libev/ev.c

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

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;                 \
      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)
{
  if (w->active)
    {
      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];

      event ((W)w, EV_TIMEOUT);

      /* 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 */
    }
}

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
periodics_reschedule (ev_tstamp diff)
{
  int i;

  /* adjust periodics after time jump */
  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 */
            }
        }
    }
}

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 ();
        }

      periodics_reschedule (diff - odiff);
      /* no timer adjustment, as the monotonic clock doesn't jump */
    }
  else
    {
      if (now > ev_now || now < ev_now - MAX_BLOCKTIME - MIN_TIMEJUMP)
        {
          periodics_reschedule (ev_now - now);

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

      now = ev_now;
    }
}

int ev_loop_done;

void ev_loop (int flags)
{
  double block;
  ev_loop_done = flags & EVLOOP_ONESHOT ? 1 : 0;

  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 - (have_monotonic ? get_clock () : ev_now) + 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);

  if (ev_loop_done != 2)
    ev_loop_done = 0;
}

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

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_clear (W w)
{
  if (w->pending)
    {
      pendings [w->pending - 1].w = 0;
      w->pending = 0;
    }
}

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

static void
ev_stop (W w)
{
  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)
{
  ev_clear ((W)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;

  assert (("timer repeat value less than zero not allowed", w->repeat >= 0.));

  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)
{
  ev_clear ((W)w);
  if (!ev_is_active (w))
    return;

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

  w->at = w->repeat;

  ev_stop ((W)w);
}

void
evtimer_again (struct ev_timer *w)
{
  if (ev_is_active (w))
    {
      if (w->repeat)
        {
          w->at = now + w->repeat;
          downheap ((WT *)timers, timercnt, w->active - 1);
        }
      else
        evtimer_stop (w);
    }
  else if (w->repeat)
    evtimer_start (w);
}

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

  assert (("periodic interval value less than zero not allowed", w->interval >= 0.));

  /* 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)
{
  ev_clear ((W)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)
{
  ev_clear ((W)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)
{
  ev_clear ((W)w);
  if (ev_is_active (w))
    return;

  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)
{
  ev_clear ((W)w);
  if (ev_is_active (w))
    return;

  checks [w->active - 1] = checks [--checkcnt];
  ev_stop ((W)w);
}

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

struct ev_once
{
  struct ev_io io;
  struct ev_timer to;
  void (*cb)(int revents, void *arg);
  void *arg;
};

static void
once_cb (struct ev_once *once, int revents)
{
  void (*cb)(int revents, void *arg) = once->cb;
  void *arg = once->arg;

  evio_stop (&once->io);
  evtimer_stop (&once->to);
  free (once);

  cb (revents, arg);
}

static void
once_cb_io (struct ev_io *w, int revents)
{
  once_cb ((struct ev_once *)(((char *)w) - offsetof (struct ev_once, io)), revents);
}

static void
once_cb_to (struct ev_timer *w, int revents)
{
  once_cb ((struct ev_once *)(((char *)w) - offsetof (struct ev_once, to)), revents);
}

void
ev_once (int fd, int events, ev_tstamp timeout, void (*cb)(int revents, void *arg), void *arg)
{
  struct ev_once *once = malloc (sizeof (struct ev_once));

  if (!once)
    cb (EV_ERROR, arg);
  else
    {
      once->cb  = cb;
      once->arg = arg;

      evw_init (&once->io, once_cb_io);

      if (fd >= 0)
        {
          evio_set (&once->io, fd, events);
          evio_start (&once->io);
        }

      evw_init (&once->to, once_cb_to);

      if (timeout >= 0.)
        {
          evtimer_set (&once->to, timeout, 0.);
          evtimer_start (&once->to);
        }
    }
}

