Commit | Line | Data |
---|---|---|
e12489f9 | 1 | /* Asynchronous timers. |
429ab54e | 2 | Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, |
8cabe764 | 3 | 2006, 2007, 2008 Free Software Foundation, Inc. |
e12489f9 GM |
4 | |
5 | This file is part of GNU Emacs. | |
6 | ||
9ec0b715 | 7 | GNU Emacs is free software: you can redistribute it and/or modify |
e12489f9 | 8 | it under the terms of the GNU General Public License as published by |
9ec0b715 GM |
9 | the Free Software Foundation, either version 3 of the License, or |
10 | (at your option) any later version. | |
e12489f9 GM |
11 | |
12 | GNU Emacs is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
9ec0b715 | 18 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
e12489f9 GM |
19 | |
20 | #include <config.h> | |
e12489f9 | 21 | #include <signal.h> |
5890e9f7 JD |
22 | #include <stdio.h> |
23 | #include <lisp.h> | |
e12489f9 GM |
24 | #include <syssignal.h> |
25 | #include <systime.h> | |
26 | #include <blockinput.h> | |
27 | #include <atimer.h> | |
e12489f9 GM |
28 | |
29 | #ifdef HAVE_UNISTD_H | |
30 | #include <unistd.h> | |
31 | #endif | |
32 | ||
33 | #ifdef HAVE_SYS_TIME_H | |
34 | #include <sys/time.h> | |
35 | #endif | |
36 | ||
e12489f9 GM |
37 | /* Free-list of atimer structures. */ |
38 | ||
39 | static struct atimer *free_atimers; | |
40 | ||
9c2e3e8d GM |
41 | /* List of currently not running timers due to a call to |
42 | lock_atimer. */ | |
43 | ||
44 | static struct atimer *stopped_atimers; | |
45 | ||
e12489f9 GM |
46 | /* List of active atimers, sorted by expiration time. The timer that |
47 | will become ripe next is always at the front of this list. */ | |
48 | ||
49 | static struct atimer *atimers; | |
50 | ||
51 | /* Non-zero means alarm_signal_handler has found ripe timers but | |
52 | interrupt_input_blocked was non-zero. In this case, timer | |
53 | functions are not called until the next UNBLOCK_INPUT because timer | |
54 | functions are expected to call X, and X cannot be assumed to be | |
55 | reentrant. */ | |
56 | ||
57 | int pending_atimers; | |
58 | ||
5f351ff1 | 59 | /* Block/unblock SIGALRM. */ |
e12489f9 GM |
60 | |
61 | #define BLOCK_ATIMERS sigblock (sigmask (SIGALRM)) | |
62 | #define UNBLOCK_ATIMERS sigunblock (sigmask (SIGALRM)) | |
63 | ||
64 | /* Function prototypes. */ | |
65 | ||
66 | static void set_alarm P_ ((void)); | |
67 | static void schedule_atimer P_ ((struct atimer *)); | |
50b1039f GM |
68 | static struct atimer *append_atimer_lists P_ ((struct atimer *, |
69 | struct atimer *)); | |
a3aca278 | 70 | SIGTYPE alarm_signal_handler (); |
e12489f9 GM |
71 | |
72 | ||
73 | /* Start a new atimer of type TYPE. TIME specifies when the timer is | |
74 | ripe. FN is the function to call when the timer fires. | |
75 | CLIENT_DATA is stored in the client_data member of the atimer | |
76 | structure returned and so made available to FN when it is called. | |
77 | ||
78 | If TYPE is ATIMER_ABSOLUTE, TIME is the absolute time at which the | |
79 | timer fires. | |
80 | ||
81 | If TYPE is ATIMER_RELATIVE, the timer is ripe TIME s/us in the | |
82 | future. | |
83 | ||
84 | In both cases, the timer is automatically freed after it has fired. | |
85 | ||
86 | If TYPE is ATIMER_CONTINUOUS, the timer fires every TIME s/us. | |
87 | ||
88 | Value is a pointer to the atimer started. It can be used in calls | |
