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 <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)
            {
              w->stop ();
              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:	1.33
Committed:	Thu Jan 19 09:47:15 2006 UTC (18 years, 4 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.32:	+62 -16 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	root	1.33	#include <cassert>
28	pcg	1.1
29	root	1.33	#include <sys/types.h>
30	pcg	1.11	#include <sys/time.h>
31
32	pcg	1.14	#if 1 // older unices need these includes for select (2)
33	pcg	1.11	# include <unistd.h>
34	root	1.19	# include <time.h>
35			#endif
36
37	root	1.33	#if IOM_CHILD
38			# include <sys/wait.h>
39			#endif
40
41	root	1.19	#if IOM_SIG
42	root	1.27	# include <csignal>
43	root	1.19	# include <fcntl.h>
44	pcg	1.11	#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	1.1	#include <sys/select.h>
49
50	root	1.19	#define TIMEVAL timeval
51			#define TV_FRAC tv_usec
52			#define TV_MULT 1000000L
53	pcg	1.1
54	root	1.19	#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	root	1.33	#if IOM_CHILD
78			static io_manager_vec<child_watcher> pw;
79			#endif
80	pcg	1.8
81	pcg	1.10	// 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	1.13	static struct tw0 : time_watcher
86	root	1.33	{
87			void cb (time_watcher &w)
88	pcg	1.10	{
89	root	1.33	// 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	1.10
95	root	1.33	tw0 ()
96			: time_watcher (this, &tw0::cb)
97			{ }
98			} tw0;
99	pcg	1.10
100	pcg	1.1	tstamp NOW;
101	root	1.19
102	root	1.33	#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			w->stop ();
122			w->call (*w, status);
123			}
124			}
125
126			}
127
128			sw0 ()
129			: sig_watcher (this, &sw0::cb)
130			{ }
131			} sw0;
132			#endif
133
134	root	1.19	#if IOM_TIME
135	root	1.24	tstamp io_manager::now ()
136	root	1.19	{
137			struct timeval tv;
138
139			gettimeofday (&tv, 0);
140	root	1.24	return (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000.;
141			}
142
143			void io_manager::set_now ()
144			{
145			NOW = now ();
146	root	1.19	}
147			#endif
148
149	pcg	1.8	static bool iom_valid;
150	root	1.19
151			// used for initialisation only
152			static struct init {
153			init ()
154			{
155	root	1.33	iom_valid = true;
156
157	root	1.19	#if IOM_SIG
158			sigemptyset (&sigs);
159
160			if (pipe (sigpipe))
161			{
162			perror ("io_manager: unable to create signal pipe, aborting.");
163			abort ();
164			}
165
166	root	1.25	fcntl (sigpipe[0], F_SETFL, O_NONBLOCK); fcntl (sigpipe[0], F_SETFD, FD_CLOEXEC);
167			fcntl (sigpipe[1], F_SETFL, O_NONBLOCK); fcntl (sigpipe[1], F_SETFD, FD_CLOEXEC);
168	root	1.19	#endif
169
170	root	1.33	#if IOM_CHILD
171			sw0.start (SIGCHLD);
172			#endif
173	root	1.19
174			#if IOM_TIME
175	root	1.24	io_manager::set_now ();
176	root	1.19
177			tw0.start (TSTAMP_MAX);
178			#endif
179			}
180
181	root	1.31	~init ()
182			{
183			iom_valid = false;
184			}
185
186	root	1.19	static void required ();
187			} init;
188
189			void
190			init::required ()
191			{
192			if (!iom_valid)
193			{
194			write (2, "io_manager: early registration attempt, aborting.\n",
195			sizeof ("io_manager: early registration attempt, aborting.\n") - 1);
196			abort ();
197			}
198			}
199	pcg	1.1
200	pcg	1.4	template<class watcher>
201	root	1.19	void io_manager::reg (watcher &w, io_manager_vec<watcher> &queue)
202	pcg	1.4	{
203	root	1.19	init::required ();
204	pcg	1.8
205	root	1.19	if (!w.active)
206	pcg	1.8	{
207	root	1.19	queue.push_back (&w);
208			w.active = queue.size ();
209	pcg	1.8	}
210	pcg	1.4	}
211
212			template<class watcher>
213	root	1.19	void io_manager::unreg (watcher &w, io_manager_vec<watcher> &queue)
214	pcg	1.4	{
215	pcg	1.8	if (!iom_valid)
216			return;
217	pcg	1.4
218	root	1.19	if (w.active)
219	pcg	1.8	{
220	root	1.19	queue [w.active - 1] = 0;
221			w.active = 0;
222	pcg	1.8	}
223	pcg	1.4	}
224
225			#if IOM_TIME
226	pcg	1.1	void time_watcher::trigger ()
227			{
228			call (*this);
229	root	1.19	io_manager::reg (*this);
230	pcg	1.1	}
231
232	root	1.19	void io_manager::reg (time_watcher &w) { io_manager::reg (w, tw); }
233			void io_manager::unreg (time_watcher &w) { io_manager::unreg (w, tw); }
234	pcg	1.8	#endif
235	pcg	1.3
236	pcg	1.8	#if IOM_IO
237	root	1.19	void io_manager::reg (io_watcher &w) { io_manager::reg (w, iow); }
238			void io_manager::unreg (io_watcher &w) { io_manager::unreg (w, iow); }
239	pcg	1.4	#endif
240	pcg	1.1
241	pcg	1.4	#if IOM_CHECK
242	root	1.19	void io_manager::reg (check_watcher &w) { io_manager::reg (w, cw); }
243			void io_manager::unreg (check_watcher &w) { io_manager::unreg (w, cw); }
244	pcg	1.4	#endif
245	pcg	1.1
246	pcg	1.7	#if IOM_IDLE
247	root	1.19	void io_manager::reg (idle_watcher &w) { io_manager::reg (w, iw); }
248			void io_manager::unreg (idle_watcher &w) { io_manager::unreg (w, iw); }
249	pcg	1.7	#endif
250
251	root	1.19	#if IOM_SIG
252			static void
253			sighandler (int signum)
254	pcg	1.1	{
255	root	1.19	sw [signum - 1]->pending = true;
256	pcg	1.1
257	root	1.19	// we use a pipe for signal notifications, as most current
258			// OSes (Linux...) do not implement pselect correctly. ugh.
