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"

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
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_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;

  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)
{
  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)
{
  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 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:	1.14
Committed:	Wed Oct 31 11:52:12 2007 UTC (16 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.13:	+20 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	#include <math.h>
2			#include <stdlib.h>
3	root	1.7	#include <unistd.h>
4			#include <fcntl.h>
5			#include <signal.h>
6	root	1.1
7			#include <stdio.h>
8
9	root	1.4	#include <assert.h>
10	root	1.1	#include <errno.h>
11			#include <sys/time.h>
12			#include <time.h>
13
14	root	1.12	#define HAVE_EPOLL 1
15
16	root	1.10	#ifndef HAVE_MONOTONIC
17			# ifdef CLOCK_MONOTONIC
18			# define HAVE_MONOTONIC 1
19			# endif
20	root	1.1	#endif
21
22	root	1.10	#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	root	1.1
34	root	1.4	#define MIN_TIMEJUMP 1. /* minimum timejump that gets detected (if monotonic clock available) */
35	root	1.1	#define MAX_BLOCKTIME 60.
36
37			#include "ev.h"
38
39	root	1.10	typedef struct ev_watcher *W;
40			typedef struct ev_watcher_list *WL;
41	root	1.12	typedef struct ev_watcher_time *WT;
42	root	1.10
43	root	1.4	static ev_tstamp now, diff; /* monotonic clock */
44	root	1.1	ev_tstamp ev_now;
45			int ev_method;
46
47			static int have_monotonic; /* runtime */
48
49			static ev_tstamp method_fudge; /* stupid epoll-returns-early bug */
50	root	1.5	static void (*method_modify)(int fd, int oev, int nev);
51	root	1.1	static void (*method_poll)(ev_tstamp timeout);
52
53	root	1.8	/*****************************************************************************/
54
55	root	1.1	ev_tstamp
56			ev_time (void)
57			{
58			#if HAVE_REALTIME
59			struct timespec ts;
60			clock_gettime (CLOCK_REALTIME, &ts);
61			return ts.tv_sec + ts.tv_nsec * 1e-9;
62			#else
63			struct timeval tv;
64			gettimeofday (&tv, 0);
65			return tv.tv_sec + tv.tv_usec * 1e-6;
66			#endif
67			}
68
69			static ev_tstamp
70			get_clock (void)
71			{
72			#if HAVE_MONOTONIC
73			if (have_monotonic)
74			{
75			struct timespec ts;
76			clock_gettime (CLOCK_MONOTONIC, &ts);
77			return ts.tv_sec + ts.tv_nsec * 1e-9;
78			}
79			#endif
80
81			return ev_time ();
82			}
83
84			#define array_needsize(base,cur,cnt,init) \
85			if ((cnt) > cur) \
86			{ \
87	root	1.2	int newcnt = cur ? cur << 1 : 16; \
88	root	1.1	fprintf (stderr, "resize(" # base ") from %d to %d\n", cur, newcnt);\
89			base = realloc (base, sizeof (base) (newcnt)); \
90			init (base + cur, newcnt - cur); \
91			cur = newcnt; \
92			}
93
94	root	1.8	/*****************************************************************************/
95
96	root	1.1	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	root	1.10	W w;
122	root	1.1	int events;
123			} ANPENDING;
124
125			static ANPENDING *pendings;
126			static int pendingmax, pendingcnt;
127
128			static void
129	root	1.10	event (W w, int events)
130	root	1.1	{
131			w->pending = ++pendingcnt;
132			array_needsize (pendings, pendingmax, pendingcnt, );
133			pendings [pendingcnt - 1].w = w;
134			pendings [pendingcnt - 1].events = events;
135			}
136
137			static void
138			fd_event (int fd, int events)
139			{
140			ANFD *anfd = anfds + fd;
141			struct ev_io *w;
142
143			for (w = anfd->head; w; w = w->next)
144			{