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

#if 0

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:	1.16
Committed:	Wed Oct 31 13:57:34 2007 UTC (16 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.15:	+97 -11 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	#include <stddef.h>
7
8	#include <stdio.h>
9
10	#include <assert.h>
11	#include <errno.h>
12	#include <sys/time.h>
13	#include <time.h>
14
15	#define HAVE_EPOLL 1
16
17	#ifndef HAVE_MONOTONIC
18	# ifdef CLOCK_MONOTONIC
19	# define HAVE_MONOTONIC 1
20	# endif
21	#endif
22
23	#ifndef HAVE_SELECT
24	# define HAVE_SELECT 1
25	#endif
26
27	#ifndef HAVE_EPOLL
28	# define HAVE_EPOLL 0
29	#endif
30
31	#ifndef HAVE_REALTIME
32	# define HAVE_REALTIME 1 /* posix requirement, but might be slower */
33	#endif
34
35	#define MIN_TIMEJUMP 1. /* minimum timejump that gets detected (if monotonic clock available) */
36	#define MAX_BLOCKTIME 60.
37
38	#include "ev.h"
39
40	typedef struct ev_watcher *W;
41	typedef struct ev_watcher_list *WL;
42	typedef struct ev_watcher_time *WT;
43
44	static ev_tstamp now, diff; /* monotonic clock */
45	ev_tstamp ev_now;
46	int ev_method;
47
48	static int have_monotonic; /* runtime */
49
50	static ev_tstamp method_fudge; /* stupid epoll-returns-early bug */
51	static void (*method_modify)(int fd, int oev, int nev);
52	static void (*method_poll)(ev_tstamp timeout);
53
54	/*****************************************************************************/
55
56	ev_tstamp
57	ev_time (void)
58	{
59	#if HAVE_REALTIME
60	struct timespec ts;
61	clock_gettime (CLOCK_REALTIME, &ts);
62	return ts.tv_sec + ts.tv_nsec * 1e-9;
63	#else
64	struct timeval tv;
65	gettimeofday (&tv, 0);
66	return tv.tv_sec + tv.tv_usec * 1e-6;
67	#endif
68	}
69
70	static ev_tstamp
71	get_clock (void)
72	{
73	#if HAVE_MONOTONIC
74	if (have_monotonic)
75	{
76	struct timespec ts;
77	clock_gettime (CLOCK_MONOTONIC, &ts);
78	return ts.tv_sec + ts.tv_nsec * 1e-9;
79	}
80	#endif
81
82	return ev_time ();
83	}
84
85	#define array_needsize(base,cur,cnt,init) \
86	if ((cnt) > cur) \
87	{ \
88	int newcnt = cur ? cur << 1 : 16; \
89	base = realloc (base, sizeof (base) (newcnt)); \
90	init (base + cur, newcnt - cur); \
91	cur = newcnt; \
92	}
93
94	/*****************************************************************************/
95
96	typedef struct
97	{
98	struct ev_io *head;
99	unsigned char wev, rev; /* want, received event set */
100	} ANFD;
101
102	static ANFD *anfds;
103	static int anfdmax;
104
105	static int *fdchanges;
106	static int fdchangemax, fdchangecnt;
107
108	static void
109	anfds_init (ANFD *base, int count)
110	{
111	while (count--)
112	{
113	base->head = 0;
114	base->wev = base->rev = EV_NONE;
115	++base;
116	}
117	}
118
119	typedef struct
120	{
121	W w;
122	int events;
123	} ANPENDING;
124
125	static ANPENDING *pendings;
126	static int pendingmax, pendingcnt;
127
128	static void
129	event (W w, int events)
130	{
131	if (w->active)
132	{
133	w->pending = ++pendingcnt;
134	array_needsize (pendings, pendingmax, pendingcnt, );
135	pendings [pendingcnt - 1].w = w;
136	pendings [pendingcnt - 1].events = events;
137	}
138	}
139
140	static void
141	fd_event (int fd, int events)
142	{
143	ANFD *anfd = anfds + fd;
144	struct ev_io *w;
