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Comparing gvpe/src/iom.C (file contents):
Revision 1.7 by pcg, Fri Mar 28 05:40:54 2003 UTC vs.
Revision 1.20 by pcg, Fri Apr 2 14:42:45 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#include <assert.h>
27
28#if 1 // older unices need these includes for select (2)
29# include <unistd.h>
30# include <sys/types.h>
31#endif
32
33// if the BSDs would at least be marginally POSIX-compatible.. *sigh*
34// until that happens, sys/select.h must come last
35#include <sys/select.h>
36
37// for IOM_SIG
24#include <functional> 38#include <signal.h>
25 39
26#include "slog.h"
27#include "iom.h" 40#include "iom.h"
28 41
29inline bool lowest_first (const time_watcher *a, const time_watcher *b) 42// TSTAMP_MAX must still fit into a positive struct timeval
30{ 43#define TSTAMP_MAX (double)(1UL<<31)
31 return a->at > b->at; 44
32} 45// this is a dummy time watcher to ensure that the first
46// time watcher is _always_ valid, this gets rid of a lot
47// of null-pointer-checks
48// (must come _before_ iom is being defined)
49static struct tw0 : time_watcher
50 {
51 void cb (time_watcher &w)
52 {
53 // should never get called
54 // reached end-of-time, or tstamp has a bogus definition,
55 // or compiler initilization order broken, or somethine else :)
56 abort ();
57 }
58
59 tw0 ()
60 : time_watcher (this, &tw0::cb)
61 { }
62 } tw0;
33 63
34tstamp NOW; 64tstamp NOW;
35 65static bool iom_valid;
36io_manager iom; 66io_manager iom;
37 67
38void time_watcher::set (tstamp when) 68template<class watcher>
69void io_manager::reg (watcher *w, io_manager_vec<watcher> &queue)
39{ 70{
40 at = when; 71 if (!iom_valid)
72 abort ();
41 73
42 if (registered) 74 if (!w->active)
43 iom.reschedule_time_watchers (); 75 {
44 else 76#if IOM_CHECK
45 iom.reg (this); 77 queue.activity = true;
78#endif
79 queue.push_back (w);
80 w->active = queue.size ();
81 }
46} 82}
47 83
84template<class watcher>
85void io_manager::unreg (watcher *w, io_manager_vec<watcher> &queue)
86{
87 if (!iom_valid)
88 return;
89
90 if (w->active)
91 {
92 queue [w->active - 1] = 0;
93 w->active = 0;
94 }
95}
96
97#if IOM_TIME
48void time_watcher::trigger () 98void time_watcher::trigger ()
49{ 99{
50 call (at); 100 call (*this);
51 101
52 if (registered)
53 iom.reschedule_time_watchers ();
54 else
55 iom.reg (this); 102 iom.reg (this);
56} 103}
57 104
58void time_watcher::start () 105void io_manager::reg (time_watcher *w) { reg (w, tw); }
59{ 106void io_manager::unreg (time_watcher *w) { unreg (w, tw); }
60 if (!registered) 107#endif
61 iom.reg (this);
62}
63 108
64void io_manager::reg (int fd, short events, io_watcher *w) 109#if IOM_IO
65{ 110void io_manager::reg (io_watcher *w) { reg (w, iow); }
66 pollfd pfd; 111void io_manager::unreg (io_watcher *w) { unreg (w, iow); }
112#endif
67 113
68 pfd.fd = fd; 114#if IOM_CHECK
69 pfd.events = events; 115void io_manager::reg (check_watcher *w) { reg (w, cw); }
116void io_manager::unreg (check_watcher *w) { unreg (w, cw); }
117#endif
70 118
71 pfs.push_back (pfd); 119#if IOM_IDLE
72 iow.push_back (w); 120void io_manager::reg (idle_watcher *w) { reg (w, iw); }
73} 121void io_manager::unreg (idle_watcher *w) { unreg (w, iw); }
