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;                 \
      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:	1.15
Committed:	Wed Oct 31 11:56:34 2007 UTC (16 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.14:	+0 -1 lines
Log Message:	rmeove remaining debugging code
#	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	base = realloc (base, sizeof (base) (newcnt)); \
89	init (base + cur, newcnt - cur); \
90	cur = newcnt; \
91	}
92
93	/*****************************************************************************/
94
95	typedef struct
96	{
97	struct ev_io *head;
98	unsigned char wev, rev; /* want, received event set */
99	} ANFD;
100
101	static ANFD *anfds;
102	static int anfdmax;
103
104	static int *fdchanges;
105	static int fdchangemax, fdchangecnt;
106
107	static void
108	anfds_init (ANFD *base, int count)
109	{
110	while (count--)
111	{
112	base->head = 0;
113	base->wev = base->rev = EV_NONE;
114	++base;
115	}
116	}
117
118	typedef struct
119	{
120	W w;
121	int events;
122	} ANPENDING;
123
124	static ANPENDING *pendings;
125	static int pendingmax, pendingcnt;
126
127	static void
128	event (W w, int events)
129	{
130	w->pending = ++pendingcnt;
131	array_needsize (pendings, pendingmax, pendingcnt, );
132	pendings [pendingcnt - 1].w = w;
133	pendings [pendingcnt - 1].events = events;
134	}
135
136	static void
137	fd_event (int fd, int events)
138	{
139	ANFD *anfd = anfds + fd;
140	struct ev_io *w;
141
142	for (w = anfd->head; w; w = w->next)
143	{
144	int ev = w->events & events;
145
146	if (ev)
147	event ((W)w, ev);
148	}
149	}
150
151	static void
152	queue_events (W *events, int eventcnt, int type)
153	{
154	int i;
155
156	for (i = 0; i < eventcnt; ++i)
157	event (events [i], type);
158	}
159
160	/*****************************************************************************/
161
162	static struct ev_timer **timers;
163	static int timermax, timercnt;
164
165	static struct ev_periodic **periodics;
166	static int periodicmax, periodiccnt;
167
168	static void
169	upheap (WT *timers, int k)
170	{
171	WT w = timers [k];
172
173	while (k && timers [k >> 1]->at > w->at)
174	{
175	timers [k] = timers [k >> 1];
176	timers [k]->active = k + 1;
177	k >>= 1;
178	}
179
180	timers [k] = w;
181	timers [k]->active = k + 1;
182
183	}
184
185	static void
186	downheap (WT *timers, int N, int k)
187	{
188	WT w = timers [k];
189
190	while (k < (N >> 1))
191	{
192	int j = k << 1;
193
194	if (j + 1 < N && timers [j]->at > timers [j + 1]->at)
195	++j;
196
197	if (w->at <= timers [j]->at)
198	break;
199
200	timers [k] = timers [j];
201	timers [k]->active = k + 1;
202	k = j;
203	}
204
205	timers [k] = w;
206	timers [k]->active = k + 1;
207	}
208
209	/*****************************************************************************/
210
211	typedef struct
212	{
213	struct ev_signal *head;
214	sig_atomic_t gotsig;
215	} ANSIG;
216
217	static ANSIG *signals;
218	static int signalmax;
219
220	static int sigpipe [2];
221	static sig_atomic_t gotsig;
222	static struct ev_io sigev;
223
224	static void
225	signals_init (ANSIG *base, int count)
226	{
227	while (count--)
228	{
229	base->head = 0;
230	base->gotsig = 0;
231	++base;
232	}
233	}
234
235	static void
236	sighandler (int signum)
237	{
238	signals [signum - 1].gotsig = 1;
239
240	if (!gotsig)
241	{