145
146	for (w = anfd->head; w; w = w->next)
147	{
148	int ev = w->events & events;
149
150	if (ev)
151	event ((W)w, ev);
152	}
153	}
154
155	static void
156	queue_events (W *events, int eventcnt, int type)
157	{
158	int i;
159
160	for (i = 0; i < eventcnt; ++i)
161	event (events [i], type);
162	}
163
164	/*****************************************************************************/
165
166	static struct ev_timer **timers;
167	static int timermax, timercnt;
168
169	static struct ev_periodic **periodics;
170	static int periodicmax, periodiccnt;
171
172	static void
173	upheap (WT *timers, int k)
174	{
175	WT w = timers [k];
176
177	while (k && timers [k >> 1]->at > w->at)
178	{
179	timers [k] = timers [k >> 1];
180	timers [k]->active = k + 1;
181	k >>= 1;
182	}
183
184	timers [k] = w;
185	timers [k]->active = k + 1;
186
187	}
188
189	static void
190	downheap (WT *timers, int N, int k)
191	{
192	WT w = timers [k];
193
194	while (k < (N >> 1))
195	{
196	int j = k << 1;
197
198	if (j + 1 < N && timers [j]->at > timers [j + 1]->at)
199	++j;
200
201	if (w->at <= timers [j]->at)
202	break;
203
204	timers [k] = timers [j];
205	timers [k]->active = k + 1;
206	k = j;
207	}
208
209	timers [k] = w;
210	timers [k]->active = k + 1;
211	}
212
213	/*****************************************************************************/
214
215	typedef struct
216	{
217	struct ev_signal *head;
218	sig_atomic_t gotsig;
219	} ANSIG;
220
221	static ANSIG *signals;
222	static int signalmax;
223
224	static int sigpipe [2];
225	static sig_atomic_t gotsig;
226	static struct ev_io sigev;
227
228	static void
229	signals_init (ANSIG *base, int count)
230	{
231	while (count--)
232	{
233	base->head = 0;
234	base->gotsig = 0;
235	++base;
236	}
237	}
238
239	static void
240	sighandler (int signum)
241	{
242	signals [signum - 1].gotsig = 1;
243
244	if (!gotsig)
245	{
246	gotsig = 1;
247	write (sigpipe [1], &gotsig, 1);
248	}
249	}
250
251	static void
252	sigcb (struct ev_io *iow, int revents)
253	{
254	struct ev_signal *w;
255	int sig;
256
257	gotsig = 0;
258	read (sigpipe [0], &revents, 1);
259
260	for (sig = signalmax; sig--; )
261	if (signals [sig].gotsig)
262	{
263	signals [sig].gotsig = 0;
264
265	for (w = signals [sig].head; w; w = w->next)
266	event ((W)w, EV_SIGNAL);
267	}
268	}
269
270	static void
271	siginit (void)
272	{
273	fcntl (sigpipe [0], F_SETFD, FD_CLOEXEC);
274	fcntl (sigpipe [1], F_SETFD, FD_CLOEXEC);
275
276	/* rather than sort out wether we really need nb, set it */
277	fcntl (sigpipe [0], F_SETFL, O_NONBLOCK);
278	fcntl (sigpipe [1], F_SETFL, O_NONBLOCK);
279
280	evio_set (&sigev, sigpipe [0], EV_READ);
281	evio_start (&sigev);
282	}
283
284	/*****************************************************************************/
285
286	static struct ev_idle **idles;
287	static int idlemax, idlecnt;
288
289	static struct ev_check **checks;
290	static int checkmax, checkcnt;
291
292	/*****************************************************************************/
293
294	#if HAVE_EPOLL
295	# include "ev_epoll.c"
296	#endif
297	#if HAVE_SELECT
298	# include "ev_select.c"
299	#endif
300
301	int ev_init (int flags)
302	{
303	#if HAVE_MONOTONIC
304	{
305	struct timespec ts;
306	if (!clock_gettime (CLOCK_MONOTONIC, &ts))