122#endif
74 123
124#if IOM_TIME
125inline void set_now (void)
126{
127 struct timeval tv;
128
129 gettimeofday (&tv, 0);
130
131 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
132}
133#endif
134
135#if IOM_SIG
136// race conditions galore
137
138void io_manager::sighandler (int signum)
139{
140 assert (0 < signum && signum <= iom.sw.size ());
141
142 sig_vec &sv = *iom.sw [signum - 1];
143
144 for (int i = sv.size (); i--; )
145 if (!sv[i])
146 sv.erase_unordered (i);
147 else
148 sv[i]->call (*sv[i]);
149}
150
151void io_manager::reg (sig_watcher *w)
152{
153 assert (0 < w->signum);
154
155 sw.reserve (w->signum);
156
157 sig_vec *&sv = sw [w->signum - 1];
158
159 if (!sv)
160 {
161 sv = new sig_vec;
162
163 struct sigaction sa;
164 sa.sa_handler = io_manager::sighandler;
165 sigfillset (&sa.sa_mask);
166 sa.sa_flags = 0;
167
168 if (sigaction (w->signum, &sa, 0))
169 {
170 perror ("Error while installing signal handler");
171 abort ();
172 }
173 }
174
175 reg (w, *sv);
176}
177
75void io_manager::unreg (io_watcher *w) 178void io_manager::unreg (sig_watcher *w)
76{ 179{
77 unsigned int sz = iow.size (); 180 assert (0 < w->signum && w->signum <= sw.size ());
78 unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin (); 181
182 unreg (w, *sw [w->signum - 1]);
183}
79 184
80 if (i != sz) 185void sig_watcher::start (int signum)
186{
187 stop ();
188 this->signum = signum;
189 iom.reg (this);
190}
191#endif
192
193void io_manager::loop ()
194{
195#if IOM_TIME
196 set_now ();
197#endif
198
199 for (;;)
81 { 200 {
82 if (sz == 1) 201 struct timeval *to = 0;
83 { 202 struct timeval tval;
84 pfs.clear (); 203
85 iow.clear (); 204#if IOM_IDLE
205 if (iw.size ())
86 } 206 {
87 else if (i == sz - 1) 207 tval.tv_sec = 0;
88 { 208 tval.tv_usec = 0;
89 iow.pop_back (); 209 to = &tval;
90 pfs.pop_back ();
91 } 210 }
92 else 211 else
212#endif
213
214 {
215#if IOM_TIME
216 time_watcher *next;
217
218 for (;;)
219 {
220 next = tw[0]; // the first time-watcher must exist at ALL times
221
222 for (int i = tw.size (); i--; )
223 if (!tw[i])
224 tw.erase_unordered (i);
225 else if (tw[i]->at < next->at)
226 next = tw[i];
227
228 if (next->at > NOW)
229 {
230 if (next != tw[0])
231 {
232 double diff = next->at - NOW;
233 tval.tv_sec = (int)diff;
234 tval.tv_usec = (int) ((diff - tval.tv_sec) * 1000000);
235 to = &tval;
236 }
237 break;
238 }
239 else
240 {
241 unreg (next);
242 next->call (*next);
243 }
244 }
245#endif
246
247 }
248
249#if IOM_CHECK
250 tw.activity = false;
251
252 for (int i = cw.size (); i--; )
253 if (!cw[i])
254 cw.erase_unordered (i);
255 else
256 cw[i]->call (*cw[i]);
257
258 if (tw.activity)
259 {
260 tval.tv_sec = 0;
261 tval.tv_usec = 0;
262 to = &tval;
263 }
264#endif
265
266#if IOM_IO
267 fd_set rfd, wfd;
268
269 FD_ZERO (&rfd);
270 FD_ZERO (&wfd);
271
272 int fds = 0;
273
274 for (io_manager_vec<io_watcher>::iterator i = iow.end (); i-- > iow.begin (); )
275 if (*i)
93 { 276 {
94 iow[i] = iow[sz - 1]; iow.pop_back (); 277 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
95 pfs[i] = pfs[sz - 1]; pfs.pop_back (); 278 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd);
279
