1 | #include <unistd.h> |
|
|
2 | /* |
1 | /* |
3 | iom.C -- I/O multiplexor |
2 | iom.C -- generic I/O multiplexer |
|
|
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 | |
|
|
22 | #include <cstdio> |
|
|
23 | #include <cstdlib> |
|
|
24 | #include <cerrno> |
21 | |
25 | |
22 | #include <sys/time.h> |
26 | #include <sys/time.h> |
23 | |
27 | |
24 | #include <algorithm> |
28 | #include <assert.h> |
25 | #include <functional> |
|
|
26 | |
29 | |
27 | #include "slog.h" |
30 | #if 1 // older unices need these includes for select (2) |
28 | |
31 | # include <unistd.h> |
|
|
32 | # include <sys/types.h> |
29 | #include "iom.h" |
33 | # include <time.h> |
|
|
34 | #endif |
30 | |
35 | |
31 | inline bool lowest_first (const time_watcher *a, const time_watcher *b) |
36 | // for IOM_SIG |
32 | { |
37 | #if IOM_SIG |
33 | return a->at > b->at; |
38 | # include <signal.h> |
34 | } |
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 |
|
|
54 | static io_manager_vec<io_watcher> iow; |
|
|
55 | #endif |
|
|
56 | #if IOM_CHECK |
|
|
57 | static io_manager_vec<check_watcher> cw; |
|
|
58 | #endif |
|
|
59 | #if IOM_TIME |
|
|
60 | static io_manager_vec<time_watcher> tw; |
|
|
61 | #endif |
|
|
62 | #if IOM_IDLE |
|
|
63 | static io_manager_vec<idle_watcher> iw; |
|
|
64 | #endif |
|
|
65 | #if IOM_SIG |
|
|
66 | static int sigpipe[2]; // signal signalling pipe |
|
|
67 | static sigset_t sigs; |
|
|
68 | struct sig_vec : io_manager_vec<sig_watcher> { |
|
|
69 | int pending; |
|
|
70 | sig_vec () |
|
|
71 | : pending (false) |
|
|
72 | { } |
|
|
73 | }; |
|
|
74 | static 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) |
|
|
81 | static 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; |
35 | |
95 | |
36 | tstamp NOW; |
96 | tstamp NOW; |
37 | |
97 | |
38 | io_manager iom; |
98 | #if IOM_TIME |
39 | |
99 | inline void set_now (void) |
40 | void time_watcher::set (tstamp when) |
|
|
41 | { |
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 | |
|
|
108 | static bool iom_valid; |
|
|
109 | |
|
|
110 | // used for initialisation only |
|
|
111 | static 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 | |
|
|
139 | void |
|
|
140 | init::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 | } |
|
|
149 | |
|
|
150 | template<class watcher> |
|
|
151 | void io_manager::reg (watcher &w, io_manager_vec<watcher> &queue) |
|
|
152 | { |
|
|
153 | init::required (); |
|
|
154 | |
|
|
155 | if (!w.active) |
|
|
156 | { |
|
|
157 | queue.push_back (&w); |
|
|
158 | w.active = queue.size (); |
|
|
159 | } |
|
|
160 | } |
|
|
161 | |
|
|
162 | template<class watcher> |
|
|
163 | void io_manager::unreg (watcher &w, io_manager_vec<watcher> &queue) |
|
|
164 | { |
|
|
165 | if (!iom_valid) |
|
|
166 | return; |
|
|
167 | |
|
|
168 | if (w.active) |
|
|
169 | { |
|
|
170 | queue [w.active - 1] = 0; |
