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Comparing rxvt-unicode/src/iom.C (file contents):
Revision 1.2 by pcg, Tue Nov 25 15:25:17 2003 UTC vs.
Revision 1.28 by root, Mon Feb 14 19:37:16 2005 UTC

1/* 1/*
2 iom.C -- generic I/O multiplexor 2 iom.C -- generic I/O multiplexer
3 Copyright (C) 2003 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
8 (at your option) any later version. 8 (at your option) any later version.
… …
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 "../config.h" 20#include "iom.h"
21 21
22#include <cstdio> 22#include <cstdio>
23#include <cstdlib>
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 <csignal>
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 45
27#include "iom.h" 46// TSTAMP_MAX must still fit into a positive struct timeval
47#define TSTAMP_MAX (double)(1UL<<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;
28 95
29tstamp NOW; 96tstamp NOW;
97
98#if IOM_TIME
99tstamp io_manager::now ()
100{
101 struct timeval tv;
102
103 gettimeofday (&tv, 0);
104 return (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000.;
105}
106
107void io_manager::set_now ()
108{
109 NOW = now ();
110}
111#endif
112
30bool iom_valid; 113static bool iom_valid;
31io_manager iom;
32 114
115// used for initialisation only
116static struct init {
117 init ()
118 {
119#if IOM_SIG
120 sigemptyset (&sigs);
121
122 if (pipe (sigpipe))
123 {
124 perror ("io_manager: unable to create signal pipe, aborting.");
125 abort ();
126 }
127
128 fcntl (sigpipe[0], F_SETFL, O_NONBLOCK); fcntl (sigpipe[0], F_SETFD, FD_CLOEXEC);
129 fcntl (sigpipe[1], F_SETFL, O_NONBLOCK); fcntl (sigpipe[1], F_SETFD, FD_CLOEXEC);
130#endif
131
132 iom_valid = true;
133
134#if IOM_TIME
135 io_manager::set_now ();
136
137 tw0.start (TSTAMP_MAX);
138#endif
139 }
140
141 static void required ();
142} init;
143
144void
145init::required ()
146{
147 if (!iom_valid)
148 {
149 write (2, "io_manager: early registration attempt, aborting.\n",
150 sizeof ("io_manager: early registration attempt, aborting.\n") - 1);
151 abort ();
152 }
153}
154
155template<class watcher>
156void io_manager::reg (watcher &w, io_manager_vec<watcher> &queue)
157{
158 init::required ();
159
160 if (!w.active)
161 {
162 queue.push_back (&w);
163 w.active = queue.size ();
164 }
165}
166
167template<class watcher>
168void io_manager::unreg (watcher &w, io_manager_vec<watcher> &queue)
169{
170 if (!iom_valid)
171 return;
172
173 if (w.active)
174 {
175 queue [w.active - 1] = 0;
176 w.active = 0;
177 }
178}
179
180#if IOM_TIME
33void time_watcher::trigger () 181void time_watcher::trigger ()
34{ 182{
35 call (*this); 183 call (*this);
36 184 io_manager::reg (*this);
37 iom.reg (this);
38} 185}
39 186
40time_watcher::~time_watcher () 187void io_manager::reg (time_watcher &w) { io_manager::reg (w, tw); }
41{ 188void io_manager::unreg (time_watcher &w) { io_manager::unreg (w, tw); }
42 if (iom_valid) 189#endif
43 iom.unreg (this);
44}
45 190
46io_watcher::~io_watcher () 191#if IOM_IO
47{ 192void io_manager::reg (io_watcher &w) { io_manager::reg (w, iow); }
48 if (iom_valid) 193void io_manager::unreg (io_watcher &w) { io_manager::unreg (w, iow); }
49 iom.unreg (this); 194#endif
50}
51 195
196#if IOM_CHECK
197void io_manager::reg (check_watcher &w) { io_manager::reg (w, cw); }
198void io_manager::unreg (check_watcher &w) { io_manager::unreg (w, cw); }
199#endif
200
201#if IOM_IDLE
202void io_manager::reg (idle_watcher &w) { io_manager::reg (w, iw); }
203void io_manager::unreg (idle_watcher &w) { io_manager::unreg (w, iw); }
204#endif
205
206#if IOM_SIG
207static void
208sighandler (int signum)
209{
210 sw [signum - 1]->pending = true;
211
212 // we use a pipe for signal notifications, as most current
213 // OSes (Linux...) do not implement pselect correctly. ugh.
