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 - 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);

  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);
    }

  ev_stop ((W)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:	1.13
Committed:	Wed Oct 31 10:50:05 2007 UTC (16 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.12:	+20 -22 lines
Log Message:	EV first rough cut
#	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	typedef struct ev_watcher *W;
40	typedef struct ev_watcher_list *WL;
41	typedef struct ev_watcher_time *WT;
42
43	static ev_tstamp now, diff; /* monotonic clock */
44	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	static void (*method_modify)(int fd, int oev, int nev);
51	static void (*method_poll)(ev_tstamp timeout);
52
53	/*****************************************************************************/
54
55	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	int newcnt = cur ? cur << 1 : 16; \
88	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	/*****************************************************************************/
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	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	event ((W)w, ev);
149	}
150	}
151
152	static void
153	queue_events (W *events, int eventcnt, int type)
154	{
155	int i;
156
157	for (i = 0; i < eventcnt; ++i)
158	event (events [i], type);
159	}
160
161	/*****************************************************************************/
162
163	static struct ev_timer **timers;
164	static int timermax, timercnt;
165
166	static struct ev_periodic **periodics;
167	static int periodicmax, periodiccnt;
168
169	static void
170	upheap (WT *timers, int k)
171	{
172	WT w = timers [k];
173
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	downheap (WT *timers, int N, int k)
188	{
189	WT w = timers [k];
190
191	while (k < (N >> 1))
192	{
193	int j = k << 1;
194
195	if (j + 1 < N && timers [j]->at > timers [j + 1]->at)
196	++j;
197
198	if (w->at <= timers [j]->at)
199	break;
200
201	timers [k] = timers [j];
202	timers [k]->active = k + 1;
203	k = j;
204	}
205
206	timers [k] = w;
207	timers [k]->active = k + 1;
208	}
209
210	/*****************************************************************************/
211
212	typedef struct
213	{
214	struct ev_signal *head;
215	sig_atomic_t gotsig;
216	} ANSIG;
217
218	static ANSIG *signals;
219	static int signalmax;
220
221	static int sigpipe [2];
222	static sig_atomic_t gotsig;
223	static struct ev_io sigev;
224
225	static void
226	signals_init (ANSIG *base, int count)
227	{
228	while (count--)
229	{
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	event ((W)w, EV_SIGNAL);
264	}
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	}
280
281	/*****************************************************************************/
282
283	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	#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	now = get_clock ();
310	diff = ev_now - now;
311
312	if (pipe (sigpipe))
313	return 0;
314
315	ev_method = EVMETHOD_NONE;
316	#if HAVE_EPOLL
317	if (ev_method == EVMETHOD_NONE) epoll_init (flags);
318	#endif
319	#if HAVE_SELECT
320	if (ev_method == EVMETHOD_NONE) select_init (flags);
321	#endif
322
323	if (ev_method)
324	{
325	evw_init (&sigev, sigcb);
326	siginit ();
327	}
328
329	return ev_method;
330	}
331
332	/*****************************************************************************/
333
334	void ev_prefork (void)
335	{
336	/* nop */
337	}
338
339	void ev_postfork_parent (void)
340	{
341	/* nop */
342	}
343
344	void ev_postfork_child (void)
345	{
346	#if HAVE_EPOLL
347	if (ev_method == EVMETHOD_EPOLL)
348	epoll_postfork_child ();
349	#endif
350
351	evio_stop (&sigev);
352	close (sigpipe [0]);
353	close (sigpipe [1]);
354	pipe (sigpipe);
355	siginit ();
356	}
357
358	/*****************************************************************************/
359
360	static void
361	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	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	timers_reify ()
407	{