145			int ev = w->events & events;
146
147			if (ev)
148	root	1.10	event ((W)w, ev);
149	root	1.1	}
150			}
151
152	root	1.9	static void
153	root	1.10	queue_events (W *events, int eventcnt, int type)
154	root	1.9	{
155			int i;
156
157			for (i = 0; i < eventcnt; ++i)
158			event (events [i], type);
159			}
160
161	root	1.8	/*****************************************************************************/
162
163	root	1.12	static struct ev_timer **timers;
164			static int timermax, timercnt;
165	root	1.4
166	root	1.12	static struct ev_periodic **periodics;
167			static int periodicmax, periodiccnt;
168	root	1.1
169			static void
170	root	1.12	upheap (WT *timers, int k)
171	root	1.1	{
172	root	1.12	WT w = timers [k];
173	root	1.1
174			while (k && timers [k >> 1]->at > w->at)
175			{
176			timers [k] = timers [k >> 1];
177			timers [k]->active = k + 1;
178			k >>= 1;
179			}
180
181			timers [k] = w;
182			timers [k]->active = k + 1;
183
184			}
185
186			static void
187	root	1.12	downheap (WT *timers, int N, int k)
188	root	1.1	{
189	root	1.12	WT w = timers [k];
190	root	1.1
191	root	1.4	while (k < (N >> 1))
192	root	1.1	{
193			int j = k << 1;
194
195	root	1.4	if (j + 1 < N && timers [j]->at > timers [j + 1]->at)
196	root	1.1	++j;
197
198			if (w->at <= timers [j]->at)
199			break;
200
201			timers [k] = timers [j];
202	root	1.2	timers [k]->active = k + 1;
203	root	1.1	k = j;
204			}
205
206			timers [k] = w;
207			timers [k]->active = k + 1;
208			}
209
210	root	1.8	/*****************************************************************************/
211
212	root	1.7	typedef struct
213			{
214			struct ev_signal *head;
215			sig_atomic_t gotsig;
216			} ANSIG;
217
218			static ANSIG *signals;
219	root	1.4	static int signalmax;
220	root	1.1
221	root	1.7	static int sigpipe [2];
222			static sig_atomic_t gotsig;
223			static struct ev_io sigev;
224
225	root	1.1	static void
226	root	1.7	signals_init (ANSIG *base, int count)
227	root	1.1	{
228			while (count--)
229	root	1.7	{
230			base->head = 0;
231			base->gotsig = 0;
232			++base;
233			}
234			}
235
236			static void
237			sighandler (int signum)
238			{
239			signals [signum - 1].gotsig = 1;
240
241			if (!gotsig)
242			{
243			gotsig = 1;
244			write (sigpipe [1], &gotsig, 1);
245			}
246			}
247
248			static void
249			sigcb (struct ev_io *iow, int revents)
250			{
251			struct ev_signal *w;
252			int sig;
253
254			gotsig = 0;
255			read (sigpipe [0], &revents, 1);
256
257			for (sig = signalmax; sig--; )
258			if (signals [sig].gotsig)
259			{
260			signals [sig].gotsig = 0;
261
262			for (w = signals [sig].head; w; w = w->next)
263	root	1.10	event ((W)w, EV_SIGNAL);
264	root	1.7	}
265			}
266
267			static void
268			siginit (void)
269			{
270			fcntl (sigpipe [0], F_SETFD, FD_CLOEXEC);
271			fcntl (sigpipe [1], F_SETFD, FD_CLOEXEC);
272
273			/* rather than sort out wether we really need nb, set it */
274			fcntl (sigpipe [0], F_SETFL, O_NONBLOCK);
275			fcntl (sigpipe [1], F_SETFL, O_NONBLOCK);
276
277			evio_set (&sigev, sigpipe [0], EV_READ);
278			evio_start (&sigev);
279	root	1.1	}
280
281	root	1.8	/*****************************************************************************/
282
283	root	1.9	static struct ev_idle **idles;
284			static int idlemax, idlecnt;
285
286			static struct ev_check **checks;
287			static int checkmax, checkcnt;
288
289			/*****************************************************************************/
290
291	root	1.1	#if HAVE_EPOLL
292			# include "ev_epoll.c"
293			#endif
294			#if HAVE_SELECT
295			# include "ev_select.c"
296			#endif
297
298			int ev_init (int flags)