214 char ch = signum; // actual content not used
215 write (sigpipe[1], &ch, 1);
216}
217
52void io_manager::reg (io_watcher *w) 218void io_manager::reg (sig_watcher &w)
53{ 219{
54 if (find (iow.begin (), iow.end (), w) == iow.end ()) 220 assert (0 < w.signum);
221
222 sw.reserve (w.signum);
223
224 while (sw.size () < w.signum) // pathetic
55 iow.push_back (w); 225 sw.push_back (0);
56}
57 226
227 sig_vec *&sv = sw[w.signum - 1];
228
229 if (!sv)
230 {
231 sv = new sig_vec;
232
233 sigaddset (&sigs, w.signum);
234 sigprocmask (SIG_BLOCK, &sigs, NULL);
235
236 struct sigaction sa;
237 sa.sa_handler = sighandler;
238 sigfillset (&sa.sa_mask);
239 sa.sa_flags = SA_RESTART;
240
241 if (sigaction (w.signum, &sa, 0))
242 {
243 perror ("io_manager: error while installing signal handler, ignoring.");
244 abort ();
245 }
246
247 }
248
249 io_manager::reg (w, *sv);
250}
251
58void io_manager::unreg (io_watcher *w) 252void io_manager::unreg (sig_watcher &w)
59{ 253{
60 iow.erase (find (iow.begin (), iow.end (), w)); 254 if (!w.active)
61} 255 return;
62 256
63void io_manager::reg (time_watcher *w) 257 assert (0 < w.signum && w.signum <= sw.size ());
64{ 258
65 if (find (tw.begin (), tw.end (), w) == tw.end ()) 259 io_manager::unreg (w, *sw[w.signum - 1]);
66 tw.push_back (w);
67} 260}
68 261
69void io_manager::unreg (time_watcher *w) 262void sig_watcher::start (int signum)
70{ 263{
71 tw.erase (find (tw.begin (), tw.end (), w)); 264 stop ();
265 this->signum = signum;
266 io_manager::reg (*this);
72} 267}
73 268#endif
74inline void set_now (void)
75{
76 struct timeval tv;
77
78 gettimeofday (&tv, 0);
79
80 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
81}
82 269
83void io_manager::loop () 270void io_manager::loop ()
84{ 271{
272 init::required ();
273
274#if IOM_TIME
85 set_now (); 275 set_now ();
276#endif
86 277
87 for (;;) 278 for (;;)
88 { 279 {
89 time_watcher *w;
90 280
91 for (;;) 281#if IOM_TIME
282 // call pending time watchers
283 {
284 bool activity;
285
286 do
287 {
288 activity = false;
289
290 for (int i = tw.size (); i--; )
291 if (!tw[i])
292 tw.erase_unordered (i);
293 else if (tw[i]->at <= NOW)
294 {
295 time_watcher &w = *tw[i];
296
297 unreg (w);
298 w.call (w);
299
300 activity = true;
301 }
302 }
303 while (activity);
304 }
305#endif
306
307#if IOM_CHECK
308 // call all check watchers
309 for (int i = cw.size (); i--; )
310 if (!cw[i])
311 cw.erase_unordered (i);
312 else
313 cw[i]->call (*cw[i]);
314#endif
315
316 struct TIMEVAL *to = 0;
317 struct TIMEVAL tval;
318
319#if IOM_IDLE
320 if (iw.size ())
92 { 321 {
93 w = tw[0]; 322 tval.tv_sec = 0;
94 323 tval.TV_FRAC = 0;
95 for (time_watcher **i = tw.begin (); i != tw.end (); ++i) 324 to = &tval;
96 if ((*i)->at < w->at)
97 w = *i;
98
99 if (w->at > NOW)
100 break;
101
102 // call it
103 w->call (*w);
104
105 // re-add it if necessary
106 if (w->at >= 0)
107 reg (w);
108 } 325 }
326 else
327#endif
328 {
329#if IOM_TIME
330 // find earliest active watcher
331 time_watcher *next = tw[0]; // the first time-watcher must exist at ALL times
109 332
110 struct timeval to; 333 for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
334 if (*i && (*i)->at < next->at)
335 next = *i;
336
337 if (next->at > NOW && next != tw[0])
338 {
111 double diff = w->at - NOW; 339 double diff = next->at - NOW;
112 to.tv_sec = (int)diff; 340 tval.tv_sec = (int)diff;
113 to.tv_usec = (int)((diff - to.tv_sec) * 1000000); 341 tval.TV_FRAC = (int) ((diff - tval.tv_sec) * TV_MULT);
342 to = &tval;
343 }
344 }
345#endif
114 346
347#if IOM_IO || IOM_SIG
115 fd_set rfd, wfd; 348 fd_set rfd, wfd;
116 349
117 FD_ZERO (&rfd); 350 FD_ZERO (&rfd);
118 FD_ZERO (&wfd); 351 FD_ZERO (&wfd);
119 352
120 int fds = 0; 353 int fds = 0;
121 354
122 for (io_watcher **w = iow.begin (); w < iow.end (); ++w) 355# if IOM_IO
356 for (io_manager_vec<io_watcher>::const_iterator i = iow.end (); i-- > iow.begin (); )
357 if (*i)
358 {
359 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
360 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd);
361
362 if ((*i)->fd >= fds) fds = (*i)->fd + 1;
363 }
364# endif
365
366 if (!to && !fds) //TODO: also check idle_watchers and check_watchers?
