, timercnt, );
  timers [timercnt - 1] = w;
  upheap (timercnt - 1);
}

void
evtimer_stop (struct ev_timer *w)
{
  if (!ev_is_active (w))
    return;

  if (w->active < timercnt--)
    {
      timers [w->active - 1] = timers [timercnt];
      downheap (w->active - 1);
    }

  ev_stop ((struct ev_watcher *)w);
}

void
evsignal_start (struct ev_signal *w)
{
  if (ev_is_active (w))
    return;

  ev_start ((struct ev_watcher *)w, 1);
  array_needsize (signals, signalmax, w->signum, signals_init);
  wlist_add ((struct ev_watcher_list **)&signals [w->signum - 1], (struct ev_watcher_list *)w);
}

void
evsignal_stop (struct ev_signal *w)
{
  if (!ev_is_active (w))
    return;

  wlist_del ((struct ev_watcher_list **)&signals [w->signum - 1], (struct ev_watcher_list *)w);
  ev_stop ((struct ev_watcher *)w);
}

/*****************************************************************************/
#if 1

static void
sin_cb (struct ev_io *w, int revents)
{
  fprintf (stderr, "sin %d, revents %d\n", w->fd, revents);
}

static void
ocb (struct ev_timer *w, int revents)
{
  fprintf (stderr, "timer %f,%f (%x) (%f) d%p\n", w->at, w->repeat, revents, w->at - ev_time (), w->data);
}

int main (void)
{
  struct ev_io sin;

  ev_init (0);

  evw_init (&sin, sin_cb, 55);
  evio_set (&sin, 0, EV_READ);
  evio_start (&sin);

  struct ev_timer t[1000];

  int i;
  for (i = 0; i < 1000; ++i)
    {
      struct ev_timer *w = t + i;
      evw_init (w, ocb, i);
      evtimer_set_rel (w, drand48 (), 0);
      evtimer_start (w);
      if (drand48 () < 0.5)
        evtimer_stop (w);
    }

  ev_loop (0);

