gvpe/src/iom.C

/*
    iom.C -- generic I/O multiplexer
    Copyright (C) 2003, 2004 Marc Lehmann <pcg@goof.com>
 
    This program 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 this program; if not, write to the Free Software
    Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA  02111-1307  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>

// TSTAMP_MAX must still fit into a positive struct timeval
#define TSTAMP_MAX (double)(1UL<<31)

#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:	1.29
Committed:	Mon Feb 14 20:51:14 2005 UTC (19 years, 3 months ago) by pcg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-1_7
Changes since 1.28:	+11 -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	1.13	Copyright (C) 2003, 2004 Marc Lehmann <pcg@goof.com>
4	pcg	1.1
5			This program is free software; you can redistribute it and/or modify
6			it under the terms of the GNU General Public License as published by
7			the Free Software Foundation; either version 2 of the License, or
8			(at your option) any later version.
9
10			This program is distributed in the hope that it will be useful,
11			but WITHOUT ANY WARRANTY; without even the implied warranty of
12			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13			GNU General Public License for more details.
14
15			You should have received a copy of the GNU General Public License
16			along with this program; if not, write to the Free Software
17			Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18			*/
19
20	pcg	1.21	#include "iom.h"
21
22	pcg	1.13	#include <cstdio>
23			#include <cstdlib>
24			#include <cerrno>
25	pcg	1.1
26	pcg	1.15	#include <sys/time.h>
27
28	pcg	1.20	#include <assert.h>
29
30	pcg	1.18	#if 1 // older unices need these includes for select (2)
31	pcg	1.15	# include <unistd.h>
32			# include <sys/types.h>
33	pcg	1.21	# include <time.h>
34			#endif
35
36			// for IOM_SIG
37			#if IOM_SIG
38	pcg	1.28	# include <csignal>
39	pcg	1.21	# include <fcntl.h>
40	pcg	1.15	#endif
41
42			// if the BSDs would at least be marginally POSIX-compatible.. sigh
43			// until that happens, sys/select.h must come last
44	pcg	1.13	#include <sys/select.h>
45	pcg	1.1
46	pcg	1.21	// TSTAMP_MAX must still fit into a positive struct timeval
47			#define TSTAMP_MAX (double)(1UL<<31)
48	pcg	1.20
49	pcg	1.21	#define TIMEVAL timeval
50			#define TV_FRAC tv_usec
51			#define TV_MULT 1000000L
52	pcg	1.11
53	pcg	1.21	#if IOM_IO
54			static io_manager_vec<io_watcher> iow;
55			#endif
56			#if IOM_CHECK
57			static io_manager_vec<check_watcher> cw;
58			#endif
59			#if IOM_TIME
60			static io_manager_vec<time_watcher> tw;
61			#endif
62			#if IOM_IDLE
63			static io_manager_vec<idle_watcher> iw;
64			#endif
65			#if IOM_SIG
66			static int sigpipe[2]; // signal signalling pipe
67			static sigset_t sigs;
68			struct sig_vec : io_manager_vec<sig_watcher> {
69			int pending;
70			sig_vec ()
71			: pending (false)
72			{ }
73			};
74			static vector<sig_vec *> sw;
75			#endif
76	pcg	1.1
77	pcg	1.14	// this is a dummy time watcher to ensure that the first
78			// time watcher is _always_ valid, this gets rid of a lot
79			// of null-pointer-checks
80			// (must come _before_ iom is being defined)
81	pcg	1.18	static struct tw0 : time_watcher
82	pcg	1.14	{
83	pcg	1.18	void cb (time_watcher &w)
84			{
85			// should never get called
86			// reached end-of-time, or tstamp has a bogus definition,
