gvpe/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
  }

  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)
{
  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)
    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:	Tue Apr 26 00:55:56 2005 UTC (19 years, 1 month ago) by pcg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-2_0
Changes since 1.31:	+1 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	pcg	1.1	/*
2	pcg	1.23	iom.C -- generic I/O multiplexer
3	pcg	1.30	Copyright (C) 2003, 2004 Marc Lehmann <gvpe@schmorp.de>
4	pcg	1.1
5	pcg	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	pcg	1.30	along with gvpe; if not, write to the Free Software
19	pcg	1.32	Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20	pcg	1.1	*/
21
22	pcg	1.21	#include "iom.h"
23
24	pcg	1.13	#include <cstdio>
25			#include <cstdlib>
26			#include <cerrno>
27	pcg	1.1
28	pcg	1.15	#include <sys/time.h>
29
30	pcg	1.20	#include <assert.h>
31
32	pcg	1.18	#if 1 // older unices need these includes for select (2)
33	pcg	1.15	# include <unistd.h>
34			# include <sys/types.h>
35	pcg	1.21	# include <time.h>
36			#endif
37
38			// for IOM_SIG
39			#if IOM_SIG
40	pcg	1.28	# include <csignal>
41	pcg	1.21	# include <fcntl.h>
42	pcg	1.15	#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	1.13	#include <sys/select.h>
47	pcg	1.1
48	pcg	1.21	#define TIMEVAL timeval
49			#define TV_FRAC tv_usec
50			#define TV_MULT 1000000L
51	pcg	1.11
52	pcg	1.21	#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	1.1
76	pcg	1.14	// 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	1.18	static struct tw0 : time_watcher
81	pcg	1.14	{
82	pcg	1.18	void cb (time_watcher &w)
83			{
84			// should never get called
85			// reached end-of-time, or tstamp has a bogus definition,
86	pcg	1.21	// or compiler initialisation order broken, or something else :)
87	pcg	1.18	abort ();
88			}
89	pcg	1.14
90	pcg	1.18	tw0 ()
91	pcg	1.21	: time_watcher (this, &tw0::cb)
92			{ }
93	pcg	1.20	} tw0;
94	pcg	1.14
95	pcg	1.10	tstamp NOW;
96	pcg	1.21
97			#if IOM_TIME
98	pcg	1.26	tstamp io_manager::now ()
99	pcg	1.21	{
100			struct timeval tv;
101
102			gettimeofday (&tv, 0);
103	pcg	1.26	return (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000.;
104			}
105
106			void io_manager::set_now ()
107			{
108			NOW = now ();
109	pcg	1.21	}
110			#endif
111
112	pcg	1.13	static bool iom_valid;
113	pcg	1.21
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	pcg	1.26	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	pcg	1.21	#endif
130
131			iom_valid = true;
132
133			#if IOM_TIME
134	pcg	1.26	io_manager::set_now ();
135	pcg	1.21
136			tw0.start (TSTAMP_MAX);
137			#endif
138			}
139
140			static void required ();
141			} init;
142
143			void
144			init::required ()
145			{
146			if (!iom_valid)
147			{
148			write (2, "io_manager: early registration attempt, aborting.\n",
149			sizeof ("io_manager: early registration attempt, aborting.\n") - 1);
150			abort ();
151			}
152			}
153	pcg	1.10
154	pcg	1.13	template<class watcher>
155	pcg	1.21	void io_manager::reg (watcher &w, io_manager_vec<watcher> &queue)
156	pcg	1.4	{
157	pcg	1.21	init::required ();
158	pcg	1.4
159	pcg	1.21	if (!w.active)
160	pcg	1.11	{
161	pcg	1.21	queue.push_back (&w);
162			w.active = queue.size ();
163	pcg	1.11	}
164	pcg	1.10	}
165
166	pcg	1.13	template<class watcher>
167	pcg	1.21	void io_manager::unreg (watcher &w, io_manager_vec<watcher> &queue)
168	pcg	1.10	{
169	pcg	1.13	if (!iom_valid)
170			return;
171	pcg	1.10
172	pcg	1.21	if (w.active)
173	pcg	1.11	{
174	pcg	1.21	queue [w.active - 1] = 0;
175			w.active = 0;
176	pcg	1.11	}
177	pcg	1.1	}
178
179	pcg	1.13	#if IOM_TIME
180			void time_watcher::trigger ()
181	pcg	1.1	{
182	pcg	1.13	call (*this);
183	pcg	1.21	io_manager::reg (*this);
184	pcg	1.1	}
185
186	pcg	1.21	void io_manager::reg (time_watcher &w) { io_manager::reg (w, tw); }
187			void io_manager::unreg (time_watcher &w) { io_manager::unreg (w, tw); }
188	pcg	1.13	#endif
189	pcg	1.6
190	pcg	1.13	#if IOM_IO
191	pcg	1.21	void io_manager::reg (io_watcher &w) { io_manager::reg (w, iow); }
192			void io_manager::unreg (io_watcher &w) { io_manager::unreg (w, iow); }
193	pcg	1.13	#endif
194	pcg	1.7
195	pcg	1.13	#if IOM_CHECK
196	pcg	1.21	void io_manager::reg (check_watcher &w) { io_manager::reg (w, cw); }
197			void io_manager::unreg (check_watcher &w) { io_manager::unreg (w, cw); }
198	pcg	1.13	#endif
199	pcg	1.1
200	pcg	1.13	#if IOM_IDLE
201	pcg	1.21	void io_manager::reg (idle_watcher &w) { io_manager::reg (w, iw); }
202			void io_manager::unreg (idle_watcher &w) { io_manager::unreg (w, iw); }
203	pcg	1.13	#endif
204	pcg	1.1
205	pcg	1.21	#if IOM_SIG
206			static void
207			sighandler (int signum)
208	pcg	1.1	{
209	pcg	1.21	sw [signum - 1]->pending = true;
210	pcg	1.1
211	pcg	1.21	// we use a pipe for signal notifications, as most current
212			// OSes (Linux...) do not implement pselect correctly. ugh.