242	gotsig = 1;
243	write (sigpipe [1], &gotsig, 1);
244	}
245	}
246
247	static void
248	sigcb (struct ev_io *iow, int revents)
249	{
250	struct ev_signal *w;
251	int sig;
252
253	gotsig = 0;
254	read (sigpipe [0], &revents, 1);
255
256	for (sig = signalmax; sig--; )
257	if (signals [sig].gotsig)
258	{
259	signals [sig].gotsig = 0;
260
261	for (w = signals [sig].head; w; w = w->next)
262	event ((W)w, EV_SIGNAL);
263	}
264	}
265
266	static void
267	siginit (void)
268	{
269	fcntl (sigpipe [0], F_SETFD, FD_CLOEXEC);
270	fcntl (sigpipe [1], F_SETFD, FD_CLOEXEC);
271
272	/* rather than sort out wether we really need nb, set it */
273	fcntl (sigpipe [0], F_SETFL, O_NONBLOCK);
274	fcntl (sigpipe [1], F_SETFL, O_NONBLOCK);
275
276	evio_set (&sigev, sigpipe [0], EV_READ);
277	evio_start (&sigev);
278	}
279
280	/*****************************************************************************/
281
282	static struct ev_idle **idles;
283	static int idlemax, idlecnt;
284
285	static struct ev_check **checks;
286	static int checkmax, checkcnt;
287
288	/*****************************************************************************/
289
290	#if HAVE_EPOLL
291	# include "ev_epoll.c"
292	#endif
293	#if HAVE_SELECT
294	# include "ev_select.c"
295	#endif
296
297	int ev_init (int flags)
298	{
299	#if HAVE_MONOTONIC
300	{
301	struct timespec ts;
302	if (!clock_gettime (CLOCK_MONOTONIC, &ts))
303	have_monotonic = 1;
304	}
305	#endif
306
307	ev_now = ev_time ();
308	now = get_clock ();
309	diff = ev_now - now;
310
311	if (pipe (sigpipe))
312	return 0;
313
314	ev_method = EVMETHOD_NONE;
315	#if HAVE_EPOLL
316	if (ev_method == EVMETHOD_NONE) epoll_init (flags);
317	#endif
318	#if HAVE_SELECT
319	if (ev_method == EVMETHOD_NONE) select_init (flags);
320	#endif
321
322	if (ev_method)
323	{
324	evw_init (&sigev, sigcb);
325	siginit ();
326	}
327
328	return ev_method;
329	}
330
331	/*****************************************************************************/
332
333	void ev_prefork (void)
334	{
335	/* nop */
336	}
337
338	void ev_postfork_parent (void)
339	{
340	/* nop */
341	}
342
343	void ev_postfork_child (void)
344	{
345	#if HAVE_EPOLL
346	if (ev_method == EVMETHOD_EPOLL)
347	epoll_postfork_child ();
348	#endif
349
350	evio_stop (&sigev);
351	close (sigpipe [0]);
352	close (sigpipe [1]);
353	pipe (sigpipe);
354	siginit ();
355	}
356
357	/*****************************************************************************/
358
359	static void
360	fd_reify (void)
361	{
362	int i;
363
364	for (i = 0; i < fdchangecnt; ++i)
365	{
366	int fd = fdchanges [i];
367	ANFD *anfd = anfds + fd;
368	struct ev_io *w;
369
370	int wev = 0;
371
372	for (w = anfd->head; w; w = w->next)
373	wev \|= w->events;
374
375	if (anfd->wev != wev)
376	{
377	method_modify (fd, anfd->wev, wev);
378	anfd->wev = wev;
379	}
380	}
381
382	fdchangecnt = 0;
383	}
384
385	static void
386	call_pending ()
387	{
388	int i;
389
390	for (i = 0; i < pendingcnt; ++i)
391	{
392	ANPENDING *p = pendings + i;
393
394	if (p->w)
395	{
396	p->w->pending = 0;
397	p->w->cb (p->w, p->events);
398	}
399	}
400
401	pendingcnt = 0;
402	}
403
404	static void
405	timers_reify ()
406	{
407	while (timercnt && timers [0]->at <= now)
408	{
409	struct ev_timer *w = timers [0];
410
411	/* first reschedule or stop timer */
412	if (w->repeat)
413	{
