gvpe/src/iom.C

/*
    iom.C -- generic I/O multiplexer
    Copyright (C) 2003-2006 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 <cassert>

#include <sys/types.h>
#include <sys/time.h>

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

#if IOM_CHILD
# include <sys/wait.h>
#endif

#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
#if IOM_CHILD
static io_manager_vec<child_watcher>  pw;
#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_CHILD
// sig_watcher for child signal(s)
static struct sw0 : sig_watcher
{
  void cb (sig_watcher &w)
  {
    // SIGCHLD, call corresponding watchera
    pid_t pid;
    int status;

    while ((pid = waitpid (-1, &status, WNOHANG)) > 0)
      for (int i = pw.size (); i--; )
        {
          child_watcher *w = pw[i];

          if (!w)
            pw.erase_unordered (i);
          else if (w->pid == pid)
            {
              io_manager::unreg (*w);
              w->call (*w, status);
            }
         }
  }

  sw0 ()
  : sig_watcher (this, &sw0::cb)
  { }
} sw0;
#endif

#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 ()
  {
    iom_valid = true;

#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

#if IOM_CHILD
    sw0.start (SIGCHLD);
#endif

#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

#if IOM_CHILD
void io_manager::reg   (child_watcher &w) { io_manager::reg   (w, pw); }
void io_manager::unreg (child_watcher &w) { io_manager::unreg (w, pw); }
#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:	1.36
Committed:	Thu Dec 14 03:18:53 2006 UTC (19 years, 9 months ago) by pcg
Content type:	text/plain
Branch:	MAIN
Changes since 1.35:	+0 -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	1.35	Copyright (C) 2003-2006 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	1.34	#include <cassert>
28	pcg	1.1
29	pcg	1.34	#include <sys/types.h>
30	pcg	1.15	#include <sys/time.h>
31
32	pcg	1.18	#if 1 // older unices need these includes for select (2)
33	pcg	1.15	# include <unistd.h>
34	pcg	1.21	# include <time.h>
35			#endif
36
37	pcg	1.34	#if IOM_CHILD
38			# include <sys/wait.h>
39			#endif
40
41	pcg	1.21	#if IOM_SIG
42	pcg	1.28	# include <csignal>
43	pcg	1.21	# include <fcntl.h>
44	pcg	1.15	#endif
45
46			// if the BSDs would at least be marginally POSIX-compatible.. sigh
47			// until that happens, sys/select.h must come last
48	pcg	1.13	#include <sys/select.h>
49	pcg	1.1
50	pcg	1.21	#define TIMEVAL timeval
51			#define TV_FRAC tv_usec
52			#define TV_MULT 1000000L
53	pcg	1.11
54	pcg	1.21	#if IOM_IO
55			static io_manager_vec<io_watcher> iow;
56			#endif
57			#if IOM_CHECK
58			static io_manager_vec<check_watcher> cw;
59			#endif
60			#if IOM_TIME
61			static io_manager_vec<time_watcher> tw;
62			#endif
63			#if IOM_IDLE
64			static io_manager_vec<idle_watcher> iw;
65			#endif
66			#if IOM_SIG
67			static int sigpipe[2]; // signal signalling pipe
68			static sigset_t sigs;
69			struct sig_vec : io_manager_vec<sig_watcher> {
70			int pending;
71			sig_vec ()
72			: pending (false)
73			{ }
74			};
75			static vector<sig_vec *> sw;
76			#endif
77	pcg	1.34	#if IOM_CHILD
78			static io_manager_vec<child_watcher> pw;
79			#endif
80	pcg	1.1
81	pcg	1.14	// this is a dummy time watcher to ensure that the first
82			// time watcher is _always_ valid, this gets rid of a lot
83			// of null-pointer-checks
84			// (must come _before_ iom is being defined)
85	pcg	1.18	static struct tw0 : time_watcher
86	pcg	1.34	{
87			void cb (time_watcher &w)
88	pcg	1.14	{
89	pcg	1.34	// should never get called
90			// reached end-of-time, or tstamp has a bogus definition,