89 | to cancel_atimer; don't free it yourself. */ | |
90 | ||
91 | struct atimer * | |
92 | start_atimer (type, time, fn, client_data) | |
93 | enum atimer_type type; | |
94 | EMACS_TIME time; | |
95 | atimer_callback fn; | |
96 | void *client_data; | |
97 | { | |
98 | struct atimer *t; | |
99 | ||
100 | /* Round TIME up to the next full second if we don't have | |
101 | itimers. */ | |
102 | #ifndef HAVE_SETITIMER | |
103 | if (EMACS_USECS (time) != 0) | |
104 | { | |
4ce94f99 EZ |
105 | EMACS_SET_USECS (time, 0); |
106 | EMACS_SET_SECS (time, EMACS_SECS (time) + 1); | |
e12489f9 GM |
107 | } |
108 | #endif /* not HAVE_SETITIMER */ | |
109 | ||
110 | /* Get an atimer structure from the free-list, or allocate | |
111 | a new one. */ | |
112 | if (free_atimers) | |
113 | { | |
114 | t = free_atimers; | |
115 | free_atimers = t->next; | |
116 | } | |
117 | else | |
118 | t = (struct atimer *) xmalloc (sizeof *t); | |
119 | ||
120 | /* Fill the atimer structure. */ | |
121 | bzero (t, sizeof *t); | |
122 | t->type = type; | |
123 | t->fn = fn; | |
124 | t->client_data = client_data; | |
125 | ||
126 | BLOCK_ATIMERS; | |
127 | ||
128 | /* Compute the timer's expiration time. */ | |
129 | switch (type) | |
130 | { | |
131 | case ATIMER_ABSOLUTE: | |
132 | t->expiration = time; | |
133 | break; | |
177c0ea7 | 134 | |
e12489f9 GM |
135 | case ATIMER_RELATIVE: |
136 | EMACS_GET_TIME (t->expiration); | |
137 | EMACS_ADD_TIME (t->expiration, t->expiration, time); | |
138 | break; | |
177c0ea7 | 139 | |
e12489f9 GM |
140 | case ATIMER_CONTINUOUS: |
141 | EMACS_GET_TIME (t->expiration); | |
142 | EMACS_ADD_TIME (t->expiration, t->expiration, time); | |
143 | t->interval = time; | |
144 | break; | |
145 | } | |
146 | ||
147 | /* Insert the timer in the list of active atimers. */ | |
148 | schedule_atimer (t); | |
149 | UNBLOCK_ATIMERS; | |
150 | ||
151 | /* Arrange for a SIGALRM at the time the next atimer is ripe. */ | |
152 | set_alarm (); | |
177c0ea7 | 153 | |
e12489f9 GM |
154 | return t; |
155 | } | |
156 | ||
157 | ||
158 | /* Cancel and free atimer TIMER. */ | |
159 | ||
160 | void | |
161 | cancel_atimer (timer) | |
162 | struct atimer *timer; | |
163 | { | |
50b1039f | 164 | int i; |
177c0ea7 | 165 | |
e12489f9 GM |
166 | BLOCK_ATIMERS; |
167 | ||
50b1039f | 168 | for (i = 0; i < 2; ++i) |
94870977 | 169 | { |
50b1039f GM |
170 | struct atimer *t, *prev; |
171 | struct atimer **list = i ? &stopped_atimers : &atimers; | |
177c0ea7 | 172 | |
94870977 | 173 | /* See if TIMER is active or stopped. */ |
4ab1d4be | 174 | for (t = *list, prev = NULL; t && t != timer; prev = t, t = t->next) |
94870977 GM |
175 | ; |
176 | ||
50b1039f | 177 | /* If it is, take it off the its list, and put in on the |
94870977 GM |
178 | free-list. We don't bother to arrange for setting a |
179 | different alarm time, since a too early one doesn't hurt. */ | |
180 | if (t) | |
181 | { | |
182 | if (prev) | |
183 | prev->next = t->next; | |
184 | else | |
185 | *list = t->next; | |
177c0ea7 | 186 | |
94870977 GM |
187 | t->next = free_atimers; |
188 | free_atimers = t; | |
4ab1d4be | 189 | break; |
94870977 | 190 | } |
e12489f9 GM |
191 | } |
192 | ||
193 | UNBLOCK_ATIMERS; | |
194 | } | |
195 | ||
196 | ||
50b1039f GM |
197 | /* Append two lists of atimers LIST1 and LIST2 and return the |
198 | result list. */ | |
199 | ||
200 | static struct atimer * | |