367 break; // no events
368
369# if IOM_SIG
370 FD_SET (sigpipe[0], &rfd);
371 if (sigpipe[0] >= fds) fds = sigpipe[0] + 1;
372# endif
373
374# if IOM_SIG
375 // there is no race, as we use a pipe for signals, so select
376 // will return if a signal is caught.
377 sigprocmask (SIG_UNBLOCK, &sigs, NULL);
378# endif
379 fds = select (fds, &rfd, &wfd, NULL, to);
380# if IOM_SIG
381 sigprocmask (SIG_BLOCK, &sigs, NULL);
382# endif
383
384# if IOM_TIME
385 {
386 // update time, try to compensate for gross non-monotonic time changes
387 tstamp diff = NOW;
388 set_now ();
389 diff = NOW - diff;
390
391 if (diff < 0)
392 for (io_manager_vec<time_watcher>::const_iterator i = tw.end (); i-- > tw.begin (); )
393 if (*i)
394 (*i)->at += diff;
395 }
396# endif
397
398 if (fds > 0)
123 { 399 {
124 if ((*w)->events & EVENT_READ ) FD_SET ((*w)->fd, &rfd); 400# if IOM_SIG
125 if ((*w)->events & EVENT_WRITE) FD_SET ((*w)->fd, &wfd); 401 if (FD_ISSET (sigpipe[0], &rfd))
402 {
403 char ch;
126 404
127 if ((*w)->fd > fds) fds = (*w)->fd; 405 while (read (sigpipe[0], &ch, 1) > 0)
406 ;
407
408 for (vector<sig_vec *>::iterator svp = sw.end (); svp-- > sw.begin (); )
409 if (*svp && (*svp)->pending)
410 {
411 sig_vec &sv = **svp;
412 for (int i = sv.size (); i--; )
413 if (!sv[i])
414 sv.erase_unordered (i);
415 else
416 sv[i]->call (*sv[i]);
417
418 sv.pending = false;
419 }
420 }
421# endif
422
423# if IOM_IO
424 for (int i = iow.size (); i--; )
425 if (!iow[i])
426 iow.erase_unordered (i);
427 else
428 {
429 io_watcher &w = *iow[i];
430 short revents = w.events;
431
432 if (!FD_ISSET (w.fd, &rfd)) revents &= ~EVENT_READ;
433 if (!FD_ISSET (w.fd, &wfd)) revents &= ~EVENT_WRITE;
434
435 if (revents)
436 w.call (w, revents);
437 }
438#endif
128 } 439 }
440 else if (fds < 0 && errno != EINTR)
441 {
442 perror ("io_manager: fatal error while waiting for I/O or time event, aborting.");
443 abort ();
444 }
445#if IOM_IDLE
446 else
447 for (int i = iw.size (); i--; )
448 if (!iw[i])
449 iw.erase_unordered (i);
450 else
451 iw[i]->call (*iw[i]);
452#endif
129 453
130 fds = select (fds + 1, &rfd, &wfd, 0, &to); 454#elif IOM_TIME
455 if (!to)
456 break;
131 457
458 select (0, 0, 0, 0, &to);
132 set_now (); 459 set_now ();
133 460#else
134 if (fds > 0) 461 break;
135 for (io_watcher **w = iow.begin (); w < iow.end (); ++w) 462#endif
136 {
137 short revents = (*w)->events;
138
139 if (!FD_ISSET ((*w)->fd, &rfd)) revents &= ~EVENT_READ;
140 if (!FD_ISSET ((*w)->fd, &wfd)) revents &= ~EVENT_WRITE;
141
142 if (revents)
143 (*w)->call (**w, revents);
144 }
145 } 463 }
146} 464}
147 465
148void io_manager::idle_cb (time_watcher &w)
149{
150 w.at = NOW + 1000000000;
151}
152
153io_manager::io_manager ()
154{
155 set_now ();
156
157 iom_valid = true;
158
159 idle = new time_watcher (this, &io_manager::idle_cb);
160 idle->start (0);
161}
162
163io_manager::~io_manager ()
164{
165 iom_valid = false;
166}
167

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