rxvt-unicode/src/iom.C

/*
    iom.C -- generic I/O multiplexer
    Copyright (C) 2003, 2004 Marc Lehmann <gvpe@schmorp.de>
 
    This file is part of GVPE.

    GVPE is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with gvpe; if not, write to the Free Software
    Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include "iom.h"

#include <cstdio>
#include <cstdlib>
#include <cerrno>

#include <sys/time.h>

#include <assert.h>

#if 1 // older unices need these includes for select (2)
# include <unistd.h>
# include <sys/types.h>
# include <time.h>
#endif

// for IOM_SIG
#if IOM_SIG
# include <csignal>
# include <fcntl.h>
#endif

// if the BSDs would at least be marginally POSIX-compatible.. *sigh*
// until that happens, sys/select.h must come last
#include <sys/select.h>

#define TIMEVAL timeval
#define TV_FRAC tv_usec
#define TV_MULT 1000000L

#if IOM_IO
static io_manager_vec<io_watcher>    iow;
#endif
#if IOM_CHECK
static io_manager_vec<check_watcher> cw;
#endif
#if IOM_TIME
static io_manager_vec<time_watcher>  tw;
#endif
#if IOM_IDLE
static io_manager_vec<idle_watcher>  iw;
#endif
#if IOM_SIG
static int sigpipe[2]; // signal signalling pipe
static sigset_t sigs;
struct sig_vec : io_manager_vec<sig_watcher> {
  int pending;
  sig_vec ()
    : pending (false)
    { }
};
static vector<sig_vec *> sw;
#endif

// this is a dummy time watcher to ensure that the first
// time watcher is _always_ valid, this gets rid of a lot
// of null-pointer-checks
// (must come _before_ iom is being defined)
static struct tw0 : time_watcher
  {
    void cb (time_watcher &w)
    {
      // should never get called
      // reached end-of-time, or tstamp has a bogus definition,
      // or compiler initialisation order broken, or something else :)
      abort ();
    }

    tw0 ()
      : time_watcher (this, &tw0::cb)
      { }
  } tw0;

tstamp NOW;

#if IOM_TIME
tstamp io_manager::now ()
{
  struct timeval tv;

  gettimeofday (&tv, 0);
  return (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000.;
}

void io_manager::set_now ()
{
  NOW = now ();
}
#endif

static bool iom_valid;

// used for initialisation only
static struct init {
  init ()
  {
#if IOM_SIG
    sigemptyset (&sigs);

    if (pipe (sigpipe))
      {
        perror ("io_manager: unable to create signal pipe, aborting.");
        abort ();
      }

    fcntl (sigpipe[0], F_SETFL, O_NONBLOCK); fcntl (sigpipe[0], F_SETFD, FD_CLOEXEC);
    fcntl (sigpipe[1], F_SETFL, O_NONBLOCK); fcntl (sigpipe[1], F_SETFD, FD_CLOEXEC);
#endif

    iom_valid = true;

#if IOM_TIME
    io_manager::set_now ();

    tw0.start (TSTAMP_MAX);
#endif
  }

  ~init ()
  {
    iom_valid = false;
  }

  static void required ();
} init;

void
init::required ()
{
  if (!iom_valid)
    {
      write (2, "io_manager: early registration attempt, aborting.\n",
                sizeof ("io_manager: early registration attempt, aborting.\n") - 1);
      abort ();
    }
}

template<class watcher>
void io_manager::reg (watcher &w, io_manager_vec<watcher> &queue)
{
  init::required ();

  if (!w.active)
    {
      queue.push_back (&w);
      w.active = queue.size ();
    }
}

template<class watcher>
void io_manager::unreg (watcher &w, io_manager_vec<watcher> &queue)
{
  if (!iom_valid)
    return;

  if (w.active)
    {
      queue [w.active - 1] = 0;
      w.active = 0;
    }
}

#if IOM_TIME
void time_watcher::trigger ()
{
  call (*this);
  io_manager::reg (*this);
}

void io_manager::reg   (time_watcher &w)  { io_manager::reg   (w, tw); }
void io_manager::unreg (time_watcher &w)  { io_manager::unreg (w, tw); }
#endif