408	while (timercnt && timers [0]->at <= now)
409	{
410	struct ev_timer *w = timers [0];
411
412	/* first reschedule or stop timer */
413	if (w->repeat)
414	{
415	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
426	static void
427	periodics_reify ()
428	{
429	while (periodiccnt && periodics [0]->at <= ev_now)
430	{
431	struct ev_periodic *w = periodics [0];
432
433	/* 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	}
440	else
441	evperiodic_stop (w); /* nonrepeating: stop timer */
442
443	event ((W)w, EV_TIMEOUT);
444	}
445	}
446
447	static void
448	periodics_reschedule (ev_tstamp diff)
449	{
450	int i;
451
452	/* adjust periodics after time jump */
453	for (i = 0; i < periodiccnt; ++i)
454	{
455	struct ev_periodic *w = periodics [i];
456
457	if (w->interval)
458	{
459	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	}
469	}
470	}
471
472	static void
473	time_update ()
474	{
475	int i;
476
477	ev_now = ev_time ();
478
479	if (have_monotonic)
480	{
481	ev_tstamp odiff = diff;
482
483	for (i = 4; --i; ) /* loop a few times, before making important decisions */
484	{
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	periodics_reschedule (diff - odiff);
495	/* no timer adjustment, as the monotonic clock doesn't jump */
496	}
497	else
498	{
499	if (now > ev_now \|\| now < ev_now - MAX_BLOCKTIME - MIN_TIMEJUMP)
500	{
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
508	now = ev_now;
509	}
510	}
511
512	int ev_loop_done;
513
514	void ev_loop (int flags)
515	{
516	double block;
517	ev_loop_done = flags & EVLOOP_ONESHOT ? 1 : 0;
518
519	if (checkcnt)
520	{
521	queue_events ((W *)checks, checkcnt, EV_CHECK);
522	call_pending ();
523	}
524
525	do
526	{
527	/* update fd-related kernel structures */
528	fd_reify ();
529
530	/* calculate blocking time */
531
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	if (flags & EVLOOP_NONBLOCK \|\| idlecnt)
536	block = 0.;
537	else
538	{
539	block = MAX_BLOCKTIME;
540
541	if (timercnt)
542	{
543	ev_tstamp to = timers [0]->at - get_clock () + method_fudge;
544	if (block > to) block = to;
545	}
546
547	if (periodiccnt)
548	{
549	ev_tstamp to = periodics [0]->at - ev_now + method_fudge;
550	if (block > to) block = to;
551	}
552
553	if (block < 0.) block = 0.;
554	}
555
556	method_poll (block);
557
558	/* update ev_now, do magic */
559	time_update ();
560
561	/* queue pending timers and reschedule them */
562	periodics_reify (); /* absolute timers first */
563	timers_reify (); /* relative timers second */
564
565	/* queue idle watchers unless io or timers are pending */
566	if (!pendingcnt)
567	queue_events ((W *)idles, idlecnt, EV_IDLE);
568
569	/* queue check and possibly idle watchers */
570	queue_events ((W *)checks, checkcnt, EV_CHECK);
571
572	call_pending ();
573	}
574	while (!ev_loop_done);
575
576	if (ev_loop_done != 2)
577	ev_loop_done = 0;
578	}
579
580	/*****************************************************************************/
581
582	static void
583	wlist_add (WL *head, WL elem)
584	{
585	elem->next = *head;
586	*head = elem;
587	}
588
589	static void
590	wlist_del (WL *head, WL elem)
591	{
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	ev_start (W w, int active)
606	{
607	w->pending = 0;
608	w->active = active;
609	}
610
611	static void
612	ev_stop (W w)
613	{
614	if (w->pending)
615	pendings [w->pending - 1].w = 0;
616
617	w->active = 0;
618	}
619
620	/*****************************************************************************/
621
622	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	ev_start ((W)w, 1);
631	array_needsize (anfds, anfdmax, fd + 1, anfds_init);
632	wlist_add ((WL *)&anfds[fd].head, (WL)w);
633
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	wlist_del ((WL *)&anfds[w->fd].head, (WL)w);
646	ev_stop ((W)w);
647
648	++fdchangecnt;
649	array_needsize (fdchanges, fdchangemax, fdchangecnt, );
650	fdchanges [fdchangecnt - 1] = w->fd;
651	}
652
653
654	void
655	evtimer_start (struct ev_timer *w)
656	{
657	if (ev_is_active (w))
658	return;
659
660	w->at += now;
661
662	assert (("timer repeat value less than zero not allowed", w->repeat >= 0.));