307	have_monotonic = 1;
308	}
309	#endif
310
311	ev_now = ev_time ();
312	now = get_clock ();
313	diff = ev_now - now;
314
315	if (pipe (sigpipe))
316	return 0;
317
318	ev_method = EVMETHOD_NONE;
319	#if HAVE_EPOLL
320	if (ev_method == EVMETHOD_NONE) epoll_init (flags);
321	#endif
322	#if HAVE_SELECT
323	if (ev_method == EVMETHOD_NONE) select_init (flags);
324	#endif
325
326	if (ev_method)
327	{
328	evw_init (&sigev, sigcb);
329	siginit ();
330	}
331
332	return ev_method;
333	}
334
335	/*****************************************************************************/
336
337	void ev_prefork (void)
338	{
339	/* nop */
340	}
341
342	void ev_postfork_parent (void)
343	{
344	/* nop */
345	}
346
347	void ev_postfork_child (void)
348	{
349	#if HAVE_EPOLL
350	if (ev_method == EVMETHOD_EPOLL)
351	epoll_postfork_child ();
352	#endif
353
354	evio_stop (&sigev);
355	close (sigpipe [0]);
356	close (sigpipe [1]);
357	pipe (sigpipe);
358	siginit ();
359	}
360
361	/*****************************************************************************/
362
363	static void
364	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	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	timers_reify ()
410	{
411	while (timercnt && timers [0]->at <= now)
412	{
413	struct ev_timer *w = timers [0];
414
415	event ((W)w, EV_TIMEOUT);
416
417	/* first reschedule or stop timer */
418	if (w->repeat)
419	{
420	w->at = now + w->repeat;
421	assert (("timer timeout in the past, negative repeat?", w->at > now));
422	downheap ((WT *)timers, timercnt, 0);
423	}
424	else
425	evtimer_stop (w); /* nonrepeating: stop timer */
426	}
427	}
428
429	static void
430	periodics_reify ()
431	{
432	while (periodiccnt && periodics [0]->at <= ev_now)
433	{
434	struct ev_periodic *w = periodics [0];
435
436	/* first reschedule or stop timer */
437	if (w->interval)
438	{
439	w->at += floor ((ev_now - w->at) / w->interval + 1.) * w->interval;
440	assert (("periodic timeout in the past, negative interval?", w->at > ev_now));
441	downheap ((WT *)periodics, periodiccnt, 0);
442	}
443	else
444	evperiodic_stop (w); /* nonrepeating: stop timer */
445
446	event ((W)w, EV_TIMEOUT);
447	}
448	}
449
450	static void
451	periodics_reschedule (ev_tstamp diff)
452	{
453	int i;
454
455	/* adjust periodics after time jump */
456	for (i = 0; i < periodiccnt; ++i)
457	{
458	struct ev_periodic *w = periodics [i];
459
460	if (w->interval)
461	{
462	ev_tstamp diff = ceil ((ev_now - w->at) / w->interval) * w->interval;
463
464	if (fabs (diff) >= 1e-4)
465	{
466	evperiodic_stop (w);
467	evperiodic_start (w);
468
469	i = 0; /* restart loop, inefficient, but time jumps should be rare */
470	}
471	}
472	}
473	}
474
475	static void
476	time_update ()
477	{
478	int i;
479
480	ev_now = ev_time ();
481
482	if (have_monotonic)
483	{
484	ev_tstamp odiff = diff;
485
486	for (i = 4; --i; ) /* loop a few times, before making important decisions */
487	{
488	now = get_clock ();
489	diff = ev_now - now;
490
491	if (fabs (odiff - diff) < MIN_TIMEJUMP)
492	return; /* all is well */
493
494	ev_now = ev_time ();
495	}
496
497	periodics_reschedule (diff - odiff);
498	/* no timer adjustment, as the monotonic clock doesn't jump */
499	}
500	else
501	{