299			{
300			#if HAVE_MONOTONIC
301			{
302			struct timespec ts;
303			if (!clock_gettime (CLOCK_MONOTONIC, &ts))
304			have_monotonic = 1;
305			}
306			#endif
307
308			ev_now = ev_time ();
309	root	1.4	now = get_clock ();
310			diff = ev_now - now;
311	root	1.1
312	root	1.7	if (pipe (sigpipe))
313			return 0;
314
315			ev_method = EVMETHOD_NONE;
316	root	1.1	#if HAVE_EPOLL
317	root	1.7	if (ev_method == EVMETHOD_NONE) epoll_init (flags);
318	root	1.1	#endif
319			#if HAVE_SELECT
320	root	1.7	if (ev_method == EVMETHOD_NONE) select_init (flags);
321	root	1.1	#endif
322
323	root	1.7	if (ev_method)
324			{
325	root	1.12	evw_init (&sigev, sigcb);
326	root	1.7	siginit ();
327			}
328
329	root	1.1	return ev_method;
330			}
331
332	root	1.8	/*****************************************************************************/
333
334	root	1.1	void ev_prefork (void)
335			{
336	root	1.11	/* nop */
337	root	1.1	}
338
339			void ev_postfork_parent (void)
340			{
341	root	1.11	/* nop */
342	root	1.1	}
343
344			void ev_postfork_child (void)
345			{
346			#if HAVE_EPOLL
347	root	1.5	if (ev_method == EVMETHOD_EPOLL)
348			epoll_postfork_child ();
349	root	1.1	#endif
350	root	1.7
351			evio_stop (&sigev);
352			close (sigpipe [0]);
353			close (sigpipe [1]);
354			pipe (sigpipe);
355			siginit ();
356	root	1.1	}
357
358	root	1.8	/*****************************************************************************/
359
360	root	1.1	static void
361	root	1.5	fd_reify (void)
362			{
363			int i;
364
365			for (i = 0; i < fdchangecnt; ++i)
366			{
367			int fd = fdchanges [i];
368			ANFD *anfd = anfds + fd;
369			struct ev_io *w;
370
371			int wev = 0;
372
373			for (w = anfd->head; w; w = w->next)
374			wev \|= w->events;
375
376			if (anfd->wev != wev)
377			{
378			method_modify (fd, anfd->wev, wev);
379			anfd->wev = wev;
380			}
381			}
382
383			fdchangecnt = 0;
384			}
385
386			static void
387	root	1.1	call_pending ()
388			{
389			int i;
390
391			for (i = 0; i < pendingcnt; ++i)
392			{
393			ANPENDING *p = pendings + i;
394
395			if (p->w)
396			{
397			p->w->pending = 0;
398			p->w->cb (p->w, p->events);
399			}
400			}
401
402			pendingcnt = 0;
403			}
404
405			static void
406	root	1.12	timers_reify ()
407	root	1.1	{
408	root	1.4	while (timercnt && timers [0]->at <= now)
409	root	1.1	{
410			struct ev_timer *w = timers [0];
411
412	root	1.4	/* first reschedule or stop timer */
413	root	1.1	if (w->repeat)
414			{
415	root	1.12	w->at = now + w->repeat;
416			assert (("timer timeout in the past, negative repeat?", w->at > now));
417			downheap ((WT *)timers, timercnt, 0);
418			}
419			else
420			evtimer_stop (w); /* nonrepeating: stop timer */
421
422			event ((W)w, EV_TIMEOUT);
423			}
424			}
425	root	1.4
426	root	1.12	static void
427			periodics_reify ()
428			{
429			while (periodiccnt && periodics [0]->at <= ev_now)
430			{
431			struct ev_periodic *w = periodics [0];
432	root	1.1
433	root	1.12	/* first reschedule or stop timer */
434			if (w->interval)
435			{
436			w->at += floor ((ev_now - w->at) / w->interval + 1.) * w->interval;
437			assert (("periodic timeout in the past, negative interval?", w->at > ev_now));
438			downheap ((WT *)periodics, periodiccnt, 0);
439	root	1.1	}
440			else
441	root	1.12	evperiodic_stop (w); /* nonrepeating: stop timer */
442
443			event ((W)w, EV_TIMEOUT);
444			}
445			}
446
447			static void
448	root	1.13	periodics_reschedule (ev_tstamp diff)
449	root	1.12	{
450			int i;
451
452	root	1.13	/* adjust periodics after time jump */
453	root	1.12	for (i = 0; i < periodiccnt; ++i)
454			{