  return 0;
}

#endif


Revision:	1.3
Committed:	Tue Oct 30 21:45:00 2007 UTC (16 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.2:	+2 -14 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	#include <math.h>
2			#include <stdlib.h>
3
4			#include <stdio.h>
5
6			#include <errno.h>
7			#include <sys/time.h>
8			#include <time.h>
9
10			#ifdef CLOCK_MONOTONIC
11			# define HAVE_MONOTONIC 1
12			#endif
13
14			#define HAVE_EPOLL 1
15			#define HAVE_REALTIME 1
16			#define HAVE_SELECT 0
17
18			#define MAX_BLOCKTIME 60.
19
20			#include "ev.h"
21
22			struct ev_watcher {
23			EV_WATCHER (ev_watcher);
24			};
25
26			struct ev_watcher_list {
27			EV_WATCHER_LIST (ev_watcher_list);
28			};
29
30			ev_tstamp ev_now;
31			int ev_method;
32
33			static int have_monotonic; /* runtime */
34
35			static ev_tstamp method_fudge; /* stupid epoll-returns-early bug */
36			static void (*method_reify)(void);
37			static void (*method_poll)(ev_tstamp timeout);
38
39			ev_tstamp
40			ev_time (void)
41			{
42			#if HAVE_REALTIME
43			struct timespec ts;
44			clock_gettime (CLOCK_REALTIME, &ts);
45			return ts.tv_sec + ts.tv_nsec * 1e-9;
46			#else
47			struct timeval tv;
48			gettimeofday (&tv, 0);
49			return tv.tv_sec + tv.tv_usec * 1e-6;
50			#endif
51			}
52
53			static ev_tstamp
54			get_clock (void)
55			{
56			#if HAVE_MONOTONIC
57			if (have_monotonic)
58			{
59			struct timespec ts;
60			clock_gettime (CLOCK_MONOTONIC, &ts);
61			return ts.tv_sec + ts.tv_nsec * 1e-9;
62			}
63			#endif
64
65			return ev_time ();
66			}
67
68			#define array_needsize(base,cur,cnt,init) \
69			if ((cnt) > cur) \
70			{ \
71	root	1.2	int newcnt = cur ? cur << 1 : 16; \
72	root	1.1	fprintf (stderr, "resize(" # base ") from %d to %d\n", cur, newcnt);\
73			base = realloc (base, sizeof (base) (newcnt)); \
74			init (base + cur, newcnt - cur); \
75			cur = newcnt; \
76			}
77
78			typedef struct
79			{
80			struct ev_io *head;
81			unsigned char wev, rev; /* want, received event set */
82			} ANFD;
83
84			static ANFD *anfds;
85			static int anfdmax;
86
87			static int *fdchanges;
88			static int fdchangemax, fdchangecnt;
89
90			static void
91			anfds_init (ANFD *base, int count)
92			{
93			while (count--)
94			{
95			base->head = 0;
96			base->wev = base->rev = EV_NONE;
97			++base;
98			}
99			}
100
101			typedef struct
102			{
103			struct ev_watcher *w;
104			int events;
105			} ANPENDING;
106
107			static ANPENDING *pendings;
108			static int pendingmax, pendingcnt;
109
110			static void
111			event (struct ev_watcher *w, int events)
112			{
113			w->pending = ++pendingcnt;
114			array_needsize (pendings, pendingmax, pendingcnt, );
115			pendings [pendingcnt - 1].w = w;
116			pendings [pendingcnt - 1].events = events;
117			}
118
119			static void
120			fd_event (int fd, int events)
121			{
122			ANFD *anfd = anfds + fd;
123			struct ev_io *w;
124
125			for (w = anfd->head; w; w = w->next)
126			{
127			int ev = w->events & events;
128
129			if (ev)
130			event ((struct ev_watcher *)w, ev);
131			}
132			}
133
134			static struct ev_timer **timers;
135			static int timermax, timercnt;
136
137			static void
138			upheap (int k)
139			{
140			struct ev_timer *w = timers [k];
141
142			while (k && timers [k >> 1]->at > w->at)
143			{
144			timers [k] = timers [k >> 1];
145			timers [k]->active = k + 1;
146			k >>= 1;
147			}
148
149			timers [k] = w;
150			timers [k]->active = k + 1;
151
152			}
153
154			static void
155			downheap (int k)
156			{
157			struct ev_timer *w = timers [k];
158
159	root	1.2	while (k < (timercnt >> 1))
160	root	1.1	{
161			int j = k << 1;
162
163			if (j + 1 < timercnt && timers [j]->at > timers [j + 1]->at)
164			++j;
165
166			if (w->at <= timers [j]->at)
167			break;
168
169			timers [k] = timers [j];
170	root	1.2	timers [k]->active = k + 1;
171	root	1.1	k = j;
172			}
173
174			timers [k] = w;
175			timers [k]->active = k + 1;
176			}
177
178			static struct ev_signal **signals;
179			static int signalmax, signalcnt;
180
181			static void
182			signals_init (struct ev_signal **base, int count)
183			{
184			while (count--)
185			*base++ = 0;
186			}
187
188			#if HAVE_EPOLL
189			# include "ev_epoll.c"
190			#endif
191			#if HAVE_SELECT
192			# include "ev_select.c"
193			#endif
194
195			int ev_init (int flags)
196			{
197			#if HAVE_MONOTONIC
198			{
199			struct timespec ts;
200			if (!clock_gettime (CLOCK_MONOTONIC, &ts))
201			have_monotonic = 1;
202			}
203			#endif
204
205			ev_now = ev_time ();
206
207			#if HAVE_EPOLL
208			if (epoll_init (flags))
209			return ev_method;
210			#endif
211			#if HAVE_SELECT
212			if (select_init (flags))
213			return ev_method;
214			#endif
215
216			ev_method = EVMETHOD_NONE;
217			return ev_method;
218			}
219
220			void ev_prefork (void)
221			{
222			}
223
224			void ev_postfork_parent (void)
225			{
226			}
227
228			void ev_postfork_child (void)
229			{
230			#if HAVE_EPOLL
231			epoll_postfork_child ();
232			#endif
233			}
234
235			static void
236			call_pending ()
237			{
238			int i;
239
240			for (i = 0; i < pendingcnt; ++i)
241			{
242			ANPENDING *p = pendings + i;
243
244			if (p->w)
245			{
246			p->w->pending = 0;
247			p->w->cb (p->w, p->events);
248			}
249			}
250
251			pendingcnt = 0;
252			}
253
254			static void
255			timer_reify (void)
256			{
