libev/ev.c

#include <math.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>

#include <stdio.h>

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

#define HAVE_EPOLL 1

#ifndef HAVE_MONOTONIC
# ifdef CLOCK_MONOTONIC
#  define HAVE_MONOTONIC 1
# endif
#endif

#ifndef HAVE_SELECT
# define HAVE_SELECT 1
#endif

#ifndef HAVE_EPOLL
# define HAVE_EPOLL 0
#endif

#ifndef HAVE_REALTIME
# define HAVE_REALTIME 1 /* posix requirement, but might be slower */
#endif

#define MIN_TIMEJUMP  1. /* minimum timejump that gets detected (if monotonic clock available) */
#define MAX_BLOCKTIME 60.

#include "ev.h"

struct ev_watcher {
  EV_WATCHER (ev_watcher);
};

struct ev_watcher_list {
  EV_WATCHER_LIST (ev_watcher_list);
};

struct ev_watcher_time {
  EV_WATCHER_TIME (ev_watcher_time);
};

typedef struct ev_watcher *W;
typedef struct ev_watcher_list *WL;
typedef struct ev_watcher_time *WT;

static ev_tstamp now, diff; /* monotonic clock */
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_modify)(int fd, int oev, int nev);
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
{
  W w;
  int events;
} ANPENDING;

static ANPENDING *pendings;
static int pendingmax, pendingcnt;

static void
event (W 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 ((W)w, ev);
    }
}

static void
queue_events (W *events, int eventcnt, int type)
{
  int i;

  for (i = 0; i < eventcnt; ++i)
    event (events [i], type);
}

/*****************************************************************************/

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

static struct ev_periodic **periodics;
static int periodicmax, periodiccnt;

static void
upheap (WT *timers, int k)
{
  WT 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 (WT *timers, int N, int k)
{
  WT w = timers [k];

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

      if (j + 1 < N && 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;
}

/*****************************************************************************/

typedef struct
{
  struct ev_signal *head;
  sig_atomic_t gotsig;
} ANSIG;

static ANSIG *signals;
static int signalmax;

static int sigpipe [2];
static sig_atomic_t gotsig;
static struct ev_io sigev;

static void
signals_init (ANSIG *base, int count)
{
  while (count--)
    {
      base->head   = 0;
      base->gotsig = 0;
      ++base;
    }
}

static void
sighandler (int signum)
{
  signals [signum - 1].gotsig = 1;

  if (!gotsig)
    {
      gotsig = 1;
      write (sigpipe [1], &gotsig, 1);
    }
}

static void
sigcb (struct ev_io *iow, int revents)
{
  struct ev_signal *w;
  int sig;

  gotsig = 0;
  read (sigpipe [0], &revents, 1);

  for (sig = signalmax; sig--; )
    if (signals [sig].gotsig)
      {
        signals [sig].gotsig = 0;

        for (w = signals [sig].head; w; w = w->next)
          event ((W)w, EV_SIGNAL);
      }
}

static void
siginit (void)
{
  fcntl (sigpipe [0], F_SETFD, FD_CLOEXEC);
  fcntl (sigpipe [1], F_SETFD, FD_CLOEXEC);

  /* rather than sort out wether we really need nb, set it */
  fcntl (sigpipe [0], F_SETFL, O_NONBLOCK);
  fcntl (sigpipe [1], F_SETFL, O_NONBLOCK);

  evio_set (&sigev, sigpipe [0], EV_READ);
  evio_start (&sigev);
}

/*****************************************************************************/

static struct ev_idle **idles;
static int idlemax, idlecnt;

static struct ev_check **checks;
static int checkmax, checkcnt;

/*****************************************************************************/

#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 ();
  now    = get_clock ();
  diff   = ev_now - now;

  if (pipe (sigpipe))
    return 0;

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

  if (ev_method)
    {
      evw_init (&sigev, sigcb);
      siginit ();
    }

  return ev_method;
}

/*****************************************************************************/

void ev_prefork (void)
{
  /* nop */
}

void ev_postfork_parent (void)
{
  /* nop */
}

void ev_postfork_child (void)
{
#if HAVE_EPOLL
  if (ev_method == EVMETHOD_EPOLL)
    epoll_postfork_child ();
#endif

  evio_stop (&sigev);
  close (sigpipe [0]);
  close (sigpipe [1]);
  pipe (sigpipe);
  siginit ();
}

