ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/gvpe/src/iom.C
(Generate patch)

Comparing gvpe/src/iom.C (file contents):
Revision 1.10 by pcg, Fri Apr 4 05:26:45 2003 UTC vs.
Revision 1.27 by pcg, Sun Dec 19 18:44:33 2004 UTC

1/* 1/*
2 iom.C -- I/O multiplexor 2 iom.C -- generic I/O multiplexer
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 "iom.h"
21
22#include <cstdio>
23#include <cstdlib>
24#include <cerrno>
20 25
21#include <sys/time.h> 26#include <sys/time.h>
22 27
23#include <algorithm> 28#include <assert.h>
24#include <functional>
25 29
26#include "slog.h" 30#if 1 // older unices need these includes for select (2)
31# include <unistd.h>
32# include <sys/types.h>
27#include "iom.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
44#include <sys/select.h>
45
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
33inline bool earliest_first (const time_watcher *a, const time_watcher *b) 115// used for initialisation only
34{ 116static struct init {
35 return a->at > b->at; 117 init ()
36} 118 {
119#if IOM_SIG
120 sigemptyset (&sigs);
37 121
38void time_watcher::set (tstamp when) 122 if (pipe (sigpipe))
39{ 123 {
40 at = when; 124 perror ("io_manager: unable to create signal pipe, aborting.");
125 abort ();
126 }
41 127
42 if (registered) 128 fcntl (sigpipe[0], F_SETFL, O_NONBLOCK); fcntl (sigpipe[0], F_SETFD, FD_CLOEXEC);
43 iom.reschedule_time_watchers (); 129 fcntl (sigpipe[1], F_SETFL, O_NONBLOCK); fcntl (sigpipe[1], F_SETFD, FD_CLOEXEC);
44 else 130#endif
45 iom.reg (this);
46}
47 131
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
48void time_watcher::trigger () 181void time_watcher::trigger ()
49{ 182{
50 call (*this); 183 call (*this);
51 184 io_manager::reg (*this);
52 if (registered)
53 iom.reschedule_time_watchers ();
54 else
55 iom.reg (this);
56} 185}
57 186
58void time_watcher::start () 187void io_manager::reg (time_watcher &w) { io_manager::reg (w, tw); }
59{ 188void io_manager::unreg (time_watcher &w) { io_manager::unreg (w, tw); }
60 if (!registered) 189#endif
61 iom.reg (this);
62}
63 190
64time_watcher::~time_watcher () 191#if IOM_IO
65{ 192void io_manager::reg (io_watcher &w) { io_manager::reg (w, iow); }
66 if (iom_valid) 193void io_manager::unreg (io_watcher &w) { io_manager::unreg (w, iow); }
67 iom.unreg (this); 194#endif
68}
69 195
70io_watcher::~io_watcher () 196#if IOM_CHECK
71{ 197void io_manager::reg (check_watcher &w) { io_manager::reg (w, cw); }
72 if (iom_valid) 198void io_manager::unreg (check_watcher &w) { io_manager::unreg (w, cw); }
73 iom.unreg (this); 199#endif
74}
75 200
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
76void io_manager::reg (io_watcher *w) 218void io_manager::reg (sig_watcher &w)
77{ 219{
78 pollfd pfd; 220 assert (0 < w.signum);
79 221
80 pfs.push_back (pfd); 222 sw.reserve (w.signum);
223
224 while (sw.size () < w.signum) // pathetic
81 iow.push_back (w); 225 sw.push_back (0);
82 226
83 w->p = &(*(pfs.end () - 1)); 227 sig_vec *&sv = sw[w.signum - 1];
84}
85 228
86void io_manager::unreg (io_watcher *w) 229 if (!sv)
87{
88 if (w->p)
89 { 230 {
90 unsigned int sz = iow.size (); 231 sv = new sig_vec;
91 unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin ();
92 232
93 assert (i != sz); 233 sigaddset (&sigs, w.signum);
234 sigprocmask (SIG_BLOCK, &sigs, NULL);
94 235
95 if (sz == 1) 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))
96 { 242 {
243 perror ("io_manager: error while installing signal handler, ignoring.");
97 pfs.clear (); 244 abort ();
98 iow.clear ();
99 } 245 }
100 else if (i == sz - 1) 246
247 }
248
249 io_manager::reg (w, *sv);
250}
251
252void io_manager::unreg (sig_watcher &w)
253{
254 if (!w.active)
255 return;
256
257 assert (0 < w.signum && w.signum <= sw.size ());
258
259 io_manager::unreg (w, *sw[w.signum - 1]);
260}
261
262void sig_watcher::start (int signum)
263{
264 stop ();
265 this->signum = signum;
266 io_manager::reg (*this);
267}
268#endif
269
270void io_manager::loop ()
271{
272 init::required ();
273
274#if IOM_TIME
275 set_now ();
276#endif
277
278 for (;;)
279 {
280
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 ())
101 { 321 {
102 iow.pop_back (); 322 tval.tv_sec = 0;
103 pfs.pop_back (); 323 tval.TV_FRAC = 0;
324 to = &tval;
104 } 325 }
105 else 326 else
327#endif
106 { 328 {
107 iow[i] = iow[sz - 1]; iow.pop_back (); 329#if IOM_TIME
108 pfs[i] = pfs[sz - 1]; pfs.pop_back (); 330 // find earliest active watcher