455			struct ev_periodic *w = periodics [i];
456
457			if (w->interval)
458	root	1.4	{
459	root	1.12	ev_tstamp diff = ceil ((ev_now - w->at) / w->interval) * w->interval;
460
461			if (fabs (diff) >= 1e-4)
462			{
463			evperiodic_stop (w);
464			evperiodic_start (w);
465
466			i = 0; /* restart loop, inefficient, but time jumps should be rare */
467			}
468	root	1.4	}
469	root	1.12	}
470	root	1.1	}
471
472	root	1.4	static void
473			time_update ()
474			{
475			int i;
476	root	1.12
477	root	1.4	ev_now = ev_time ();
478
479			if (have_monotonic)
480			{
481			ev_tstamp odiff = diff;
482
483	root	1.12	for (i = 4; --i; ) /* loop a few times, before making important decisions */
484	root	1.4	{
485			now = get_clock ();
486			diff = ev_now - now;
487
488			if (fabs (odiff - diff) < MIN_TIMEJUMP)
489			return; /* all is well */
490
491			ev_now = ev_time ();
492			}
493
494	root	1.13	periodics_reschedule (diff - odiff);
495			/* no timer adjustment, as the monotonic clock doesn't jump */
496	root	1.4	}
497			else
498			{
499			if (now > ev_now \|\| now < ev_now - MAX_BLOCKTIME - MIN_TIMEJUMP)
500	root	1.13	{
501			periodics_reschedule (ev_now - now);
502
503			/* adjust timers. this is easy, as the offset is the same for all */
504			for (i = 0; i < timercnt; ++i)
505			timers [i]->at += diff;
506			}
507	root	1.4
508			now = ev_now;
509			}
510			}
511
512	root	1.1	int ev_loop_done;
513
514	root	1.4	void ev_loop (int flags)
515	root	1.1	{
516			double block;
517	root	1.13	ev_loop_done = flags & EVLOOP_ONESHOT ? 1 : 0;
518	root	1.1
519	root	1.9	if (checkcnt)
520			{
521	root	1.10	queue_events ((W *)checks, checkcnt, EV_CHECK);
522	root	1.9	call_pending ();
523			}
524
525	root	1.1	do
526			{
527			/* update fd-related kernel structures */
528	root	1.5	fd_reify ();
529	root	1.1
530			/* calculate blocking time */
531	root	1.12
532			/* we only need this for !monotonic clock, but as we always have timers, we just calculate it every time */
533			ev_now = ev_time ();
534
535	root	1.9	if (flags & EVLOOP_NONBLOCK \|\| idlecnt)
536	root	1.1	block = 0.;
537			else
538			{
539	root	1.4	block = MAX_BLOCKTIME;
540
541	root	1.12	if (timercnt)
542	root	1.4	{
543	root	1.14	ev_tstamp to = timers [0]->at - (have_monotonic ? get_clock () : ev_now) + method_fudge;
544	root	1.4	if (block > to) block = to;
545			}
546
547	root	1.12	if (periodiccnt)
548	root	1.4	{
549	root	1.12	ev_tstamp to = periodics [0]->at - ev_now + method_fudge;
550	root	1.4	if (block > to) block = to;
551			}
552
553	root	1.1	if (block < 0.) block = 0.;
554			}
555
556			method_poll (block);
557
558	root	1.4	/* update ev_now, do magic */
559			time_update ();
560
561	root	1.9	/* queue pending timers and reschedule them */
562	root	1.12	periodics_reify (); /* absolute timers first */
563			timers_reify (); /* relative timers second */
564	root	1.1
565	root	1.9	/* queue idle watchers unless io or timers are pending */
566			if (!pendingcnt)
567	root	1.10	queue_events ((W *)idles, idlecnt, EV_IDLE);
568	root	1.9
569			/* queue check and possibly idle watchers */
570	root	1.10	queue_events ((W *)checks, checkcnt, EV_CHECK);
571	root	1.9
572	root	1.1	call_pending ();
573			}
574			while (!ev_loop_done);
575	root	1.13
576			if (ev_loop_done != 2)
577			ev_loop_done = 0;
578	root	1.1	}
579
580	root	1.8	/*****************************************************************************/
581
582	root	1.1	static void
583	root	1.10	wlist_add (WL *head, WL elem)
584	root	1.1	{
585			elem->next = *head;
586			*head = elem;
587			}
588
589			static void
590	root	1.10	wlist_del (WL *head, WL elem)