|
|
171 | w.active = 0; |
|
|
172 | } |
|
|
173 | } |
|
|
174 | |
|
|
175 | #if IOM_TIME |
|
|
176 | void time_watcher::trigger () |
|
|
177 | { |
|
|
178 | call (*this); |
42 | iom.unreg (this); |
179 | io_manager::reg (*this); |
43 | at = when; |
|
|
44 | iom.reg (this); |
|
|
45 | } |
180 | } |
46 | |
181 | |
47 | void io_manager::reg (int fd, short events, io_watcher *w) |
182 | void io_manager::reg (time_watcher &w) { io_manager::reg (w, tw); } |
48 | { |
183 | void io_manager::unreg (time_watcher &w) { io_manager::unreg (w, tw); } |
49 | pollfd pfd; |
184 | #endif |
50 | |
185 | |
51 | pfd.fd = fd; |
186 | #if IOM_IO |
52 | pfd.events = events; |
187 | void io_manager::reg (io_watcher &w) { io_manager::reg (w, iow); } |
|
|
188 | void io_manager::unreg (io_watcher &w) { io_manager::unreg (w, iow); } |
|
|
189 | #endif |
53 | |
190 | |
54 | pfs.push_back (pfd); |
191 | #if IOM_CHECK |
55 | iow.push_back (w); |
192 | void io_manager::reg (check_watcher &w) { io_manager::reg (w, cw); } |
56 | } |
193 | void io_manager::unreg (check_watcher &w) { io_manager::unreg (w, cw); } |
|
|
194 | #endif |
57 | |
195 | |
|
|
196 | #if IOM_IDLE |
|
|
197 | void io_manager::reg (idle_watcher &w) { io_manager::reg (w, iw); } |
|
|
198 | void io_manager::unreg (idle_watcher &w) { io_manager::unreg (w, iw); } |
|
|
199 | #endif |
|
|
200 | |
|
|
201 | #if IOM_SIG |
|
|
202 | static void |
|
|
203 | sighandler (int signum) |
|
|
204 | { |
|
|
205 | sw [signum - 1]->pending = true; |
|
|
206 | |
|
|
207 | // we use a pipe for signal notifications, as most current |
|
|
208 | // OSes (Linux...) do not implement pselect correctly. ugh. |
|
|
209 | char ch = signum; // actual content not used |
|
|
210 | write (sigpipe[1], &ch, 1); |
|
|
211 | } |
|
|
212 | |
58 | void io_manager::unreg (io_watcher *w) |
213 | void io_manager::reg (sig_watcher &w) |
59 | { |
214 | { |
60 | unsigned int sz = iow.size (); |
215 | assert (0 < w.signum); |
61 | unsigned int i = find (iow.begin (), iow.end (), w) - iow.begin (); |
|
|
62 | |
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 | |
63 | if (i != sz) |
224 | if (!sv) |
64 | { |
225 | { |
65 | if (sz == 1) |
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)) |
66 | { |
237 | { |
|
|
238 | perror ("io_manager: error while installing signal handler, ignoring."); |
67 | pfs.clear (); |
239 | abort (); |
68 | iow.clear (); |
|
|
69 | } |
240 | } |
70 | else if (i == sz - 1) |
241 | |
|
|
242 | } |
|
|
243 | |
|
|
244 | io_manager::reg (w, *sv); |
|
|
245 | } |
|
|
246 | |
|
|
247 | void 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 | |
|
|
257 | void sig_watcher::start (int signum) |
|
|
258 | { |
|
|
259 | stop (); |
|
|
260 | this->signum = signum; |
|
|
261 | io_manager::reg (*this); |
|
|
262 | } |
|
|
263 | #endif |
|
|
264 | |
|
|