87	pcg	1.21	// or compiler initialisation order broken, or something else :)
88	pcg	1.18	abort ();
89			}
90	pcg	1.14
91	pcg	1.18	tw0 ()
92	pcg	1.21	: time_watcher (this, &tw0::cb)
93			{ }
94	pcg	1.20	} tw0;
95	pcg	1.14
96	pcg	1.10	tstamp NOW;
97	pcg	1.21
98			#if IOM_TIME
99	pcg	1.26	tstamp io_manager::now ()
100	pcg	1.21	{
101			struct timeval tv;
102
103			gettimeofday (&tv, 0);
104	pcg	1.26	return (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000.;
105			}
106
107			void io_manager::set_now ()
108			{
109			NOW = now ();
110	pcg	1.21	}
111			#endif
112
113	pcg	1.13	static bool iom_valid;
114	pcg	1.21
115			// used for initialisation only
116			static struct init {
117			init ()
118			{
119			#if IOM_SIG
120			sigemptyset (&sigs);
121
122			if (pipe (sigpipe))
123			{
124			perror ("io_manager: unable to create signal pipe, aborting.");
125			abort ();
126			}
127
128	pcg	1.26	fcntl (sigpipe[0], F_SETFL, O_NONBLOCK); fcntl (sigpipe[0], F_SETFD, FD_CLOEXEC);
129			fcntl (sigpipe[1], F_SETFL, O_NONBLOCK); fcntl (sigpipe[1], F_SETFD, FD_CLOEXEC);
130	pcg	1.21	#endif
131
132			iom_valid = true;
133
134			#if IOM_TIME
135	pcg	1.26	io_manager::set_now ();
136	pcg	1.21
137			tw0.start (TSTAMP_MAX);
138			#endif
139			}
140
141			static void required ();
142			} init;
143
144			void
145			init::required ()
146			{
147			if (!iom_valid)
148			{
149			write (2, "io_manager: early registration attempt, aborting.\n",
150			sizeof ("io_manager: early registration attempt, aborting.\n") - 1);
151			abort ();
152			}
153			}
154	pcg	1.10
155	pcg	1.13	template<class watcher>
156	pcg	1.21	void io_manager::reg (watcher &w, io_manager_vec<watcher> &queue)
157	pcg	1.4	{
158	pcg	1.21	init::required ();
159	pcg	1.4
160	pcg	1.21	if (!w.active)
161	pcg	1.11	{
162	pcg	1.21	queue.push_back (&w);
163			w.active = queue.size ();
164	pcg	1.11	}
165	pcg	1.10	}
166
167	pcg	1.13	template<class watcher>
168	pcg	1.21	void io_manager::unreg (watcher &w, io_manager_vec<watcher> &queue)
169	pcg	1.10	{
170	pcg	1.13	if (!iom_valid)
171			return;
172	pcg	1.10
173	pcg	1.21	if (w.active)
174	pcg	1.11	{
175	pcg	1.21	queue [w.active - 1] = 0;
176			w.active = 0;
177	pcg	1.11	}
178	pcg	1.1	}
179
180	pcg	1.13	#if IOM_TIME
181			void time_watcher::trigger ()
182	pcg	1.1	{
183	pcg	1.13	call (*this);
184	pcg	1.21	io_manager::reg (*this);
185	pcg	1.1	}
186
187	pcg	1.21	void io_manager::reg (time_watcher &w) { io_manager::reg (w, tw); }
188			void io_manager::unreg (time_watcher &w) { io_manager::unreg (w, tw); }
189	pcg	1.13	#endif
190	pcg	1.6
191	pcg	1.13	#if IOM_IO
192	pcg	1.21	void io_manager::reg (io_watcher &w) { io_manager::reg (w, iow); }
193			void io_manager::unreg (io_watcher &w) { io_manager::unreg (w, iow); }
194	pcg	1.13	#endif
195	pcg	1.7
196	pcg	1.13	#if IOM_CHECK
197	pcg	1.21	void io_manager::reg (check_watcher &w) { io_manager::reg (w, cw); }
198			void io_manager::unreg (check_watcher &w) { io_manager::unreg (w, cw); }
199	pcg	1.13	#endif
200	pcg	1.1
201	pcg	1.13	#if IOM_IDLE
202	pcg	1.21	void io_manager::reg (idle_watcher &w) { io_manager::reg (w, iw); }
203			void io_manager::unreg (idle_watcher &w) { io_manager::unreg (w, iw); }
204	pcg	1.13	#endif
205	pcg	1.1
206	pcg	1.21	#if IOM_SIG
207			static void
208			sighandler (int signum)
209	pcg	1.1	{
210	pcg	1.21	sw [signum - 1]->pending = true;
211	pcg	1.1
212	pcg	1.21	// we use a pipe for signal notifications, as most current
213			// OSes (Linux...) do not implement pselect correctly. ugh.
