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Comparing gvpe/src/iom.C (file contents):
Revision 1.3 by pcg, Fri Mar 21 21:21:02 2003 UTC vs.
Revision 1.17 by pcg, Thu Jan 29 23:17:39 2004 UTC

1/* 1/*
2 iom.C -- I/O multiplexor 2 iom.C -- generic I/O multiplexor
3 Copyright (C) 2003, 2004 Marc Lehmann <pcg@goof.com>
3 4
4 This program is free software; you can redistribute it and/or modify 5 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 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 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version. 8 (at your option) any later version.
… …
14 You should have received a copy of the GNU General Public License 15 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 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 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17*/ 18*/
18 19
19#include "config.h" 20#include <cstdio>
21#include <cstdlib>
22#include <cerrno>
20 23
21#include <sys/time.h> 24#include <sys/time.h>
22 25
23#include <algorithm> 26#if 1 // older unices need these includes for select(2)
24#include <functional> 27# include <unistd.h>
28# include <sys/types.h>
29#endif
25 30
26#include "slog.h" 31// if the BSDs would at least be marginally POSIX-compatible.. *sigh*
32// until that happens, sys/select.h must come last
33#include <sys/select.h>
34
27#include "iom.h" 35#include "iom.h"
28 36
29inline bool lowest_first (const time_watcher *a, const time_watcher *b) 37// TSTAMP_MAX must still fit into a positive struct timeval
30{ 38#define TSTAMP_MAX (double)(1UL<<31)
31 return a->at > b->at; 39
32} 40// this is a dummy time watcher to ensure that the first
41// time watcher is _always_ valid, this gets rid of a lot
42// of null-pointer-checks
43// (must come _before_ iom is being defined)
44static struct tw0 : time_watcher {
45 void cb (time_watcher &w)
46 {
47 // should never get called
48 // reached end-of-time, or tstamp has a bogus definition,
49 // or compiler initilization order broken, or somethine else :)
50 abort ();
51 }
52
53 tw0()
54 : time_watcher (this, &tw0::cb)
55 { }
56} tw0;
33 57
34tstamp NOW; 58tstamp NOW;
35 59static bool iom_valid;
36io_manager iom; 60io_manager iom;
37 61
38void time_watcher::set (tstamp when) 62template<class watcher>
63void io_manager::reg (watcher *w, io_manager_vec<watcher> &queue)
39{ 64{
40 iom.unreg (this); 65 if (!iom_valid)
41 at = when; 66 abort ();
67
68 if (!w->active)
69 {
70#if IOM_CHECK
71 queue.activity = true;
72#endif
73 queue.push_back (w);
74 w->active = queue.size ();
75 }
76}
77
78template<class watcher>
79void io_manager::unreg (watcher *w, io_manager_vec<watcher> &queue)
80{
81 if (!iom_valid)
82 return;
83
84 if (w->active)
85 {
86 queue [w->active - 1] = 0;
87 w->active = 0;
88 }
89}
90
91#if IOM_TIME
92void time_watcher::trigger ()
93{
94 call (*this);
95
42 iom.reg (this); 96 iom.reg (this);
43} 97}
44 98
45void io_manager::reg (int fd, short events, io_watcher *w) 99void io_manager::reg (time_watcher *w) { reg (w, tw); }
46{ 100void io_manager::unreg (time_watcher *w) { unreg (w, tw); }
47 pollfd pfd; 101#endif
48 102
49 pfd.fd = fd; 103#if IOM_IO
50 pfd.events = events; 104void io_manager::reg (io_watcher *w) { reg (w, iow); }
51
52 pfs.push_back (pfd);
53 iow.push_back (w);
54}
55
56void io_manager::unreg (io_watcher *w) 105void io_manager::unreg (io_watcher *w) { unreg (w, iow); }
57{ 106#endif
58 unsigned int sz = iow.size ();
59 unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin ();
60 107
61 if (i != sz) 108#if IOM_CHECK
109void io_manager::reg (check_watcher *w) { reg (w, cw); }
110void io_manager::unreg (check_watcher *w) { unreg (w, cw); }
111#endif
112
113#if IOM_IDLE
114void io_manager::reg (idle_watcher *w) { reg (w, iw); }
115void io_manager::unreg (idle_watcher *w) { unreg (w, iw); }
116#endif
117
118#if IOM_TIME
119inline void set_now (void)
120{
121 struct timeval tv;
122
123 gettimeofday (&tv, 0);
124
125 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
126#endif
127}
128
129void io_manager::loop ()
130{
131#if IOM_TIME
132 set_now ();
133#endif
134
135 for (;;)
62 { 136 {
63 if (sz == 1) 137 struct timeval *to = 0;
64 { 138 struct timeval tval;
65 pfs.clear (); 139
66 iow.clear (); 140#if IOM_IDLE
141 if (iw.size ())