#if IOM_IO
void io_manager::reg   (io_watcher &w)    { io_manager::reg   (w, iow); }
void io_manager::unreg (io_watcher &w)    { io_manager::unreg (w, iow); }
#endif

#if IOM_CHECK
void io_manager::reg   (check_watcher &w) { io_manager::reg   (w, cw); }
void io_manager::unreg (check_watcher &w) { io_manager::unreg (w, cw); }
#endif

#if IOM_IDLE
void io_manager::reg   (idle_watcher &w)  { io_manager::reg   (w, iw); }
void io_manager::unreg (idle_watcher &w)  { io_manager::unreg (w, iw); }
#endif

#if IOM_SIG
static void
sighandler (int signum)
{
  sw [signum - 1]->pending = true;

  // we use a pipe for signal notifications, as most current
  // OSes (Linux...) do not implement pselect correctly. ugh.
  char ch = signum; // actual content not used
  write (sigpipe[1], &ch, 1);
}

void io_manager::reg (sig_watcher &w)
{
  init::required ();

  assert (0 < w.signum);

  sw.reserve (w.signum);

  while (sw.size () < w.signum) // pathetic
    sw.push_back (0);

  sig_vec *&sv = sw[w.signum - 1];

  if (!sv)
    {
      sv = new sig_vec;

      sigaddset (&sigs, w.signum);
      sigprocmask (SIG_BLOCK, &sigs, NULL);

      struct sigaction sa;
      sa.sa_handler = sighandler;
      sigfillset (&sa.sa_mask);
      sa.sa_flags = SA_RESTART;

      if (sigaction (w.signum, &sa, 0))
        {
          perror ("io_manager: error while installing signal handler, ignoring.");
          abort ();
        }

    }

  io_manager::reg (w, *sv);
}

void io_manager::unreg (sig_watcher &w)
{
  if (!w.active || !iom_valid)
    return;

  assert (0 < w.signum && w.signum <= sw.size ());
  
  io_manager::unreg (w, *sw[w.signum - 1]);
}

void sig_watcher::start (int signum)
{
  stop ();
  this->signum = signum;
  io_manager::reg (*this);
}
#endif

void io_manager::loop ()
{
  init::required ();

#if IOM_TIME
  set_now ();
#endif

  for (;;)
    {

#if IOM_TIME
      // call pending time watchers
      {
        bool activity;

        do
          {
            activity = false;

            for (int i = tw.size (); i--; )
              if (!tw[i])
                tw.erase_unordered (i);
              else if (tw[i]->at <= NOW)
                {
                  time_watcher &w = *tw[i];
                  
                  unreg (w);
                  w.call (w);

                  activity = true;
                }
          }
        while (activity);
      }
#endif

#if IOM_CHECK
      // call all check watchers
      for (int i = cw.size (); i--; )
        if (!cw[i])
          cw.erase_unordered (i);
        else
          cw[i]->call (*cw[i]);
#endif

      struct TIMEVAL *to = 0;
      struct TIMEVAL tval;

#if IOM_IDLE
      if (iw.size ())
        {
          tval.tv_sec  = 0;
          tval.TV_FRAC = 0;
          to = &tval;
        }
      else
#endif
        {
#if IOM_TIME
          // find earliest active watcher
          time_watcher *next = tw[0]; // the first time-watcher must exist at ALL times

          for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
            if (*i && (*i)->at < next->at)
              next = *i;

          if (next->at > NOW && next != tw[0])
            {
              double diff = next->at - NOW;
              tval.tv_sec  = (int)diff;
              tval.TV_FRAC = (int) ((diff - tval.tv_sec) * TV_MULT);
              to = &tval;
            }
        }
#endif

#if IOM_IO || IOM_SIG
      fd_set rfd, wfd;

