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Comparing rxvt-unicode/src/iom.C (file contents):
Revision 1.9 by pcg, Sat Jan 17 01:20:01 2004 UTC vs.
Revision 1.35 by root, Sat Jan 21 14:25:05 2006 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) 2003-2006 Marc Lehmann <gvpe@schmorp.de>
4 4
5 This file is part of GVPE.
6
5 This program is free software; you can redistribute it and/or modify 7 GVPE is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by 8 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 9 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version. 10 (at your option) any later version.
9 11
10 This program is distributed in the hope that it will be useful, 12 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details. 15 GNU General Public License for more details.
14 16
15 You should have received a copy of the GNU General Public License 17 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software 18 along with gvpe; if not, write to the Free Software
17 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18*/ 20*/
21
22#include "iom.h"
19 23
20#include <cstdio> 24#include <cstdio>
21#include <cstdlib> 25#include <cstdlib>
22#include <cerrno> 26#include <cerrno>
27#include <cassert>
23 28
29#include <sys/types.h>
30#include <sys/time.h>
31
32#if 1 // older unices need these includes for select (2)
33# include <unistd.h>
34# include <time.h>
35#endif
36
37#if IOM_CHILD
38# include <sys/wait.h>
39#endif
40
41#if IOM_SIG
42# include <csignal>
43# include <fcntl.h>
44#endif
45
46// if the BSDs would at least be marginally POSIX-compatible.. *sigh*
47// until that happens, sys/select.h must come last
24#include <sys/select.h> 48#include <sys/select.h>
25#include <sys/time.h>
26 49
27#include "iom.h" 50#define TIMEVAL timeval
51#define TV_FRAC tv_usec
52#define TV_MULT 1000000L
28 53
29// TSTAMP_MAX must still fit into a positive struct timeval 54#if IOM_IO
30#define TSTAMP_MAX (double)(1UL<<31) 55static io_manager_vec<io_watcher> iow;
56#endif
57#if IOM_CHECK
58static io_manager_vec<check_watcher> cw;
59#endif
60#if IOM_TIME
61static io_manager_vec<time_watcher> tw;
62#endif
63#if IOM_IDLE
64static io_manager_vec<idle_watcher> iw;
65#endif
66#if IOM_SIG
67static int sigpipe[2]; // signal signalling pipe
68static sigset_t sigs;
69struct sig_vec : io_manager_vec<sig_watcher> {
70 int pending;
71 sig_vec ()
72 : pending (false)
73 { }
74};
75static vector<sig_vec *> sw;
76#endif
77#if IOM_CHILD
78static io_manager_vec<child_watcher> pw;
79#endif
80
81// this is a dummy time watcher to ensure that the first
82// time watcher is _always_ valid, this gets rid of a lot
83// of null-pointer-checks
84// (must come _before_ iom is being defined)
85static struct tw0 : time_watcher
86{
87 void cb (time_watcher &w)
88 {
89 // should never get called
90 // reached end-of-time, or tstamp has a bogus definition,
91 // or compiler initialisation order broken, or something else :)
92 abort ();
93 }
94
95 tw0 ()
96 : time_watcher (this, &tw0::cb)
97 { }
98} tw0;
31 99
32tstamp NOW; 100tstamp NOW;
101
102#if IOM_CHILD
103// sig_watcher for child signal(s)
104static struct sw0 : sig_watcher
105{
106 void cb (sig_watcher &w)
107 {
108 // SIGCHLD, call corresponding watchera
109 pid_t pid;
110 int status;
111
112 while ((pid = waitpid (-1, &status, WNOHANG)) > 0)
113 for (int i = pw.size (); i--; )
114 {
115 child_watcher *w = pw[i];
116
117 if (!w)
118 pw.erase_unordered (i);
119 else if (w->pid == pid)
120 {
121 io_manager::unreg (*w);
122 w->call (*w, status);
123 }
124 }
125
126 }
127
128 sw0 ()
129 : sig_watcher (this, &sw0::cb)
130 { }
131} sw0;
132#endif
133
134#if IOM_TIME
135tstamp io_manager::now ()
136{
137 struct timeval tv;
138
139 gettimeofday (&tv, 0);
140 return (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000.;
