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 *
#	Content
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	int newcnt = cur ? cur << 1 : 16; \
72	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	while (k < (timercnt >> 1))
160	{
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	timers [k]->active = k + 1;
171	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	w->at += ceil ((ev_now - w->at) / w->repeat + 1.) * w->repeat;
266	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	/* this formula differs from the one in timer_reify becuse we do not round up */
394	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	if (w->active < timercnt--)
413	{
414	timers [w->active - 1] = timers [timercnt];
415	downheap (w->active - 1);
416	}
417
418	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	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
480	ev_loop (0);
481
482	return 0;
483	}
484
485	#endif
486
487
488
489