      FD_ZERO (&rfd);
      FD_ZERO (&wfd);

      int fds = 0;

# if IOM_IO
      for (io_manager_vec<io_watcher>::const_iterator i = iow.end (); i-- > iow.begin (); )
        if (*i)
          {
            if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
            if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd);

            if ((*i)->fd >= fds) fds = (*i)->fd + 1;
          }
# endif

      if (!to && !fds) //TODO: also check idle_watchers and check_watchers?
        break; // no events

# if IOM_SIG
      FD_SET (sigpipe[0], &rfd);
      if (sigpipe[0] >= fds) fds = sigpipe[0] + 1;
# endif

# if IOM_SIG
      // there is no race, as we use a pipe for signals, so select
      // will return if a signal is caught.
      sigprocmask (SIG_UNBLOCK, &sigs, NULL);
# endif
      fds = select (fds, &rfd, &wfd, NULL, to);
# if IOM_SIG
      sigprocmask (SIG_BLOCK, &sigs, NULL);
# endif

# if IOM_TIME
      {
        // update time, try to compensate for gross non-monotonic time changes
        tstamp diff = NOW;
        set_now ();
        diff = NOW - diff;

        if (diff < 0)
          for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
            if (*i)
              (*i)->at += diff;
      }
# endif

      if (fds > 0)
        {
# if IOM_SIG
          if (FD_ISSET (sigpipe[0], &rfd))
            {
              char ch;

              while (read (sigpipe[0], &ch, 1) > 0)
                ;

              for (vector<sig_vec *>::iterator svp = sw.end (); svp-- > sw.begin (); )
                if (*svp && (*svp)->pending)
                  {
                    sig_vec &sv = **svp;
                    for (int i = sv.size (); i--; )
                      if (!sv[i])
                        sv.erase_unordered (i);
                      else
                        sv[i]->call (*sv[i]);

                    sv.pending = false;
                  }
            }
# endif

# if IOM_IO
          for (int i = iow.size (); i--; )
            if (!iow[i])
              iow.erase_unordered (i);
            else
              {
                io_watcher &w = *iow[i];
                short revents = w.events;

                if (!FD_ISSET (w.fd, &rfd)) revents &= ~EVENT_READ;
                if (!FD_ISSET (w.fd, &wfd)) revents &= ~EVENT_WRITE;

                if (revents)
                  w.call (w, revents);
              }
#endif
        }
      else if (fds < 0 && errno != EINTR)
        {
          perror ("io_manager: fatal error while waiting for I/O or time event, aborting.");
          abort ();
        }
#if IOM_IDLE
      else
        for (int i = iw.size (); i--; )
          if (!iw[i])
            iw.erase_unordered (i);
          else
            iw[i]->call (*iw[i]);
#endif

#elif IOM_TIME
      if (!to)
        break;