201 | append_atimer_lists (list1, list2) | |
202 | struct atimer *list1, *list2; | |
203 | { | |
204 | if (list1 == NULL) | |
205 | return list2; | |
206 | else if (list2 == NULL) | |
207 | return list1; | |
208 | else | |
209 | { | |
210 | struct atimer *p; | |
177c0ea7 | 211 | |
50b1039f GM |
212 | for (p = list1; p->next; p = p->next) |
213 | ; | |
214 | p->next = list2; | |
215 | return list1; | |
216 | } | |
217 | } | |
218 | ||
219 | ||
220 | /* Stop all timers except timer T. T null means stop all timers. */ | |
9c2e3e8d GM |
221 | |
222 | void | |
223 | stop_other_atimers (t) | |
224 | struct atimer *t; | |
225 | { | |
226 | BLOCK_ATIMERS; | |
177c0ea7 | 227 | |
9c2e3e8d GM |
228 | if (t) |
229 | { | |
2503c8b1 | 230 | struct atimer *p, *prev; |
177c0ea7 | 231 | |
2503c8b1 | 232 | /* See if T is active. */ |
96013ba9 | 233 | for (p = atimers, prev = NULL; p && p != t; prev = p, p = p->next) |
2503c8b1 GM |
234 | ; |
235 | ||
236 | if (p == t) | |
237 | { | |
238 | if (prev) | |
239 | prev->next = t->next; | |
240 | else | |
241 | atimers = t->next; | |
242 | t->next = NULL; | |
243 | } | |
244 | else | |
245 | /* T is not active. Let's handle this like T == 0. */ | |
246 | t = NULL; | |
9c2e3e8d | 247 | } |
177c0ea7 | 248 | |
50b1039f | 249 | stopped_atimers = append_atimer_lists (atimers, stopped_atimers); |
9c2e3e8d GM |
250 | atimers = t; |
251 | UNBLOCK_ATIMERS; | |
252 | } | |
253 | ||
254 | ||
255 | /* Run all timers again, if some have been stopped with a call to | |
256 | stop_other_atimers. */ | |
257 | ||
258 | void | |
259 | run_all_atimers () | |
260 | { | |
261 | if (stopped_atimers) | |
262 | { | |
263 | struct atimer *t = atimers; | |
50b1039f | 264 | struct atimer *next; |
177c0ea7 | 265 | |
9c2e3e8d GM |
266 | BLOCK_ATIMERS; |
267 | atimers = stopped_atimers; | |
268 | stopped_atimers = NULL; | |
177c0ea7 | 269 | |
50b1039f GM |
270 | while (t) |
271 | { | |
272 | next = t->next; | |
273 | schedule_atimer (t); | |
274 | t = next; | |
275 | } | |
177c0ea7 | 276 | |
9c2e3e8d GM |
277 | UNBLOCK_ATIMERS; |
278 | } | |
279 | } | |
280 | ||
281 | ||
282 | /* A version of run_all_timers suitable for a record_unwind_protect. */ | |
283 | ||
284 | Lisp_Object | |
285 | unwind_stop_other_atimers (dummy) | |
286 | Lisp_Object dummy; | |
287 | { | |
288 | run_all_atimers (); | |
289 | return Qnil; | |
290 | } | |
291 | ||
292 | ||
e12489f9 GM |
293 | /* Arrange for a SIGALRM to arrive when the next timer is ripe. */ |
294 | ||
295 | static void | |
296 | set_alarm () | |
297 | { | |
e12489f9 GM |
298 | #if defined (USG) && !defined (POSIX_SIGNALS) |
299 | /* USG systems forget handlers when they are used; | |
300 | must reestablish each time. */ | |
301 | signal (SIGALRM, alarm_signal_handler); | |
302 | #endif /* USG */ | |
177c0ea7 | 303 | |
e12489f9 GM |
304 | if (atimers) |
305 | { | |
306 | EMACS_TIME now, time; | |
307 | #ifdef HAVE_SETITIMER | |
308 | struct itimerval it; | |
309 | #endif | |
310 | ||
311 | /* Determine s/us till the next timer is ripe. */ | |
312 | EMACS_GET_TIME (now); | |
313 | EMACS_SUB_TIME (time, atimers->expiration, now); | |
314 | ||
315 | #ifdef HAVE_SETITIMER | |
316 | /* Don't set the interval to 0; this disables the timer. */ | |
317 | if (EMACS_TIME_LE (atimers->expiration, now)) | |
318 | { | |
319 | EMACS_SET_SECS (time, 0); | |
320 | EMACS_SET_USECS (time, 1000); | |
321 | } | |