91			// or compiler initialisation order broken, or something else :)
92			abort ();
93			}
94	pcg	1.14
95	pcg	1.34	tw0 ()
96			: time_watcher (this, &tw0::cb)
97			{ }
98			} tw0;
99	pcg	1.14
100	pcg	1.10	tstamp NOW;
101	pcg	1.21
102	pcg	1.34	#if IOM_CHILD
103			// sig_watcher for child signal(s)
104			static struct sw0 : sig_watcher
105			{
106			void cb (sig_watcher &w)
107			{
108			// SIGCHLD, call corresponding watchera
109			pid_t pid;
110			int status;
111
112			while ((pid = waitpid (-1, &status, WNOHANG)) > 0)
113			for (int i = pw.size (); i--; )
114			{
115			child_watcher *w = pw[i];
116
117			if (!w)
118			pw.erase_unordered (i);
119			else if (w->pid == pid)
120			{
121	pcg	1.35	io_manager::unreg (*w);
122	pcg	1.34	w->call (*w, status);
123			}
124			}
125			}
126
127			sw0 ()
128			: sig_watcher (this, &sw0::cb)
129			{ }
130			} sw0;
131			#endif
132
133	pcg	1.21	#if IOM_TIME
134	pcg	1.26	tstamp io_manager::now ()
135	pcg	1.21	{
136			struct timeval tv;
137
138			gettimeofday (&tv, 0);
139	pcg	1.26	return (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000.;
140			}
141
142			void io_manager::set_now ()
143			{
144			NOW = now ();
145	pcg	1.21	}
146			#endif
147
148	pcg	1.13	static bool iom_valid;
149	pcg	1.21
150			// used for initialisation only
151			static struct init {
152			init ()
153			{
154	pcg	1.34	iom_valid = true;
155
156	pcg	1.21	#if IOM_SIG
157			sigemptyset (&sigs);
158
159			if (pipe (sigpipe))
160			{
161			perror ("io_manager: unable to create signal pipe, aborting.");
162			abort ();
163			}
164
165	pcg	1.26	fcntl (sigpipe[0], F_SETFL, O_NONBLOCK); fcntl (sigpipe[0], F_SETFD, FD_CLOEXEC);
166			fcntl (sigpipe[1], F_SETFL, O_NONBLOCK); fcntl (sigpipe[1], F_SETFD, FD_CLOEXEC);
167	pcg	1.21	#endif
168
169	pcg	1.34	#if IOM_CHILD
170			sw0.start (SIGCHLD);
171			#endif
172	pcg	1.21
173			#if IOM_TIME
174	pcg	1.26	io_manager::set_now ();
175	pcg	1.21
176			tw0.start (TSTAMP_MAX);
177			#endif
178			}
179
180	pcg	1.33	~init ()
181			{
182			iom_valid = false;
183			}
184
185	pcg	1.21	static void required ();
186			} init;
187
188			void
189			init::required ()
190			{
191			if (!iom_valid)
192			{
193			write (2, "io_manager: early registration attempt, aborting.\n",
194			sizeof ("io_manager: early registration attempt, aborting.\n") - 1);
195			abort ();
196			}
197			}
198	pcg	1.10
199	pcg	1.13	template<class watcher>
200	pcg	1.21	void io_manager::reg (watcher &w, io_manager_vec<watcher> &queue)
201	pcg	1.4	{
202	pcg	1.21	init::required ();
203	pcg	1.4
204	pcg	1.21	if (!w.active)
205	pcg	1.11	{
206	pcg	1.21	queue.push_back (&w);
207			w.active = queue.size ();
208	pcg	1.11	}
209	pcg	1.10	}
210
211	pcg	1.13	template<class watcher>
212	pcg	1.21	void io_manager::unreg (watcher &w, io_manager_vec<watcher> &queue)
213	pcg	1.10	{
214	pcg	1.13	if (!iom_valid)
215			return;
216	pcg	1.10
217	pcg	1.21	if (w.active)
218	pcg	1.11	{
219	pcg	1.21	queue [w.active - 1] = 0;
220			w.active = 0;
221	pcg	1.11	}
222	pcg	1.1	}
223
224	pcg	1.13	#if IOM_TIME
225			void time_watcher::trigger ()
226	pcg	1.1	{
227	pcg	1.13	call (*this);
228	pcg	1.21	io_manager::reg (*this);
229	pcg	1.1	}
230
231	pcg	1.21	void io_manager::reg (time_watcher &w) { io_manager::reg (w, tw); }
232			void io_manager::unreg (time_watcher &w) { io_manager::unreg (w, tw); }
233	pcg	1.13	#endif
234	pcg	1.6
235	pcg	1.13	#if IOM_IO
236	pcg	1.21	void io_manager::reg (io_watcher &w) { io_manager::reg (w, iow); }
237			void io_manager::unreg (io_watcher &w) { io_manager::unreg (w, iow); }
238	pcg	1.13	#endif
239	pcg	1.7