      select (0, 0, 0, 0, &to);
      set_now ();
#else
      break;
#endif
    }
}

Revision:	1.32
Committed:	Wed Jan 11 21:24:41 2006 UTC (18 years, 4 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-7_0
Changes since 1.31:	+3 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	pcg	1.1	/*
2	root	1.23	iom.C -- generic I/O multiplexer
3	root	1.30	Copyright (C) 2003, 2004 Marc Lehmann <gvpe@schmorp.de>
4	pcg	1.1
5	root	1.30	This file is part of GVPE.
6
7			GVPE is free software; you can redistribute it and/or modify
8	pcg	1.1	it under the terms of the GNU General Public License as published by
9			the Free Software Foundation; either version 2 of the License, or
10			(at your option) any later version.
11
12			This program is distributed in the hope that it will be useful,
13			but WITHOUT ANY WARRANTY; without even the implied warranty of
14			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15			GNU General Public License for more details.
16
17			You should have received a copy of the GNU General Public License
18	root	1.30	along with gvpe; if not, write to the Free Software
19	root	1.29	Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20	pcg	1.1	*/
21
22	root	1.19	#include "iom.h"
23
24	pcg	1.1	#include <cstdio>
25	pcg	1.8	#include <cstdlib>
26			#include <cerrno>
27	pcg	1.1
28	pcg	1.11	#include <sys/time.h>
29
30	pcg	1.16	#include <assert.h>
31
32	pcg	1.14	#if 1 // older unices need these includes for select (2)
33	pcg	1.11	# include <unistd.h>
34			# include <sys/types.h>
35	root	1.19	# include <time.h>
36			#endif
37
38			// for IOM_SIG
39			#if IOM_SIG
40	root	1.27	# include <csignal>
41	root	1.19	# include <fcntl.h>
42	pcg	1.11	#endif
43
44			// if the BSDs would at least be marginally POSIX-compatible.. sigh
45			// until that happens, sys/select.h must come last
46	pcg	1.1	#include <sys/select.h>
47
48	root	1.19	#define TIMEVAL timeval
49			#define TV_FRAC tv_usec
50			#define TV_MULT 1000000L
51	pcg	1.1
52	root	1.19	#if IOM_IO
53			static io_manager_vec<io_watcher> iow;
54			#endif
55			#if IOM_CHECK
56			static io_manager_vec<check_watcher> cw;
57			#endif
58			#if IOM_TIME
59			static io_manager_vec<time_watcher> tw;
60			#endif
61			#if IOM_IDLE
62			static io_manager_vec<idle_watcher> iw;
63			#endif
64			#if IOM_SIG
65			static int sigpipe[2]; // signal signalling pipe
66			static sigset_t sigs;
67			struct sig_vec : io_manager_vec<sig_watcher> {
68			int pending;
69			sig_vec ()
70			: pending (false)
71			{ }
72			};
73			static vector<sig_vec *> sw;
74			#endif
75	pcg	1.8
76	pcg	1.10	// this is a dummy time watcher to ensure that the first
77			// time watcher is _always_ valid, this gets rid of a lot
78			// of null-pointer-checks
79			// (must come _before_ iom is being defined)
80	pcg	1.13	static struct tw0 : time_watcher
81	pcg	1.10	{
82	pcg	1.13	void cb (time_watcher &w)
83			{
84			// should never get called
85			// reached end-of-time, or tstamp has a bogus definition,
86	root	1.17	// or compiler initialisation order broken, or something else :)
87	pcg	1.13	abort ();
88			}
89	pcg	1.10
90	pcg	1.14	tw0 ()
91	root	1.19	: time_watcher (this, &tw0::cb)
92			{ }
93	pcg	1.16	} tw0;
94	pcg	1.10