141}
142
143void io_manager::set_now ()
144{
145 NOW = now ();
146}
147#endif
148
33static bool iom_valid; 149static bool iom_valid;
34io_manager iom; 150
151// used for initialisation only
152static struct init {
153 init ()
154 {
155 iom_valid = true;
156
157#if IOM_SIG
158 sigemptyset (&sigs);
159
160 if (pipe (sigpipe))
161 {
162 perror ("io_manager: unable to create signal pipe, aborting.");
163 abort ();
164 }
165
166 fcntl (sigpipe[0], F_SETFL, O_NONBLOCK); fcntl (sigpipe[0], F_SETFD, FD_CLOEXEC);
167 fcntl (sigpipe[1], F_SETFL, O_NONBLOCK); fcntl (sigpipe[1], F_SETFD, FD_CLOEXEC);
168#endif
169
170#if IOM_CHILD
171 sw0.start (SIGCHLD);
172#endif
173
174#if IOM_TIME
175 io_manager::set_now ();
176
177 tw0.start (TSTAMP_MAX);
178#endif
179 }
180
181 ~init ()
182 {
183 iom_valid = false;
184 }
185
186 static void required ();
187} init;
188
189void
190init::required ()
191{
192 if (!iom_valid)
193 {
194 write (2, "io_manager: early registration attempt, aborting.\n",
195 sizeof ("io_manager: early registration attempt, aborting.\n") - 1);
196 abort ();
197 }
198}
35 199
36template<class watcher> 200template<class watcher>
37void io_manager::reg (watcher *w, io_manager_vec<watcher> &queue) 201void io_manager::reg (watcher &w, io_manager_vec<watcher> &queue)
38{ 202{
39 if (!iom_valid) 203 init::required ();
40 abort ();
41 204
42 if (!w->active) 205 if (!w.active)
43 { 206 {
44 queue.push_back (w); 207 queue.push_back (&w);
45 w->active = queue.size (); 208 w.active = queue.size ();
46 } 209 }
47} 210}
48 211
49template<class watcher> 212template<class watcher>
50void io_manager::unreg (watcher *w, io_manager_vec<watcher> &queue) 213void io_manager::unreg (watcher &w, io_manager_vec<watcher> &queue)
51{ 214{
52 if (!iom_valid) 215 if (!iom_valid)
53 return; 216 return;
54 217
55 if (w->active) 218 if (w.active)
56 { 219 {
57 queue [w->active - 1] = 0; 220 queue [w.active - 1] = 0;
58 w->active = 0; 221 w.active = 0;
59 } 222 }
60} 223}
61 224
62#if IOM_TIME 225#if IOM_TIME
63void time_watcher::trigger () 226void time_watcher::trigger ()
64{ 227{
65 call (*this); 228 call (*this);
66 229 io_manager::reg (*this);
67 iom.reg (this);
68} 230}
69 231
70void io_manager::reg (time_watcher *w) { reg (w, tw); } 232void io_manager::reg (time_watcher &w) { io_manager::reg (w, tw); }
71void io_manager::unreg (time_watcher *w) { unreg (w, tw); } 233void io_manager::unreg (time_watcher &w) { io_manager::unreg (w, tw); }
72#endif 234#endif
73 235
74#if IOM_IO 236#if IOM_IO
75void io_manager::reg (io_watcher *w) { reg (w, iow); } 237void io_manager::reg (io_watcher &w) { io_manager::reg (w, iow); }
76void io_manager::unreg (io_watcher *w) { unreg (w, iow); } 238void io_manager::unreg (io_watcher &w) { io_manager::unreg (w, iow); }
77#endif 239#endif
78 240
79#if IOM_CHECK 241#if IOM_CHECK
80void io_manager::reg (check_watcher *w) { reg (w, cw); } 242void io_manager::reg (check_watcher &w) { io_manager::reg (w, cw); }
81void io_manager::unreg (check_watcher *w) { unreg (w, cw); } 243void io_manager::unreg (check_watcher &w) { io_manager::unreg (w, cw); }
82#endif 244#endif
83 245
84#if IOM_IDLE 246#if IOM_IDLE
85void io_manager::reg (idle_watcher *w) { reg (w, iw); } 247void io_manager::reg (idle_watcher &w) { io_manager::reg (w, iw); }
86void io_manager::unreg (idle_watcher *w) { unreg (w, iw); } 248void io_manager::unreg (idle_watcher &w) { io_manager::unreg (w, iw); }
87#endif 249#endif
88 250
89#if IOM_TIME 251#if IOM_SIG
90inline void set_now (void) 252static void
253sighandler (int signum)
91{ 254{
92 struct timeval tv; 255 sw [signum - 1]->pending = true;
93 256
94 gettimeofday (&tv, 0); 257 // we use a pipe for signal notifications, as most current
95 258 // OSes (Linux...) do not implement pselect correctly. ugh.
