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Comparing gvpe/src/iom.C (file contents):
Revision 1.13 by pcg, Sat Jan 17 01:18:36 2004 UTC vs.
Revision 1.23 by pcg, Fri Nov 12 10:23:33 2004 UTC

1/* 1/*
2 iom.C -- generic I/O multiplexor 2 iom.C -- generic I/O multiplexer
3 Copyright (C) 2003, 2004 Marc Lehmann <pcg@goof.com> 3 Copyright (C) 2003, 2004 Marc Lehmann <pcg@goof.com>
4 4
5 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
6 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
7 the Free Software Foundation; either version 2 of the License, or 7 the Free Software Foundation; either version 2 of the License, or
… …
15 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
16 along with this program; if not, write to the Free Software 16 along with this program; if not, write to the Free Software
17 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
18*/ 18*/
19 19
20#include "iom.h"
21
20#include <cstdio> 22#include <cstdio>
21#include <cstdlib> 23#include <cstdlib>
22#include <cerrno> 24#include <cerrno>
23 25
26#include <sys/time.h>
27
28#include <assert.h>
29
30#if 1 // older unices need these includes for select (2)
31# include <unistd.h>
32# include <sys/types.h>
33# include <time.h>
34#endif
35
36// for IOM_SIG
37#if IOM_SIG
38# include <signal.h>
39# include <fcntl.h>
40#endif
41
42// if the BSDs would at least be marginally POSIX-compatible.. *sigh*
43// until that happens, sys/select.h must come last
24#include <sys/select.h> 44#include <sys/select.h>
25#include <sys/time.h>
26
27#include "iom.h"
28 45
29// TSTAMP_MAX must still fit into a positive struct timeval 46// TSTAMP_MAX must still fit into a positive struct timeval
30#define TSTAMP_MAX (double)(1UL<<31) 47#define TSTAMP_MAX (double)(1UL<<31)
31 48
49#define TIMEVAL timeval
50#define TV_FRAC tv_usec
51#define TV_MULT 1000000L
52
53#if IOM_IO
54static io_manager_vec<io_watcher> iow;
55#endif
56#if IOM_CHECK
57static io_manager_vec<check_watcher> cw;
58#endif
59#if IOM_TIME
60static io_manager_vec<time_watcher> tw;
61#endif
62#if IOM_IDLE
63static io_manager_vec<idle_watcher> iw;
64#endif
65#if IOM_SIG
66static int sigpipe[2]; // signal signalling pipe
67static sigset_t sigs;
68struct sig_vec : io_manager_vec<sig_watcher> {
69 int pending;
70 sig_vec ()
71 : pending (false)
72 { }
73};
74static vector<sig_vec *> sw;
75#endif
76
77// this is a dummy time watcher to ensure that the first
78// time watcher is _always_ valid, this gets rid of a lot
79// of null-pointer-checks
80// (must come _before_ iom is being defined)
81static struct tw0 : time_watcher
82 {
83 void cb (time_watcher &w)
84 {
85 // should never get called
86 // reached end-of-time, or tstamp has a bogus definition,
87 // or compiler initialisation order broken, or something else :)
88 abort ();
89 }
90
91 tw0 ()
92 : time_watcher (this, &tw0::cb)
93 { }
94 } tw0;
95
32tstamp NOW; 96tstamp NOW;
97
98#if IOM_TIME
99inline void set_now (void)
100{
101 struct timeval tv;
102
103 gettimeofday (&tv, 0);
104 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000.;
105}
106#endif
107
33static bool iom_valid; 108static bool iom_valid;
34io_manager iom; 109
110// used for initialisation only
111static struct init {
112 init ()
113 {
114#if IOM_SIG
115 sigemptyset (&sigs);
116