414	w->at = now + w->repeat;
415	assert (("timer timeout in the past, negative repeat?", w->at > now));
416	downheap ((WT *)timers, timercnt, 0);
417	}
418	else
419	evtimer_stop (w); /* nonrepeating: stop timer */
420
421	event ((W)w, EV_TIMEOUT);
422	}
423	}
424
425	static void
426	periodics_reify ()
427	{
428	while (periodiccnt && periodics [0]->at <= ev_now)
429	{
430	struct ev_periodic *w = periodics [0];
431
432	/* first reschedule or stop timer */
433	if (w->interval)
434	{
435	w->at += floor ((ev_now - w->at) / w->interval + 1.) * w->interval;
436	assert (("periodic timeout in the past, negative interval?", w->at > ev_now));
437	downheap ((WT *)periodics, periodiccnt, 0);
438	}
439	else
440	evperiodic_stop (w); /* nonrepeating: stop timer */
441
442	event ((W)w, EV_TIMEOUT);
443	}
444	}
445
446	static void
447	periodics_reschedule (ev_tstamp diff)
448	{
449	int i;
450
451	/* adjust periodics after time jump */
452	for (i = 0; i < periodiccnt; ++i)
453	{
454	struct ev_periodic *w = periodics [i];
455
456	if (w->interval)
457	{
458	ev_tstamp diff = ceil ((ev_now - w->at) / w->interval) * w->interval;
459
460	if (fabs (diff) >= 1e-4)
461	{
462	evperiodic_stop (w);
463	evperiodic_start (w);
464
465	i = 0; /* restart loop, inefficient, but time jumps should be rare */
466	}
467	}
468	}
469	}
470
471	static void
472	time_update ()
473	{
474	int i;
475
476	ev_now = ev_time ();
477
478	if (have_monotonic)
479	{
480	ev_tstamp odiff = diff;
481
482	for (i = 4; --i; ) /* loop a few times, before making important decisions */
483	{
484	now = get_clock ();
485	diff = ev_now - now;
486
487	if (fabs (odiff - diff) < MIN_TIMEJUMP)
488	return; /* all is well */
489
490	ev_now = ev_time ();
491	}
492
493	periodics_reschedule (diff - odiff);
494	/* no timer adjustment, as the monotonic clock doesn't jump */
495	}
496	else
497	{
498	if (now > ev_now \|\| now < ev_now - MAX_BLOCKTIME - MIN_TIMEJUMP)
499	{
500	periodics_reschedule (ev_now - now);
501
502	/* adjust timers. this is easy, as the offset is the same for all */
503	for (i = 0; i < timercnt; ++i)
504	timers [i]->at += diff;
505	}
506
507	now = ev_now;
508	}
509	}
510
511	int ev_loop_done;
512
513	void ev_loop (int flags)
514	{
515	double block;
516	ev_loop_done = flags & EVLOOP_ONESHOT ? 1 : 0;
517
518	if (checkcnt)
519	{
520	queue_events ((W *)checks, checkcnt, EV_CHECK);
521	call_pending ();
522	}
523
524	do
525	{
526	/* update fd-related kernel structures */
527	fd_reify ();
528
529	/* calculate blocking time */
530
531	/* we only need this for !monotonic clock, but as we always have timers, we just calculate it every time */
532	ev_now = ev_time ();
533
534	if (flags & EVLOOP_NONBLOCK \|\| idlecnt)
535	block = 0.;
536	else
537	{
538	block = MAX_BLOCKTIME;
539
540	if (timercnt)
541	{
542	ev_tstamp to = timers [0]->at - (have_monotonic ? get_clock () : ev_now) + method_fudge;
543	if (block > to) block = to;
544	}
545
546	if (periodiccnt)
547	{
548	ev_tstamp to = periodics [0]->at - ev_now + method_fudge;
549	if (block > to) block = to;
550	}
551
552	if (block < 0.) block = 0.;
553	}
554
555	method_poll (block);
556
557	/* update ev_now, do magic */
558	time_update ();
559
560	/* queue pending timers and reschedule them */
561	periodics_reify (); /* absolute timers first */
562	timers_reify (); /* relative timers second */