/*****************************************************************************/

static void
fd_reify (void)
{
  int i;

  for (i = 0; i < fdchangecnt; ++i)
    {
      int fd = fdchanges [i];
      ANFD *anfd = anfds + fd;
      struct ev_io *w;

      int wev = 0;

      for (w = anfd->head; w; w = w->next)
        wev |= w->events;

      if (anfd->wev != wev)
        {
          method_modify (fd, anfd->wev, wev);
          anfd->wev = wev;
        }
    }

  fdchangecnt = 0;
}

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
timers_reify ()
{
  while (timercnt && timers [0]->at <= now)
    {
      struct ev_timer *w = timers [0];

      /* first reschedule or stop timer */
      if (w->repeat)
        {
          w->at = now + w->repeat;
          assert (("timer timeout in the past, negative repeat?", w->at > now));
          downheap ((WT *)timers, timercnt, 0);
        }
      else
        evtimer_stop (w); /* nonrepeating: stop timer */

      event ((W)w, EV_TIMEOUT);
    }
}

static void
periodics_reify ()
{
  while (periodiccnt && periodics [0]->at <= ev_now)
    {
      struct ev_periodic *w = periodics [0];

      /* first reschedule or stop timer */
      if (w->interval)
        {
          w->at += floor ((ev_now - w->at) / w->interval + 1.) * w->interval;
          assert (("periodic timeout in the past, negative interval?", w->at > ev_now));
          downheap ((WT *)periodics, periodiccnt, 0);
        }
      else
        evperiodic_stop (w); /* nonrepeating: stop timer */

      event ((W)w, EV_TIMEOUT);
    }
}

static void
time_jump (ev_tstamp diff)
{
  int i;

  /* adjust periodics */
  for (i = 0; i < periodiccnt; ++i)
    {
      struct ev_periodic *w = periodics [i];

      if (w->interval)
        {
          ev_tstamp diff = ceil ((ev_now - w->at) / w->interval) * w->interval;

          if (fabs (diff) >= 1e-4)
            {
              evperiodic_stop (w);
              evperiodic_start (w);

              i = 0; /* restart loop, inefficient, but time jumps should be rare */
            }
        }
    }

  /* adjust timers. this is easy, as the offset is the same for all */
  for (i = 0; i < timercnt; ++i)
    timers [i]->at += diff;
}

static void
time_update ()
{
  int i;

  ev_now = ev_time ();

  if (have_monotonic)
    {
      ev_tstamp odiff = diff;

      for (i = 4; --i; ) /* loop a few times, before making important decisions */
        {
          now = get_clock ();
          diff = ev_now - now;

          if (fabs (odiff - diff) < MIN_TIMEJUMP)
            return; /* all is well */

          ev_now = ev_time ();
        }

      time_jump (diff - odiff);
    }
  else
    {
      if (now > ev_now || now < ev_now - MAX_BLOCKTIME - MIN_TIMEJUMP)
        time_jump (ev_now - now);

      now = ev_now;
    }
}

int ev_loop_done;

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

  if (checkcnt)
    {
      queue_events ((W *)checks, checkcnt, EV_CHECK);
      call_pending ();
    }

  do
    {
      /* update fd-related kernel structures */
      fd_reify ();

      /* calculate blocking time */

      /* we only need this for !monotonic clock, but as we always have timers, we just calculate it every time */
      ev_now = ev_time ();

      if (flags & EVLOOP_NONBLOCK || idlecnt)
        block = 0.;
      else
        {
          block = MAX_BLOCKTIME;

          if (timercnt)
            {
              ev_tstamp to = timers [0]->at - get_clock () + method_fudge;
              if (block > to) block = to;
            }

          if (periodiccnt)
            {
              ev_tstamp to = periodics [0]->at - ev_now + method_fudge;
              if (block > to) block = to;
            }

          if (block < 0.) block = 0.;
        }

      method_poll (block);

      /* update ev_now, do magic */
      time_update ();

      /* queue pending timers and reschedule them */
      periodics_reify (); /* absolute timers first */
      timers_reify (); /* relative timers second */

      /* queue idle watchers unless io or timers are pending */
      if (!pendingcnt)
        queue_events ((W *)idles, idlecnt, EV_IDLE);