117 if (pipe (sigpipe))
118 {
119 perror ("io_manager: unable to create signal pipe, aborting.");
120 abort ();
121 }
122
123 fcntl (sigpipe[0], F_SETFL, O_NONBLOCK);
124 fcntl (sigpipe[1], F_SETFL, O_NONBLOCK);
125#endif
126
127 iom_valid = true;
128
129#if IOM_TIME
130 set_now ();
131
132 tw0.start (TSTAMP_MAX);
133#endif
134 }
135
136 static void required ();
137} init;
138
139void
140init::required ()
141{
142 if (!iom_valid)
143 {
144 write (2, "io_manager: early registration attempt, aborting.\n",
145 sizeof ("io_manager: early registration attempt, aborting.\n") - 1);
146 abort ();
147 }
148}
35 149
36template<class watcher> 150template<class watcher>
37void io_manager::reg (watcher *w, io_manager_vec<watcher> &queue) 151void io_manager::reg (watcher &w, io_manager_vec<watcher> &queue)
38{ 152{
39 if (!iom_valid) 153 init::required ();
40 abort ();
41 154
42 if (!w->active) 155 if (!w.active)
43 { 156 {
44 queue.push_back (w); 157 queue.push_back (&w);
45 w->active = queue.size (); 158 w.active = queue.size ();
46 } 159 }
47} 160}
48 161
49template<class watcher> 162template<class watcher>
50void io_manager::unreg (watcher *w, io_manager_vec<watcher> &queue) 163void io_manager::unreg (watcher &w, io_manager_vec<watcher> &queue)
51{ 164{
52 if (!iom_valid) 165 if (!iom_valid)
53 return; 166 return;
54 167
55 if (w->active) 168 if (w.active)
56 { 169 {
57 queue [w->active - 1] = 0; 170 queue [w.active - 1] = 0;
58 w->active = 0; 171 w.active = 0;
59 } 172 }
60} 173}
61 174
62#if IOM_TIME 175#if IOM_TIME
63void time_watcher::trigger () 176void time_watcher::trigger ()
64{ 177{
65 call (*this); 178 call (*this);
66 179 io_manager::reg (*this);
67 iom.reg (this);
68} 180}
69 181
70void io_manager::reg (time_watcher *w) { reg (w, tw); } 182void io_manager::reg (time_watcher &w) { io_manager::reg (w, tw); }
71void io_manager::unreg (time_watcher *w) { unreg (w, tw); } 183void io_manager::unreg (time_watcher &w) { io_manager::unreg (w, tw); }
72#endif 184#endif
73 185
74#if IOM_IO 186#if IOM_IO
75void io_manager::reg (io_watcher *w) { reg (w, iow); } 187void io_manager::reg (io_watcher &w) { io_manager::reg (w, iow); }
76void io_manager::unreg (io_watcher *w) { unreg (w, iow); } 188void io_manager::unreg (io_watcher &w) { io_manager::unreg (w, iow); }
77#endif 189#endif
78 190
79#if IOM_CHECK 191#if IOM_CHECK
80void io_manager::reg (check_watcher *w) { reg (w, cw); } 192void io_manager::reg (check_watcher &w) { io_manager::reg (w, cw); }
81void io_manager::unreg (check_watcher *w) { unreg (w, cw); } 193void io_manager::unreg (check_watcher &w) { io_manager::unreg (w, cw); }
82#endif 194#endif
83 195
84#if IOM_IDLE 196#if IOM_IDLE
85void io_manager::reg (idle_watcher *w) { reg (w, iw); } 197void io_manager::reg (idle_watcher &w) { io_manager::reg (w, iw); }
86void io_manager::unreg (idle_watcher *w) { unreg (w, iw); } 198void io_manager::unreg (idle_watcher &w) { io_manager::unreg (w, iw); }
87#endif 199#endif
88 200
89#if IOM_TIME 201#if IOM_SIG
90inline void set_now (void) 202static void
203sighandler (int signum)
91{ 204{
92 struct timeval tv; 205 sw [signum - 1]->pending = true;
93 206
94 gettimeofday (&tv, 0); 207 // we use a pipe for signal notifications, as most current
95 208 // OSes (Linux...) do not implement pselect correctly. ugh.