259			char ch = signum; // actual content not used
260			write (sigpipe[1], &ch, 1);
261	pcg	1.16	}
262
263	root	1.19	void io_manager::reg (sig_watcher &w)
264	pcg	1.16	{
265	root	1.32	init::required ();
266
267	root	1.19	assert (0 < w.signum);
268	pcg	1.16
269	root	1.19	sw.reserve (w.signum);
270	pcg	1.16
271	root	1.19	while (sw.size () < w.signum) // pathetic
272			sw.push_back (0);
273	pcg	1.16
274	root	1.19	sig_vec *&sv = sw[w.signum - 1];
275	pcg	1.16
276			if (!sv)
277			{
278			sv = new sig_vec;
279
280	root	1.19	sigaddset (&sigs, w.signum);
281			sigprocmask (SIG_BLOCK, &sigs, NULL);
282
283	pcg	1.16	struct sigaction sa;
284	root	1.19	sa.sa_handler = sighandler;
285	pcg	1.16	sigfillset (&sa.sa_mask);
286	root	1.19	sa.sa_flags = SA_RESTART;
287	pcg	1.16
288	root	1.19	if (sigaction (w.signum, &sa, 0))
289	pcg	1.16	{
290	root	1.19	perror ("io_manager: error while installing signal handler, ignoring.");
291	pcg	1.16	abort ();
292			}
293	root	1.19
294	pcg	1.16	}
295
296	root	1.19	io_manager::reg (w, *sv);
297	pcg	1.16	}
298
299	root	1.19	void io_manager::unreg (sig_watcher &w)
300	pcg	1.16	{
301	root	1.32	if (!w.active \|\| !iom_valid)
302	root	1.19	return;
303
304			assert (0 < w.signum && w.signum <= sw.size ());
305	pcg	1.16
306	root	1.19	io_manager::unreg (w, *sw[w.signum - 1]);
307	pcg	1.16	}
308
309			void sig_watcher::start (int signum)
310			{
311			stop ();
312			this->signum = signum;
313	root	1.19	io_manager::reg (*this);
314	pcg	1.16	}
315			#endif
316	root	1.19
317	root	1.33	#if IOM_CHILD
318			void io_manager::reg (child_watcher &w) { io_manager::reg (w, pw); }
319			void io_manager::unreg (child_watcher &w) { io_manager::unreg (w, pw); }
320			#endif
321
322	pcg	1.1	void io_manager::loop ()
323			{
324	root	1.19	init::required ();
325
326	pcg	1.4	#if IOM_TIME
327	pcg	1.1	set_now ();
328	pcg	1.4	#endif
329	pcg	1.1
330			for (;;)
331			{
332
333	pcg	1.7	#if IOM_TIME
334	root	1.23	// call pending time watchers
335			{
336			bool activity;
337	pcg	1.1
338	root	1.23	do
339			{
340			activity = false;
341	pcg	1.1
342	root	1.23	for (int i = tw.size (); i--; )
343			if (!tw[i])
344			tw.erase_unordered (i);
345			else if (tw[i]->at <= NOW)
346			{
347			time_watcher &w = *tw[i];
348
349			unreg (w);
350			w.call (w);
351	pcg	1.7
352	root	1.23	activity = true;
353	pcg	1.7	}
354	root	1.23	}
355			while (activity);
356			}
357	pcg	1.7	#endif
358	pcg	1.6
359			#if IOM_CHECK
360	root	1.23	// call all check watchers
361	pcg	1.8	for (int i = cw.size (); i--; )
362			if (!cw[i])
363			cw.erase_unordered (i);
364			else
365			cw[i]->call (*cw[i]);
366	root	1.23	#endif
367	pcg	1.12
368	root	1.23	struct TIMEVAL *to = 0;
369			struct TIMEVAL tval;
370
371			#if IOM_IDLE
372			if (iw.size ())
373	pcg	1.12	{
374			tval.tv_sec = 0;
375	root	1.19	tval.TV_FRAC = 0;
376	pcg	1.12	to = &tval;
377			}
378	root	1.23	else
379			#endif
380			{
381			#if IOM_TIME
382			// find earliest active watcher
383			time_watcher *next = tw[0]; // the first time-watcher must exist at ALL times
384
385			for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
386			if (i && (i)->at < next->at)
387			next = *i;
388
389			if (next->at > NOW && next != tw[0])
390			{
391			double diff = next->at - NOW;