      /* queue check and possibly idle watchers */
      queue_events ((W *)checks, checkcnt, EV_CHECK);

      call_pending ();
    }
  while (!ev_loop_done);
}

/*****************************************************************************/

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

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

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

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

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

  w->active = 0;
}

/*****************************************************************************/

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

  int fd = w->fd;

  ev_start ((W)w, 1);
  array_needsize (anfds, anfdmax, fd + 1, anfds_init);
  wlist_add ((WL *)&anfds[fd].head, (WL)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 ((WL *)&anfds[w->fd].head, (WL)w);
  ev_stop ((W)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;

  w->at += now;

  ev_start ((W)w, ++timercnt);
  array_needsize (timers, timermax, timercnt, );
  timers [timercnt - 1] = w;
  upheap ((WT *)timers, 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 ((WT *)timers, timercnt, w->active - 1);
    }

  ev_stop ((W)w);
}

void
evperiodic_start (struct ev_periodic *w)
{
  if (ev_is_active (w))
    return;

  /* this formula differs from the one in periodic_reify because we do not always round up */
  if (w->interval)
    w->at += ceil ((ev_now - w->at) / w->interval) * w->interval;

  ev_start ((W)w, ++periodiccnt);
  array_needsize (periodics, periodicmax, periodiccnt, );
  periodics [periodiccnt - 1] = w;
  upheap ((WT *)periodics, periodiccnt - 1);
}

void
evperiodic_stop (struct ev_periodic *w)
{
  if (!ev_is_active (w))
    return;

  if (w->active < periodiccnt--)
    {
      periodics [w->active - 1] = periodics [periodiccnt];
      downheap ((WT *)periodics, periodiccnt, w->active - 1);
    }

  ev_stop ((W)w);
}

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

  ev_start ((W)w, 1);
  array_needsize (signals, signalmax, w->signum, signals_init);
  wlist_add ((WL *)&signals [w->signum - 1].head, (WL)w);

  if (!w->next)
    {
      struct sigaction sa;
      sa.sa_handler = sighandler;
      sigfillset (&sa.sa_mask);
      sa.sa_flags = 0;
      sigaction (w->signum, &sa, 0);
    }
}

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

  wlist_del ((WL *)&signals [w->signum - 1].head, (WL)w);
  ev_stop ((W)w);

  if (!signals [w->signum - 1].head)
    signal (w->signum, SIG_DFL);
}

void evidle_start (struct ev_idle *w)
{
  if (ev_is_active (w))
    return;

  ev_start ((W)w, ++idlecnt);
  array_needsize (idles, idlemax, idlecnt, );
  idles [idlecnt - 1] = w;
}

void evidle_stop (struct ev_idle *w)
{
  idles [w->active - 1] = idles [--idlecnt];
  ev_stop ((W)w);
}

void evcheck_start (struct ev_check *w)
{
  if (ev_is_active (w))
    return;

  ev_start ((W)w, ++checkcnt);
  array_needsize (checks, checkmax, checkcnt, );
  checks [checkcnt - 1] = w;
}

void evcheck_stop (struct ev_check *w)
{
  checks [w->active - 1] = checks [--checkcnt];
  ev_stop ((W)w);
}

/*****************************************************************************/

#if 1

struct ev_io wio;

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);
  evtimer_stop (w);
  evtimer_start (w);
}

static void
scb (struct ev_signal *w, int revents)
{
  fprintf (stderr, "signal %x,%d\n", revents, w->signum);
  evio_stop (&wio);
  evio_start (&wio);
}

static void
gcb (struct ev_signal *w, int revents)
{
  fprintf (stderr, "generic %x\n", revents);

}

int main (void)
{
  ev_init (0);

  evio_init (&wio, sin_cb, 0, EV_READ);
  evio_start (&wio);

  struct ev_timer t[10000];

#if 0
  int i;
  for (i = 0; i < 10000; ++i)
    {
      struct ev_timer *w = t + i;
      evw_init (w, ocb, i);
      evtimer_init_abs (w, ocb, drand48 (), 0.99775533);
      evtimer_start (w);
      if (drand48 () < 0.5)
        evtimer_stop (w);
    }
#endif

  struct ev_timer t1;
  evtimer_init (&t1, ocb, 5, 10);
  evtimer_start (&t1);

  struct ev_signal sig;
  evsignal_init (&sig, scb, SIGQUIT);
  evsignal_start (&sig);

  struct ev_check cw;
  evcheck_init (&cw, gcb);
  evcheck_start (&cw);

  struct ev_idle iw;
  evidle_init (&iw, gcb);
  evidle_start (&iw);

  ev_loop (0);

