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Comparing gvpe/src/iom.C (file contents):
Revision 1.16 by pcg, Sat Jan 17 16:49:01 2004 UTC vs.
Revision 1.25 by pcg, Sun Nov 14 22:47:00 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
24#include <sys/time.h> 26#include <sys/time.h>
25 27
28#include <assert.h>
29
26#if 1 // older unices need these includes for select(2) 30#if 1 // older unices need these includes for select (2)
27# include <unistd.h> 31# include <unistd.h>
28# include <sys/types.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>
29#endif 40#endif
30 41
31// if the BSDs would at least be marginally POSIX-compatible.. *sigh* 42// if the BSDs would at least be marginally POSIX-compatible.. *sigh*
32// until that happens, sys/select.h must come last 43// until that happens, sys/select.h must come last
33#include <sys/select.h> 44#include <sys/select.h>
34 45
35#include "iom.h"
36
37// TSTAMP_MAX must still fit into a positive struct timeval 46// TSTAMP_MAX must still fit into a positive struct timeval
38#define TSTAMP_MAX (double)(1UL<<31) 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
39 76
40// this is a dummy time watcher to ensure that the first 77// this is a dummy time watcher to ensure that the first
41// time watcher is _always_ valid, this gets rid of a lot 78// time watcher is _always_ valid, this gets rid of a lot
42// of null-pointer-checks 79// of null-pointer-checks
43// (must come _before_ iom is being defined) 80// (must come _before_ iom is being defined)
44static struct tw0 : time_watcher { 81static struct tw0 : time_watcher
45 void cb (time_watcher &w)
46 { 82 {
83 void cb (time_watcher &w)
84 {
47 // should never get called 85 // should never get called
48 // reached end-of-time, or tstamp has a bogus definition, 86 // reached end-of-time, or tstamp has a bogus definition,
49 // or compiler initilization order broken, or somethine else :) 87 // or compiler initialisation order broken, or something else :)
50 abort (); 88 abort ();
89 }
90
91 tw0 ()
92 : time_watcher (this, &tw0::cb)
93 { }
94 } tw0;
95
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
108static bool iom_valid;
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
51 } 134 }
52 135
53 tw0() 136 static void required ();
54 : time_watcher (this, &tw0::cb) 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 ();
55 { } 147 }
56} tw0; 148}
57
58tstamp NOW;
59static bool iom_valid;
60io_manager iom;
61 149
62template<class watcher> 150template<class watcher>
63void io_manager::reg (watcher *w, io_manager_vec<watcher> &queue) 151void io_manager::reg (watcher &w, io_manager_vec<watcher> &queue)
64{ 152{
65 if (!iom_valid) 153 init::required ();
66 abort ();
67 154
68 if (!w->active) 155 if (!w.active)
69 { 156 {
70 queue.push_back (w); 157 queue.push_back (&w);
71 w->active = queue.size (); 158 w.active = queue.size ();
72 } 159 }
73} 160}
74 161
75template<class watcher> 162template<class watcher>
76void io_manager::unreg (watcher *w, io_manager_vec<watcher> &queue) 163void io_manager::unreg (watcher &w, io_manager_vec<watcher> &queue)
77{ 164{
78 if (!iom_valid) 165 if (!iom_valid)
79 return; 166 return;
80 167
81 if (w->active) 168 if (w.active)
82 { 169 {
83 queue [w->active - 1] = 0; 170 queue [w.active - 1] = 0;
84 w->active = 0; 171 w.active = 0;
85 } 172 }
86} 173}
87 174
88#if IOM_TIME 175#if IOM_TIME
89void time_watcher::trigger () 176void time_watcher::trigger ()
90{ 177{
91 call (*this); 178 call (*this);
92 179 io_manager::reg (*this);
93 iom.reg (this);
94} 180}
95 181
96void io_manager::reg (time_watcher *w) { reg (w, tw); } 182void io_manager::reg (time_watcher &w) { io_manager::reg (w, tw); }
97void io_manager::unreg (time_watcher *w) { unreg (w, tw); } 183void io_manager::unreg (time_watcher &w) { io_manager::unreg (w, tw); }
98#endif 184#endif
99 185
100#if IOM_IO 186#if IOM_IO
101void io_manager::reg (io_watcher *w) { reg (w, iow); } 187void io_manager::reg (io_watcher &w) { io_manager::reg (w, iow); }
102void io_manager::unreg (io_watcher *w) { unreg (w, iow); } 188void io_manager::unreg (io_watcher &w) { io_manager::unreg (w, iow); }
103#endif 189#endif
104 190
105#if IOM_CHECK 191#if IOM_CHECK
106void io_manager::reg (check_watcher *w) { reg (w, cw); } 192void io_manager::reg (check_watcher &w) { io_manager::reg (w, cw); }
107void io_manager::unreg (check_watcher *w) { unreg (w, cw); } 193void io_manager::unreg (check_watcher &w) { io_manager::unreg (w, cw); }
108#endif 194#endif
109 195
110#if IOM_IDLE 196#if IOM_IDLE
111void io_manager::reg (idle_watcher *w) { reg (w, iw); } 197void io_manager::reg (idle_watcher &w) { io_manager::reg (w, iw); }
112void io_manager::unreg (idle_watcher *w) { unreg (w, iw); } 198void io_manager::unreg (idle_watcher &w) { io_manager::unreg (w, iw); }
113#endif 199#endif
114 200
115#if IOM_TIME 201#if IOM_SIG
116inline void set_now (void) 202static void
203sighandler (int signum)
117{ 204{
118 struct timeval tv; 205 sw [signum - 1]->pending = true;
119 206
120 gettimeofday (&tv, 0); 207 // we use a pipe for signal notifications, as most current
121 208 // OSes (Linux...) do not implement pselect correctly. ugh.
