gvpe/src/iom.C

/*
    iom.C -- I/O multiplexor
 
    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 <sys/time.h>

#include <algorithm>
#include <functional>

#include "gettext.h"

#include "slog.h"
#include "iom.h"

tstamp NOW;
bool iom_valid;
io_manager iom;

inline bool earliest_first (const time_watcher *a, const time_watcher *b)
{
  return a->at > b->at;
}

void time_watcher::set (tstamp when)
{
  at = when;

  if (registered)
    iom.reschedule_time_watchers ();
}

void time_watcher::trigger ()
{
  call (*this);

  if (registered)
    iom.reschedule_time_watchers ();
  else
    iom.reg (this);
}

time_watcher::~time_watcher ()
{
  if (iom_valid)
    iom.unreg (this);
}

void io_watcher::set(int fd_, short events_)
{
  fd     = fd_;
  events = events_;

  if (registered)
    {
      iom.unreg (this);
      iom.reg (this);
    }
}

io_watcher::~io_watcher ()
{
  if (iom_valid)
    iom.unreg (this);
}

void io_manager::reg (io_watcher *w)
{
  if (!w->registered)
    {
      w->registered = true;

      pollfd pfd;

      pfd.fd     = w->fd;
      pfd.events = w->events;

      pfs.push_back (pfd);
      iow.push_back (w);
    }
}

void io_manager::unreg (io_watcher *w)
{
  if (w->registered)
    {
      w->registered = false;

      unsigned int sz = iow.size ();
      unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin ();

      assert (i != sz);

      if (sz == 1)
        {
          pfs.clear ();
          iow.clear ();
        }
      else if (i == sz - 1)
        {
          iow.pop_back ();
          pfs.pop_back ();
        }
      else
        {
          iow[i] = iow[sz - 1]; iow.pop_back ();
          pfs[i] = pfs[sz - 1]; pfs.pop_back ();
        }
    }
}

void io_manager::reschedule_time_watchers ()
{
  make_heap (tw.begin (), tw.end (), earliest_first);
}

void io_manager::reg (time_watcher *w)
{
  if (!w->registered)
    {
      w->registered = true;

      tw.push_back (w);
      push_heap (tw.begin (), tw.end (), earliest_first);
    }
}

void io_manager::unreg (time_watcher *w)
{
  if (w->registered)
    {
      w->registered = false;

      unsigned int sz = tw.size ();
      unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin ();

      assert (i != sz);
      
      if (i != sz - 1)
        tw[i] = tw[sz - 1];

      tw.pop_back ();
      reschedule_time_watchers ();
    }
}

inline void set_now (void)
{
  struct timeval tv;

  gettimeofday (&tv, 0);

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

void io_manager::loop ()
{
  set_now ();

  for (;;)
    {
      while (tw[0]->at <= NOW)
        {
          // remove the first watcher
          time_watcher *w = tw[0];

          pop_heap (tw.begin (), tw.end (), earliest_first);
          tw.pop_back ();

          w->registered = false;

          // call it
          w->call (*w);

          // re-add it if necessary
          if (w->at >= 0 && !w->registered)
            reg (w);
        }

      int timeout = (int) ((tw[0]->at - NOW) * 1000);

      int fds = poll (&pfs[0], pfs.size (), timeout);

      set_now ();

      vector<io_watcher *>::iterator w;
      vector<pollfd>::iterator p;

      for (w = iow.begin (), p = pfs.begin ();
           fds > 0 && w < iow.end ();
           ++w, ++p)
        if (p->revents)
          {
            --fds;

            if (p->revents & POLLNVAL)
              {
                slog (L_ERR, _("io_watcher started on illegal file descriptor, disabling."));
                (*w)->stop ();
              }
            else
              (*w)->call (**w, p->revents);
          }
    }
}

void io_manager::idle_cb (time_watcher &w)
{
  w.at = NOW + 86400; // wake up every day, for no good reason
}

io_manager::io_manager ()
{
  iom_valid = true;

  set_now ();
  idle = new time_watcher (this, &io_manager::idle_cb);
  idle->start (0);
}

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

Revision:	1.11
Committed:	Sat Apr 5 02:32:40 2003 UTC (21 years, 1 month ago) by pcg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	VPE_0_9, VPE_1_0
Changes since 1.10:	+43 -21 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	pcg	1.1	/*
2			iom.C -- I/O multiplexor
3
4			This program is free software; you can redistribute it and/or modify
5			it under the terms of the GNU General Public License as published by
6			the Free Software Foundation; either version 2 of the License, or
7			(at your option) any later version.
8
9			This program is distributed in the hope that it will be useful,
10			but WITHOUT ANY WARRANTY; without even the implied warranty of
11			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12			GNU General Public License for more details.
13
14			You should have received a copy of the GNU General Public License
15			along with this program; if not, write to the Free Software
16			Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17			*/
18
19			#include "config.h"
20
21			#include <sys/time.h>
22
23			#include <algorithm>
24			#include <functional>
25
26	pcg	1.11	#include "gettext.h"
27
28	pcg	1.1	#include "slog.h"
29			#include "iom.h"
30
31	pcg	1.10	tstamp NOW;
32			bool iom_valid;
33			io_manager iom;
34
35	pcg	1.9	inline bool earliest_first (const time_watcher a, const time_watcher b)
36	pcg	1.1	{
37			return a->at > b->at;
38			}
39
40	pcg	1.2	void time_watcher::set (tstamp when)
41	pcg	1.1	{
42			at = when;
43	pcg	1.6
44			if (registered)
45			iom.reschedule_time_watchers ();
46	pcg	1.1	}
47
48	pcg	1.4	void time_watcher::trigger ()
49			{
50	pcg	1.9	call (*this);
51	pcg	1.6
52			if (registered)
53			iom.reschedule_time_watchers ();
54			else
55			iom.reg (this);
56	pcg	1.4	}
57
58	pcg	1.11	time_watcher::~time_watcher ()
59	pcg	1.4	{
60	pcg	1.11	if (iom_valid)
61			iom.unreg (this);
62	pcg	1.4	}
63
64	pcg	1.11	void io_watcher::set(int fd_, short events_)
65	pcg	1.10	{
66	pcg	1.11	fd = fd_;
67			events = events_;
68
69			if (registered)
70			{
71			iom.unreg (this);
72			iom.reg (this);
73			}
74	pcg	1.10	}
75
76			io_watcher::~io_watcher ()
77			{
78			if (iom_valid)
79			iom.unreg (this);
80			}
81
82	pcg	1.9	void io_manager::reg (io_watcher *w)
83	pcg	1.1	{
84	pcg	1.11	if (!w->registered)
85			{
86			w->registered = true;
87
88			pollfd pfd;
89	pcg	1.1
90	pcg	1.11	pfd.fd = w->fd;
91			pfd.events = w->events;
92	pcg	1.10
93	pcg	1.11	pfs.push_back (pfd);
94			iow.push_back (w);
95			}
96	pcg	1.1	}
97
98	pcg	1.7	void io_manager::unreg (io_watcher *w)
99	pcg	1.1	{
100	pcg	1.11	if (w->registered)
101	pcg	1.10	{
102	pcg	1.11	w->registered = false;
103
104	pcg	1.10	unsigned int sz = iow.size ();
105			unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin ();
106
107			assert (i != sz);
108	pcg	1.1
109			if (sz == 1)
110			{
111			pfs.clear ();
112			iow.clear ();
113			}
114			else if (i == sz - 1)
115			{
116			iow.pop_back ();
117			pfs.pop_back ();
118			}
119			else
120			{
121			iow[i] = iow[sz - 1]; iow.pop_back ();
122			pfs[i] = pfs[sz - 1]; pfs.pop_back ();
123			}
124			}
125			}
126
127	pcg	1.6	void io_manager::reschedule_time_watchers ()
128			{
129	pcg	1.9	make_heap (tw.begin (), tw.end (), earliest_first);
130	pcg	1.6	}
131
132	pcg	1.1	void io_manager::reg (time_watcher *w)
133			{
134	pcg	1.11	if (!w->registered)
135			{
136			w->registered = true;
137	pcg	1.7
138	pcg	1.11	tw.push_back (w);
139			push_heap (tw.begin (), tw.end (), earliest_first);
140			}
141	pcg	1.1	}
142
143	pcg	1.7	void io_manager::unreg (time_watcher *w)
144	pcg	1.1	{
145	pcg	1.7	if (w->registered)
146			{
147	pcg	1.11	w->registered = false;
148
149	pcg	1.7	unsigned int sz = tw.size ();
150			unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin ();
151	pcg	1.1
152	pcg	1.10	assert (i != sz);
153
154			if (i != sz - 1)
155			tw[i] = tw[sz - 1];
156	pcg	1.7
157	pcg	1.10	tw.pop_back ();
158			reschedule_time_watchers ();
159	pcg	1.1	}
160			}
161
162			inline void set_now (void)
163			{
164			struct timeval tv;
165
166			gettimeofday (&tv, 0);
167
168	pcg	1.2	NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
169	pcg	1.1	}
170
171			void io_manager::loop ()
172			{
173			set_now ();
174
175	pcg	1.4	for (;;)
176	pcg	1.1	{
177	pcg	1.4	while (tw[0]->at <= NOW)
178			{
179	pcg	1.7	// remove the first watcher
180			time_watcher *w = tw[0];
181
182	pcg	1.9	pop_heap (tw.begin (), tw.end (), earliest_first);
183	pcg	1.6	tw.pop_back ();
184	pcg	1.1
185	pcg	1.7	w->registered = false;
186
187			// call it
188	pcg	1.9	w->call (*w);
189	pcg	1.7
190			// re-add it if necessary
191			if (w->at >= 0 && !w->registered)
192			reg (w);
193	pcg	1.4	}
194	pcg	1.1
195	pcg	1.4	int timeout = (int) ((tw[0]->at - NOW) * 1000);
196	pcg	1.1
197	pcg	1.4	int fds = poll (&pfs[0], pfs.size (), timeout);
198	pcg	1.1
199	pcg	1.4	set_now ();
200	pcg	1.1
201	pcg	1.9	vector<io_watcher *>::iterator w;
202			vector<pollfd>::iterator p;
203
204			for (w = iow.begin (), p = pfs.begin ();
205			fds > 0 && w < iow.end ();
206			++w, ++p)
207			if (p->revents)
208	pcg	1.4	{
209			--fds;
210	pcg	1.11
211			if (p->revents & POLLNVAL)
212			{
213			slog (L_ERR, _("io_watcher started on illegal file descriptor, disabling."));
214			(*w)->stop ();
215			}
216			else
217			(w)->call (*w, p->revents);
218	pcg	1.4	}
219	pcg	1.1	}
220			}
221
222	pcg	1.9	void io_manager::idle_cb (time_watcher &w)
223	pcg	1.4	{
224	pcg	1.9	w.at = NOW + 86400; // wake up every day, for no good reason
225	pcg	1.4	}
226
227	pcg	1.1	io_manager::io_manager ()
228			{
229	pcg	1.10	iom_valid = true;
230
231	pcg	1.1	set_now ();
232	pcg	1.4	idle = new time_watcher (this, &io_manager::idle_cb);
233			idle->start (0);
234	pcg	1.1	}
235
236			io_manager::~io_manager ()
237			{
238	pcg	1.10	iom_valid = false;
239	pcg	1.1	}
240