  return 0;
}

#endif


Revision:	1.12
Committed:	Wed Oct 31 09:23:17 2007 UTC (16 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.11:	+134 -84 lines
Log Message:	* empty log message *
#	Content
1	#include <math.h>
2	#include <stdlib.h>
3	#include <unistd.h>
4	#include <fcntl.h>
5	#include <signal.h>
6
7	#include <stdio.h>
8
9	#include <assert.h>
10	#include <errno.h>
11	#include <sys/time.h>
12	#include <time.h>
13
14	#define HAVE_EPOLL 1
15
16	#ifndef HAVE_MONOTONIC
17	# ifdef CLOCK_MONOTONIC
18	# define HAVE_MONOTONIC 1
19	# endif
20	#endif
21
22	#ifndef HAVE_SELECT
23	# define HAVE_SELECT 1
24	#endif
25
26	#ifndef HAVE_EPOLL
27	# define HAVE_EPOLL 0
28	#endif
29
30	#ifndef HAVE_REALTIME
31	# define HAVE_REALTIME 1 /* posix requirement, but might be slower */
32	#endif
33
34	#define MIN_TIMEJUMP 1. /* minimum timejump that gets detected (if monotonic clock available) */
35	#define MAX_BLOCKTIME 60.
36
37	#include "ev.h"
38
39	struct ev_watcher {
40	EV_WATCHER (ev_watcher);
41	};
42
43	struct ev_watcher_list {
44	EV_WATCHER_LIST (ev_watcher_list);
45	};
46
47	struct ev_watcher_time {
48	EV_WATCHER_TIME (ev_watcher_time);
49	};
50
51	typedef struct ev_watcher *W;
52	typedef struct ev_watcher_list *WL;
53	typedef struct ev_watcher_time *WT;
54
55	static ev_tstamp now, diff; /* monotonic clock */
56	ev_tstamp ev_now;
57	int ev_method;
58
59	static int have_monotonic; /* runtime */
60
61	static ev_tstamp method_fudge; /* stupid epoll-returns-early bug */
62	static void (*method_modify)(int fd, int oev, int nev);
63	static void (*method_poll)(ev_tstamp timeout);
64
65	/*****************************************************************************/
66
67	ev_tstamp
68	ev_time (void)
69	{
70	#if HAVE_REALTIME
71	struct timespec ts;
72	clock_gettime (CLOCK_REALTIME, &ts);
73	return ts.tv_sec + ts.tv_nsec * 1e-9;
74	#else
75	struct timeval tv;
76	gettimeofday (&tv, 0);
77	return tv.tv_sec + tv.tv_usec * 1e-6;
78	#endif
79	}
80
81	static ev_tstamp
82	get_clock (void)
83	{
84	#if HAVE_MONOTONIC
85	if (have_monotonic)
86	{
87	struct timespec ts;
88	clock_gettime (CLOCK_MONOTONIC, &ts);
89	return ts.tv_sec + ts.tv_nsec * 1e-9;
90	}
91	#endif
92
93	return ev_time ();
94	}
95
96	#define array_needsize(base,cur,cnt,init) \
97	if ((cnt) > cur) \
98	{ \
99	int newcnt = cur ? cur << 1 : 16; \
100	fprintf (stderr, "resize(" # base ") from %d to %d\n", cur, newcnt);\
101	base = realloc (base, sizeof (base) (newcnt)); \
102	init (base + cur, newcnt - cur); \
103	cur = newcnt; \
104	}
105
106	/*****************************************************************************/
107
108	typedef struct
109	{
110	struct ev_io *head;
111	unsigned char wev, rev; /* want, received event set */
112	} ANFD;
113
114	static ANFD *anfds;
115	static int anfdmax;
116
117	static int *fdchanges;
118	static int fdchangemax, fdchangecnt;
119
120	static void
121	anfds_init (ANFD *base, int count)
122	{
123	while (count--)
124	{
125	base->head = 0;
126	base->wev = base->rev = EV_NONE;
127	++base;
128	}
129	}
130
131	typedef struct
132	{
133	W w;
134	int events;
135	} ANPENDING;
136
137	static ANPENDING *pendings;
138	static int pendingmax, pendingcnt;
139
140	static void
141	event (W w, int events)
142	{
143	w->pending = ++pendingcnt;
144	array_needsize (pendings, pendingmax, pendingcnt, );
145	pendings [pendingcnt - 1].w = w;
146	pendings [pendingcnt - 1].events = events;
147	}
148
149	static void
150	fd_event (int fd, int events)
151	{
152	ANFD *anfd = anfds + fd;
153	struct ev_io *w;
154
155	for (w = anfd->head; w; w = w->next)
156	{