213			char ch = signum; // actual content not used
214			write (sigpipe[1], &ch, 1);
215	pcg	1.20	}
216
217	pcg	1.21	void io_manager::reg (sig_watcher &w)
218	pcg	1.20	{
219	pcg	1.21	assert (0 < w.signum);
220	pcg	1.20
221	pcg	1.21	sw.reserve (w.signum);
222	pcg	1.20
223	pcg	1.21	while (sw.size () < w.signum) // pathetic
224			sw.push_back (0);
225	pcg	1.20
226	pcg	1.21	sig_vec *&sv = sw[w.signum - 1];
227	pcg	1.20
228			if (!sv)
229			{
230			sv = new sig_vec;
231
232	pcg	1.21	sigaddset (&sigs, w.signum);
233			sigprocmask (SIG_BLOCK, &sigs, NULL);
234
235	pcg	1.20	struct sigaction sa;
236	pcg	1.21	sa.sa_handler = sighandler;
237	pcg	1.20	sigfillset (&sa.sa_mask);
238	pcg	1.21	sa.sa_flags = SA_RESTART;
239	pcg	1.20
240	pcg	1.21	if (sigaction (w.signum, &sa, 0))
241	pcg	1.20	{
242	pcg	1.21	perror ("io_manager: error while installing signal handler, ignoring.");
243	pcg	1.20	abort ();
244			}
245	pcg	1.21
246	pcg	1.20	}
247
248	pcg	1.21	io_manager::reg (w, *sv);
249	pcg	1.20	}
250
251	pcg	1.21	void io_manager::unreg (sig_watcher &w)
252	pcg	1.20	{
253	pcg	1.21	if (!w.active)
254			return;
255
256			assert (0 < w.signum && w.signum <= sw.size ());
257	pcg	1.20
258	pcg	1.21	io_manager::unreg (w, *sw[w.signum - 1]);
259	pcg	1.20	}
260
261			void sig_watcher::start (int signum)
262			{
263			stop ();
264			this->signum = signum;
265	pcg	1.21	io_manager::reg (*this);
266	pcg	1.20	}
267			#endif
268	pcg	1.21
269	pcg	1.1	void io_manager::loop ()
270			{
271	pcg	1.21	init::required ();
272
273	pcg	1.13	#if IOM_TIME
274	pcg	1.1	set_now ();
275	pcg	1.13	#endif
276	pcg	1.1
277	pcg	1.4	for (;;)
278	pcg	1.1	{
279	pcg	1.13
280			#if IOM_TIME
281	pcg	1.22	// call pending time watchers
282			{
283			bool activity;
284	pcg	1.7
285	pcg	1.22	do
286			{
287			activity = false;
288	pcg	1.13
289	pcg	1.22	for (int i = tw.size (); i--; )
290			if (!tw[i])
291			tw.erase_unordered (i);
292	pcg	1.24	else if (tw[i]->at <= NOW)
293	pcg	1.22	{
294			time_watcher &w = *tw[i];
295
296			unreg (w);
297			w.call (w);
298	pcg	1.13
299	pcg	1.22	activity = true;
300	pcg	1.13	}
301	pcg	1.22	}
302			while (activity);
303			}
304	pcg	1.13	#endif
305	pcg	1.1
306	pcg	1.13	#if IOM_CHECK
307	pcg	1.22	// call all check watchers
308	pcg	1.13	for (int i = cw.size (); i--; )
309			if (!cw[i])
310			cw.erase_unordered (i);
311			else
312			cw[i]->call (*cw[i]);
313	pcg	1.22	#endif
314	pcg	1.17
315	pcg	1.22	struct TIMEVAL *to = 0;
316			struct TIMEVAL tval;
317
318			#if IOM_IDLE
319			if (iw.size ())
320	pcg	1.17	{
321			tval.tv_sec = 0;
322	pcg	1.21	tval.TV_FRAC = 0;
323	pcg	1.17	to = &tval;
324			}
325	pcg	1.22	else
326			#endif
327			{
328			#if IOM_TIME
329			// find earliest active watcher
330			time_watcher *next = tw[0]; // the first time-watcher must exist at ALL times
331
332			for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
333			if (i && (i)->at < next->at)
334			next = *i;
335
336			if (next->at > NOW && next != tw[0])
337			{
338			double diff = next->at - NOW;
339			tval.tv_sec = (int)diff;
340			tval.TV_FRAC = (int) ((diff - tval.tv_sec) * TV_MULT);
341			to = &tval;