663
664	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	{
678	timers [w->active - 1] = timers [timercnt];
679	downheap ((WT *)timers, timercnt, w->active - 1);
680	}
681
682	ev_stop ((W)w);
683	}
684
685	void
686	evperiodic_start (struct ev_periodic *w)
687	{
688	if (ev_is_active (w))
689	return;
690
691	assert (("periodic interval value less than zero not allowed", w->interval >= 0.));
692
693	/* this formula differs from the one in periodic_reify because we do not always round up */
694	if (w->interval)
695	w->at += ceil ((ev_now - w->at) / w->interval) * w->interval;
696
697	ev_start ((W)w, ++periodiccnt);
698	array_needsize (periodics, periodicmax, periodiccnt, );
699	periodics [periodiccnt - 1] = w;
700	upheap ((WT *)periodics, periodiccnt - 1);
701	}
702
703	void
704	evperiodic_stop (struct ev_periodic *w)
705	{
706	if (!ev_is_active (w))
707	return;
708
709	if (w->active < periodiccnt--)
710	{
711	periodics [w->active - 1] = periodics [periodiccnt];
712	downheap ((WT *)periodics, periodiccnt, w->active - 1);
713	}
714
715	ev_stop ((W)w);
716	}
717
718	void
719	evsignal_start (struct ev_signal *w)
720	{
721	if (ev_is_active (w))
722	return;
723
724	ev_start ((W)w, 1);
725	array_needsize (signals, signalmax, w->signum, signals_init);
726	wlist_add ((WL *)&signals [w->signum - 1].head, (WL)w);
727
728	if (!w->next)
729	{
730	struct sigaction sa;
731	sa.sa_handler = sighandler;
732	sigfillset (&sa.sa_mask);
733	sa.sa_flags = 0;
734	sigaction (w->signum, &sa, 0);
735	}
736	}
737
738	void
739	evsignal_stop (struct ev_signal *w)
740	{
741	if (!ev_is_active (w))
742	return;
743
744	wlist_del ((WL *)&signals [w->signum - 1].head, (WL)w);
745	ev_stop ((W)w);
746
747	if (!signals [w->signum - 1].head)
748	signal (w->signum, SIG_DFL);
749	}
750
751	void evidle_start (struct ev_idle *w)
752	{
753	if (ev_is_active (w))
754	return;
755
756	ev_start ((W)w, ++idlecnt);
757	array_needsize (idles, idlemax, idlecnt, );
758	idles [idlecnt - 1] = w;
759	}
760
761	void evidle_stop (struct ev_idle *w)
762	{
763	idles [w->active - 1] = idles [--idlecnt];
764	ev_stop ((W)w);
765	}
766
767	void evcheck_start (struct ev_check *w)
768	{
769	if (ev_is_active (w))
770	return;
771
772	ev_start ((W)w, ++checkcnt);
773	array_needsize (checks, checkmax, checkcnt, );
774	checks [checkcnt - 1] = w;
775	}
776
777	void evcheck_stop (struct ev_check *w)
778	{
779	checks [w->active - 1] = checks [--checkcnt];
780	ev_stop ((W)w);
781	}
782
783	/*****************************************************************************/
784
785	#if 0
786
787	struct ev_io wio;
788
789	static void
790	sin_cb (struct ev_io *w, int revents)
791	{
792	fprintf (stderr, "sin %d, revents %d\n", w->fd, revents);
793	}
794
795	static void
796	ocb (struct ev_timer *w, int revents)
797	{
798	//fprintf (stderr, "timer %f,%f (%x) (%f) d%p\n", w->at, w->repeat, revents, w->at - ev_time (), w->data);
799	evtimer_stop (w);
800	evtimer_start (w);
801	}
802
803	static void
804	scb (struct ev_signal *w, int revents)
805	{
806	fprintf (stderr, "signal %x,%d\n", revents, w->signum);
807	evio_stop (&wio);
808	evio_start (&wio);
809	}
810
811	static void
812	gcb (struct ev_signal *w, int revents)
813	{
814	fprintf (stderr, "generic %x\n", revents);
815
816	}
817
818	int main (void)
819	{
820	ev_init (0);
821
822	evio_init (&wio, sin_cb, 0, EV_READ);
823	evio_start (&wio);
824
825	struct ev_timer t[10000];
826
827	#if 0
828	int i;
829	for (i = 0; i < 10000; ++i)
830	{
831	struct ev_timer *w = t + i;
832	evw_init (w, ocb, i);
833	evtimer_init_abs (w, ocb, drand48 (), 0.99775533);
834	evtimer_start (w);
835	if (drand48 () < 0.5)
836	evtimer_stop (w);
837	}
838	#endif
839
840	struct ev_timer t1;
841	evtimer_init (&t1, ocb, 5, 10);
842	evtimer_start (&t1);
843
844	struct ev_signal sig;
845	evsignal_init (&sig, scb, SIGQUIT);
846	evsignal_start (&sig);
847
848	struct ev_check cw;
849	evcheck_init (&cw, gcb);
850	evcheck_start (&cw);
851
852	struct ev_idle iw;
853	evidle_init (&iw, gcb);
854	evidle_start (&iw);
855
856	ev_loop (0);
857
858	return 0;
859	}
860
861	#endif
862
863
864
865