591	root	1.1	{
592			while (*head)
593			{
594			if (*head == elem)
595			{
596			*head = elem->next;
597			return;
598			}
599
600			head = &(*head)->next;
601			}
602			}
603
604			static void
605	root	1.10	ev_start (W w, int active)
606	root	1.1	{
607			w->pending = 0;
608			w->active = active;
609			}
610
611			static void
612	root	1.10	ev_stop (W w)
613	root	1.1	{
614			if (w->pending)
615			pendings [w->pending - 1].w = 0;
616
617			w->active = 0;
618			}
619
620	root	1.8	/*****************************************************************************/
621
622	root	1.1	void
623			evio_start (struct ev_io *w)
624			{
625			if (ev_is_active (w))
626			return;
627
628			int fd = w->fd;
629
630	root	1.10	ev_start ((W)w, 1);
631	root	1.1	array_needsize (anfds, anfdmax, fd + 1, anfds_init);
632	root	1.10	wlist_add ((WL *)&anfds[fd].head, (WL)w);
633	root	1.1
634			++fdchangecnt;
635			array_needsize (fdchanges, fdchangemax, fdchangecnt, );
636			fdchanges [fdchangecnt - 1] = fd;
637			}
638
639			void
640			evio_stop (struct ev_io *w)
641			{
642			if (!ev_is_active (w))
643			return;
644
645	root	1.10	wlist_del ((WL *)&anfds[w->fd].head, (WL)w);
646			ev_stop ((W)w);
647	root	1.1
648			++fdchangecnt;
649			array_needsize (fdchanges, fdchangemax, fdchangecnt, );
650			fdchanges [fdchangecnt - 1] = w->fd;
651			}
652
653	root	1.12
654	root	1.1	void
655			evtimer_start (struct ev_timer *w)
656			{
657			if (ev_is_active (w))
658			return;
659
660	root	1.12	w->at += now;
661
662	root	1.13	assert (("timer repeat value less than zero not allowed", w->repeat >= 0.));
663
664	root	1.12	ev_start ((W)w, ++timercnt);
665			array_needsize (timers, timermax, timercnt, );
666			timers [timercnt - 1] = w;
667			upheap ((WT *)timers, timercnt - 1);
668			}
669
670			void
671			evtimer_stop (struct ev_timer *w)
672			{
673			if (!ev_is_active (w))
674			return;
675
676			if (w->active < timercnt--)
677	root	1.1	{
678	root	1.12	timers [w->active - 1] = timers [timercnt];
679			downheap ((WT *)timers, timercnt, w->active - 1);
680			}
681	root	1.4
682	root	1.14	w->at = w->repeat;
683
684	root	1.12	ev_stop ((W)w);
685			}
686	root	1.4
687	root	1.12	void
688	root	1.14	evtimer_again (struct ev_timer *w)
689			{
690			if (ev_is_active (w))
691			{
692			if (w->repeat)
693			{
694			w->at = now + w->repeat;
695			downheap ((WT *)timers, timercnt, w->active - 1);
696			}
697			else
698			evtimer_stop (w);
699			}
700			else if (w->repeat)
701			evtimer_start (w);
702			}
703
704			void
705	root	1.12	evperiodic_start (struct ev_periodic *w)
706			{
707			if (ev_is_active (w))
708			return;
709	root	1.1
710	root	1.13	assert (("periodic interval value less than zero not allowed", w->interval >= 0.));
711
712	root	1.12	/* this formula differs from the one in periodic_reify because we do not always round up */
713			if (w->interval)
714			w->at += ceil ((ev_now - w->at) / w->interval) * w->interval;
715
716			ev_start ((W)w, ++periodiccnt);
717			array_needsize (periodics, periodicmax, periodiccnt, );
718			periodics [periodiccnt - 1] = w;
719			upheap ((WT *)periodics, periodiccnt - 1);
720	root	1.1	}
721
722			void
723	root	1.12	evperiodic_stop (struct ev_periodic *w)
724	root	1.1	{
725			if (!ev_is_active (w))
726			return;
727
728	root	1.12	if (w->active < periodiccnt--)
729	root	1.2	{
730	root	1.12	periodics [w->active - 1] = periodics [periodiccnt];
731			downheap ((WT *)periodics, periodiccnt, w->active - 1);
732	root	1.2	}
733
734	root	1.10	ev_stop ((W)w);
735	root	1.1	}
736
737			void
738			evsignal_start (struct ev_signal *w)
739			{