563
564	/* queue idle watchers unless io or timers are pending */
565	if (!pendingcnt)
566	queue_events ((W *)idles, idlecnt, EV_IDLE);
567
568	/* queue check and possibly idle watchers */
569	queue_events ((W *)checks, checkcnt, EV_CHECK);
570
571	call_pending ();
572	}
573	while (!ev_loop_done);
574
575	if (ev_loop_done != 2)
576	ev_loop_done = 0;
577	}
578
579	/*****************************************************************************/
580
581	static void
582	wlist_add (WL *head, WL elem)
583	{
584	elem->next = *head;
585	*head = elem;
586	}
587
588	static void
589	wlist_del (WL *head, WL elem)
590	{
591	while (*head)
592	{
593	if (*head == elem)
594	{
595	*head = elem->next;
596	return;
597	}
598
599	head = &(*head)->next;
600	}
601	}
602
603	static void
604	ev_start (W w, int active)
605	{
606	w->pending = 0;
607	w->active = active;
608	}
609
610	static void
611	ev_stop (W w)
612	{
613	if (w->pending)
614	pendings [w->pending - 1].w = 0;
615
616	w->active = 0;
617	}
618
619	/*****************************************************************************/
620
621	void
622	evio_start (struct ev_io *w)
623	{
624	if (ev_is_active (w))
625	return;
626
627	int fd = w->fd;
628
629	ev_start ((W)w, 1);
630	array_needsize (anfds, anfdmax, fd + 1, anfds_init);
631	wlist_add ((WL *)&anfds[fd].head, (WL)w);
632
633	++fdchangecnt;
634	array_needsize (fdchanges, fdchangemax, fdchangecnt, );
635	fdchanges [fdchangecnt - 1] = fd;
636	}
637
638	void
639	evio_stop (struct ev_io *w)
640	{
641	if (!ev_is_active (w))
642	return;
643
644	wlist_del ((WL *)&anfds[w->fd].head, (WL)w);
645	ev_stop ((W)w);
646
647	++fdchangecnt;
648	array_needsize (fdchanges, fdchangemax, fdchangecnt, );
649	fdchanges [fdchangecnt - 1] = w->fd;
650	}
651
652
653	void
654	evtimer_start (struct ev_timer *w)
655	{
656	if (ev_is_active (w))
657	return;
658
659	w->at += now;
660
661	assert (("timer repeat value less than zero not allowed", w->repeat >= 0.));
662
663	ev_start ((W)w, ++timercnt);
664	array_needsize (timers, timermax, timercnt, );
665	timers [timercnt - 1] = w;
666	upheap ((WT *)timers, timercnt - 1);
667	}
668
669	void
670	evtimer_stop (struct ev_timer *w)
671	{
672	if (!ev_is_active (w))
673	return;
674
675	if (w->active < timercnt--)
676	{
677	timers [w->active - 1] = timers [timercnt];
678	downheap ((WT *)timers, timercnt, w->active - 1);
679	}
680
681	w->at = w->repeat;
682
683	ev_stop ((W)w);
684	}
685
686	void
687	evtimer_again (struct ev_timer *w)
688	{
689	if (ev_is_active (w))
690	{
691	if (w->repeat)
692	{
693	w->at = now + w->repeat;
694	downheap ((WT *)timers, timercnt, w->active - 1);
695	}
696	else
697	evtimer_stop (w);
698	}
699	else if (w->repeat)
700	evtimer_start (w);
701	}
702
703	void
704	evperiodic_start (struct ev_periodic *w)
705	{
706	if (ev_is_active (w))
707	return;
708
709	assert (("periodic interval value less than zero not allowed", w->interval >= 0.));
710
711	/* this formula differs from the one in periodic_reify because we do not always round up */
712	if (w->interval)
713	w->at += ceil ((ev_now - w->at) / w->interval) * w->interval;
714
715	ev_start ((W)w, ++periodiccnt);
716	array_needsize (periodics, periodicmax, periodiccnt, );
717	periodics [periodiccnt - 1] = w;
718	upheap ((WT *)periodics, periodiccnt - 1);
719	}
720