157	int ev = w->events & events;
158
159	if (ev)
160	event ((W)w, ev);
161	}
162	}
163
164	static void
165	queue_events (W *events, int eventcnt, int type)
166	{
167	int i;
168
169	for (i = 0; i < eventcnt; ++i)
170	event (events [i], type);
171	}
172
173	/*****************************************************************************/
174
175	static struct ev_timer **timers;
176	static int timermax, timercnt;
177
178	static struct ev_periodic **periodics;
179	static int periodicmax, periodiccnt;
180
181	static void
182	upheap (WT *timers, int k)
183	{
184	WT w = timers [k];
185
186	while (k && timers [k >> 1]->at > w->at)
187	{
188	timers [k] = timers [k >> 1];
189	timers [k]->active = k + 1;
190	k >>= 1;
191	}
192
193	timers [k] = w;
194	timers [k]->active = k + 1;
195
196	}
197
198	static void
199	downheap (WT *timers, int N, int k)
200	{
201	WT w = timers [k];
202
203	while (k < (N >> 1))
204	{
205	int j = k << 1;
206
207	if (j + 1 < N && timers [j]->at > timers [j + 1]->at)
208	++j;
209
210	if (w->at <= timers [j]->at)
211	break;
212
213	timers [k] = timers [j];
214	timers [k]->active = k + 1;
215	k = j;
216	}
217
218	timers [k] = w;
219	timers [k]->active = k + 1;
220	}
221
222	/*****************************************************************************/
223
224	typedef struct
225	{
226	struct ev_signal *head;
227	sig_atomic_t gotsig;
228	} ANSIG;
229
230	static ANSIG *signals;
231	static int signalmax;
232
233	static int sigpipe [2];
234	static sig_atomic_t gotsig;
235	static struct ev_io sigev;
236
237	static void
238	signals_init (ANSIG *base, int count)
239	{
240	while (count--)
241	{
242	base->head = 0;
243	base->gotsig = 0;
244	++base;
245	}
246	}
247
248	static void
249	sighandler (int signum)
250	{
251	signals [signum - 1].gotsig = 1;
252
253	if (!gotsig)
254	{
255	gotsig = 1;
256	write (sigpipe [1], &gotsig, 1);
257	}
258	}
259
260	static void
261	sigcb (struct ev_io *iow, int revents)
262	{
263	struct ev_signal *w;
264	int sig;
265
266	gotsig = 0;
267	read (sigpipe [0], &revents, 1);
268
269	for (sig = signalmax; sig--; )
270	if (signals [sig].gotsig)
271	{
272	signals [sig].gotsig = 0;
273
274	for (w = signals [sig].head; w; w = w->next)
275	event ((W)w, EV_SIGNAL);
276	}
277	}
278
279	static void
280	siginit (void)
281	{
282	fcntl (sigpipe [0], F_SETFD, FD_CLOEXEC);
283	fcntl (sigpipe [1], F_SETFD, FD_CLOEXEC);
284
285	/* rather than sort out wether we really need nb, set it */
286	fcntl (sigpipe [0], F_SETFL, O_NONBLOCK);
287	fcntl (sigpipe [1], F_SETFL, O_NONBLOCK);
288
289	evio_set (&sigev, sigpipe [0], EV_READ);
290	evio_start (&sigev);
291	}
292
293	/*****************************************************************************/
294
295	static struct ev_idle **idles;
296	static int idlemax, idlecnt;
297
298	static struct ev_check **checks;
299	static int checkmax, checkcnt;
300
301	/*****************************************************************************/
302
303	#if HAVE_EPOLL
304	# include "ev_epoll.c"
305	#endif
306	#if HAVE_SELECT
307	# include "ev_select.c"
308	#endif
309
310	int ev_init (int flags)
311	{
312	#if HAVE_MONOTONIC
313	{
314	struct timespec ts;
315	if (!clock_gettime (CLOCK_MONOTONIC, &ts))
316	have_monotonic = 1;
317	}
318	#endif
319
320	ev_now = ev_time ();
321	now = get_clock ();
322	diff = ev_now - now;
323
324	if (pipe (sigpipe))
325	return 0;
326
327	ev_method = EVMETHOD_NONE;
328	#if HAVE_EPOLL
329	if (ev_method == EVMETHOD_NONE) epoll_init (flags);
330	#endif
331	#if HAVE_SELECT
332	if (ev_method == EVMETHOD_NONE) select_init (flags);
333	#endif
334
335	if (ev_method)
336	{
