Commit | Line | Data |
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e12489f9 | 1 | /* Asynchronous timers. |
aaef169d TTN |
2 | Copyright (C) 2000, 2002, 2003, 2004, 2005, |
3 | 2006 Free Software Foundation, Inc. | |
e12489f9 GM |
4 | |
5 | This file is part of GNU Emacs. | |
6 | ||
7 | GNU Emacs is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
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 | |
18 | along with GNU Emacs; see the file COPYING. If not, write to | |
4fc5845f LK |
19 | the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
20 | Boston, MA 02110-1301, USA. */ | |
e12489f9 GM |
21 | |
22 | #include <config.h> | |
e12489f9 | 23 | #include <signal.h> |
5890e9f7 JD |
24 | #include <stdio.h> |
25 | #include <lisp.h> | |
e12489f9 GM |
26 | #include <syssignal.h> |
27 | #include <systime.h> | |
28 | #include <blockinput.h> | |
29 | #include <atimer.h> | |
e12489f9 GM |
30 | |
31 | #ifdef HAVE_UNISTD_H | |
32 | #include <unistd.h> | |
33 | #endif | |
34 | ||
35 | #ifdef HAVE_SYS_TIME_H | |
36 | #include <sys/time.h> | |
37 | #endif | |
38 | ||
e12489f9 GM |
39 | /* Free-list of atimer structures. */ |
40 | ||
41 | static struct atimer *free_atimers; | |
42 | ||
9c2e3e8d GM |
43 | /* List of currently not running timers due to a call to |
44 | lock_atimer. */ | |
45 | ||
46 | static struct atimer *stopped_atimers; | |
47 | ||
e12489f9 GM |
48 | /* List of active atimers, sorted by expiration time. The timer that |
49 | will become ripe next is always at the front of this list. */ | |
50 | ||
51 | static struct atimer *atimers; | |
52 | ||
53 | /* Non-zero means alarm_signal_handler has found ripe timers but | |
54 | interrupt_input_blocked was non-zero. In this case, timer | |
55 | functions are not called until the next UNBLOCK_INPUT because timer | |
56 | functions are expected to call X, and X cannot be assumed to be | |
57 | reentrant. */ | |
58 | ||
59 | int pending_atimers; | |
60 | ||
5f351ff1 | 61 | /* Block/unblock SIGALRM. */ |
e12489f9 GM |
62 | |
63 | #define BLOCK_ATIMERS sigblock (sigmask (SIGALRM)) | |
64 | #define UNBLOCK_ATIMERS sigunblock (sigmask (SIGALRM)) | |
65 | ||
66 | /* Function prototypes. */ | |
67 | ||
68 | static void set_alarm P_ ((void)); | |
69 | static void schedule_atimer P_ ((struct atimer *)); | |
50b1039f GM |
70 | static struct atimer *append_atimer_lists P_ ((struct atimer *, |
71 | struct atimer *)); | |
a3aca278 | 72 | SIGTYPE alarm_signal_handler (); |
e12489f9 GM |
73 | |
74 | ||
75 | /* Start a new atimer of type TYPE. TIME specifies when the timer is | |
76 | ripe. FN is the function to call when the timer fires. | |
77 | CLIENT_DATA is stored in the client_data member of the atimer | |
78 | structure returned and so made available to FN when it is called. | |
79 | ||
80 | If TYPE is ATIMER_ABSOLUTE, TIME is the absolute time at which the | |
81 | timer fires. | |
82 | ||
83 | If TYPE is ATIMER_RELATIVE, the timer is ripe TIME s/us in the | |
84 | future. | |
85 | ||
86 | In both cases, the timer is automatically freed after it has fired. | |
87 | ||
88 | If TYPE is ATIMER_CONTINUOUS, the timer fires every TIME s/us. | |
89 | ||
90 | Value is a pointer to the atimer started. It can be used in calls | |
91 | to cancel_atimer; don't free it yourself. */ | |
92 | ||
93 | struct atimer * | |
94 | start_atimer (type, time, fn, client_data) | |