265 | void io_manager::loop () |
|
|
266 | { |
|
|
267 | init::required (); |
|
|
268 | |
|
|
269 | #if IOM_TIME |
|
|
270 | set_now (); |
|
|
271 | #endif |
|
|
272 | |
|
|
273 | for (;;) |
|
|
274 | { |
|
|
275 | |
|
|
276 | #if IOM_TIME |
|
|
277 | // call pending time watchers |
|
|
278 | { |
|
|
279 | bool activity; |
|
|
280 | |
|
|
281 | do |
|
|
282 | { |
|
|
283 | activity = false; |
|
|
284 | |
|
|
285 | for (int i = tw.size (); i--; ) |
|
|
286 | if (!tw[i]) |
|
|
287 | tw.erase_unordered (i); |
|
|
288 | else if (tw[i]->at <= NOW + IOM_ACCURACY) |
|
|
289 | { |
|
|
290 | time_watcher &w = *tw[i]; |
|
|
291 | |
|
|
292 | unreg (w); |
|
|
293 | w.call (w); |
|
|
294 | |
|
|
295 | activity = true; |
|
|
296 | } |
|
|
297 | } |
|
|
298 | while (activity); |
|
|
299 | } |
|
|
300 | #endif |
|
|
301 | |
|
|
302 | #if IOM_CHECK |
|
|
303 | // call all check watchers |
|
|
304 | for (int i = cw.size (); i--; ) |
|
|
305 | if (!cw[i]) |
|
|
306 | cw.erase_unordered (i); |
|
|
307 | else |
|
|
308 | cw[i]->call (*cw[i]); |
|
|
309 | #endif |
|
|
310 | |
|
|
311 | struct TIMEVAL *to = 0; |
|
|
312 | struct TIMEVAL tval; |
|
|
313 | |
|
|
314 | #if IOM_IDLE |
|
|
315 | if (iw.size ()) |
71 | { |
316 | { |
72 | iow.pop_back (); |
317 | tval.tv_sec = 0; |
73 | pfs.pop_back (); |
318 | tval.TV_FRAC = 0; |
|
|
319 | to = &tval; |
74 | } |
320 | } |
75 | else |
321 | else |
|
|
322 | #endif |
76 | { |
323 | { |
77 | iow[i] = iow[sz - 1]; iow.pop_back (); |
324 | #if IOM_TIME |
78 | pfs[i] = pfs[sz - 1]; pfs.pop_back (); |
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 | } |
79 | } |
339 | } |
80 | } |
340 | #endif |
81 | } |
|
|
82 | |
341 | |
83 | void io_manager::reg (time_watcher *w) |
342 | #if IOM_IO || IOM_SIG |
84 | { |
343 | fd_set rfd, wfd; |
85 | tw.push_back (w); |
|
|
86 | push_heap (tw.begin (), tw.end (), lowest_first); |
|
|
87 | } |
|
|
88 | |
344 | |
89 | void io_manager::unreg (time_watcher *w) |
345 | FD_ZERO (&rfd); |
90 | { |
346 | FD_ZERO (&wfd); |
91 | unsigned int sz = tw.size (); |
|
|
92 | unsigned int i = find (tw.begin (), tw.end (), w) - tw.begin (); |
|
|
93 | |
347 | |
94 | if (i != sz) |
348 | int fds = 0; |
95 | { |
349 | |
96 | if (sz == 1) |
350 | # if IOM_IO |
97 | tw.clear (); |
351 | for (io_manager_vec<io_watcher>::const_iterator i = iow.end (); i-- > iow.begin (); ) |
98 | else |
352 | if (*i) |
|
|
353 | { |
|
|
354 | if ((*i)->events & EVENT_READ ) FD_SET ((*i)->fd, &rfd); |
|
|
355 | if ((*i)->events & EVENT_WRITE) FD_SET ((*i)->fd, &wfd); |
|
|
356 | |
|
|
357 | if ((*i)->fd >= fds) fds = (*i)->fd + 1; |
|
|
358 | } |
|
|
359 | # endif |
|
|
360 | |
|
|
361 | if (!to && !fds) //TODO: also check idle_watchers and check_watchers? |
|
|
362 | break; // no events |
|
|
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 |
|
|
374 | fds = select (fds, &rfd, &wfd, NULL, to); |