502	if (now > ev_now \|\| now < ev_now - MAX_BLOCKTIME - MIN_TIMEJUMP)
503	{
504	periodics_reschedule (ev_now - now);
505
506	/* adjust timers. this is easy, as the offset is the same for all */
507	for (i = 0; i < timercnt; ++i)
508	timers [i]->at += diff;
509	}
510
511	now = ev_now;
512	}
513	}
514
515	int ev_loop_done;
516
517	void ev_loop (int flags)
518	{
519	double block;
520	ev_loop_done = flags & EVLOOP_ONESHOT ? 1 : 0;
521
522	if (checkcnt)
523	{
524	queue_events ((W *)checks, checkcnt, EV_CHECK);
525	call_pending ();
526	}
527
528	do
529	{
530	/* update fd-related kernel structures */
531	fd_reify ();
532
533	/* calculate blocking time */
534
535	/* we only need this for !monotonic clock, but as we always have timers, we just calculate it every time */
536	ev_now = ev_time ();
537
538	if (flags & EVLOOP_NONBLOCK \|\| idlecnt)
539	block = 0.;
540	else
541	{
542	block = MAX_BLOCKTIME;
543
544	if (timercnt)
545	{
546	ev_tstamp to = timers [0]->at - (have_monotonic ? get_clock () : ev_now) + method_fudge;
547	if (block > to) block = to;
548	}
549
550	if (periodiccnt)
551	{
552	ev_tstamp to = periodics [0]->at - ev_now + method_fudge;
553	if (block > to) block = to;
554	}
555
556	if (block < 0.) block = 0.;
557	}
558
559	method_poll (block);
560
561	/* update ev_now, do magic */
562	time_update ();
563
564	/* queue pending timers and reschedule them */
565	periodics_reify (); /* absolute timers first */
566	timers_reify (); /* relative timers second */
567
568	/* queue idle watchers unless io or timers are pending */
569	if (!pendingcnt)
570	queue_events ((W *)idles, idlecnt, EV_IDLE);
571
572	/* queue check and possibly idle watchers */
573	queue_events ((W *)checks, checkcnt, EV_CHECK);
574
575	call_pending ();
576	}
577	while (!ev_loop_done);
578
579	if (ev_loop_done != 2)
580	ev_loop_done = 0;
581	}
582
583	/*****************************************************************************/
584
585	static void
586	wlist_add (WL *head, WL elem)
587	{
588	elem->next = *head;
589	*head = elem;
590	}
591
592	static void
593	wlist_del (WL *head, WL elem)
594	{
595	while (*head)
596	{
597	if (*head == elem)
598	{
599	*head = elem->next;
600	return;
601	}
602
603	head = &(*head)->next;
604	}
605	}
606
607	static void
608	ev_clear (W w)
609	{
610	if (w->pending)
611	{
612	pendings [w->pending - 1].w = 0;
613	w->pending = 0;
614	}
615	}
616
617	static void
618	ev_start (W w, int active)
619	{
620	w->active = active;
621	}
622
623	static void
624	ev_stop (W w)
625	{
626	w->active = 0;
627	}
628
629	/*****************************************************************************/
630
631	void
632	evio_start (struct ev_io *w)
633	{
634	if (ev_is_active (w))
635	return;
636
637	int fd = w->fd;
638
639	ev_start ((W)w, 1);
640	array_needsize (anfds, anfdmax, fd + 1, anfds_init);
641	wlist_add ((WL *)&anfds[fd].head, (WL)w);
642
643	++fdchangecnt;
644	array_needsize (fdchanges, fdchangemax, fdchangecnt, );
645	fdchanges [fdchangecnt - 1] = fd;
646	}
647
648	void
649	evio_stop (struct ev_io *w)
650	{
651	ev_clear ((W)w);
652	if (!ev_is_active (w))
653	return;
654
655	wlist_del ((WL *)&anfds[w->fd].head, (WL)w);
656	ev_stop ((W)w);
657
658	++fdchangecnt;
659	array_needsize (fdchanges, fdchangemax, fdchangecnt, );