342			}
343			}
344	pcg	1.13	#endif
345
346	pcg	1.21	#if IOM_IO \|\| IOM_SIG
347	pcg	1.18	fd_set rfd, wfd;
348	pcg	1.7
349	pcg	1.13	FD_ZERO (&rfd);
350			FD_ZERO (&wfd);
351	pcg	1.7
352	pcg	1.13	int fds = 0;
353
354	pcg	1.21	# if IOM_IO
355	pcg	1.22	for (io_manager_vec<io_watcher>::const_iterator i = iow.end (); i-- > iow.begin (); )
356	pcg	1.13	if (*i)
357			{
358			if ((i)->events & EVENT_READ ) FD_SET ((i)->fd, &rfd);
359			if ((i)->events & EVENT_WRITE) FD_SET ((i)->fd, &wfd);
360	pcg	1.1
361	pcg	1.13	if ((i)->fd >= fds) fds = (i)->fd + 1;
362			}
363	pcg	1.21	# endif
364	pcg	1.1
365	pcg	1.22	if (!to && !fds) //TODO: also check idle_watchers and check_watchers?
366	pcg	1.13	break; // no events
367	pcg	1.1
368	pcg	1.21	# if IOM_SIG
369			FD_SET (sigpipe[0], &rfd);
370			if (sigpipe[0] >= fds) fds = sigpipe[0] + 1;
371			# endif
372
373			# if IOM_SIG
374			// there is no race, as we use a pipe for signals, so select
375			// will return if a signal is caught.
376			sigprocmask (SIG_UNBLOCK, &sigs, NULL);
377			# endif
378	pcg	1.19	fds = select (fds, &rfd, &wfd, NULL, to);
379	pcg	1.21	# if IOM_SIG
380			sigprocmask (SIG_BLOCK, &sigs, NULL);
381			# endif
382
383	pcg	1.13	# if IOM_TIME
384	pcg	1.29	{
385			// update time, try to compensate for gross non-monotonic time changes
386			tstamp diff = NOW;
387			set_now ();
388			diff = NOW - diff;
389
390			if (diff < 0)
391			for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
392			if (*i)
393			(*i)->at += diff;
394			}
395	pcg	1.13	# endif
396	pcg	1.1
397	pcg	1.13	if (fds > 0)
398	pcg	1.21	{
399			# if IOM_SIG
400			if (FD_ISSET (sigpipe[0], &rfd))
401	pcg	1.13	{
402	pcg	1.21	char ch;
403
404			while (read (sigpipe[0], &ch, 1) > 0)
405			;
406	pcg	1.13
407	pcg	1.25	for (vector<sig_vec *>::iterator svp = sw.end (); svp-- > sw.begin (); )
408	pcg	1.21	if (svp && (svp)->pending)
409			{
410			sig_vec &sv = **svp;
411			for (int i = sv.size (); i--; )
412			if (!sv[i])
413			sv.erase_unordered (i);
414			else
415			sv[i]->call (*sv[i]);
416	pcg	1.13
417	pcg	1.21	sv.pending = false;
418			}
419	pcg	1.13	}
420	pcg	1.21	# endif
421
422			# if IOM_IO
423			for (int i = iow.size (); i--; )
424			if (!iow[i])
425			iow.erase_unordered (i);
426			else
427			{
428	pcg	1.27	io_watcher &w = *iow[i];
429			short revents = w.events;
430	pcg	1.21
431	pcg	1.27	if (!FD_ISSET (w.fd, &rfd)) revents &= ~EVENT_READ;
432			if (!FD_ISSET (w.fd, &wfd)) revents &= ~EVENT_WRITE;
433	pcg	1.21
434			if (revents)
435	pcg	1.27	w.call (w, revents);
436	pcg	1.21	}
437			#endif
438			}
439	pcg	1.13	else if (fds < 0 && errno != EINTR)
440			{
441	pcg	1.21	perror ("io_manager: fatal error while waiting for I/O or time event, aborting.");
442	pcg	1.13	abort ();
443			}
444			#if IOM_IDLE
445			else
446			for (int i = iw.size (); i--; )
447			if (!iw[i])
448			iw.erase_unordered (i);
449			else
450			iw[i]->call (*iw[i]);
451			#endif
452
453			#elif IOM_TIME
454			if (!to)
455			break;
456	pcg	1.9
457	pcg	1.13	select (0, 0, 0, 0, &to);
458			set_now ();
459			#else
460			break;
461			#endif
462	pcg	1.1	}
463			}
464