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 "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 ();
  else
    iom.reg (this);
}

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

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

void time_watcher::start ()
{
  if (!registered)
    iom.reg (this);
}

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

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

void io_manager::reg (io_watcher *w)
{
  pollfd pfd;

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

  w->p = &(*(pfs.end () - 1));
}

void io_manager::unreg (io_watcher *w)
{
  if (w->p)
    {
      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 ();
        }

      w->p = 0;
    }
}

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

void io_manager::reg (time_watcher *w)
{
  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)
    {
      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 ();

      w->registered = false;
    }
}

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;
            (*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:	1.10
Committed:	Fri Apr 4 05:26:45 2003 UTC (21 years, 1 month ago) by pcg
Content type:	text/plain
Branch:	MAIN
Changes since 1.9:	+35 -22 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			#include "slog.h"
27			#include "iom.h"
28
29	pcg	1.10	tstamp NOW;
30			bool iom_valid;
31			io_manager iom;
32
33	pcg	1.9	inline bool earliest_first (const time_watcher a, const time_watcher b)
34	pcg	1.1	{
35			return a->at > b->at;
36			}
37
38	pcg	1.2	void time_watcher::set (tstamp when)
39	pcg	1.1	{
40			at = when;
41	pcg	1.6
42			if (registered)
43			iom.reschedule_time_watchers ();
44			else
45			iom.reg (this);
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			void time_watcher::start ()
59			{
60	pcg	1.6	if (!registered)
61			iom.reg (this);
62	pcg	1.4	}
63
64	pcg	1.10	time_watcher::~time_watcher ()
65			{
66			if (iom_valid)
67			iom.unreg (this);
68			}
69
70			io_watcher::~io_watcher ()
71			{
72			if (iom_valid)
73			iom.unreg (this);
74			}
75
76	pcg	1.9	void io_manager::reg (io_watcher *w)
77	pcg	1.1	{
78			pollfd pfd;
79
80			pfs.push_back (pfd);
81			iow.push_back (w);
82	pcg	1.10
83			w->p = &(*(pfs.end () - 1));
84	pcg	1.1	}
85
86	pcg	1.7	void io_manager::unreg (io_watcher *w)
87	pcg	1.1	{
88	pcg	1.10	if (w->p)
89			{
90			unsigned int sz = iow.size ();
91			unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin ();
92
93			assert (i != sz);
94	pcg	1.1
95			if (sz == 1)
96			{
97			pfs.clear ();
98			iow.clear ();
99			}
100			else if (i == sz - 1)
101			{
102			iow.pop_back ();
103			pfs.pop_back ();
104			}
105			else
106			{
107			iow[i] = iow[sz - 1]; iow.pop_back ();
108			pfs[i] = pfs[sz - 1]; pfs.pop_back ();
109			}
110	pcg	1.10
111			w->p = 0;
112	pcg	1.1	}
113			}
114
115	pcg	1.6	void io_manager::reschedule_time_watchers ()
116			{
117	pcg	1.9	make_heap (tw.begin (), tw.end (), earliest_first);
118	pcg	1.6	}
119
120	pcg	1.1	void io_manager::reg (time_watcher *w)
121			{
122	pcg	1.7	w->registered = true;
123
124	pcg	1.1	tw.push_back (w);
125	pcg	1.9	push_heap (tw.begin (), tw.end (), earliest_first);
126	pcg	1.1	}
127
128	pcg	1.7	void io_manager::unreg (time_watcher *w)
129	pcg	1.1	{
130	pcg	1.7	if (w->registered)
131			{
132			unsigned int sz = tw.size ();
133			unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin ();
134	pcg	1.1
135	pcg	1.10	assert (i != sz);
136
137			if (i != sz - 1)
138			tw[i] = tw[sz - 1];
139	pcg	1.7
140	pcg	1.10	tw.pop_back ();
141			reschedule_time_watchers ();
142	pcg	1.1
143	pcg	1.7	w->registered = false;
144	pcg	1.1	}
145			}
146
147			inline void set_now (void)
148			{
149			struct timeval tv;
150
151			gettimeofday (&tv, 0);
152
153	pcg	1.2	NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
154	pcg	1.1	}
155
156			void io_manager::loop ()
157			{
158			set_now ();
159
160	pcg	1.4	for (;;)
161	pcg	1.1	{
162	pcg	1.4	while (tw[0]->at <= NOW)
163			{
164	pcg	1.7	// remove the first watcher
165			time_watcher *w = tw[0];
166
167	pcg	1.9	pop_heap (tw.begin (), tw.end (), earliest_first);
168	pcg	1.6	tw.pop_back ();
169	pcg	1.1
170	pcg	1.7	w->registered = false;
171
172			// call it
173	pcg	1.9	w->call (*w);
174	pcg	1.7
175			// re-add it if necessary
176			if (w->at >= 0 && !w->registered)
177			reg (w);
178	pcg	1.4	}
179	pcg	1.1
180	pcg	1.4	int timeout = (int) ((tw[0]->at - NOW) * 1000);
181	pcg	1.1
182	pcg	1.4	int fds = poll (&pfs[0], pfs.size (), timeout);
183	pcg	1.1
184	pcg	1.4	set_now ();
185	pcg	1.1
186	pcg	1.9	vector<io_watcher *>::iterator w;
187			vector<pollfd>::iterator p;
188
189			for (w = iow.begin (), p = pfs.begin ();
190			fds > 0 && w < iow.end ();
191			++w, ++p)
192			if (p->revents)
193	pcg	1.4	{
194			--fds;
195	pcg	1.9	(w)->call (*w, p->revents);
196	pcg	1.4	}
197	pcg	1.1	}
198			}
199
200	pcg	1.9	void io_manager::idle_cb (time_watcher &w)
201	pcg	1.4	{
202	pcg	1.9	w.at = NOW + 86400; // wake up every day, for no good reason
203	pcg	1.4	}
204
205	pcg	1.1	io_manager::io_manager ()
206			{
207	pcg	1.10	iom_valid = true;
208
209	pcg	1.1	set_now ();
210	pcg	1.4	idle = new time_watcher (this, &io_manager::idle_cb);
211			idle->start (0);
212	pcg	1.1	}
213
214			io_manager::~io_manager ()
215			{
216	pcg	1.10	iom_valid = false;
217	pcg	1.1	}
218