96 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000; 259 char ch = signum; // actual content not used
97#endif 260 write (sigpipe[1], &ch, 1);
98} 261}
262
263void io_manager::reg (sig_watcher &w)
264{
265 init::required ();
266
267 assert (0 < w.signum);
268
269 sw.reserve (w.signum);
270
271 while (sw.size () < w.signum) // pathetic
272 sw.push_back (0);
273
274 sig_vec *&sv = sw[w.signum - 1];
275
276 if (!sv)
277 {
278 sv = new sig_vec;
279
280 sigaddset (&sigs, w.signum);
281 sigprocmask (SIG_BLOCK, &sigs, NULL);
282
283 struct sigaction sa;
284 sa.sa_handler = sighandler;
285 sigfillset (&sa.sa_mask);
286 sa.sa_flags = SA_RESTART;
287
288 if (sigaction (w.signum, &sa, 0))
289 {
290 perror ("io_manager: error while installing signal handler, ignoring.");
291 abort ();
292 }
293
294 }
295
296 io_manager::reg (w, *sv);
297}
298
299void io_manager::unreg (sig_watcher &w)
300{
301 if (!w.active || !iom_valid)
302 return;
303
304 assert (0 < w.signum && w.signum <= sw.size ());
305
306 io_manager::unreg (w, *sw[w.signum - 1]);
307}
308
309void sig_watcher::start (int signum)
310{
311 stop ();
312 this->signum = signum;
313 io_manager::reg (*this);
314}
315#endif
316
317#if IOM_CHILD
318void io_manager::reg (child_watcher &w) { io_manager::reg (w, pw); }
319void io_manager::unreg (child_watcher &w) { io_manager::unreg (w, pw); }
320#endif
99 321
100void io_manager::loop () 322void io_manager::loop ()
101{ 323{
324 init::required ();
325
102#if IOM_TIME 326#if IOM_TIME
103 set_now (); 327 set_now ();
104#endif 328#endif
105 329
106 for (;;) 330 for (;;)
107 { 331 {
108 struct timeval *to = 0;
109 struct timeval tval;
110 332
111#if IOM_IDLE 333#if IOM_TIME
112 if (iw.size ()) 334 // call pending time watchers
113 { 335 {
114 tval.tv_sec = 0; 336 bool activity;
115 tval.tv_usec = 0; 337
116 to = &tval;
117 } 338 do
118 else
119#endif
120 {
121#if IOM_TIME
122 time_watcher *next;
123
124 for (;;)
125 { 339 {
126 next = tw[0]; // the first time-watcher must exist at ALL times 340 activity = false;
127 341
128 for (int i = tw.size (); i--; ) 342 for (int i = tw.size (); i--; )
129 if (!tw[i]) 343 if (!tw[i])
130 tw.erase_unordered (i); 344 tw.erase_unordered (i);
131 else if (tw[i]->at < next->at) 345 else if (tw[i]->at <= NOW)
132 next = tw[i];
133
134 if (next->at > NOW)
135 { 346 {
136 if (next != tw[0]) 347 time_watcher &w = *tw[i];
137 { 348
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; 349 unreg (w);
350 w.call (w);
351
352 activity = true;
144 } 353 }
145 else
146 {
147 unreg (next);
148 next->call (*next);
149 }
150 } 354 }
151#endif 355 while (activity);
152 } 356 }
357#endif
153 358
154#if IOM_CHECK 359#if IOM_CHECK
360 // call all check watchers
155 for (int i = cw.size (); i--; ) 361 for (int i = cw.size (); i--; )
156 if (!cw[i]) 362 if (!cw[i])
157 cw.erase_unordered (i); 363 cw.erase_unordered (i);
158 else 364 else
159 cw[i]->call (*cw[i]); 365 cw[i]->call (*cw[i]);
160#endif 366#endif
161 367
368 struct TIMEVAL *to = 0;
369 struct TIMEVAL tval;
370
162#if IOM_IO 371#if IOM_IDLE
372 if (iw.size ())
373 {
374 tval.tv_sec = 0;
375 tval.TV_FRAC = 0;
376 to = &tval;
377 }
378 else
379#endif
380 {
381#if IOM_TIME
382 // find earliest active watcher
383 time_watcher *next = tw[0]; // the first time-watcher must exist at ALL times
384
385 for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
386 if (*i && (*i)->at < next->at)
387 next = *i;
388
389 if (next->at > NOW && next != tw[0])
390 {
391 double diff = next->at - NOW;
392 tval.tv_sec = (int)diff;
393 tval.TV_FRAC = (int) ((diff - tval.tv_sec) * TV_MULT);
394 to = &tval;
395 }
396 }
397#endif
398
399#if IOM_IO || IOM_SIG
163 fd_set rfd, wfd, efd; 400 fd_set rfd, wfd;
164 401
165 FD_ZERO (&rfd); 402 FD_ZERO (&rfd);
166 FD_ZERO (&wfd); 403 FD_ZERO (&wfd);
167 404
168 int fds = 0; 405 int fds = 0;
169 406
407# if IOM_IO
170 for (io_manager_vec<io_watcher>::iterator i = iow.end (); i-- > iow.begin (); ) 408 for (io_manager_vec<io_watcher>::const_iterator i = iow.end (); i-- > iow.begin (); )
171 if (*i) 409 if (*i)
172 { 410 {
173 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd); 411 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
174 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd); 412 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd);
175 413
176 if ((*i)->fd >= fds) fds = (*i)->fd + 1; 414 if ((*i)->fd >= fds) fds = (*i)->fd + 1;
177 } 415 }
416# endif
178 417
179 if (!to && !fds) //TODO: also check idle_watchers and check_watchers 418 if (!to && !fds) //TODO: also check idle_watchers and check_watchers?