240	pcg	1.13	#if IOM_CHECK
241	pcg	1.21	void io_manager::reg (check_watcher &w) { io_manager::reg (w, cw); }
242			void io_manager::unreg (check_watcher &w) { io_manager::unreg (w, cw); }
243	pcg	1.13	#endif
244	pcg	1.1
245	pcg	1.13	#if IOM_IDLE
246	pcg	1.21	void io_manager::reg (idle_watcher &w) { io_manager::reg (w, iw); }
247			void io_manager::unreg (idle_watcher &w) { io_manager::unreg (w, iw); }
248	pcg	1.13	#endif
249	pcg	1.1
250	pcg	1.21	#if IOM_SIG
251			static void
252			sighandler (int signum)
253	pcg	1.1	{
254	pcg	1.21	sw [signum - 1]->pending = true;
255	pcg	1.1
256	pcg	1.21	// we use a pipe for signal notifications, as most current
257			// OSes (Linux...) do not implement pselect correctly. ugh.
258			char ch = signum; // actual content not used
259			write (sigpipe[1], &ch, 1);
260	pcg	1.20	}
261
262	pcg	1.21	void io_manager::reg (sig_watcher &w)
263	pcg	1.20	{
264	pcg	1.33	init::required ();
265
266	pcg	1.21	assert (0 < w.signum);
267	pcg	1.20
268	pcg	1.21	sw.reserve (w.signum);
269	pcg	1.20
270	pcg	1.21	while (sw.size () < w.signum) // pathetic
271			sw.push_back (0);
272	pcg	1.20
273	pcg	1.21	sig_vec *&sv = sw[w.signum - 1];
274	pcg	1.20
275			if (!sv)
276			{
277			sv = new sig_vec;
278
279	pcg	1.21	sigaddset (&sigs, w.signum);
280			sigprocmask (SIG_BLOCK, &sigs, NULL);
281
282	pcg	1.20	struct sigaction sa;
283	pcg	1.21	sa.sa_handler = sighandler;
284	pcg	1.20	sigfillset (&sa.sa_mask);
285	pcg	1.21	sa.sa_flags = SA_RESTART;
286	pcg	1.20
287	pcg	1.21	if (sigaction (w.signum, &sa, 0))
288	pcg	1.20	{
289	pcg	1.21	perror ("io_manager: error while installing signal handler, ignoring.");
290	pcg	1.20	abort ();
291			}
292	pcg	1.21
293	pcg	1.20	}
294
295	pcg	1.21	io_manager::reg (w, *sv);
296	pcg	1.20	}
297
298	pcg	1.21	void io_manager::unreg (sig_watcher &w)
299	pcg	1.20	{
300	pcg	1.33	if (!w.active \|\| !iom_valid)
301	pcg	1.21	return;
302
303			assert (0 < w.signum && w.signum <= sw.size ());
304	pcg	1.20
305	pcg	1.21	io_manager::unreg (w, *sw[w.signum - 1]);
306	pcg	1.20	}
307
308			void sig_watcher::start (int signum)
309			{
310			stop ();
311			this->signum = signum;
312	pcg	1.21	io_manager::reg (*this);
313	pcg	1.20	}
314			#endif
315	pcg	1.21
316	pcg	1.34	#if IOM_CHILD
317			void io_manager::reg (child_watcher &w) { io_manager::reg (w, pw); }
318			void io_manager::unreg (child_watcher &w) { io_manager::unreg (w, pw); }
319			#endif
320
321	pcg	1.1	void io_manager::loop ()
322			{
323	pcg	1.21	init::required ();
324
325	pcg	1.13	#if IOM_TIME
326	pcg	1.1	set_now ();
327	pcg	1.13	#endif
328	pcg	1.1
329	pcg	1.4	for (;;)
330	pcg	1.1	{
331	pcg	1.13
332			#if IOM_TIME
333	pcg	1.22	// call pending time watchers
334			{
335			bool activity;
336	pcg	1.7
337	pcg	1.22	do
338			{
339			activity = false;
340	pcg	1.13
341	pcg	1.22	for (int i = tw.size (); i--; )
342			if (!tw[i])
343			tw.erase_unordered (i);
344	pcg	1.24	else if (tw[i]->at <= NOW)
345	pcg	1.22	{
346			time_watcher &w = *tw[i];
347
348			unreg (w);
349			w.call (w);
350	pcg	1.13
351	pcg	1.22	activity = true;
352	pcg	1.13	}
353	pcg	1.22	}
354			while (activity);
355			}
356	pcg	1.13	#endif
357	pcg	1.1
358	pcg	1.13	#if IOM_CHECK
359	pcg	1.22	// call all check watchers
360	pcg	1.13	for (int i = cw.size (); i--; )
361			if (!cw[i])
362			cw.erase_unordered (i);
363			else
364			cw[i]->call (*cw[i]);
365	pcg	1.22	#endif
366	pcg	1.17
367	pcg	1.22	struct TIMEVAL *to = 0;
368			struct TIMEVAL tval;
369
370			#if IOM_IDLE
371			if (iw.size ())
372	pcg	1.17	{
373			tval.tv_sec = 0;
374	pcg	1.21	tval.TV_FRAC = 0;
375	pcg	1.17	to = &tval;
376			}
377	pcg	1.22	else