214			char ch = signum; // actual content not used
215			write (sigpipe[1], &ch, 1);
216	pcg	1.20	}
217
218	pcg	1.21	void io_manager::reg (sig_watcher &w)
219	pcg	1.20	{
220	pcg	1.21	assert (0 < w.signum);
221	pcg	1.20
222	pcg	1.21	sw.reserve (w.signum);
223	pcg	1.20
224	pcg	1.21	while (sw.size () < w.signum) // pathetic
225			sw.push_back (0);
226	pcg	1.20
227	pcg	1.21	sig_vec *&sv = sw[w.signum - 1];
228	pcg	1.20
229			if (!sv)
230			{
231			sv = new sig_vec;
232
233	pcg	1.21	sigaddset (&sigs, w.signum);
234			sigprocmask (SIG_BLOCK, &sigs, NULL);
235
236	pcg	1.20	struct sigaction sa;
237	pcg	1.21	sa.sa_handler = sighandler;
238	pcg	1.20	sigfillset (&sa.sa_mask);
239	pcg	1.21	sa.sa_flags = SA_RESTART;
240	pcg	1.20
241	pcg	1.21	if (sigaction (w.signum, &sa, 0))
242	pcg	1.20	{
243	pcg	1.21	perror ("io_manager: error while installing signal handler, ignoring.");
244	pcg	1.20	abort ();
245			}
246	pcg	1.21
247	pcg	1.20	}
248
249	pcg	1.21	io_manager::reg (w, *sv);
250	pcg	1.20	}
251
252	pcg	1.21	void io_manager::unreg (sig_watcher &w)
253	pcg	1.20	{
254	pcg	1.21	if (!w.active)
255			return;
256
257			assert (0 < w.signum && w.signum <= sw.size ());
258	pcg	1.20
259	pcg	1.21	io_manager::unreg (w, *sw[w.signum - 1]);
260	pcg	1.20	}
261
262			void sig_watcher::start (int signum)
263			{
264			stop ();
265			this->signum = signum;
266	pcg	1.21	io_manager::reg (*this);
267	pcg	1.20	}
268			#endif
269	pcg	1.21
270	pcg	1.1	void io_manager::loop ()
271			{
272	pcg	1.21	init::required ();
273
274	pcg	1.13	#if IOM_TIME
275	pcg	1.1	set_now ();
276	pcg	1.13	#endif
277	pcg	1.1
278	pcg	1.4	for (;;)
279	pcg	1.1	{
280	pcg	1.13
281			#if IOM_TIME
282	pcg	1.22	// call pending time watchers
283			{
284			bool activity;
285	pcg	1.7
286	pcg	1.22	do
287			{
288			activity = false;
289	pcg	1.13
290	pcg	1.22	for (int i = tw.size (); i--; )
291			if (!tw[i])
292			tw.erase_unordered (i);
293	pcg	1.24	else if (tw[i]->at <= NOW)
294	pcg	1.22	{
295			time_watcher &w = *tw[i];
296
297			unreg (w);
298			w.call (w);
299	pcg	1.13
300	pcg	1.22	activity = true;
301	pcg	1.13	}
302	pcg	1.22	}
303			while (activity);
304			}
305	pcg	1.13	#endif
306	pcg	1.1
307	pcg	1.13	#if IOM_CHECK
308	pcg	1.22	// call all check watchers
309	pcg	1.13	for (int i = cw.size (); i--; )
310			if (!cw[i])
311			cw.erase_unordered (i);
312			else
313			cw[i]->call (*cw[i]);
314	pcg	1.22	#endif
315	pcg	1.17
316	pcg	1.22	struct TIMEVAL *to = 0;
317			struct TIMEVAL tval;
318
319			#if IOM_IDLE
320			if (iw.size ())
321	pcg	1.17	{
322			tval.tv_sec = 0;
323	pcg	1.21	tval.TV_FRAC = 0;
324	pcg	1.17	to = &tval;
325			}
326	pcg	1.22	else
327			#endif
328			{
329			#if IOM_TIME
330			// find earliest active watcher
331			time_watcher *next = tw[0]; // the first time-watcher must exist at ALL times
332
333			for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
334			if (i && (i)->at < next->at)
335			next = *i;
336
337			if (next->at > NOW && next != tw[0])
338			{
339			double diff = next->at - NOW;
340			tval.tv_sec = (int)diff;
341			tval.TV_FRAC = (int) ((diff - tval.tv_sec) * TV_MULT);
342			to = &tval;
343			}
344			}
345	pcg	1.13	#endif
346
347	pcg	1.21	#if IOM_IO \|\| IOM_SIG
348	pcg	1.18	fd_set rfd, wfd;
349	pcg	1.7
350	pcg	1.13	FD_ZERO (&rfd);
351			FD_ZERO (&wfd);
352	pcg	1.7
353	pcg	1.13	int fds = 0;
354
355	pcg	1.21	# if IOM_IO
356	pcg	1.22	for (io_manager_vec<io_watcher>::const_iterator i = iow.end (); i-- > iow.begin (); )
357	pcg	1.13	if (*i)
358			{
359			if ((i)->events & EVENT_READ ) FD_SET ((i)->fd, &rfd);
360			if ((i)->events & EVENT_WRITE) FD_SET ((i)->fd, &wfd);
361	pcg	1.1
362	pcg	1.13	if ((i)->fd >= fds) fds = (i)->fd + 1;
363			}
364	pcg	1.21	# endif
365	pcg	1.1
366	pcg	1.22	if (!to && !fds) //TODO: also check idle_watchers and check_watchers?
