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"

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

tstamp NOW;

io_manager iom;

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);
}

void io_manager::reg (io_watcher *w)
{
  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)
{
  unsigned int sz = iow.size ();
  unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin ();

  if (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)
    slog (L_CRIT, "FATAL: io_manager::reg(time_watcher) called on already-registered watcher");

  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 ();

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

io_manager::~io_manager ()
{
  //
}

Revision:	1.9
Committed:	Wed Apr 2 21:02:25 2003 UTC (21 years, 1 month ago) by pcg
Content type:	text/plain
Branch:	MAIN
Changes since 1.8:	+19 -14 lines
Log Message:	壯
#	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	1.9	inline bool earliest_first (const time_watcher a, const time_watcher b)
30	pcg	1.1	{
31			return a->at > b->at;
32			}
33
34	pcg	1.2	tstamp NOW;
35	pcg	1.1
36			io_manager iom;
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	1.9	void io_manager::reg (io_watcher *w)
65	pcg	1.1	{
66			pollfd pfd;
67
68	pcg	1.9	pfd.fd = w->fd;
69			pfd.events = w->events;
70	pcg	1.1
71			pfs.push_back (pfd);
72			iow.push_back (w);
73			}
74
75	pcg	1.7	void io_manager::unreg (io_watcher *w)
76	pcg	1.1	{
77			unsigned int sz = iow.size ();
78			unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin ();
79
80			if (i != sz)
81			{
82			if (sz == 1)
83			{
84			pfs.clear ();
85			iow.clear ();
86			}
87			else if (i == sz - 1)
88			{
89			iow.pop_back ();
90			pfs.pop_back ();
91			}
92			else
93			{
94			iow[i] = iow[sz - 1]; iow.pop_back ();
95			pfs[i] = pfs[sz - 1]; pfs.pop_back ();
96			}
97			}
98			}
99
100	pcg	1.6	void io_manager::reschedule_time_watchers ()
101			{
102	pcg	1.9	make_heap (tw.begin (), tw.end (), earliest_first);
103	pcg	1.6	}
104
105	pcg	1.1	void io_manager::reg (time_watcher *w)
106			{
107	pcg	1.6	if (w->registered)
108			slog (L_CRIT, "FATAL: io_manager::reg(time_watcher) called on already-registered watcher");
109
110	pcg	1.7	w->registered = true;
111
112	pcg	1.1	tw.push_back (w);
113	pcg	1.9	push_heap (tw.begin (), tw.end (), earliest_first);
114	pcg	1.1	}
115
116	pcg	1.7	void io_manager::unreg (time_watcher *w)
117	pcg	1.1	{
118	pcg	1.7	if (w->registered)
119			{
120			unsigned int sz = tw.size ();
121			unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin ();
122	pcg	1.1
123	pcg	1.7	if (i != sz)
124			{
125			if (i != sz - 1)
126			tw[i] = tw[sz - 1];
127
128			tw.pop_back ();
129			reschedule_time_watchers ();
130			}
131	pcg	1.1
132	pcg	1.7	w->registered = false;
133	pcg	1.1	}
134			}
135
136			inline void set_now (void)
137			{
138			struct timeval tv;
139
140			gettimeofday (&tv, 0);
141
142	pcg	1.2	NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
143	pcg	1.1	}
144
145			void io_manager::loop ()
146			{
147			set_now ();
148
149	pcg	1.4	for (;;)
150	pcg	1.1	{
151	pcg	1.4	while (tw[0]->at <= NOW)
152			{
153	pcg	1.7	// remove the first watcher
154			time_watcher *w = tw[0];
155
156	pcg	1.9	pop_heap (tw.begin (), tw.end (), earliest_first);
157	pcg	1.6	tw.pop_back ();
158	pcg	1.1
159	pcg	1.7	w->registered = false;
160
161			// call it
162	pcg	1.9	w->call (*w);
163	pcg	1.7
164			// re-add it if necessary
165			if (w->at >= 0 && !w->registered)
166			reg (w);
167	pcg	1.4	}
168	pcg	1.1
169	pcg	1.4	int timeout = (int) ((tw[0]->at - NOW) * 1000);
170	pcg	1.1
171	pcg	1.4	int fds = poll (&pfs[0], pfs.size (), timeout);
172	pcg	1.1
173	pcg	1.4	set_now ();
174	pcg	1.1
175	pcg	1.9	vector<io_watcher *>::iterator w;
176			vector<pollfd>::iterator p;
177
178			for (w = iow.begin (), p = pfs.begin ();
179			fds > 0 && w < iow.end ();
180			++w, ++p)
181			if (p->revents)
182	pcg	1.4	{
183			--fds;
184	pcg	1.9	(w)->call (*w, p->revents);
185	pcg	1.4	}
186	pcg	1.1	}
187			}
188
189	pcg	1.9	void io_manager::idle_cb (time_watcher &w)
190	pcg	1.4	{
191	pcg	1.9	w.at = NOW + 86400; // wake up every day, for no good reason
192	pcg	1.4	}
193
194	pcg	1.1	io_manager::io_manager ()
195			{
196			set_now ();
197	pcg	1.4	idle = new time_watcher (this, &io_manager::idle_cb);
198			idle->start (0);
199	pcg	1.1	}
200
201			io_manager::~io_manager ()
202			{
203			//
204			}
205