122 NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000; 209 char ch = signum; // actual content not used
123#endif 210 write (sigpipe[1], &ch, 1);
124} 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
125 264
126void io_manager::loop () 265void io_manager::loop ()
127{ 266{
267 init::required ();
268
128#if IOM_TIME 269#if IOM_TIME
129 set_now (); 270 set_now ();
130#endif 271#endif
131 272
132 for (;;) 273 for (;;)
133 { 274 {
134 struct timeval *to = 0;
135 struct timeval tval;
136 275
137#if IOM_IDLE 276#if IOM_TIME
138 if (iw.size ()) 277 // call pending time watchers
139 { 278 {
140 tval.tv_sec = 0; 279 bool activity;
141 tval.tv_usec = 0; 280
142 to = &tval;
143 } 281 do
144 else
145#endif
146 {
147#if IOM_TIME
148 time_watcher *next;
149
150 for (;;)
151 { 282 {
152 next = tw[0]; // the first time-watcher must exist at ALL times 283 activity = false;
153 284
154 for (int i = tw.size (); i--; ) 285 for (int i = tw.size (); i--; )
155 if (!tw[i]) 286 if (!tw[i])
156 tw.erase_unordered (i); 287 tw.erase_unordered (i);
157 else if (tw[i]->at < next->at) 288 else if (tw[i]->at <= NOW)
158 next = tw[i];
159
160 if (next->at > NOW)
161 { 289 {
162 if (next != tw[0]) 290 time_watcher &w = *tw[i];
163 { 291
164 double diff = next->at - NOW;
165 tval.tv_sec = (int)diff;
166 tval.tv_usec = (int)((diff - tval.tv_sec) * 1000000);
167 to = &tval;
168 }
169 break; 292 unreg (w);
293 w.call (w);
294
295 activity = true;
170 } 296 }
171 else
172 {
173 unreg (next);
174 next->call (*next);
175 }
176 } 297 }
177#endif 298 while (activity);
178 } 299 }
300#endif
179 301
180#if IOM_CHECK 302#if IOM_CHECK
303 // call all check watchers
181 for (int i = cw.size (); i--; ) 304 for (int i = cw.size (); i--; )
182 if (!cw[i]) 305 if (!cw[i])
183 cw.erase_unordered (i); 306 cw.erase_unordered (i);
184 else 307 else
185 cw[i]->call (*cw[i]); 308 cw[i]->call (*cw[i]);
186#endif 309#endif
187 310
311 struct TIMEVAL *to = 0;
312 struct TIMEVAL tval;
313
188#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
189 fd_set rfd, wfd, efd; 343 fd_set rfd, wfd;
190 344
191 FD_ZERO (&rfd); 345 FD_ZERO (&rfd);
192 FD_ZERO (&wfd); 346 FD_ZERO (&wfd);
193 347
194 int fds = 0; 348 int fds = 0;
195 349
350# if IOM_IO
196 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 (); )
197 if (*i) 352 if (*i)
198 { 353 {
199 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd); 354 if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd);
200 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd); 355 if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd);
201 356
202 if ((*i)->fd >= fds) fds = (*i)->fd + 1; 357 if ((*i)->fd >= fds) fds = (*i)->fd + 1;
203 } 358 }
359# endif
204 360
205 if (!to && !fds) //TODO: also check idle_watchers and check_watchers 361 if (!to && !fds) //TODO: also check idle_watchers and check_watchers?
206 break; // no events 362 break; // no events
207 363
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
208 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
209# if IOM_TIME 379# if IOM_TIME
210 set_now (); 380 set_now ();
211# endif 381# endif
212 382
213 if (fds > 0) 383 if (fds > 0)
214 for (int i = iow.size (); i--; ) 384 {
215 if (!iow[i]) 385# if IOM_SIG
216 iow.erase_unordered (i); 386 if (FD_ISSET (sigpipe[0], &rfd))
217 else
218 { 387 {
219 short revents = iow[i]->events; 388 char ch;
220 389
221 if (!FD_ISSET (iow[i]->fd, &rfd)) revents &= ~EVENT_READ; 390 while (read (sigpipe[0], &ch, 1) > 0)
222 if (!FD_ISSET (iow[i]->fd, &wfd)) revents &= ~EVENT_WRITE; 391 ;
223 392
224 if (revents) 393 for (vector<sig_vec *>::iterator svp = sw.end (); svp-- > sw.begin (); )
225 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 }
226 } 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 }
227 else if (fds < 0 && errno != EINTR) 424 else if (fds < 0 && errno != EINTR)
228 { 425 {
229 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.");
230 abort (); 427 abort ();
231 } 428 }
232#if IOM_IDLE 429#if IOM_IDLE
233 else 430 else
234 for (int i = iw.size (); i--; ) 431 for (int i = iw.size (); i--; )
… …
248 break; 445 break;
249#endif 446#endif
250 } 447 }
251} 448}
252 449
253io_manager::io_manager ()
254{
255 iom_valid = true;
256
257#if IOM_TIME
258 set_now ();
259
260 tw0.start (TSTAMP_MAX);
261#endif
262}
263
264io_manager::~io_manager ()
265{
266 iom_valid = false;
267}
268

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