95	pcg	1.1	tstamp NOW;
96	root	1.19
97			#if IOM_TIME
98	root	1.24	tstamp io_manager::now ()
99	root	1.19	{
100			struct timeval tv;
101
102			gettimeofday (&tv, 0);
103	root	1.24	return (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000.;
104			}
105
106			void io_manager::set_now ()
107			{
108			NOW = now ();
109	root	1.19	}
110			#endif
111
112	pcg	1.8	static bool iom_valid;
113	root	1.19
114			// used for initialisation only
115			static struct init {
116			init ()
117			{
118			#if IOM_SIG
119			sigemptyset (&sigs);
120
121			if (pipe (sigpipe))
122			{
123			perror ("io_manager: unable to create signal pipe, aborting.");
124			abort ();
125			}
126
127	root	1.25	fcntl (sigpipe[0], F_SETFL, O_NONBLOCK); fcntl (sigpipe[0], F_SETFD, FD_CLOEXEC);
128			fcntl (sigpipe[1], F_SETFL, O_NONBLOCK); fcntl (sigpipe[1], F_SETFD, FD_CLOEXEC);
129	root	1.19	#endif
130
131			iom_valid = true;
132
133			#if IOM_TIME
134	root	1.24	io_manager::set_now ();
135	root	1.19
136			tw0.start (TSTAMP_MAX);
137			#endif
138			}
139
140	root	1.31	~init ()
141			{
142			iom_valid = false;
143			}
144
145	root	1.19	static void required ();
146			} init;
147
148			void
149			init::required ()
150			{
151			if (!iom_valid)
152			{
153			write (2, "io_manager: early registration attempt, aborting.\n",
154			sizeof ("io_manager: early registration attempt, aborting.\n") - 1);
155			abort ();
156			}
157			}
158	pcg	1.1
159	pcg	1.4	template<class watcher>
160	root	1.19	void io_manager::reg (watcher &w, io_manager_vec<watcher> &queue)
161	pcg	1.4	{
162	root	1.19	init::required ();
163	pcg	1.8
164	root	1.19	if (!w.active)
165	pcg	1.8	{
166	root	1.19	queue.push_back (&w);
167			w.active = queue.size ();
168	pcg	1.8	}
169	pcg	1.4	}
170
171			template<class watcher>
172	root	1.19	void io_manager::unreg (watcher &w, io_manager_vec<watcher> &queue)
173	pcg	1.4	{
174	pcg	1.8	if (!iom_valid)
175			return;
176	pcg	1.4
177	root	1.19	if (w.active)
178	pcg	1.8	{
179	root	1.19	queue [w.active - 1] = 0;
180			w.active = 0;
181	pcg	1.8	}
182	pcg	1.4	}
183
184			#if IOM_TIME
185	pcg	1.1	void time_watcher::trigger ()
186			{
187			call (*this);
188	root	1.19	io_manager::reg (*this);
189	pcg	1.1	}
190
191	root	1.19	void io_manager::reg (time_watcher &w) { io_manager::reg (w, tw); }
192			void io_manager::unreg (time_watcher &w) { io_manager::unreg (w, tw); }
193	pcg	1.8	#endif
194	pcg	1.3
195	pcg	1.8	#if IOM_IO
196	root	1.19	void io_manager::reg (io_watcher &w) { io_manager::reg (w, iow); }
197			void io_manager::unreg (io_watcher &w) { io_manager::unreg (w, iow); }
198	pcg	1.4	#endif
199	pcg	1.1
200	pcg	1.4	#if IOM_CHECK
201	root	1.19	void io_manager::reg (check_watcher &w) { io_manager::reg (w, cw); }
202			void io_manager::unreg (check_watcher &w) { io_manager::unreg (w, cw); }
203	pcg	1.4	#endif
204	pcg	1.1
205	pcg	1.7	#if IOM_IDLE
206	root	1.19	void io_manager::reg (idle_watcher &w) { io_manager::reg (w, iw); }
207			void io_manager::unreg (idle_watcher &w) { io_manager::unreg (w, iw); }
208	pcg	1.7	#endif
209
210	root	1.19	#if IOM_SIG
211			static void
212			sighandler (int signum)
213	pcg	1.1	{
214	root	1.19	sw [signum - 1]->pending = true;
215	pcg	1.1
216	root	1.19	// we use a pipe for signal notifications, as most current
217			// OSes (Linux...) do not implement pselect correctly. ugh.
218			char ch = signum; // actual content not used
219			write (sigpipe[1], &ch, 1);
220	pcg	1.16	}
221
222	root	1.19	void io_manager::reg (sig_watcher &w)
223	pcg	1.16	{
224	root	1.32	init::required ();
225
226	root	1.19	assert (0 < w.signum);
227	pcg	1.16
228	root	1.19	sw.reserve (w.signum);
229	pcg	1.16
230	root	1.19	while (sw.size () < w.signum) // pathetic
231			sw.push_back (0);
232	pcg	1.16
233	root	1.19	sig_vec *&sv = sw[w.signum - 1];
234	pcg	1.16
235			if (!sv)
236			{
237			sv = new sig_vec;
238
239	root	1.19	sigaddset (&sigs, w.signum);
240			sigprocmask (SIG_BLOCK, &sigs, NULL);
241
242	pcg	1.16	struct sigaction sa;
243	root	1.19	sa.sa_handler = sighandler;
244	pcg	1.16	sigfillset (&sa.sa_mask);
245	root	1.19	sa.sa_flags = SA_RESTART;
246	pcg	1.16
247	root	1.19	if (sigaction (w.signum, &sa, 0))
248	pcg	1.16	{
249	root	1.19	perror ("io_manager: error while installing signal handler, ignoring.");
250	pcg	1.16	abort ();
251			}
252	root	1.19
253	pcg	1.16	}
254
255	root	1.19	io_manager::reg (w, *sv);
256	pcg	1.16	}
257
258	root	1.19	void io_manager::unreg (sig_watcher &w)
259	pcg	1.16	{
260	root	1.32	if (!w.active \|\| !iom_valid)
261	root	1.19	return;
262
263			assert (0 < w.signum && w.signum <= sw.size ());
264	pcg	1.16
265	root	1.19	io_manager::unreg (w, *sw[w.signum - 1]);
266	pcg	1.16	}
267
268			void sig_watcher::start (int signum)
269			{
270			stop ();
271			this->signum = signum;
272	root	1.19	io_manager::reg (*this);
273	pcg	1.16	}
274			#endif
275	root	1.19
276	pcg	1.1	void io_manager::loop ()
277			{
278	root	1.19	init::required ();
279
280	pcg	1.4	#if IOM_TIME
281	pcg	1.1	set_now ();
282	pcg	1.4	#endif
283	pcg	1.1
284			for (;;)
285			{
286
287	pcg	1.7	#if IOM_TIME
288	root	1.23	// call pending time watchers
289			{
290			bool activity;
291	pcg	1.1
292	root	1.23	do
293			{
294			activity = false;
295	pcg	1.1
296	root	1.23	for (int i = tw.size (); i--; )
297			if (!tw[i])
298			tw.erase_unordered (i);
299			else if (tw[i]->at <= NOW)
300			{
301			time_watcher &w = *tw[i];
302
303			unreg (w);
304			w.call (w);
305	pcg	1.7
306	root	1.23	activity = true;
307	pcg	1.7	}
308	root	1.23	}
309			while (activity);
310			}
311	pcg	1.7	#endif
312	pcg	1.6
313			#if IOM_CHECK
314	root	1.23	// call all check watchers
315	pcg	1.8	for (int i = cw.size (); i--; )
316			if (!cw[i])
317			cw.erase_unordered (i);
318			else
319			cw[i]->call (*cw[i]);
320	root	1.23	#endif
321	pcg	1.12
322	root	1.23	struct TIMEVAL *to = 0;
323			struct TIMEVAL tval;
324
325			#if IOM_IDLE
326			if (iw.size ())
327	pcg	1.12	{
328			tval.tv_sec = 0;
329	root	1.19	tval.TV_FRAC = 0;
330	pcg	1.12	to = &tval;
331			}
332	root	1.23	else
333			#endif
334			{
335			#if IOM_TIME
336			// find earliest active watcher
337			time_watcher *next = tw[0]; // the first time-watcher must exist at ALL times
338
339			for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
340			if (i && (i)->at < next->at)
341			next = *i;
342
343			if (next->at > NOW && next != tw[0])
344			{
345			double diff = next->at - NOW;
346			tval.tv_sec = (int)diff;
347			tval.TV_FRAC = (int) ((diff - tval.tv_sec) * TV_MULT);
348			to = &tval;
349			}
350			}
351	pcg	1.4	#endif
352	pcg	1.1
353	root	1.19	#if IOM_IO \|\| IOM_SIG
354	pcg	1.15	fd_set rfd, wfd;
355	pcg	1.1
356			FD_ZERO (&rfd);
357			FD_ZERO (&wfd);
358
359			int fds = 0;
360
361	root	1.19	# if IOM_IO
362	root	1.23	for (io_manager_vec<io_watcher>::const_iterator i = iow.end (); i-- > iow.begin (); )
363	pcg	1.8	if (*i)
364			{
365			if ((i)->events & EVENT_READ ) FD_SET ((i)->fd, &rfd);
366			if ((i)->events & EVENT_WRITE) FD_SET ((i)->fd, &wfd);
367	pcg	1.1
368	pcg	1.8	if ((i)->fd >= fds) fds = (i)->fd + 1;
369			}
370	root	1.19	# endif
371	pcg	1.1
372	root	1.23	if (!to && !fds) //TODO: also check idle_watchers and check_watchers?
373	pcg	1.5	break; // no events
374
375	root	1.19	# if IOM_SIG
376			FD_SET (sigpipe[0], &rfd);
377			if (sigpipe[0] >= fds) fds = sigpipe[0] + 1;
378			# endif
379
380			# if IOM_SIG
381			// there is no race, as we use a pipe for signals, so select
382			// will return if a signal is caught.
383			sigprocmask (SIG_UNBLOCK, &sigs, NULL);
384			# endif
385	pcg	1.15	fds = select (fds, &rfd, &wfd, NULL, to);
386	root	1.19	# if IOM_SIG
387			sigprocmask (SIG_BLOCK, &sigs, NULL);
388			# endif
389
390	pcg	1.4	# if IOM_TIME
391	root	1.28	{
392			// update time, try to compensate for gross non-monotonic time changes
393			tstamp diff = NOW;
394			set_now ();
395			diff = NOW - diff;
396
397			if (diff < 0)
398			for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
399			if (*i)
400			(*i)->at += diff;
401			}
402	pcg	1.4	# endif
403	pcg	1.1
404			if (fds > 0)
405	root	1.19	{
406			# if IOM_SIG
407			if (FD_ISSET (sigpipe[0], &rfd))
408	pcg	1.8	{
409	root	1.19	char ch;
410
411			while (read (sigpipe[0], &ch, 1) > 0)
412			;
413	pcg	1.1
414	root	1.23	for (vector<sig_vec *>::iterator svp = sw.end (); svp-- > sw.begin (); )
415	root	1.19	if (svp && (svp)->pending)
416			{
417			sig_vec &sv = **svp;
418			for (int i = sv.size (); i--; )
419			if (!sv[i])
420			sv.erase_unordered (i);
421			else
422			sv[i]->call (*sv[i]);
423	pcg	1.4
424	root	1.19	sv.pending = false;
425			}
426	pcg	1.8	}
427	root	1.19	# endif
428
429			# if IOM_IO
430			for (int i = iow.size (); i--; )
431			if (!iow[i])
432			iow.erase_unordered (i);
433			else
434			{
435	root	1.27	io_watcher &w = *iow[i];
436			short revents = w.events;
437	root	1.19
438	root	1.27	if (!FD_ISSET (w.fd, &rfd)) revents &= ~EVENT_READ;
439			if (!FD_ISSET (w.fd, &wfd)) revents &= ~EVENT_WRITE;
440	root	1.19
441			if (revents)
442	root	1.27	w.call (w, revents);
443	root	1.19	}
444			#endif
445			}
446	pcg	1.8	else if (fds < 0 && errno != EINTR)
447			{
448	root	1.19	perror ("io_manager: fatal error while waiting for I/O or time event, aborting.");
449	pcg	1.8	abort ();
450			}
451	pcg	1.7	#if IOM_IDLE
452	pcg	1.8	else
453			for (int i = iw.size (); i--; )
454			if (!iw[i])
455			iw.erase_unordered (i);
456			else
457			iw[i]->call (*iw[i]);
458	pcg	1.7	#endif
459
460	pcg	1.4	#elif IOM_TIME
461	pcg	1.5	if (!to)
462			break;
463
464	pcg	1.4	select (0, 0, 0, 0, &to);
465			set_now ();
466	pcg	1.5	#else
467			break;
468	pcg	1.4	#endif
469	pcg	1.5	}
470	pcg	1.1	}
471