660	fdchanges [fdchangecnt - 1] = w->fd;
661	}
662
663	void
664	evtimer_start (struct ev_timer *w)
665	{
666	if (ev_is_active (w))
667	return;
668
669	w->at += now;
670
671	assert (("timer repeat value less than zero not allowed", w->repeat >= 0.));
672
673	ev_start ((W)w, ++timercnt);
674	array_needsize (timers, timermax, timercnt, );
675	timers [timercnt - 1] = w;
676	upheap ((WT *)timers, timercnt - 1);
677	}
678
679	void
680	evtimer_stop (struct ev_timer *w)
681	{
682	ev_clear ((W)w);
683	if (!ev_is_active (w))
684	return;
685
686	if (w->active < timercnt--)
687	{
688	timers [w->active - 1] = timers [timercnt];
689	downheap ((WT *)timers, timercnt, w->active - 1);
690	}
691
692	w->at = w->repeat;
693
694	ev_stop ((W)w);
695	}
696
697	void
698	evtimer_again (struct ev_timer *w)
699	{
700	if (ev_is_active (w))
701	{
702	if (w->repeat)
703	{
704	w->at = now + w->repeat;
705	downheap ((WT *)timers, timercnt, w->active - 1);
706	}
707	else
708	evtimer_stop (w);
709	}
710	else if (w->repeat)
711	evtimer_start (w);
712	}
713
714	void
715	evperiodic_start (struct ev_periodic *w)
716	{
717	if (ev_is_active (w))
718	return;
719
720	assert (("periodic interval value less than zero not allowed", w->interval >= 0.));
721
722	/* this formula differs from the one in periodic_reify because we do not always round up */
723	if (w->interval)
724	w->at += ceil ((ev_now - w->at) / w->interval) * w->interval;
725
726	ev_start ((W)w, ++periodiccnt);
727	array_needsize (periodics, periodicmax, periodiccnt, );
728	periodics [periodiccnt - 1] = w;
729	upheap ((WT *)periodics, periodiccnt - 1);
730	}
731
732	void
733	evperiodic_stop (struct ev_periodic *w)
734	{
735	ev_clear ((W)w);
736	if (!ev_is_active (w))
737	return;
738
739	if (w->active < periodiccnt--)
740	{
741	periodics [w->active - 1] = periodics [periodiccnt];
742	downheap ((WT *)periodics, periodiccnt, w->active - 1);
743	}
744
745	ev_stop ((W)w);
746	}
747
748	void
749	evsignal_start (struct ev_signal *w)
750	{
751	if (ev_is_active (w))
752	return;
753
754	ev_start ((W)w, 1);
755	array_needsize (signals, signalmax, w->signum, signals_init);
756	wlist_add ((WL *)&signals [w->signum - 1].head, (WL)w);
757
758	if (!w->next)
759	{
760	struct sigaction sa;
761	sa.sa_handler = sighandler;
762	sigfillset (&sa.sa_mask);
763	sa.sa_flags = 0;
764	sigaction (w->signum, &sa, 0);
765	}
766	}
767
768	void
769	evsignal_stop (struct ev_signal *w)
770	{
771	ev_clear ((W)w);
772	if (!ev_is_active (w))
773	return;
774
775	wlist_del ((WL *)&signals [w->signum - 1].head, (WL)w);
776	ev_stop ((W)w);
777
778	if (!signals [w->signum - 1].head)
779	signal (w->signum, SIG_DFL);
780	}
781
782	void evidle_start (struct ev_idle *w)
783	{
784	if (ev_is_active (w))
785	return;
786
787	ev_start ((W)w, ++idlecnt);
788	array_needsize (idles, idlemax, idlecnt, );
789	idles [idlecnt - 1] = w;
790	}
791
792	void evidle_stop (struct ev_idle *w)
793	{
794	ev_clear ((W)w);
795	if (ev_is_active (w))
796	return;
797
798	idles [w->active - 1] = idles [--idlecnt];
799	ev_stop ((W)w);
800	}
801
802	void evcheck_start (struct ev_check *w)
803	{
804	if (ev_is_active (w))
805	return;
806
807	ev_start ((W)w, ++checkcnt);
808	array_needsize (checks, checkmax, checkcnt, );
809	checks [checkcnt - 1] = w;