|
|
375 | # if IOM_SIG |
|
|
376 | sigprocmask (SIG_BLOCK, &sigs, NULL); |
|
|
377 | # endif |
|
|
378 | |
|
|
379 | # if IOM_TIME |
|
|
380 | set_now (); |
|
|
381 | # endif |
|
|
382 | |
|
|
383 | if (fds > 0) |
99 | { |
384 | { |
100 | if (i != sz - 1) |
385 | # if IOM_SIG |
101 | tw[i] = tw[sz - 1]; |
386 | if (FD_ISSET (sigpipe[0], &rfd)) |
|
|
387 | { |
|
|
388 | char ch; |
102 | |
389 | |
103 | tw.pop_back (); |
390 | while (read (sigpipe[0], &ch, 1) > 0) |
104 | make_heap (tw.begin (), tw.end (), lowest_first); |
391 | ; |
|
|
392 | |
|
|
393 | for (sig_vec **svp = sw.end (); svp-- > sw.begin (); ) |
|
|
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 | } |
|
|
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 |
105 | } |
423 | } |
106 | } |
424 | else if (fds < 0 && errno != EINTR) |
107 | } |
|
|
108 | |
|
|
109 | inline void set_now (void) |
|
|
110 | { |
|
|
111 | struct timeval tv; |
|
|
112 | |
|
|
113 | gettimeofday (&tv, 0); |
|
|
114 | |
|
|
115 | NOW = (tstamp)tv.tv_sec + (tstamp)tv.tv_usec / 1000000; |
|
|
116 | } |
|
|
117 | |
|
|
118 | void io_manager::loop () |
|
|
119 | { |
|
|
120 | set_now (); |
|
|
121 | |
|
|
122 | while (!(iow.empty () && tw.empty ())) |
|
|
123 | { |
|
|
124 | int timeout = tw.empty () |
|
|
125 | ? 3600 * 1000 // wake up at least every hour |
|
|
126 | : (int) ((tw[0]->at - NOW) * 1000); |
|
|
127 | |
|
|
128 | printf ("s%d t%d #%d\n", pfs.size (), timeout, tw.size ()); |
|
|
129 | |
|
|
130 | if (timeout >= 0) |
|
|
131 | { |
425 | { |
132 | int fds = poll (&pfs[0], pfs.size (), timeout); |
426 | perror ("io_manager: fatal error while waiting for I/O or time event, aborting."); |
133 | |
|
|
134 | set_now (); |
427 | abort (); |
135 | |
|
|
136 | for (unsigned int i = iow.size (); fds && i--; ) |
|
|
137 | if (pfs[i].revents) |
|
|
138 | { |
|
|
139 | --fds; |
|
|
140 | iow[i]->call (pfs[i].revents); |
|
|
141 | } |
|
|
142 | } |
428 | } |
|
|
429 | #if IOM_IDLE |
|
|
430 | else |
|
|
431 | for (int i = iw.size (); i--; ) |
|
|
432 | if (!iw[i]) |
|
|
433 | iw.erase_unordered (i); |
|
|
434 | else |
|
|
435 | iw[i]->call (*iw[i]); |
|
|
436 | #endif |
143 | |
437 | |
144 | while (!tw.empty () && tw[0]->at <= NOW) |
438 | #elif IOM_TIME |
145 | { |
439 | if (!to) |
146 | pop_heap (tw.begin (), tw.end (), lowest_first); |
440 | break; |
147 | (*(tw.end () - 1))->trigger (); |
|
|
148 | push_heap (tw.begin (), tw.end (), lowest_first); |
|
|
149 | } |
|
|
150 | } |
|
|
151 | } |
|
|
152 | |
441 | |
153 | io_manager::io_manager () |
442 | select (0, 0, 0, 0, &to); |
154 | { |
|
|
155 | set_now (); |
443 | set_now (); |
|
|
444 | #else |
|
|
445 | break; |
|
|
446 | #endif |
|
|
447 | } |
156 | } |
448 | } |
157 | |
449 | |
158 | io_manager::~io_manager () |
|
|
159 | { |
|
|
160 | // |
|
|
161 | } |
|
|
162 | |
|
|