740			if (ev_is_active (w))
741			return;
742
743	root	1.10	ev_start ((W)w, 1);
744	root	1.1	array_needsize (signals, signalmax, w->signum, signals_init);
745	root	1.10	wlist_add ((WL *)&signals [w->signum - 1].head, (WL)w);
746	root	1.7
747			if (!w->next)
748			{
749			struct sigaction sa;
750			sa.sa_handler = sighandler;
751			sigfillset (&sa.sa_mask);
752			sa.sa_flags = 0;
753			sigaction (w->signum, &sa, 0);
754			}
755	root	1.1	}
756
757			void
758			evsignal_stop (struct ev_signal *w)
759			{
760			if (!ev_is_active (w))
761			return;
762
763	root	1.10	wlist_del ((WL *)&signals [w->signum - 1].head, (WL)w);
764			ev_stop ((W)w);
765	root	1.7
766			if (!signals [w->signum - 1].head)
767			signal (w->signum, SIG_DFL);
768	root	1.1	}
769
770	root	1.9	void evidle_start (struct ev_idle *w)
771			{
772			if (ev_is_active (w))
773			return;
774
775	root	1.10	ev_start ((W)w, ++idlecnt);
776	root	1.9	array_needsize (idles, idlemax, idlecnt, );
777			idles [idlecnt - 1] = w;
778			}
779
780			void evidle_stop (struct ev_idle *w)
781			{
782			idles [w->active - 1] = idles [--idlecnt];
783	root	1.10	ev_stop ((W)w);
784	root	1.9	}
785
786			void evcheck_start (struct ev_check *w)
787			{
788			if (ev_is_active (w))
789			return;
790
791	root	1.10	ev_start ((W)w, ++checkcnt);
792	root	1.9	array_needsize (checks, checkmax, checkcnt, );
793			checks [checkcnt - 1] = w;
794			}
795
796			void evcheck_stop (struct ev_check *w)
797			{
798			checks [w->active - 1] = checks [--checkcnt];
799	root	1.10	ev_stop ((W)w);
800	root	1.9	}
801
802	root	1.1	/*****************************************************************************/
803	root	1.10
804	root	1.13	#if 0
805	root	1.12
806			struct ev_io wio;
807	root	1.1
808			static void
809			sin_cb (struct ev_io *w, int revents)
810			{
811			fprintf (stderr, "sin %d, revents %d\n", w->fd, revents);
812			}
813
814			static void
815			ocb (struct ev_timer *w, int revents)
816			{
817	root	1.4	//fprintf (stderr, "timer %f,%f (%x) (%f) d%p\n", w->at, w->repeat, revents, w->at - ev_time (), w->data);
818			evtimer_stop (w);
819			evtimer_start (w);
820	root	1.1	}
821
822	root	1.7	static void
823			scb (struct ev_signal *w, int revents)
824			{
825			fprintf (stderr, "signal %x,%d\n", revents, w->signum);
826	root	1.12	evio_stop (&wio);
827			evio_start (&wio);
828	root	1.7	}
829
830	root	1.9	static void
831			gcb (struct ev_signal *w, int revents)
832			{
833			fprintf (stderr, "generic %x\n", revents);
834	root	1.12
835	root	1.9	}
836
837	root	1.1	int main (void)
838			{
839			ev_init (0);
840
841	root	1.12	evio_init (&wio, sin_cb, 0, EV_READ);
842			evio_start (&wio);
843	root	1.1
844	root	1.4	struct ev_timer t[10000];
845	root	1.2
846	root	1.9	#if 0
847	root	1.2	int i;
848	root	1.4	for (i = 0; i < 10000; ++i)
849	root	1.2	{
850			struct ev_timer *w = t + i;
851			evw_init (w, ocb, i);
852	root	1.12	evtimer_init_abs (w, ocb, drand48 (), 0.99775533);
853	root	1.2	evtimer_start (w);
854			if (drand48 () < 0.5)
855			evtimer_stop (w);
856			}
857	root	1.4	#endif
858
859			struct ev_timer t1;
860	root	1.12	evtimer_init (&t1, ocb, 5, 10);
861	root	1.4	evtimer_start (&t1);
862	root	1.1
863	root	1.7	struct ev_signal sig;
864	root	1.12	evsignal_init (&sig, scb, SIGQUIT);
865	root	1.7	evsignal_start (&sig);
866
867	root	1.9	struct ev_check cw;
868	root	1.12	evcheck_init (&cw, gcb);
869	root	1.9	evcheck_start (&cw);
870
871			struct ev_idle iw;
872	root	1.12	evidle_init (&iw, gcb);
873	root	1.9	evidle_start (&iw);
874
875	root	1.1	ev_loop (0);
876
877			return 0;
878			}
879
880			#endif
881
882
883
884