96 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000; 209 char ch = signum; // actual content not used
97#endif 210 write (sigpipe[1], &ch, 1);
98} 211}
212
213void io_manager::reg (sig_watcher &w)
214{
215 assert (0 < w.signum);
216
217 sw.reserve (w.signum);
218
219 while (sw.size () < w.signum) // pathetic
220 sw.push_back (0);
221
222 sig_vec *&sv = sw[w.signum - 1];
223
224 if (!sv)
225 {
226 sv = new sig_vec;
227
228 sigaddset (&sigs, w.signum);
229 sigprocmask (SIG_BLOCK, &sigs, NULL);
230
231 struct sigaction sa;
232 sa.sa_handler = sighandler;
233 sigfillset (&sa.sa_mask);
234 sa.sa_flags = SA_RESTART;
235
236 if (sigaction (w.signum, &sa, 0))
237 {
238 perror ("io_manager: error while installing signal handler, ignoring.");
239 abort ();
240 }
241
242 }
243
244 io_manager::reg (w, *sv);
245}
246
247void io_manager::unreg (sig_watcher &w)
248{
249 if (!w.active)
250 return;
251
252 assert (0 < w.signum && w.signum <= sw.size ());
253
254 io_manager::unreg (w, *sw[w.signum - 1]);
255}
256
257void sig_watcher::start (int signum)
258{
259 stop ();
260 this->signum = signum;
261 io_manager::reg (*this);
262}
263#endif
99 264
100void io_manager::loop () 265void io_manager::loop ()
101{ 266{
267 init::required ();
268
102#if IOM_TIME 269#if IOM_TIME
103 set_now (); 270 set_now ();
104#endif 271#endif
105 272
106 for (;;) 273 for (;;)
107 { 274 {
108 struct timeval *to = 0;
109 struct timeval tval;
110 275
111#if IOM_IDLE 276#if IOM_TIME
112 if (iw.size ()) 277 // call pending time watchers
113 { 278 {
114 tval.tv_sec = 0; 279 bool activity;
115 tval.tv_usec = 0; 280
116 to = &tval;
117 } 281 do
118 else
119#endif
120 {
121#if IOM_TIME
122 time_watcher *next;
123
124 for (;;)
125 { 282 {
126 next = tw[0]; // the first time-watcher must exist at ALL times 283 activity = false;
127 284
128 for (int i = tw.size (); i--; ) 285 for (int i = tw.size (); i--; )
129 if (!tw[i]) 286 if (!tw[i])
130 tw.erase_unordered (i); 287 tw.erase_unordered (i);
131 else if (tw[i]->at < next->at) 288 else if (tw[i]->at <= NOW + IOM_ACCURACY)
132 next = tw[i];
133
134 if (next->at > NOW)
135 { 289 {
136 if (next != tw[0]) 290 time_watcher &w = *tw[i];
137 { 291
138 double diff = next->at - NOW;
139 tval.tv_sec = (int)diff;
140 tval.tv_usec = (int)((diff - tval.tv_sec) * 1000000);
141 to = &tval;
142 }
143 break; 292 unreg (w);
293 w.call (w);
294
295 activity = true;
144 } 296 }
145 else
146 {
147 unreg (next);
148 next->call (*next);
149 }
150 } 297 }
151#endif 298 while (activity);
152 } 299 }
300#endif
153 301
154#if IOM_CHECK 302#if IOM_CHECK
303 // call all check watchers
155 for (int i = cw.size (); i--; ) 304 for (int i = cw.size (); i--; )
156 if (!cw[i]) 305 if (!cw[i])
157 cw.erase_unordered (i); 306 cw.erase_unordered (i);
158 else 307 else
159 cw[i]->call (*cw[i]); 308 cw[i]->call (*cw[i]);
160#endif 309#endif
161 310
311 struct TIMEVAL *to = 0;
312 struct TIMEVAL tval;
313
162#if IOM_IO 314#if IOM_IDLE
315 if (iw.size ())
316 {
317 tval.tv_sec = 0;
318 tval.TV_FRAC = 0;
319 to = &tval;
320 }
321 else
322#endif
323 {
324#if IOM_TIME
325 // find earliest active watcher
326 time_watcher *next = tw[0]; // the first time-watcher must exist at ALL times
327
328 for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
329 if (*i && (*i)->at < next->at)
330 next = *i;
331
332 if (next->at > NOW && next != tw[0])
333 {
334 double diff = next->at - NOW;
335 tval.tv_sec = (int)diff;
336 tval.TV_FRAC = (int) ((diff - tval.tv_sec) * TV_MULT);
337 to = &tval;
338 }
339 }
340#endif
341
342#if IOM_IO || IOM_SIG
163 fd_set rfd, wfd, efd; 343 fd_set rfd, wfd;
164 344
165 FD_ZERO (&rfd); 345 FD_ZERO (&rfd);
166 FD_ZERO (&wfd); 346 FD_ZERO (&wfd);
167 347
168 int fds = 0; 348 int fds = 0;
169 349
350# if IOM_IO
170 for (io_manager_vec<io_watcher>::iterator i = iow.end (); i-- > iow.begin (); ) 351 for (io_manager_vec<io_watcher>::const_iterator i = iow.end (); i-- > iow.begin (); )
171 if (*i) 352 if (*i)
172 { 353 {
173 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd); 354 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
174 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd); 355 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd);
175 356
176 if ((*i)->fd >= fds) fds = (*i)->fd + 1; 357 if ((*i)->fd >= fds) fds = (*i)->fd + 1;
177 } 358 }
359# endif
178 360
179 if (!to && !fds) //TODO: also check idle_watchers and check_watchers 361 if (!to && !fds) //TODO: also check idle_watchers and check_watchers?