177c0ea7 | 322 | |
e12489f9 GM |
323 | bzero (&it, sizeof it); |
324 | it.it_value = time; | |
325 | setitimer (ITIMER_REAL, &it, 0); | |
326 | #else /* not HAVE_SETITIMER */ | |
327 | alarm (max (EMACS_SECS (time), 1)); | |
328 | #endif /* not HAVE_SETITIMER */ | |
329 | } | |
330 | } | |
331 | ||
332 | ||
333 | /* Insert timer T into the list of active atimers `atimers', keeping | |
334 | the list sorted by expiration time. T must not be in this list | |
335 | already. */ | |
336 | ||
337 | static void | |
338 | schedule_atimer (t) | |
339 | struct atimer *t; | |
340 | { | |
341 | struct atimer *a = atimers, *prev = NULL; | |
342 | ||
343 | /* Look for the first atimer that is ripe after T. */ | |
344 | while (a && EMACS_TIME_GT (t->expiration, a->expiration)) | |
345 | prev = a, a = a->next; | |
346 | ||
347 | /* Insert T in front of the atimer found, if any. */ | |
348 | if (prev) | |
349 | prev->next = t; | |
350 | else | |
351 | atimers = t; | |
177c0ea7 | 352 | |
e12489f9 GM |
353 | t->next = a; |
354 | } | |
355 | ||
170c80be JD |
356 | static void |
357 | run_timers () | |
e12489f9 GM |
358 | { |
359 | EMACS_TIME now; | |
177c0ea7 | 360 | |
e12489f9 | 361 | EMACS_GET_TIME (now); |
177c0ea7 | 362 | |
e12489f9 GM |
363 | while (atimers |
364 | && (pending_atimers = interrupt_input_blocked) == 0 | |
365 | && EMACS_TIME_LE (atimers->expiration, now)) | |
366 | { | |
367 | struct atimer *t; | |
177c0ea7 | 368 | |
e12489f9 GM |
369 | t = atimers; |
370 | atimers = atimers->next; | |
371 | t->fn (t); | |
177c0ea7 | 372 | |
e12489f9 GM |
373 | if (t->type == ATIMER_CONTINUOUS) |
374 | { | |
375 | EMACS_ADD_TIME (t->expiration, now, t->interval); | |
376 | schedule_atimer (t); | |
377 | } | |
378 | else | |
379 | { | |
380 | t->next = free_atimers; | |
381 | free_atimers = t; | |
382 | } | |
177c0ea7 | 383 | |
e12489f9 GM |
384 | EMACS_GET_TIME (now); |
385 | } | |
177c0ea7 | 386 | |
fcdb28b4 JD |
387 | if (! pending_atimers) |
388 | set_alarm (); | |
e12489f9 GM |
389 | } |
390 | ||
391 | ||
170c80be JD |
392 | /* Signal handler for SIGALRM. SIGNO is the signal number, i.e. |
393 | SIGALRM. */ | |
394 | ||
395 | SIGTYPE | |
396 | alarm_signal_handler (signo) | |
397 | int signo; | |
398 | { | |
399 | pending_atimers = 1; | |
400 | #ifndef SYNC_INPUT | |
401 | run_timers (); | |
402 | #endif | |
403 | } | |
404 | ||
405 | ||
e12489f9 GM |
406 | /* Call alarm_signal_handler for pending timers. */ |
407 | ||
408 | void | |
409 | do_pending_atimers () | |
410 | { | |
411 | if (pending_atimers) | |
412 | { | |
413 | BLOCK_ATIMERS; | |
170c80be | 414 | run_timers (); |
e12489f9 GM |
415 | UNBLOCK_ATIMERS; |
416 | } | |
417 | } | |
418 | ||
419 | ||
420 | /* Turn alarms on/off. This seems to be temporarily necessary on | |
421 | some systems like HPUX (see process.c). */ | |
422 | ||
423 | void | |
424 | turn_on_atimers (on) | |
425 | int on; | |
426 | { | |
427 | if (on) | |
428 | { | |
429 | signal (SIGALRM, alarm_signal_handler); | |
430 | set_alarm (); | |
431 | } | |
432 | else | |
433 | alarm (0); | |
434 | } | |
435 | ||
436 | ||
437 | void | |
438 | init_atimer () | |
439 | { | |
440 | free_atimers = atimers = NULL; | |
441 | pending_atimers = 0; | |
442 | signal (SIGALRM, alarm_signal_handler); | |
443 | } | |
ab5796a9 MB |
444 | |
445 | /* arch-tag: e6308261-eec6-404b-89fb-6e5909518d70 | |
446 | (do not change this comment) */ |