95 | enum atimer_type type; | |
96 | EMACS_TIME time; | |
97 | atimer_callback fn; | |
98 | void *client_data; | |
99 | { | |
100 | struct atimer *t; | |
101 | ||
102 | /* Round TIME up to the next full second if we don't have | |
103 | itimers. */ | |
104 | #ifndef HAVE_SETITIMER | |
105 | if (EMACS_USECS (time) != 0) | |
106 | { | |
4ce94f99 EZ |
107 | EMACS_SET_USECS (time, 0); |
108 | EMACS_SET_SECS (time, EMACS_SECS (time) + 1); | |
e12489f9 GM |
109 | } |
110 | #endif /* not HAVE_SETITIMER */ | |
111 | ||
112 | /* Get an atimer structure from the free-list, or allocate | |
113 | a new one. */ | |
114 | if (free_atimers) | |
115 | { | |
116 | t = free_atimers; | |
117 | free_atimers = t->next; | |
118 | } | |
119 | else | |
120 | t = (struct atimer *) xmalloc (sizeof *t); | |
121 | ||
122 | /* Fill the atimer structure. */ | |
123 | bzero (t, sizeof *t); | |
124 | t->type = type; | |
125 | t->fn = fn; | |
126 | t->client_data = client_data; | |
127 | ||
128 | BLOCK_ATIMERS; | |
129 | ||
130 | /* Compute the timer's expiration time. */ | |
131 | switch (type) | |
132 | { | |
133 | case ATIMER_ABSOLUTE: | |
134 | t->expiration = time; | |
135 | break; | |
177c0ea7 | 136 | |
e12489f9 GM |
137 | case ATIMER_RELATIVE: |
138 | EMACS_GET_TIME (t->expiration); | |
139 | EMACS_ADD_TIME (t->expiration, t->expiration, time); | |
140 | break; | |
177c0ea7 | 141 | |
e12489f9 GM |
142 | case ATIMER_CONTINUOUS: |
143 | EMACS_GET_TIME (t->expiration); | |
144 | EMACS_ADD_TIME (t->expiration, t->expiration, time); | |
145 | t->interval = time; | |
146 | break; | |
147 | } | |
148 | ||
149 | /* Insert the timer in the list of active atimers. */ | |
150 | schedule_atimer (t); | |
151 | UNBLOCK_ATIMERS; | |
152 | ||
153 | /* Arrange for a SIGALRM at the time the next atimer is ripe. */ | |
154 | set_alarm (); | |
177c0ea7 | 155 | |
e12489f9 GM |
156 | return t; |
157 | } | |
158 | ||
159 | ||
160 | /* Cancel and free atimer TIMER. */ | |
161 | ||
162 | void | |
163 | cancel_atimer (timer) | |
164 | struct atimer *timer; | |
165 | { | |
50b1039f | 166 | int i; |
177c0ea7 | 167 | |
e12489f9 GM |
168 | BLOCK_ATIMERS; |
169 | ||
50b1039f | 170 | for (i = 0; i < 2; ++i) |
94870977 | 171 | { |
50b1039f GM |
172 | struct atimer *t, *prev; |
173 | struct atimer **list = i ? &stopped_atimers : &atimers; | |
177c0ea7 | 174 | |
94870977 | 175 | /* See if TIMER is active or stopped. */ |
4ab1d4be | 176 | for (t = *list, prev = NULL; t && t != timer; prev = t, t = t->next) |
94870977 GM |
177 | ; |
178 | ||
50b1039f | 179 | /* If it is, take it off the its list, and put in on the |
94870977 GM |
180 | free-list. We don't bother to arrange for setting a |
181 | different alarm time, since a too early one doesn't hurt. */ | |
182 | if (t) | |
183 | { | |
184 | if (prev) | |
185 | prev->next = t->next; | |
186 | else | |
187 | *list = t->next; | |
177c0ea7 | 188 | |
94870977 GM |
189 | t->next = free_atimers; |
190 | free_atimers = t; | |
4ab1d4be | 191 | break; |
94870977 | 192 | } |
e12489f9 GM |
193 | } |
194 | ||
195 | UNBLOCK_ATIMERS; | |
196 | } | |
197 | ||
198 | ||
50b1039f GM |
199 | /* Append two lists of atimers LIST1 and LIST2 and return the |
200 | result list. */ | |
201 | ||
202 | static struct atimer * | |
203 | append_atimer_lists (list1, list2) | |
204 | struct atimer *list1, *list2; | |
205 | { | |
206 | if (list1 == NULL) | |