392			tval.tv_sec = (int)diff;
393			tval.TV_FRAC = (int) ((diff - tval.tv_sec) * TV_MULT);
394			to = &tval;
395			}
396			}
397	pcg	1.4	#endif
398	pcg	1.1
399	root	1.19	#if IOM_IO \|\| IOM_SIG
400	pcg	1.15	fd_set rfd, wfd;
401	pcg	1.1
402			FD_ZERO (&rfd);
403			FD_ZERO (&wfd);
404
405			int fds = 0;
406
407	root	1.19	# if IOM_IO
408	root	1.23	for (io_manager_vec<io_watcher>::const_iterator i = iow.end (); i-- > iow.begin (); )
409	pcg	1.8	if (*i)
410			{
411			if ((i)->events & EVENT_READ ) FD_SET ((i)->fd, &rfd);
412			if ((i)->events & EVENT_WRITE) FD_SET ((i)->fd, &wfd);
413	pcg	1.1
414	pcg	1.8	if ((i)->fd >= fds) fds = (i)->fd + 1;
415			}
416	root	1.19	# endif
417	pcg	1.1
418	root	1.23	if (!to && !fds) //TODO: also check idle_watchers and check_watchers?
419	pcg	1.5	break; // no events
420
421	root	1.19	# if IOM_SIG
422			FD_SET (sigpipe[0], &rfd);
423			if (sigpipe[0] >= fds) fds = sigpipe[0] + 1;
424			# endif
425
426			# if IOM_SIG
427			// there is no race, as we use a pipe for signals, so select
428			// will return if a signal is caught.
429			sigprocmask (SIG_UNBLOCK, &sigs, NULL);
430			# endif
431	pcg	1.15	fds = select (fds, &rfd, &wfd, NULL, to);
432	root	1.19	# if IOM_SIG
433			sigprocmask (SIG_BLOCK, &sigs, NULL);
434			# endif
435
436	pcg	1.4	# if IOM_TIME
437	root	1.28	{
438			// update time, try to compensate for gross non-monotonic time changes
439			tstamp diff = NOW;
440			set_now ();
441			diff = NOW - diff;
442
443			if (diff < 0)
444			for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
445			if (*i)
446			(*i)->at += diff;
447			}
448	pcg	1.4	# endif
449	pcg	1.1
450			if (fds > 0)
451	root	1.19	{
452			# if IOM_SIG
453			if (FD_ISSET (sigpipe[0], &rfd))
454	pcg	1.8	{
455	root	1.19	char ch;
456
457			while (read (sigpipe[0], &ch, 1) > 0)
458			;
459	pcg	1.1
460	root	1.23	for (vector<sig_vec *>::iterator svp = sw.end (); svp-- > sw.begin (); )
461	root	1.19	if (svp && (svp)->pending)
462			{
463			sig_vec &sv = **svp;
464			for (int i = sv.size (); i--; )
465			if (!sv[i])
466			sv.erase_unordered (i);
467			else
468			sv[i]->call (*sv[i]);
469	pcg	1.4
470	root	1.19	sv.pending = false;
471			}
472	pcg	1.8	}
473	root	1.19	# endif
474
475			# if IOM_IO
476			for (int i = iow.size (); i--; )
477			if (!iow[i])
478			iow.erase_unordered (i);
479			else
480			{
481	root	1.27	io_watcher &w = *iow[i];
482			short revents = w.events;
483	root	1.19
484	root	1.27	if (!FD_ISSET (w.fd, &rfd)) revents &= ~EVENT_READ;
485			if (!FD_ISSET (w.fd, &wfd)) revents &= ~EVENT_WRITE;
486	root	1.19
487			if (revents)
488	root	1.27	w.call (w, revents);
489	root	1.19	}
490			#endif
491			}
492	pcg	1.8	else if (fds < 0 && errno != EINTR)
493			{
494	root	1.19	perror ("io_manager: fatal error while waiting for I/O or time event, aborting.");
495	pcg	1.8	abort ();
496			}
497	pcg	1.7	#if IOM_IDLE
498	pcg	1.8	else
499			for (int i = iw.size (); i--; )
500			if (!iw[i])
501			iw.erase_unordered (i);
502			else
503			iw[i]->call (*iw[i]);
504	pcg	1.7	#endif
505
506	pcg	1.4	#elif IOM_TIME
507	pcg	1.5	if (!to)
508			break;
509
510	pcg	1.4	select (0, 0, 0, 0, &to);
511			set_now ();
512	pcg	1.5	#else
513			break;
514	pcg	1.4	#endif
515	pcg	1.5	}
516	pcg	1.1	}
517