257			while (timercnt && timers [0]->at <= ev_now)
258			{
259			struct ev_timer *w = timers [0];
260
261			/* first reschedule timer */
262			if (w->repeat)
263			{
264			if (w->is_abs)
265	root	1.2	w->at += ceil ((ev_now - w->at) / w->repeat + 1.) * w->repeat;
266	root	1.1	else
267			w->at = ev_now + w->repeat;
268
269			downheap (0);
270			}
271			else
272			evtimer_stop (w); /* nonrepeating: stop timer */
273
274			event ((struct ev_watcher *)w, EV_TIMEOUT);
275			}
276			}
277
278			int ev_loop_done;
279
280			int ev_loop (int flags)
281			{
282			double block;
283			ev_loop_done = flags & EVLOOP_ONESHOT;
284
285			do
286			{
287			/* update fd-related kernel structures */
288			method_reify (); fdchangecnt = 0;
289
290			/* calculate blocking time */
291			ev_now = ev_time ();
292
293			if (flags & EVLOOP_NONBLOCK)
294			block = 0.;
295			else if (!timercnt)
296			block = MAX_BLOCKTIME;
297			else
298			{
299			block = timers [0]->at - ev_now + method_fudge;
300			if (block < 0.) block = 0.;
301			else if (block > MAX_BLOCKTIME) block = MAX_BLOCKTIME;
302			}
303
304			method_poll (block);
305
306			/* put pending timers into pendign queue and reschedule them */
307			timer_reify ();
308
309			ev_now = ev_time ();
310			call_pending ();
311			}
312			while (!ev_loop_done);
313			}
314
315			static void
316			wlist_add (struct ev_watcher_list *head, struct ev_watcher_list elem)
317			{
318			elem->next = *head;
319			*head = elem;
320			}
321
322			static void
323			wlist_del (struct ev_watcher_list *head, struct ev_watcher_list elem)
324			{
325			while (*head)
326			{
327			if (*head == elem)
328			{
329			*head = elem->next;
330			return;
331			}
332
333			head = &(*head)->next;
334			}
335			}
336
337			static void
338			ev_start (struct ev_watcher *w, int active)
339			{
340			w->pending = 0;
341			w->active = active;
342			}
343
344			static void
345			ev_stop (struct ev_watcher *w)
346			{
347			if (w->pending)
348			pendings [w->pending - 1].w = 0;
349
350			w->active = 0;
351			/* nop */
352			}
353
354			void
355			evio_start (struct ev_io *w)
356			{
357			if (ev_is_active (w))
358			return;
359
360			int fd = w->fd;
361
362			ev_start ((struct ev_watcher *)w, 1);
363			array_needsize (anfds, anfdmax, fd + 1, anfds_init);
364			wlist_add ((struct ev_watcher_list *)&anfds[fd].head, (struct ev_watcher_list )w);
365
366			++fdchangecnt;
367			array_needsize (fdchanges, fdchangemax, fdchangecnt, );
368			fdchanges [fdchangecnt - 1] = fd;
369			}
370
371			void
372			evio_stop (struct ev_io *w)
373			{
374			if (!ev_is_active (w))
375			return;
376
377			wlist_del ((struct ev_watcher_list *)&anfds[w->fd].head, (struct ev_watcher_list )w);
378			ev_stop ((struct ev_watcher *)w);
379
380			++fdchangecnt;
381			array_needsize (fdchanges, fdchangemax, fdchangecnt, );
382			fdchanges [fdchangecnt - 1] = w->fd;
383			}
384
385			void
386			evtimer_start (struct ev_timer *w)
387			{
388			if (ev_is_active (w))
389			return;
390
391			if (w->is_abs)
392			{
393	root	1.2	/* this formula differs from the one in timer_reify becuse we do not round up */
394	root	1.1	if (w->repeat)
395			w->at += ceil ((ev_now - w->at) / w->repeat) * w->repeat;
396			}
397			else
398			w->at += ev_now;
399
400			ev_start ((struct ev_watcher *)w, ++timercnt);
401			array_needsize (timers, timermax, timercnt, );
402			timers [timercnt - 1] = w;
403			upheap (timercnt - 1);
404			}
405
406			void
407			evtimer_stop (struct ev_timer *w)
408			{
409			if (!ev_is_active (w))
410			return;
411
412	root	1.3	if (w->active < timercnt--)
413	root	1.2	{
414	root	1.3	timers [w->active - 1] = timers [timercnt];
415	root	1.2	downheap (w->active - 1);
416			}
417
418	root	1.1	ev_stop ((struct ev_watcher *)w);
419			}
420
421			void
422			evsignal_start (struct ev_signal *w)
423			{
424			if (ev_is_active (w))
425			return;
426
427			ev_start ((struct ev_watcher *)w, 1);
428			array_needsize (signals, signalmax, w->signum, signals_init);
429			wlist_add ((struct ev_watcher_list *)&signals [w->signum - 1], (struct ev_watcher_list )w);
430			}
431
432			void
433			evsignal_stop (struct ev_signal *w)
434			{
435			if (!ev_is_active (w))
436			return;
437
438			wlist_del ((struct ev_watcher_list *)&signals [w->signum - 1], (struct ev_watcher_list )w);
439			ev_stop ((struct ev_watcher *)w);
440			}
441
442			/*****************************************************************************/
443			#if 1
444
445			static void
446			sin_cb (struct ev_io *w, int revents)
447			{
448			fprintf (stderr, "sin %d, revents %d\n", w->fd, revents);
449			}
450
451			static void
452			ocb (struct ev_timer *w, int revents)
453			{
454			fprintf (stderr, "timer %f,%f (%x) (%f) d%p\n", w->at, w->repeat, revents, w->at - ev_time (), w->data);
455			}
456
457			int main (void)
458			{
459			struct ev_io sin;
460
461			ev_init (0);
462
463			evw_init (&sin, sin_cb, 55);
464			evio_set (&sin, 0, EV_READ);
465			evio_start (&sin);
466
467	root	1.2	struct ev_timer t[1000];
468
469			int i;
470			for (i = 0; i < 1000; ++i)
471			{
472			struct ev_timer *w = t + i;
473			evw_init (w, ocb, i);
474			evtimer_set_rel (w, drand48 (), 0);
475			evtimer_start (w);
476			if (drand48 () < 0.5)
477			evtimer_stop (w);
478			}
479	root	1.1
480			ev_loop (0);
481
482			return 0;
483			}
484
485			#endif
486
487
488
489