337	evw_init (&sigev, sigcb);
338	siginit ();
339	}
340
341	return ev_method;
342	}
343
344	/*****************************************************************************/
345
346	void ev_prefork (void)
347	{
348	/* nop */
349	}
350
351	void ev_postfork_parent (void)
352	{
353	/* nop */
354	}
355
356	void ev_postfork_child (void)
357	{
358	#if HAVE_EPOLL
359	if (ev_method == EVMETHOD_EPOLL)
360	epoll_postfork_child ();
361	#endif
362
363	evio_stop (&sigev);
364	close (sigpipe [0]);
365	close (sigpipe [1]);
366	pipe (sigpipe);
367	siginit ();
368	}
369
370	/*****************************************************************************/
371
372	static void
373	fd_reify (void)
374	{
375	int i;
376
377	for (i = 0; i < fdchangecnt; ++i)
378	{
379	int fd = fdchanges [i];
380	ANFD *anfd = anfds + fd;
381	struct ev_io *w;
382
383	int wev = 0;
384
385	for (w = anfd->head; w; w = w->next)
386	wev \|= w->events;
387
388	if (anfd->wev != wev)
389	{
390	method_modify (fd, anfd->wev, wev);
391	anfd->wev = wev;
392	}
393	}
394
395	fdchangecnt = 0;
396	}
397
398	static void
399	call_pending ()
400	{
401	int i;
402
403	for (i = 0; i < pendingcnt; ++i)
404	{
405	ANPENDING *p = pendings + i;
406
407	if (p->w)
408	{
409	p->w->pending = 0;
410	p->w->cb (p->w, p->events);
411	}
412	}
413
414	pendingcnt = 0;
415	}
416
417	static void
418	timers_reify ()
419	{
420	while (timercnt && timers [0]->at <= now)
421	{
422	struct ev_timer *w = timers [0];
423
424	/* first reschedule or stop timer */
425	if (w->repeat)
426	{
427	w->at = now + w->repeat;
428	assert (("timer timeout in the past, negative repeat?", w->at > now));
429	downheap ((WT *)timers, timercnt, 0);
430	}
431	else
432	evtimer_stop (w); /* nonrepeating: stop timer */
433
434	event ((W)w, EV_TIMEOUT);
435	}
436	}
437
438	static void
439	periodics_reify ()
440	{
441	while (periodiccnt && periodics [0]->at <= ev_now)
442	{
443	struct ev_periodic *w = periodics [0];
444
445	/* first reschedule or stop timer */
446	if (w->interval)
447	{
448	w->at += floor ((ev_now - w->at) / w->interval + 1.) * w->interval;
449	assert (("periodic timeout in the past, negative interval?", w->at > ev_now));
450	downheap ((WT *)periodics, periodiccnt, 0);
451	}
452	else
453	evperiodic_stop (w); /* nonrepeating: stop timer */
454
455	event ((W)w, EV_TIMEOUT);
456	}
457	}
458
459	static void
460	time_jump (ev_tstamp diff)
461	{
462	int i;
463
464	/* adjust periodics */
465	for (i = 0; i < periodiccnt; ++i)
466	{
467	struct ev_periodic *w = periodics [i];
468
469	if (w->interval)
470	{
471	ev_tstamp diff = ceil ((ev_now - w->at) / w->interval) * w->interval;
472
473	if (fabs (diff) >= 1e-4)
474	{
475	evperiodic_stop (w);
476	evperiodic_start (w);
477
478	i = 0; /* restart loop, inefficient, but time jumps should be rare */
479	}
480	}
481	}
482
483	/* adjust timers. this is easy, as the offset is the same for all */
484	for (i = 0; i < timercnt; ++i)
485	timers [i]->at += diff;
486	}
487
488	static void
489	time_update ()
490	{
491	int i;
492
493	ev_now = ev_time ();
494
495	if (have_monotonic)
496	{
497	ev_tstamp odiff = diff;
498
499	for (i = 4; --i; ) /* loop a few times, before making important decisions */
500	{
501	now = get_clock ();
502	diff = ev_now - now;
503
504	if (fabs (odiff - diff) < MIN_TIMEJUMP)
505	return; /* all is well */
506
507	ev_now = ev_time ();
508	}
509
510	time_jump (diff - odiff);
511	}
512	else
513	{
514	if (now > ev_now \|\| now < ev_now - MAX_BLOCKTIME - MIN_TIMEJUMP)
515	time_jump (ev_now - now);
516
517	now = ev_now;
518	}
519	}
520
521	int ev_loop_done;
522