378			#endif
379			{
380			#if IOM_TIME
381			// find earliest active watcher
382			time_watcher *next = tw[0]; // the first time-watcher must exist at ALL times
383
384			for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
385			if (i && (i)->at < next->at)
386			next = *i;
387
388			if (next->at > NOW && next != tw[0])
389			{
390			double diff = next->at - NOW;
391			tval.tv_sec = (int)diff;
392			tval.TV_FRAC = (int) ((diff - tval.tv_sec) * TV_MULT);
393			to = &tval;
394			}
395			}
396	pcg	1.13	#endif
397
398	pcg	1.21	#if IOM_IO \|\| IOM_SIG
399	pcg	1.18	fd_set rfd, wfd;
400	pcg	1.7
401	pcg	1.13	FD_ZERO (&rfd);
402			FD_ZERO (&wfd);
403	pcg	1.7
404	pcg	1.13	int fds = 0;
405
406	pcg	1.21	# if IOM_IO
407	pcg	1.22	for (io_manager_vec<io_watcher>::const_iterator i = iow.end (); i-- > iow.begin (); )
408	pcg	1.13	if (*i)
409			{
410			if ((i)->events & EVENT_READ ) FD_SET ((i)->fd, &rfd);
411			if ((i)->events & EVENT_WRITE) FD_SET ((i)->fd, &wfd);
412	pcg	1.1
413	pcg	1.13	if ((i)->fd >= fds) fds = (i)->fd + 1;
414			}
415	pcg	1.21	# endif
416	pcg	1.1
417	pcg	1.22	if (!to && !fds) //TODO: also check idle_watchers and check_watchers?
418	pcg	1.13	break; // no events
419	pcg	1.1
420	pcg	1.21	# if IOM_SIG
421			FD_SET (sigpipe[0], &rfd);
422			if (sigpipe[0] >= fds) fds = sigpipe[0] + 1;
423			# endif
424
425			# if IOM_SIG
426			// there is no race, as we use a pipe for signals, so select
427			// will return if a signal is caught.
428			sigprocmask (SIG_UNBLOCK, &sigs, NULL);
429			# endif
430	pcg	1.19	fds = select (fds, &rfd, &wfd, NULL, to);
431	pcg	1.21	# if IOM_SIG
432			sigprocmask (SIG_BLOCK, &sigs, NULL);
433			# endif
434
435	pcg	1.13	# if IOM_TIME
436	pcg	1.29	{
437			// update time, try to compensate for gross non-monotonic time changes
438			tstamp diff = NOW;
439			set_now ();
440			diff = NOW - diff;
441
442			if (diff < 0)
443			for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
444			if (*i)
445			(*i)->at += diff;
446			}
447	pcg	1.13	# endif
448	pcg	1.1
449	pcg	1.13	if (fds > 0)
450	pcg	1.21	{
451			# if IOM_SIG
452			if (FD_ISSET (sigpipe[0], &rfd))
453	pcg	1.13	{
454	pcg	1.21	char ch;
455
456			while (read (sigpipe[0], &ch, 1) > 0)
457			;
458	pcg	1.13
459	pcg	1.25	for (vector<sig_vec *>::iterator svp = sw.end (); svp-- > sw.begin (); )
460	pcg	1.21	if (svp && (svp)->pending)
461			{
462			sig_vec &sv = **svp;
463			for (int i = sv.size (); i--; )
464			if (!sv[i])
465			sv.erase_unordered (i);
466			else
467			sv[i]->call (*sv[i]);
468	pcg	1.13
469	pcg	1.21	sv.pending = false;
470			}
471	pcg	1.13	}
472	pcg	1.21	# endif
473
474			# if IOM_IO
475			for (int i = iow.size (); i--; )
476			if (!iow[i])
477			iow.erase_unordered (i);
478			else
479			{
480	pcg	1.27	io_watcher &w = *iow[i];
481			short revents = w.events;
482	pcg	1.21
483	pcg	1.27	if (!FD_ISSET (w.fd, &rfd)) revents &= ~EVENT_READ;
484			if (!FD_ISSET (w.fd, &wfd)) revents &= ~EVENT_WRITE;
485	pcg	1.21
486			if (revents)
487	pcg	1.27	w.call (w, revents);
488	pcg	1.21	}
489			#endif
490			}
491	pcg	1.13	else if (fds < 0 && errno != EINTR)
492			{
493	pcg	1.21	perror ("io_manager: fatal error while waiting for I/O or time event, aborting.");
494	pcg	1.13	abort ();
495			}
496			#if IOM_IDLE
497			else
498			for (int i = iw.size (); i--; )
499			if (!iw[i])
500			iw.erase_unordered (i);
501			else
502			iw[i]->call (*iw[i]);
503			#endif
504
505			#elif IOM_TIME
506			if (!to)
507			break;
508	pcg	1.9
509	pcg	1.13	select (0, 0, 0, 0, &to);
510			set_now ();
511			#else
512			break;
513			#endif
514	pcg	1.1	}
515			}
516