rxvt-unicode/src/iom.C

/*
    iom.C -- generic I/O multiplexor
    Copyright (C) 2003 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 "../config.h"

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

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

#include "iom.h"

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

tstamp NOW;
static bool iom_valid;
io_manager iom;

template<class watcher>
void io_manager::reg (watcher *w, simplevec<watcher *> &queue)
{
  if (!iom_valid)
    abort ();

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

template<class watcher>
void io_manager::unreg (watcher *w, simplevec<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);

  iom.reg (this);
}

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

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

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

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

#if IOM_TIME
inline void set_now (void)
{
  struct timeval tv;

  gettimeofday (&tv, 0);

  NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
#endif
}

void io_manager::loop ()
{
#if IOM_TIME
  set_now ();
#endif

  for (;;)
    {
      struct timeval *to = 0;
      struct timeval tval;

#if IOM_IDLE
      if (iw.size ())
        {
          tval.tv_sec  = 0;
          tval.tv_usec = 0;
          to = &tval;
        }
      else
#endif
        {
#if IOM_TIME
          time_watcher *next;

          for (;;)
            {
              next = tw[0]; // the first time-watcher must exist at ALL times

              for (int i = tw.size (); i--; )
                if (!tw[i])
                  tw.erase_unordered (i);
                else if (tw[i]->at < next->at)
                  next = tw[i];

              if (next->at > NOW)
                {
                  if (next != tw[0])
                    {
                      double diff = next->at - NOW;
                      tval.tv_sec  = (int)diff;
                      tval.tv_usec = (int)((diff - tval.tv_sec) * 1000000);
                      to = &tval;
                    }
                  break;
                }
              else if (next->at >= 0)
                {
                  unreg (next);
                  next->call (*next);
                }
            }
#endif
        }

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

#if IOM_IO
      fd_set rfd, wfd, efd;

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

      int fds = 0;

      for (io_watcher **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;
          }

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

      fds = select (fds, &rfd, &wfd, &efd, to);
# if IOM_TIME
      set_now ();
# endif

      if (fds > 0)
        for (int i = iow.size (); i--; )
          if (!iow[i])
            iow.erase_unordered (i);
          else
            {
              short revents = iow[i]->events;

              if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ;
              if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE;

              if (revents)
                iow[i]->call (*iow[i], revents);
            }
      else if (fds < 0 && errno != EINTR)
        {
          perror ("Error while waiting for I/O or time event");
          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
    }
}

// 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
static struct tw0 : time_watcher {
  void cb (time_watcher &w)
  {
    // should never get called
    // reached end-of-time, or tstamp has a bogus definition :)
    abort ();
  }

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

io_manager::io_manager ()
{
  iom_valid = true;

#if IOM_TIME
  set_now ();