523	void ev_loop (int flags)
524	{
525	double block;
526	ev_loop_done = flags & EVLOOP_ONESHOT;
527
528	if (checkcnt)
529	{
530	queue_events ((W *)checks, checkcnt, EV_CHECK);
531	call_pending ();
532	}
533
534	do
535	{
536	/* update fd-related kernel structures */
537	fd_reify ();
538
539	/* calculate blocking time */
540
541	/* we only need this for !monotonic clock, but as we always have timers, we just calculate it every time */
542	ev_now = ev_time ();
543
544	if (flags & EVLOOP_NONBLOCK \|\| idlecnt)
545	block = 0.;
546	else
547	{
548	block = MAX_BLOCKTIME;
549
550	if (timercnt)
551	{
552	ev_tstamp to = timers [0]->at - get_clock () + method_fudge;
553	if (block > to) block = to;
554	}
555
556	if (periodiccnt)
557	{
558	ev_tstamp to = periodics [0]->at - ev_now + method_fudge;
559	if (block > to) block = to;
560	}
561
562	if (block < 0.) block = 0.;
563	}
564
565	method_poll (block);
566
567	/* update ev_now, do magic */
568	time_update ();
569
570	/* queue pending timers and reschedule them */
571	periodics_reify (); /* absolute timers first */
572	timers_reify (); /* relative timers second */
573
574	/* queue idle watchers unless io or timers are pending */
575	if (!pendingcnt)
576	queue_events ((W *)idles, idlecnt, EV_IDLE);
577
578	/* queue check and possibly idle watchers */
579	queue_events ((W *)checks, checkcnt, EV_CHECK);
580
581	call_pending ();
582	}
583	while (!ev_loop_done);
584	}
585
586	/*****************************************************************************/
587
588	static void
589	wlist_add (WL *head, WL elem)
590	{
591	elem->next = *head;
592	*head = elem;
593	}
594
595	static void
596	wlist_del (WL *head, WL elem)
597	{
598	while (*head)
599	{
600	if (*head == elem)
601	{
602	*head = elem->next;
603	return;
604	}
605
606	head = &(*head)->next;
607	}
608	}
609
610	static void
611	ev_start (W w, int active)
612	{
613	w->pending = 0;
614	w->active = active;
615	}
616
617	static void
618	ev_stop (W w)
619	{
620	if (w->pending)
621	pendings [w->pending - 1].w = 0;
622
623	w->active = 0;
624	}
625
626	/*****************************************************************************/
627
628	void
629	evio_start (struct ev_io *w)
630	{
631	if (ev_is_active (w))
632	return;
633
634	int fd = w->fd;
635
636	ev_start ((W)w, 1);
637	array_needsize (anfds, anfdmax, fd + 1, anfds_init);
638	wlist_add ((WL *)&anfds[fd].head, (WL)w);
639
640	++fdchangecnt;
641	array_needsize (fdchanges, fdchangemax, fdchangecnt, );
642	fdchanges [fdchangecnt - 1] = fd;
643	}
644
645	void
646	evio_stop (struct ev_io *w)
647	{
648	if (!ev_is_active (w))
649	return;
650
651	wlist_del ((WL *)&anfds[w->fd].head, (WL)w);
652	ev_stop ((W)w);
653
654	++fdchangecnt;
655	array_needsize (fdchanges, fdchangemax, fdchangecnt, );
656	fdchanges [fdchangecnt - 1] = w->fd;
657	}
658
659
660	void
661	evtimer_start (struct ev_timer *w)
662	{
663	if (ev_is_active (w))
664	return;
665
666	w->at += now;
667
668	ev_start ((W)w, ++timercnt);
669	array_needsize (timers, timermax, timercnt, );
670	timers [timercnt - 1] = w;
671	upheap ((WT *)timers, timercnt - 1);
672	}
673
674	void
675	evtimer_stop (struct ev_timer *w)
676	{
677	if (!ev_is_active (w))
678	return;
679
680	if (w->active < timercnt--)
681	{
682	timers [w->active - 1] = timers [timercnt];
683	downheap ((WT *)timers, timercnt, w->active - 1);
684	}
685
686	ev_stop ((W)w);
687	}
688
689	void
690	evperiodic_start (struct ev_periodic *w)
691	{
692	if (ev_is_active (w))
693	return;
694
695	/* this formula differs from the one in periodic_reify because we do not always round up */
696	if (w->interval)