810	}
811
812	void evcheck_stop (struct ev_check *w)
813	{
814	ev_clear ((W)w);
815	if (ev_is_active (w))
816	return;
817
818	checks [w->active - 1] = checks [--checkcnt];
819	ev_stop ((W)w);
820	}
821
822	/*****************************************************************************/
823
824	struct ev_once
825	{
826	struct ev_io io;
827	struct ev_timer to;
828	void (cb)(int revents, void arg);
829	void *arg;
830	};
831
832	static void
833	once_cb (struct ev_once *once, int revents)
834	{
835	void (cb)(int revents, void arg) = once->cb;
836	void *arg = once->arg;
837
838	evio_stop (&once->io);
839	evtimer_stop (&once->to);
840	free (once);
841
842	cb (revents, arg);
843	}
844
845	static void
846	once_cb_io (struct ev_io *w, int revents)
847	{
848	once_cb ((struct ev_once )(((char )w) - offsetof (struct ev_once, io)), revents);
849	}
850
851	static void
852	once_cb_to (struct ev_timer *w, int revents)
853	{
854	once_cb ((struct ev_once )(((char )w) - offsetof (struct ev_once, to)), revents);
855	}
856
857	void
858	ev_once (int fd, int events, ev_tstamp timeout, void (cb)(int revents, void arg), void *arg)
859	{
860	struct ev_once *once = malloc (sizeof (struct ev_once));
861
862	if (!once)
863	cb (EV_ERROR, arg);
864	else
865	{
866	once->cb = cb;
867	once->arg = arg;
868
869	evw_init (&once->io, once_cb_io);
870
871	if (fd >= 0)
872	{
873	evio_set (&once->io, fd, events);
874	evio_start (&once->io);
875	}
876
877	evw_init (&once->to, once_cb_to);
878
879	if (timeout >= 0.)
880	{
881	evtimer_set (&once->to, timeout, 0.);
882	evtimer_start (&once->to);
883	}
884	}
885	}
886
887	/*****************************************************************************/
888
889	#if 0
890
891	struct ev_io wio;
892
893	static void
894	sin_cb (struct ev_io *w, int revents)
895	{
896	fprintf (stderr, "sin %d, revents %d\n", w->fd, revents);
897	}
898
899	static void
900	ocb (struct ev_timer *w, int revents)
901	{
902	//fprintf (stderr, "timer %f,%f (%x) (%f) d%p\n", w->at, w->repeat, revents, w->at - ev_time (), w->data);
903	evtimer_stop (w);
904	evtimer_start (w);
905	}
906
907	static void
908	scb (struct ev_signal *w, int revents)
909	{
910	fprintf (stderr, "signal %x,%d\n", revents, w->signum);
911	evio_stop (&wio);
912	evio_start (&wio);
913	}
914
915	static void
916	gcb (struct ev_signal *w, int revents)
917	{
918	fprintf (stderr, "generic %x\n", revents);
919
920	}
921
922	int main (void)
923	{
924	ev_init (0);
925
926	evio_init (&wio, sin_cb, 0, EV_READ);
927	evio_start (&wio);
928
929	struct ev_timer t[10000];
930
931	#if 0
932	int i;
933	for (i = 0; i < 10000; ++i)
934	{
935	struct ev_timer *w = t + i;
936	evw_init (w, ocb, i);
937	evtimer_init_abs (w, ocb, drand48 (), 0.99775533);
938	evtimer_start (w);
939	if (drand48 () < 0.5)
940	evtimer_stop (w);
941	}
942	#endif
943
944	struct ev_timer t1;
945	evtimer_init (&t1, ocb, 5, 10);
946	evtimer_start (&t1);
947
948	struct ev_signal sig;
949	evsignal_init (&sig, scb, SIGQUIT);
950	evsignal_start (&sig);
951
952	struct ev_check cw;
953	evcheck_init (&cw, gcb);
954	evcheck_start (&cw);
955
956	struct ev_idle iw;
957	evidle_init (&iw, gcb);
958	evidle_start (&iw);
959
960	ev_loop (0);
961
962	return 0;
963	}
964
965	#endif
966
967
968
969