207 | return list2; | |
208 | else if (list2 == NULL) | |
209 | return list1; | |
210 | else | |
211 | { | |
212 | struct atimer *p; | |
177c0ea7 | 213 | |
50b1039f GM |
214 | for (p = list1; p->next; p = p->next) |
215 | ; | |
216 | p->next = list2; | |
217 | return list1; | |
218 | } | |
219 | } | |
220 | ||
221 | ||
222 | /* Stop all timers except timer T. T null means stop all timers. */ | |
9c2e3e8d GM |
223 | |
224 | void | |
225 | stop_other_atimers (t) | |
226 | struct atimer *t; | |
227 | { | |
228 | BLOCK_ATIMERS; | |
177c0ea7 | 229 | |
9c2e3e8d GM |
230 | if (t) |
231 | { | |
2503c8b1 | 232 | struct atimer *p, *prev; |
177c0ea7 | 233 | |
2503c8b1 | 234 | /* See if T is active. */ |
96013ba9 | 235 | for (p = atimers, prev = NULL; p && p != t; prev = p, p = p->next) |
2503c8b1 GM |
236 | ; |
237 | ||
238 | if (p == t) | |
239 | { | |
240 | if (prev) | |
241 | prev->next = t->next; | |
242 | else | |
243 | atimers = t->next; | |
244 | t->next = NULL; | |
245 | } | |
246 | else | |
247 | /* T is not active. Let's handle this like T == 0. */ | |
248 | t = NULL; | |
9c2e3e8d | 249 | } |
177c0ea7 | 250 | |
50b1039f | 251 | stopped_atimers = append_atimer_lists (atimers, stopped_atimers); |
9c2e3e8d GM |
252 | atimers = t; |
253 | UNBLOCK_ATIMERS; | |
254 | } | |
255 | ||
256 | ||
257 | /* Run all timers again, if some have been stopped with a call to | |
258 | stop_other_atimers. */ | |
259 | ||
260 | void | |
261 | run_all_atimers () | |
262 | { | |
263 | if (stopped_atimers) | |
264 | { | |
265 | struct atimer *t = atimers; | |
50b1039f | 266 | struct atimer *next; |
177c0ea7 | 267 | |
9c2e3e8d GM |
268 | BLOCK_ATIMERS; |
269 | atimers = stopped_atimers; | |
270 | stopped_atimers = NULL; | |
177c0ea7 | 271 | |
50b1039f GM |
272 | while (t) |
273 | { | |
274 | next = t->next; | |
275 | schedule_atimer (t); | |
276 | t = next; | |
277 | } | |
177c0ea7 | 278 | |
9c2e3e8d GM |
279 | UNBLOCK_ATIMERS; |
280 | } | |
281 | } | |
282 | ||
283 | ||
284 | /* A version of run_all_timers suitable for a record_unwind_protect. */ | |
285 | ||
286 | Lisp_Object | |
287 | unwind_stop_other_atimers (dummy) | |
288 | Lisp_Object dummy; | |
289 | { | |
290 | run_all_atimers (); | |
291 | return Qnil; | |
292 | } | |
293 | ||
294 | ||
e12489f9 GM |
295 | /* Arrange for a SIGALRM to arrive when the next timer is ripe. */ |
296 | ||
297 | static void | |
298 | set_alarm () | |
299 | { | |
e12489f9 GM |
300 | #if defined (USG) && !defined (POSIX_SIGNALS) |
301 | /* USG systems forget handlers when they are used; | |
302 | must reestablish each time. */ | |
303 | signal (SIGALRM, alarm_signal_handler); | |
304 | #endif /* USG */ | |
177c0ea7 | 305 | |
e12489f9 GM |
306 | if (atimers) |
307 | { | |
308 | EMACS_TIME now, time; | |
309 | #ifdef HAVE_SETITIMER | |
310 | struct itimerval it; | |
311 | #endif | |
312 | ||
313 | /* Determine s/us till the next timer is ripe. */ | |
314 | EMACS_GET_TIME (now); | |
315 | EMACS_SUB_TIME (time, atimers->expiration, now); | |
316 | ||
317 | #ifdef HAVE_SETITIMER | |
318 | /* Don't set the interval to 0; this disables the timer. */ | |
319 | if (EMACS_TIME_LE (atimers->expiration, now)) | |
320 | { | |
321 | EMACS_SET_SECS (time, 0); | |
322 | EMACS_SET_USECS (time, 1000); | |
323 | } | |
177c0ea7 | 324 | |
e12489f9 GM |
325 | bzero (&it, sizeof it); |
326 | it.it_value = time; | |