697	w->at += ceil ((ev_now - w->at) / w->interval) * w->interval;
698
699	ev_start ((W)w, ++periodiccnt);
700	array_needsize (periodics, periodicmax, periodiccnt, );
701	periodics [periodiccnt - 1] = w;
702	upheap ((WT *)periodics, periodiccnt - 1);
703	}
704
705	void
706	evperiodic_stop (struct ev_periodic *w)
707	{
708	if (!ev_is_active (w))
709	return;
710
711	if (w->active < periodiccnt--)
712	{
713	periodics [w->active - 1] = periodics [periodiccnt];
714	downheap ((WT *)periodics, periodiccnt, w->active - 1);
715	}
716
717	ev_stop ((W)w);
718	}
719
720	void
721	evsignal_start (struct ev_signal *w)
722	{
723	if (ev_is_active (w))
724	return;
725
726	ev_start ((W)w, 1);
727	array_needsize (signals, signalmax, w->signum, signals_init);
728	wlist_add ((WL *)&signals [w->signum - 1].head, (WL)w);
729
730	if (!w->next)
731	{
732	struct sigaction sa;
733	sa.sa_handler = sighandler;
734	sigfillset (&sa.sa_mask);
735	sa.sa_flags = 0;
736	sigaction (w->signum, &sa, 0);
737	}
738	}
739
740	void
741	evsignal_stop (struct ev_signal *w)
742	{
743	if (!ev_is_active (w))
744	return;
745
746	wlist_del ((WL *)&signals [w->signum - 1].head, (WL)w);
747	ev_stop ((W)w);
748
749	if (!signals [w->signum - 1].head)
750	signal (w->signum, SIG_DFL);
751	}
752
753	void evidle_start (struct ev_idle *w)
754	{
755	if (ev_is_active (w))
756	return;
757
758	ev_start ((W)w, ++idlecnt);
759	array_needsize (idles, idlemax, idlecnt, );
760	idles [idlecnt - 1] = w;
761	}
762
763	void evidle_stop (struct ev_idle *w)
764	{
765	idles [w->active - 1] = idles [--idlecnt];
766	ev_stop ((W)w);
767	}
768
769	void evcheck_start (struct ev_check *w)
770	{
771	if (ev_is_active (w))
772	return;
773
774	ev_start ((W)w, ++checkcnt);
775	array_needsize (checks, checkmax, checkcnt, );
776	checks [checkcnt - 1] = w;
777	}
778
779	void evcheck_stop (struct ev_check *w)
780	{
781	checks [w->active - 1] = checks [--checkcnt];
782	ev_stop ((W)w);
783	}
784
785	/*****************************************************************************/
786
787	#if 1
788
789	struct ev_io wio;
790
791	static void
792	sin_cb (struct ev_io *w, int revents)
793	{
794	fprintf (stderr, "sin %d, revents %d\n", w->fd, revents);
795	}
796
797	static void
798	ocb (struct ev_timer *w, int revents)
799	{
800	//fprintf (stderr, "timer %f,%f (%x) (%f) d%p\n", w->at, w->repeat, revents, w->at - ev_time (), w->data);
801	evtimer_stop (w);
802	evtimer_start (w);
803	}
804
805	static void
806	scb (struct ev_signal *w, int revents)
807	{
808	fprintf (stderr, "signal %x,%d\n", revents, w->signum);
809	evio_stop (&wio);
810	evio_start (&wio);
811	}
812
813	static void
814	gcb (struct ev_signal *w, int revents)
815	{
816	fprintf (stderr, "generic %x\n", revents);
817
818	}
819
820	int main (void)
821	{
822	ev_init (0);
823
824	evio_init (&wio, sin_cb, 0, EV_READ);
825	evio_start (&wio);
826
827	struct ev_timer t[10000];
828
829	#if 0
830	int i;
831	for (i = 0; i < 10000; ++i)
832	{
833	struct ev_timer *w = t + i;
834	evw_init (w, ocb, i);
835	evtimer_init_abs (w, ocb, drand48 (), 0.99775533);
836	evtimer_start (w);
837	if (drand48 () < 0.5)
838	evtimer_stop (w);
839	}
840	#endif
841
842	struct ev_timer t1;
843	evtimer_init (&t1, ocb, 5, 10);
844	evtimer_start (&t1);
845
846	struct ev_signal sig;
847	evsignal_init (&sig, scb, SIGQUIT);
848	evsignal_start (&sig);
849
850	struct ev_check cw;
851	evcheck_init (&cw, gcb);
852	evcheck_start (&cw);
853
854	struct ev_idle iw;
855	evidle_init (&iw, gcb);
856	evidle_start (&iw);
857
858	ev_loop (0);
859
860	return 0;
861	}
862
863	#endif
864
865
866
867