180 break; // no events 419 break; // no events
181 420
421# if IOM_SIG
422 FD_SET (sigpipe[0], &rfd);
423 if (sigpipe[0] >= fds) fds = sigpipe[0] + 1;
424# endif
425
426# if IOM_SIG
427 // there is no race, as we use a pipe for signals, so select
428 // will return if a signal is caught.
429 sigprocmask (SIG_UNBLOCK, &sigs, NULL);
430# endif
182 fds = select (fds, &rfd, &wfd, &efd, to); 431 fds = select (fds, &rfd, &wfd, NULL, to);
432# if IOM_SIG
433 sigprocmask (SIG_BLOCK, &sigs, NULL);
434# endif
435
183# if IOM_TIME 436# if IOM_TIME
437 {
438 // update time, try to compensate for gross non-monotonic time changes
439 tstamp diff = NOW;
184 set_now (); 440 set_now ();
441 diff = NOW - diff;
442
443 if (diff < 0)
444 for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
445 if (*i)
446 (*i)->at += diff;
447 }
185# endif 448# endif
186 449
187 if (fds > 0) 450 if (fds > 0)
188 for (int i = iow.size (); i--; ) 451 {
189 if (!iow[i]) 452# if IOM_SIG
190 iow.erase_unordered (i); 453 if (FD_ISSET (sigpipe[0], &rfd))
191 else
192 { 454 {
193 short revents = iow[i]->events; 455 char ch;
194 456
195 if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ; 457 while (read (sigpipe[0], &ch, 1) > 0)
196 if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE; 458 ;
197 459
198 if (revents) 460 for (vector<sig_vec *>::iterator svp = sw.end (); svp-- > sw.begin (); )
199 iow[i]->call (*iow[i], revents); 461 if (*svp && (*svp)->pending)
462 {
463 sig_vec &sv = **svp;
464 for (int i = sv.size (); i--; )
465 if (!sv[i])
466 sv.erase_unordered (i);
467 else
468 sv[i]->call (*sv[i]);
469
470 sv.pending = false;
471 }
200 } 472 }
473# endif
474
475# if IOM_IO
476 for (int i = iow.size (); i--; )
477 if (!iow[i])
478 iow.erase_unordered (i);
479 else
480 {
481 io_watcher &w = *iow[i];
482 short revents = w.events;
483
484 if (!FD_ISSET (w.fd, &rfd)) revents &= ~EVENT_READ;
485 if (!FD_ISSET (w.fd, &wfd)) revents &= ~EVENT_WRITE;
486
487 if (revents)
488 w.call (w, revents);
489 }
490#endif
491 }
201 else if (fds < 0 && errno != EINTR) 492 else if (fds < 0 && errno != EINTR)
202 { 493 {
203 perror ("Error while waiting for I/O or time event"); 494 perror ("io_manager: fatal error while waiting for I/O or time event, aborting.");
204 abort (); 495 abort ();
205 } 496 }
206#if IOM_IDLE 497#if IOM_IDLE
207 else 498 else
208 for (int i = iw.size (); i--; ) 499 for (int i = iw.size (); i--; )
… …
222 break; 513 break;
223#endif 514#endif
224 } 515 }
225} 516}
226 517
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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