280 if ((*i)->fd >= fds) fds = (*i)->fd + 1;
96 } 281 }
97 }
98}
99 282
100void io_manager::reschedule_time_watchers () 283 if (!to && !fds) //TODO: also check idle_watchers and check_watchers
101{ 284 break; // no events
102 make_heap (tw.begin (), tw.end (), lowest_first);
103}
104 285
105void io_manager::reg (time_watcher *w) 286 fds = select (fds, &rfd, &wfd, NULL, to);
106{ 287# if IOM_TIME
107 if (w->registered) 288 set_now ();
108 slog (L_CRIT, "FATAL: io_manager::reg(time_watcher) called on already-registered watcher"); 289# endif
109 290
110 w->registered = true; 291 if (fds > 0)
111 292 for (int i = iow.size (); i--; )
112 tw.push_back (w); 293 if (!iow[i])
113 push_heap (tw.begin (), tw.end (), lowest_first); 294 iow.erase_unordered (i);
114} 295 else
115
116void io_manager::unreg (time_watcher *w)
117{
118 if (w->registered)
119 {
120 unsigned int sz = tw.size ();
121 unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin ();
122
123 if (i != sz)
124 { 296 {
125 if (i != sz - 1) 297 short revents = iow[i]->events;
126 tw[i] = tw[sz - 1];
127 298
128 tw.pop_back (); 299 if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ;
129 reschedule_time_watchers (); 300 if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE;
301
302 if (revents)
303 iow[i]->call (*iow[i], revents);
304 }
305 else if (fds < 0 && errno != EINTR)
130 } 306 {
307 perror ("Error while waiting for I/O or time event");
308 abort ();
309 }
310#if IOM_IDLE
311 else
312 for (int i = iw.size (); i--; )
313 if (!iw[i])
314 iw.erase_unordered (i);
315 else
316 iw[i]->call (*iw[i]);
317#endif
131 318
132 w->registered = false; 319#elif IOM_TIME
133 } 320 if (!to)
134} 321 break;
135 322
136inline void set_now (void) 323 select (0, 0, 0, 0, &to);
137{ 324 set_now ();
138 struct timeval tv; 325#else
326 break;
327#endif
139 328
140 gettimeofday (&tv, 0); 329 }
141
142 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
143} 330}
144 331
145void io_manager::loop () 332io_manager::io_manager ()
146{ 333{
334 iom_valid = true;
335
336#if IOM_TIME
147 set_now (); 337 set_now ();
148 338
149 for (;;) 339 tw0.start (TSTAMP_MAX);
150 { 340#endif
151 while (tw[0]->at <= NOW)
152 {
153 // remove the first watcher
154 time_watcher *w = tw[0];
155
156 pop_heap (tw.begin (), tw.end (), lowest_first);
157 tw.pop_back ();
158
159 w->registered = false;
160
161 // call it
162 w->call (w->at);
163
164 // re-add it if necessary
165 if (w->at >= 0 && !w->registered)
166 reg (w);
167 }
168
169 int timeout = (int) ((tw[0]->at - NOW) * 1000);
170
171 int fds = poll (&pfs[0], pfs.size (), timeout);
172
173 set_now ();
174
175 for (unsigned int i = iow.size (); fds > 0 && i--; )
176 if (pfs[i].revents)
177 {
178 --fds;
179 iow[i]->call (pfs[i].revents);
180 }
181 }
182}
183
184void io_manager::idle_cb (tstamp &ts)
185{
186 ts = NOW + 86400; // wake up every day, for no good reason
187}
188
189io_manager::io_manager ()
190{
191 set_now ();
192 idle = new time_watcher (this, &io_manager::idle_cb);
193 idle->start (0);
194} 341}
195 342
196io_manager::~io_manager () 343io_manager::~io_manager ()
197{ 344{
198 // 345 iom_valid = false;
199} 346}
200 347

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