721	void
722	evperiodic_stop (struct ev_periodic *w)
723	{
724	if (!ev_is_active (w))
725	return;
726
727	if (w->active < periodiccnt--)
728	{
729	periodics [w->active - 1] = periodics [periodiccnt];
730	downheap ((WT *)periodics, periodiccnt, w->active - 1);
731	}
732
733	ev_stop ((W)w);
734	}
735
736	void
737	evsignal_start (struct ev_signal *w)
738	{
739	if (ev_is_active (w))
740	return;
741
742	ev_start ((W)w, 1);
743	array_needsize (signals, signalmax, w->signum, signals_init);
744	wlist_add ((WL *)&signals [w->signum - 1].head, (WL)w);
745
746	if (!w->next)
747	{
748	struct sigaction sa;
749	sa.sa_handler = sighandler;
750	sigfillset (&sa.sa_mask);
751	sa.sa_flags = 0;
752	sigaction (w->signum, &sa, 0);
753	}
754	}
755
756	void
757	evsignal_stop (struct ev_signal *w)
758	{
759	if (!ev_is_active (w))
760	return;
761
762	wlist_del ((WL *)&signals [w->signum - 1].head, (WL)w);
763	ev_stop ((W)w);
764
765	if (!signals [w->signum - 1].head)
766	signal (w->signum, SIG_DFL);
767	}
768
769	void evidle_start (struct ev_idle *w)
770	{
771	if (ev_is_active (w))
772	return;
773
774	ev_start ((W)w, ++idlecnt);
775	array_needsize (idles, idlemax, idlecnt, );
776	idles [idlecnt - 1] = w;
777	}
778
779	void evidle_stop (struct ev_idle *w)
780	{
781	idles [w->active - 1] = idles [--idlecnt];
782	ev_stop ((W)w);
783	}
784
785	void evcheck_start (struct ev_check *w)
786	{
787	if (ev_is_active (w))
788	return;
789
790	ev_start ((W)w, ++checkcnt);
791	array_needsize (checks, checkmax, checkcnt, );
792	checks [checkcnt - 1] = w;
793	}
794
795	void evcheck_stop (struct ev_check *w)
796	{
797	checks [w->active - 1] = checks [--checkcnt];
798	ev_stop ((W)w);
799	}
800
801	/*****************************************************************************/
802
803	#if 0
804
805	struct ev_io wio;
806
807	static void
808	sin_cb (struct ev_io *w, int revents)
809	{
810	fprintf (stderr, "sin %d, revents %d\n", w->fd, revents);
811	}
812
813	static void
814	ocb (struct ev_timer *w, int revents)
815	{
816	//fprintf (stderr, "timer %f,%f (%x) (%f) d%p\n", w->at, w->repeat, revents, w->at - ev_time (), w->data);
817	evtimer_stop (w);
818	evtimer_start (w);
819	}
820
821	static void
822	scb (struct ev_signal *w, int revents)
823	{
824	fprintf (stderr, "signal %x,%d\n", revents, w->signum);
825	evio_stop (&wio);
826	evio_start (&wio);
827	}
828
829	static void
830	gcb (struct ev_signal *w, int revents)
831	{
832	fprintf (stderr, "generic %x\n", revents);
833
834	}
835
836	int main (void)
837	{
838	ev_init (0);
839
840	evio_init (&wio, sin_cb, 0, EV_READ);
841	evio_start (&wio);
842
843	struct ev_timer t[10000];
844
845	#if 0
846	int i;
847	for (i = 0; i < 10000; ++i)
848	{
849	struct ev_timer *w = t + i;
850	evw_init (w, ocb, i);
851	evtimer_init_abs (w, ocb, drand48 (), 0.99775533);
852	evtimer_start (w);
853	if (drand48 () < 0.5)
854	evtimer_stop (w);
855	}
856	#endif
857
858	struct ev_timer t1;
859	evtimer_init (&t1, ocb, 5, 10);
860	evtimer_start (&t1);
861
862	struct ev_signal sig;
863	evsignal_init (&sig, scb, SIGQUIT);
864	evsignal_start (&sig);
865
866	struct ev_check cw;
867	evcheck_init (&cw, gcb);
868	evcheck_start (&cw);
869
870	struct ev_idle iw;
871	evidle_init (&iw, gcb);
872	evidle_start (&iw);
873
874	ev_loop (0);
875
876	return 0;
877	}
878
879	#endif
880
881
882
883