367	pcg	1.13	break; // no events
368	pcg	1.1
369	pcg	1.21	# if IOM_SIG
370			FD_SET (sigpipe[0], &rfd);
371			if (sigpipe[0] >= fds) fds = sigpipe[0] + 1;
372			# endif
373
374			# if IOM_SIG
375			// there is no race, as we use a pipe for signals, so select
376			// will return if a signal is caught.
377			sigprocmask (SIG_UNBLOCK, &sigs, NULL);
378			# endif
379	pcg	1.19	fds = select (fds, &rfd, &wfd, NULL, to);
380	pcg	1.21	# if IOM_SIG
381			sigprocmask (SIG_BLOCK, &sigs, NULL);
382			# endif
383
384	pcg	1.13	# if IOM_TIME
385	pcg	1.29	{
386			// update time, try to compensate for gross non-monotonic time changes
387			tstamp diff = NOW;
388			set_now ();
389			diff = NOW - diff;
390
391			if (diff < 0)
392			for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
393			if (*i)
394			(*i)->at += diff;
395			}
396	pcg	1.13	# endif
397	pcg	1.1
398	pcg	1.13	if (fds > 0)
399	pcg	1.21	{
400			# if IOM_SIG
401			if (FD_ISSET (sigpipe[0], &rfd))
402	pcg	1.13	{
403	pcg	1.21	char ch;
404
405			while (read (sigpipe[0], &ch, 1) > 0)
406			;
407	pcg	1.13
408	pcg	1.25	for (vector<sig_vec *>::iterator svp = sw.end (); svp-- > sw.begin (); )
409	pcg	1.21	if (svp && (svp)->pending)
410			{
411			sig_vec &sv = **svp;
412			for (int i = sv.size (); i--; )
413			if (!sv[i])
414			sv.erase_unordered (i);
415			else
416			sv[i]->call (*sv[i]);
417	pcg	1.13
418	pcg	1.21	sv.pending = false;
419			}
420	pcg	1.13	}
421	pcg	1.21	# endif
422
423			# if IOM_IO
424			for (int i = iow.size (); i--; )
425			if (!iow[i])
426			iow.erase_unordered (i);
427			else
428			{
429	pcg	1.27	io_watcher &w = *iow[i];
430			short revents = w.events;
431	pcg	1.21
432	pcg	1.27	if (!FD_ISSET (w.fd, &rfd)) revents &= ~EVENT_READ;
433			if (!FD_ISSET (w.fd, &wfd)) revents &= ~EVENT_WRITE;
434	pcg	1.21
435			if (revents)
436	pcg	1.27	w.call (w, revents);
437	pcg	1.21	}
438			#endif
439			}
440	pcg	1.13	else if (fds < 0 && errno != EINTR)
441			{
442	pcg	1.21	perror ("io_manager: fatal error while waiting for I/O or time event, aborting.");
443	pcg	1.13	abort ();
444			}
445			#if IOM_IDLE
446			else
447			for (int i = iw.size (); i--; )
448			if (!iw[i])
449			iw.erase_unordered (i);
450			else
451			iw[i]->call (*iw[i]);
452			#endif
453
454			#elif IOM_TIME
455			if (!to)
456			break;
457	pcg	1.9
458	pcg	1.13	select (0, 0, 0, 0, &to);
459			set_now ();
460			#else
461			break;
462			#endif
463	pcg	1.1	}
464			}
465