  tw0.start (TSTAMP_MAX);
#endif
}

io_manager::~io_manager ()
{
  iom_valid = false;
}

Revision:	1.8
Committed:	Fri Jan 16 22:11:09 2004 UTC (20 years, 5 months ago) by pcg
Content type:	text/plain
Branch:	MAIN
Changes since 1.7:	+109 -109 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	pcg	1.1	/*
2			iom.C -- generic I/O multiplexor
3			Copyright (C) 2003 Marc Lehmann <pcg@goof.com>
4
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			#include "../config.h"
21
22			#include <cstdio>
23	pcg	1.8	#include <cstdlib>
24			#include <cerrno>
25	pcg	1.1
26			#include <sys/select.h>
27			#include <sys/time.h>
28
29			#include "iom.h"
30
31	pcg	1.8	// TSTAMP_MAX must still fit into a positive struct timeval
32			#define TSTAMP_MAX (double)(1UL<<31)
33
34	pcg	1.1	tstamp NOW;
35	pcg	1.8	static bool iom_valid;
36	pcg	1.1	io_manager iom;
37
38	pcg	1.4	template<class watcher>
39			void io_manager::reg (watcher w, simplevec<watcher > &queue)
40			{
41	pcg	1.8	if (!iom_valid)
42			abort ();
43
44			if (!w->active)
45			{
46			queue.push_back (w);
47			w->active = queue.size ();
48			}
49	pcg	1.4	}
50
51			template<class watcher>
52			void io_manager::unreg (watcher w, simplevec<watcher > &queue)
53			{
54	pcg	1.8	if (!iom_valid)
55			return;
56	pcg	1.4
57	pcg	1.8	if (w->active)
58			{
59			queue [w->active - 1] = 0;
60			w->active = 0;
61			}
62	pcg	1.4	}
63
64			#if IOM_TIME
65	pcg	1.1	void time_watcher::trigger ()
66			{
67			call (*this);
68
69			iom.reg (this);
70			}
71
72	pcg	1.8	void io_manager::reg (time_watcher *w) { reg (w, tw); }
73			void io_manager::unreg (time_watcher *w) { unreg (w, tw); }
74			#endif
75	pcg	1.3
76	pcg	1.8	#if IOM_IO
77			void io_manager::reg (io_watcher *w) { reg (w, iow); }
78			void io_manager::unreg (io_watcher *w) { unreg (w, iow); }
79	pcg	1.4	#endif
80	pcg	1.1
81	pcg	1.4	#if IOM_CHECK
82	pcg	1.8	void io_manager::reg (check_watcher *w) { reg (w, cw); }
83			void io_manager::unreg (check_watcher *w) { unreg (w, cw); }
84	pcg	1.4	#endif
85	pcg	1.1
86	pcg	1.7	#if IOM_IDLE
87	pcg	1.8	void io_manager::reg (idle_watcher *w) { reg (w, iw); }
88			void io_manager::unreg (idle_watcher *w) { unreg (w, iw); }
89	pcg	1.7	#endif
90
91	pcg	1.4	#if IOM_TIME
92	pcg	1.1	inline void set_now (void)
93			{
94			struct timeval tv;
95
96			gettimeofday (&tv, 0);
97
98			NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
99	pcg	1.4	#endif
100	pcg	1.1	}
101
102			void io_manager::loop ()
103			{
104	pcg	1.4	#if IOM_TIME
105	pcg	1.1	set_now ();
106	pcg	1.4	#endif
107	pcg	1.1
108			for (;;)
109			{
110	pcg	1.5	struct timeval *to = 0;
111			struct timeval tval;
112	pcg	1.1
113	pcg	1.7	#if IOM_IDLE
114			if (iw.size ())
115			{
116			tval.tv_sec = 0;
117			tval.tv_usec = 0;
118			to = &tval;
119			}
120			else
121			#endif
122	pcg	1.1	{
123	pcg	1.7	#if IOM_TIME
124	pcg	1.8	time_watcher *next;
125	pcg	1.1
126	pcg	1.8	for (;;)
127	pcg	1.7	{
128	pcg	1.8	next = tw[0]; // the first time-watcher must exist at ALL times
129	pcg	1.1
130	pcg	1.8	for (int i = tw.size (); i--; )
131			if (!tw[i])
132			tw.erase_unordered (i);
133			else if (tw[i]->at < next->at)
134			next = tw[i];
135	pcg	1.7
136	pcg	1.8	if (next->at > NOW)
137	pcg	1.7	{
138	pcg	1.8	if (next != tw[0])
139			{
140			double diff = next->at - NOW;
141			tval.tv_sec = (int)diff;
142			tval.tv_usec = (int)((diff - tval.tv_sec) * 1000000);
143			to = &tval;
144			}
145	pcg	1.7	break;
146			}
147	pcg	1.8	else if (next->at >= 0)
148			{
149			unreg (next);
150			next->call (*next);
151			}
152	pcg	1.5	}
153	pcg	1.7	#endif
154	pcg	1.1	}
155	pcg	1.6
156			#if IOM_CHECK
157	pcg	1.8	for (int i = cw.size (); i--; )
158			if (!cw[i])
159			cw.erase_unordered (i);
160			else
161			cw[i]->call (*cw[i]);
162	pcg	1.4	#endif
163	pcg	1.1
164	pcg	1.4	#if IOM_IO
165	pcg	1.8	fd_set rfd, wfd, efd;
166	pcg	1.1
167			FD_ZERO (&rfd);
168			FD_ZERO (&wfd);
169
170			int fds = 0;
171
172	pcg	1.8	for (io_watcher **i = iow.end (); i-- > iow.begin (); )
173			if (*i)
174			{
175			if ((i)->events & EVENT_READ ) FD_SET ((i)->fd, &rfd);
176			if ((i)->events & EVENT_WRITE) FD_SET ((i)->fd, &wfd);
177	pcg	1.1
178	pcg	1.8	if ((i)->fd >= fds) fds = (i)->fd + 1;
179			}
180	pcg	1.1
181	pcg	1.8	if (!to && !fds) //TODO: also check idle_watchers and check_watchers
182	pcg	1.5	break; // no events
183
184	pcg	1.8	fds = select (fds, &rfd, &wfd, &efd, to);
185	pcg	1.4	# if IOM_TIME
186	pcg	1.1	set_now ();
187	pcg	1.4	# endif
188	pcg	1.1
189			if (fds > 0)
190	pcg	1.8	for (int i = iow.size (); i--; )
191			if (!iow[i])
192			iow.erase_unordered (i);
193			else
194			{
195			short revents = iow[i]->events;
196	pcg	1.1
197	pcg	1.8	if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ;
198			if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE;
199	pcg	1.4
200	pcg	1.8	if (revents)
201			iow[i]->call (*iow[i], revents);
202			}
203			else if (fds < 0 && errno != EINTR)
204			{
205			perror ("Error while waiting for I/O or time event");
206			abort ();
207			}
208	pcg	1.7	#if IOM_IDLE
209	pcg	1.8	else
210			for (int i = iw.size (); i--; )
211			if (!iw[i])
212			iw.erase_unordered (i);
213			else
214			iw[i]->call (*iw[i]);
215	pcg	1.7	#endif
216
217	pcg	1.4	#elif IOM_TIME
218	pcg	1.5	if (!to)
219			break;
220
221	pcg	1.4	select (0, 0, 0, 0, &to);
222			set_now ();
223	pcg	1.5	#else
224			break;
225	pcg	1.4	#endif
226	pcg	1.5	}
227	pcg	1.1	}
228
229	pcg	1.8	// this is a dummy time watcher to ensure that the first
230			// time watcher is _always_ valid, this gets rid of a lot
231			// of null-pointer-checks
232			static struct tw0 : time_watcher {
233			void cb (time_watcher &w)
234			{
235			// should never get called
236			// reached end-of-time, or tstamp has a bogus definition :)
237			abort ();
238			}
239
240			tw0()
241			: time_watcher (this, &tw0::cb)
242			{ }
243			} tw0;
244
245	pcg	1.1	io_manager::io_manager ()
246			{
247	pcg	1.8	iom_valid = true;
248
249	pcg	1.5	#if IOM_TIME
250	pcg	1.1	set_now ();
251	pcg	1.8
252			tw0.start (TSTAMP_MAX);
253	pcg	1.5	#endif
254	pcg	1.1	}
255
256			io_manager::~io_manager ()
257			{
258			iom_valid = false;
259			}
260