67 } 142 {
68 else if (i == sz - 1) 143 tval.tv_sec = 0;
69 { 144 tval.tv_usec = 0;
70 iow.pop_back (); 145 to = &tval;
71 pfs.pop_back ();
72 } 146 }
73 else 147 else
148#endif
149 {
150#if IOM_TIME
151 time_watcher *next;
152
153 for (;;)
154 {
155 next = tw[0]; // the first time-watcher must exist at ALL times
156
157 for (int i = tw.size (); i--; )
158 if (!tw[i])
159 tw.erase_unordered (i);
160 else if (tw[i]->at < next->at)
161 next = tw[i];
162
163 if (next->at > NOW)
164 {
165 if (next != tw[0])
166 {
167 double diff = next->at - NOW;
168 tval.tv_sec = (int)diff;
169 tval.tv_usec = (int)((diff - tval.tv_sec) * 1000000);
170 to = &tval;
171 }
172 break;
173 }
174 else
175 {
176 unreg (next);
177 next->call (*next);
178 }
179 }
180#endif
181 }
182
183#if IOM_CHECK
184 tw.activity = false;
185
186 for (int i = cw.size (); i--; )
187 if (!cw[i])
188 cw.erase_unordered (i);
189 else
190 cw[i]->call (*cw[i]);
191
192 if (tw.activity)
193 {
194 tval.tv_sec = 0;
195 tval.tv_usec = 0;
196 to = &tval;
197 }
198#endif
199
200#if IOM_IO
201 fd_set rfd, wfd, efd;
202
203 FD_ZERO (&rfd);
204 FD_ZERO (&wfd);
205
206 int fds = 0;
207
208 for (io_manager_vec<io_watcher>::iterator i = iow.end (); i-- > iow.begin (); )
209 if (*i)
74 { 210 {
75 iow[i] = iow[sz - 1]; iow.pop_back (); 211 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
76 pfs[i] = pfs[sz - 1]; pfs.pop_back (); 212 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd);
213
214 if ((*i)->fd >= fds) fds = (*i)->fd + 1;
77 } 215 }
216
217 if (!to && !fds) //TODO: also check idle_watchers and check_watchers
218 break; // no events
219
220 fds = select (fds, &rfd, &wfd, &efd, to);
221# if IOM_TIME
222 set_now ();
223# endif
224
225 if (fds > 0)
226 for (int i = iow.size (); i--; )
227 if (!iow[i])
228 iow.erase_unordered (i);
229 else
230 {
231 short revents = iow[i]->events;
232
233 if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ;
234 if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE;
235
236 if (revents)
237 iow[i]->call (*iow[i], revents);
238 }
239 else if (fds < 0 && errno != EINTR)
240 {
241 perror ("Error while waiting for I/O or time event");
242 abort ();
243 }
244#if IOM_IDLE
245 else
246 for (int i = iw.size (); i--; )
247 if (!iw[i])
248 iw.erase_unordered (i);
249 else
250 iw[i]->call (*iw[i]);
251#endif
252
253#elif IOM_TIME
254 if (!to)
255 break;
256
257 select (0, 0, 0, 0, &to);
258 set_now ();
259#else
260 break;
261#endif
78 } 262 }
79} 263}
80 264
81void io_manager::reg (time_watcher *w) 265io_manager::io_manager ()
82{ 266{
83 tw.push_back (w); 267 iom_valid = true;
84 push_heap (tw.begin (), tw.end (), lowest_first);
85}
86 268
87void io_manager::unreg (time_watcher *w) 269#if IOM_TIME
88{
89 unsigned int sz = tw.size ();
90 unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin ();
91
92 if (i != sz)
93 {
94 if (sz == 1)
95 tw.clear ();
96 else
97 {
98 if (i != sz - 1)
99 tw[i] = tw[sz - 1];
100
101 tw.pop_back ();
102 make_heap (tw.begin (), tw.end (), lowest_first);
103 }
104 }
105}
106
107inline void set_now (void)
108{
109 struct timeval tv;
110
111 gettimeofday (&tv, 0);
112
113 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
114}
115
116void io_manager::loop ()
117{
118 set_now (); 270 set_now ();
119 271
120 while (!(iow.empty () && tw.empty ())) 272 tw0.start (TSTAMP_MAX);
121 { 273#endif
122 int timeout = tw.empty ()
123 ? 3600 * 1000 // wake up at least every hour
124 : (int) ((tw[0]->at - NOW) * 1000);
125
126 printf ("s%d t%d #%d\n", pfs.size (), timeout, tw.size ());
127
128 if (timeout >= 0)
129 {
130 int fds = poll (&pfs[0], pfs.size (), timeout);
131
132 set_now ();
133
134 for (unsigned int i = iow.size (); fds && i--; )
135 if (pfs[i].revents)
136 {
137 --fds;
138 iow[i]->call (pfs[i].revents);
139 }
140 }
141
142 while (!tw.empty () && tw[0]->at <= NOW)
143 {
144 pop_heap (tw.begin (), tw.end (), lowest_first);
145 (*(tw.end () - 1))->trigger ();
146 push_heap (tw.begin (), tw.end (), lowest_first);
147 }
148 }
149}
150
151io_manager::io_manager ()
152{
153 set_now ();
154} 274}
155 275
156io_manager::~io_manager () 276io_manager::~io_manager ()
157{ 277{
158 // 278 iom_valid = false;
159} 279}
160 280

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