180 break; // no events 362 break; // no events
181 363
364# if IOM_SIG
365 FD_SET (sigpipe[0], &rfd);
366 if (sigpipe[0] >= fds) fds = sigpipe[0] + 1;
367# endif
368
369# if IOM_SIG
370 // there is no race, as we use a pipe for signals, so select
371 // will return if a signal is caught.
372 sigprocmask (SIG_UNBLOCK, &sigs, NULL);
373# endif
182 fds = select (fds, &rfd, &wfd, &efd, to); 374 fds = select (fds, &rfd, &wfd, NULL, to);
375# if IOM_SIG
376 sigprocmask (SIG_BLOCK, &sigs, NULL);
377# endif
378
183# if IOM_TIME 379# if IOM_TIME
184 set_now (); 380 set_now ();
185# endif 381# endif
186 382
187 if (fds > 0) 383 if (fds > 0)
188 for (int i = iow.size (); i--; ) 384 {
189 if (!iow[i]) 385# if IOM_SIG
190 iow.erase_unordered (i); 386 if (FD_ISSET (sigpipe[0], &rfd))
191 else
192 { 387 {
193 short revents = iow[i]->events; 388 char ch;
194 389
195 if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ; 390 while (read (sigpipe[0], &ch, 1) > 0)
196 if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE; 391 ;
197 392
198 if (revents) 393 for (sig_vec **svp = sw.end (); svp-- > sw.begin (); )
199 iow[i]->call (*iow[i], revents); 394 if (*svp && (*svp)->pending)
395 {
396 sig_vec &sv = **svp;
397 for (int i = sv.size (); i--; )
398 if (!sv[i])
399 sv.erase_unordered (i);
400 else
401 sv[i]->call (*sv[i]);
402
403 sv.pending = false;
404 }
200 } 405 }
406# endif
407
408# if IOM_IO
409 for (int i = iow.size (); i--; )
410 if (!iow[i])
411 iow.erase_unordered (i);
412 else
413 {
414 short revents = iow[i]->events;
415
416 if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ;
417 if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE;
418
419 if (revents)
420 iow[i]->call (*iow[i], revents);
421 }
422#endif
423 }
201 else if (fds < 0 && errno != EINTR) 424 else if (fds < 0 && errno != EINTR)
202 { 425 {
203 perror ("Error while waiting for I/O or time event"); 426 perror ("io_manager: fatal error while waiting for I/O or time event, aborting.");
204 abort (); 427 abort ();
205 } 428 }
206#if IOM_IDLE 429#if IOM_IDLE
207 else 430 else
208 for (int i = iw.size (); i--; ) 431 for (int i = iw.size (); i--; )
… …
222 break; 445 break;
223#endif 446#endif
224 } 447 }
225} 448}
226 449
227// this is a dummy time watcher to ensure that the first
228// time watcher is _always_ valid, this gets rid of a lot
229// of null-pointer-checks
230static struct tw0 : time_watcher {
231 void cb (time_watcher &w)
232 {
233 // should never get called
234 // reached end-of-time, or tstamp has a bogus definition :)
235 abort ();
236 }
237
238 tw0()
239 : time_watcher (this, &tw0::cb)
240 { }
241} tw0;
242
243io_manager::io_manager ()
244{
245 iom_valid = true;
246
247#if IOM_TIME
248 set_now ();
249
250 tw0.start (TSTAMP_MAX);
251#endif
252}
253
254io_manager::~io_manager ()
255{
256 iom_valid = false;
257}
258

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