327 | setitimer (ITIMER_REAL, &it, 0); | |
328 | #else /* not HAVE_SETITIMER */ | |
329 | alarm (max (EMACS_SECS (time), 1)); | |
330 | #endif /* not HAVE_SETITIMER */ | |
331 | } | |
332 | } | |
333 | ||
334 | ||
335 | /* Insert timer T into the list of active atimers `atimers', keeping | |
336 | the list sorted by expiration time. T must not be in this list | |
337 | already. */ | |
338 | ||
339 | static void | |
340 | schedule_atimer (t) | |
341 | struct atimer *t; | |
342 | { | |
343 | struct atimer *a = atimers, *prev = NULL; | |
344 | ||
345 | /* Look for the first atimer that is ripe after T. */ | |
346 | while (a && EMACS_TIME_GT (t->expiration, a->expiration)) | |
347 | prev = a, a = a->next; | |
348 | ||
349 | /* Insert T in front of the atimer found, if any. */ | |
350 | if (prev) | |
351 | prev->next = t; | |
352 | else | |
353 | atimers = t; | |
177c0ea7 | 354 | |
e12489f9 GM |
355 | t->next = a; |
356 | } | |
357 | ||
358 | ||
359 | /* Signal handler for SIGALRM. SIGNO is the signal number, i.e. | |
360 | SIGALRM. */ | |
361 | ||
362 | SIGTYPE | |
363 | alarm_signal_handler (signo) | |
364 | int signo; | |
365 | { | |
366 | EMACS_TIME now; | |
177c0ea7 | 367 | |
333f1b6f JD |
368 | SIGNAL_THREAD_CHECK (signo); |
369 | ||
e12489f9 GM |
370 | EMACS_GET_TIME (now); |
371 | pending_atimers = 0; | |
177c0ea7 | 372 | |
e12489f9 GM |
373 | while (atimers |
374 | && (pending_atimers = interrupt_input_blocked) == 0 | |
375 | && EMACS_TIME_LE (atimers->expiration, now)) | |
376 | { | |
377 | struct atimer *t; | |
177c0ea7 | 378 | |
e12489f9 GM |
379 | t = atimers; |
380 | atimers = atimers->next; | |
e082ac9d | 381 | #ifndef MAC_OSX |
e12489f9 | 382 | t->fn (t); |
e082ac9d | 383 | #endif |
177c0ea7 | 384 | |
e12489f9 GM |
385 | if (t->type == ATIMER_CONTINUOUS) |
386 | { | |
387 | EMACS_ADD_TIME (t->expiration, now, t->interval); | |
388 | schedule_atimer (t); | |
389 | } | |
390 | else | |
391 | { | |
392 | t->next = free_atimers; | |
393 | free_atimers = t; | |
394 | } | |
e082ac9d ST |
395 | #ifdef MAC_OSX |
396 | /* Fix for Ctrl-G. Perhaps this should apply to all platforms. */ | |
397 | t->fn (t); | |
398 | #endif | |
177c0ea7 | 399 | |
e12489f9 GM |
400 | EMACS_GET_TIME (now); |
401 | } | |
177c0ea7 | 402 | |
fcdb28b4 JD |
403 | if (! pending_atimers) |
404 | set_alarm (); | |
e12489f9 GM |
405 | } |
406 | ||
407 | ||
408 | /* Call alarm_signal_handler for pending timers. */ | |
409 | ||
410 | void | |
411 | do_pending_atimers () | |
412 | { | |
413 | if (pending_atimers) | |
414 | { | |
415 | BLOCK_ATIMERS; | |
416 | alarm_signal_handler (SIGALRM); | |
417 | UNBLOCK_ATIMERS; | |
418 | } | |
419 | } | |
420 | ||
421 | ||
422 | /* Turn alarms on/off. This seems to be temporarily necessary on | |
423 | some systems like HPUX (see process.c). */ | |
424 | ||
425 | void | |
426 | turn_on_atimers (on) | |
427 | int on; | |
428 | { | |
429 | if (on) | |
430 | { | |
431 | signal (SIGALRM, alarm_signal_handler); | |
432 | set_alarm (); | |
433 | } | |
434 | else | |
435 | alarm (0); | |
436 | } | |
437 | ||
438 | ||
439 | void | |
440 | init_atimer () | |
441 | { | |
442 | free_atimers = atimers = NULL; | |
443 | pending_atimers = 0; | |
444 | signal (SIGALRM, alarm_signal_handler); | |
445 | } | |
ab5796a9 MB |
446 | |
447 | /* arch-tag: e6308261-eec6-404b-89fb-6e5909518d70 | |
448 | (do not change this comment) */ |