331 time_watcher *next = tw[0]; // the first time-watcher must exist at ALL times
332
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 {
339 double diff = next->at - NOW;
340 tval.tv_sec = (int)diff;
341 tval.TV_FRAC = (int) ((diff - tval.tv_sec) * TV_MULT);
342 to = &tval;
343 }
109 } 344 }
345#endif
110 346
111 w->p = 0; 347#if IOM_IO || IOM_SIG
112 } 348 fd_set rfd, wfd;
113}
114 349
115void io_manager::reschedule_time_watchers () 350 FD_ZERO (&rfd);
116{ 351 FD_ZERO (&wfd);
117 make_heap (tw.begin (), tw.end (), earliest_first);
118}
119 352
120void io_manager::reg (time_watcher *w) 353 int fds = 0;
121{
122 w->registered = true;
123 354
124 tw.push_back (w); 355# if IOM_IO
125 push_heap (tw.begin (), tw.end (), earliest_first); 356 for (io_manager_vec<io_watcher>::const_iterator i = iow.end (); i-- > iow.begin (); )
126} 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);
127 361
128void io_manager::unreg (time_watcher *w) 362 if ((*i)->fd >= fds) fds = (*i)->fd + 1;
129{ 363 }
130 if (w->registered) 364# endif
131 {
132 unsigned int sz = tw.size ();
133 unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin ();
134 365
135 assert (i != sz); 366 if (!to && !fds) //TODO: also check idle_watchers and check_watchers?
136 367 break; // no events
137 if (i != sz - 1)
138 tw[i] = tw[sz - 1];
139 368
140 tw.pop_back (); 369# if IOM_SIG
141 reschedule_time_watchers (); 370 FD_SET (sigpipe[0], &rfd);
371 if (sigpipe[0] >= fds) fds = sigpipe[0] + 1;
372# endif
142 373
143 w->registered = false; 374# if IOM_SIG
144 } 375 // there is no race, as we use a pipe for signals, so select
145} 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
146 383
147inline void set_now (void) 384# if IOM_TIME
148{
149 struct timeval tv;
150
151 gettimeofday (&tv, 0);
152
153 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000;
154}
155
156void io_manager::loop ()
157{
158 set_now (); 385 set_now ();
386# endif
159 387
160 for (;;) 388 if (fds > 0)
161 {
162 while (tw[0]->at <= NOW)
163 { 389 {
164 // remove the first watcher 390# if IOM_SIG
165 time_watcher *w = tw[0]; 391 if (FD_ISSET (sigpipe[0], &rfd))
392 {
393 char ch;
166 394
167 pop_heap (tw.begin (), tw.end (), earliest_first); 395 while (read (sigpipe[0], &ch, 1) > 0)
168 tw.pop_back (); 396 ;
169 397
170 w->registered = false; 398 for (vector<sig_vec *>::iterator svp = sw.end (); svp-- > sw.begin (); )
399 if (*svp && (*svp)->pending)
400 {
401 sig_vec &sv = **svp;
402 for (int i = sv.size (); i--; )
403 if (!sv[i])
404 sv.erase_unordered (i);
405 else
406 sv[i]->call (*sv[i]);
171 407
172 // call it 408 sv.pending = false;
173 w->call (*w); 409 }
410 }
411# endif
174 412
175 // re-add it if necessary 413# if IOM_IO
176 if (w->at >= 0 && !w->registered) 414 for (int i = iow.size (); i--; )
177 reg (w); 415 if (!iow[i])
416 iow.erase_unordered (i);
417 else
418 {
419 io_watcher &w = *iow[i];
420 short revents = w.events;
421
422 if (!FD_ISSET (w.fd, &rfd)) revents &= ~EVENT_READ;
423 if (!FD_ISSET (w.fd, &wfd)) revents &= ~EVENT_WRITE;
424
425 if (revents)
426 w.call (w, revents);
427 }
428#endif
178 } 429 }
430 else if (fds < 0 && errno != EINTR)
431 {
432 perror ("io_manager: fatal error while waiting for I/O or time event, aborting.");
433 abort ();
434 }
435#if IOM_IDLE
436 else
437 for (int i = iw.size (); i--; )
438 if (!iw[i])
439 iw.erase_unordered (i);
440 else
441 iw[i]->call (*iw[i]);
442#endif
179 443
180 int timeout = (int) ((tw[0]->at - NOW) * 1000); 444#elif IOM_TIME
445 if (!to)
446 break;
181 447
182 int fds = poll (&pfs[0], pfs.size (), timeout); 448 select (0, 0, 0, 0, &to);
183
184 set_now (); 449 set_now ();
185 450#else
186 vector<io_watcher *>::iterator w; 451 break;
187 vector<pollfd>::iterator p; 452#endif
188
189 for (w = iow.begin (), p = pfs.begin ();
190 fds > 0 && w < iow.end ();
191 ++w, ++p)
192 if (p->revents)
193 {
194 --fds;
195 (*w)->call (**w, p->revents);
196 }
197 } 453 }
198} 454}
199 455
200void io_manager::idle_cb (time_watcher &w)
201{
202 w.at = NOW + 86400; // wake up every day, for no good reason
203}
204
205io_manager::io_manager ()
206{
207 iom_valid = true;
208
209 set_now ();
210 idle = new time_watcher (this, &io_manager::idle_cb);
211 idle->start (0);
212}
213
214io_manager::~io_manager ()
215{
216 iom_valid = false;
217}
218

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines