Commit | Line | Data |
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e12489f9 | 1 | /* Asynchronous timers. |
acaf905b | 2 | Copyright (C) 2000-2012 Free Software Foundation, Inc. |
e12489f9 GM |
3 | |
4 | This file is part of GNU Emacs. | |
5 | ||
9ec0b715 | 6 | GNU Emacs is free software: you can redistribute it and/or modify |
e12489f9 | 7 | it under the terms of the GNU General Public License as published by |
9ec0b715 GM |
8 | the Free Software Foundation, either version 3 of the License, or |
9 | (at your option) any later version. | |
e12489f9 GM |
10 | |
11 | GNU Emacs is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
9ec0b715 | 17 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
e12489f9 GM |
18 | |
19 | #include <config.h> | |
e12489f9 | 20 | #include <signal.h> |
5890e9f7 | 21 | #include <stdio.h> |
d7306fe6 | 22 | #include <setjmp.h> |
898b4c5c DN |
23 | #include "lisp.h" |
24 | #include "syssignal.h" | |
25 | #include "systime.h" | |
26 | #include "blockinput.h" | |
27 | #include "atimer.h" | |
e12489f9 | 28 | #include <unistd.h> |
e12489f9 | 29 | |
e12489f9 GM |
30 | /* Free-list of atimer structures. */ |
31 | ||
32 | static struct atimer *free_atimers; | |
33 | ||
9c2e3e8d GM |
34 | /* List of currently not running timers due to a call to |
35 | lock_atimer. */ | |
36 | ||
37 | static struct atimer *stopped_atimers; | |
38 | ||
e12489f9 GM |
39 | /* List of active atimers, sorted by expiration time. The timer that |
40 | will become ripe next is always at the front of this list. */ | |
41 | ||
42 | static struct atimer *atimers; | |
43 | ||
20ef56db | 44 | /* Non-zero means alarm signal handler has found ripe timers but |
e12489f9 GM |
45 | interrupt_input_blocked was non-zero. In this case, timer |
46 | functions are not called until the next UNBLOCK_INPUT because timer | |
47 | functions are expected to call X, and X cannot be assumed to be | |
48 | reentrant. */ | |
49 | ||
50 | int pending_atimers; | |
51 | ||
5f351ff1 | 52 | /* Block/unblock SIGALRM. */ |
e12489f9 GM |
53 | |
54 | #define BLOCK_ATIMERS sigblock (sigmask (SIGALRM)) | |
55 | #define UNBLOCK_ATIMERS sigunblock (sigmask (SIGALRM)) | |
56 | ||
57 | /* Function prototypes. */ | |
58 | ||
f57e2426 J |
59 | static void set_alarm (void); |
60 | static void schedule_atimer (struct atimer *); | |
61 | static struct atimer *append_atimer_lists (struct atimer *, | |
62 | struct atimer *); | |
e12489f9 GM |
63 | |
64 | /* Start a new atimer of type TYPE. TIME specifies when the timer is | |
65 | ripe. FN is the function to call when the timer fires. | |
66 | CLIENT_DATA is stored in the client_data member of the atimer | |
67 | structure returned and so made available to FN when it is called. | |
68 | ||
69 | If TYPE is ATIMER_ABSOLUTE, TIME is the absolute time at which the | |
70 | timer fires. | |
71 | ||
72 | If TYPE is ATIMER_RELATIVE, the timer is ripe TIME s/us in the | |
73 | future. | |
74 | ||
75 | In both cases, the timer is automatically freed after it has fired. | |
76 | ||
77 | If TYPE is ATIMER_CONTINUOUS, the timer fires every TIME s/us. | |
78 | ||
79 | Value is a pointer to the atimer started. It can be used in calls | |
80 | to cancel_atimer; don't free it yourself. */ | |
81 | ||
82 | struct atimer * | |
3e7d6594 | 83 | start_atimer (enum atimer_type type, EMACS_TIME timestamp, atimer_callback fn, |
e5447b22 | 84 | void *client_data) |
e12489f9 GM |
85 | { |
86 | struct atimer *t; | |
87 | ||
88 | /* Round TIME up to the next full second if we don't have | |
89 | itimers. */ | |
90 | #ifndef HAVE_SETITIMER | |
d35af63c PE |
91 | if (EMACS_NSECS (timestamp) != 0 |
92 | && EMACS_SECS (timestamp) < TYPE_MAXIMUM (time_t)) | |
e9a9ae03 | 93 | timestamp = make_emacs_time (EMACS_SECS (timestamp) + 1, 0); |
e12489f9 GM |
94 | #endif /* not HAVE_SETITIMER */ |
95 | ||
96 | /* Get an atimer structure from the free-list, or allocate | |
97 | a new one. */ | |
98 | if (free_atimers) | |
99 | { | |
100 | t = free_atimers; | |
101 | free_atimers = t->next; | |
102 | } | |
103 | else | |
23f86fce | 104 | t = xmalloc (sizeof *t); |
e12489f9 GM |
105 | |
106 | /* Fill the atimer structure. */ | |
72af86bd | 107 | memset (t, 0, sizeof *t); |
e12489f9 GM |
108 | t->type = type; |
109 | t->fn = fn; | |
110 | t->client_data = client_data; | |
111 | ||
112 | BLOCK_ATIMERS; | |
113 | ||
114 | /* Compute the timer's expiration time. */ | |
115 | switch (type) | |
116 | { | |
117 | case ATIMER_ABSOLUTE: | |
3e7d6594 | 118 | t->expiration = timestamp; |
e12489f9 | 119 | break; |
177c0ea7 | 120 | |
e12489f9 | 121 | case ATIMER_RELATIVE: |
e9a9ae03 | 122 | t->expiration = add_emacs_time (current_emacs_time (), timestamp); |
e12489f9 | 123 | break; |
177c0ea7 | 124 | |
e12489f9 | 125 | case ATIMER_CONTINUOUS: |
e9a9ae03 | 126 | t->expiration = add_emacs_time (current_emacs_time (), timestamp); |
3e7d6594 | 127 | t->interval = timestamp; |
e12489f9 GM |
128 | break; |
129 | } | |
130 | ||
131 | /* Insert the timer in the list of active atimers. */ | |
132 | schedule_atimer (t); | |
133 | UNBLOCK_ATIMERS; | |
134 | ||
135 | /* Arrange for a SIGALRM at the time the next atimer is ripe. */ | |
136 | set_alarm (); | |
177c0ea7 | 137 | |
e12489f9 GM |
138 | return t; |
139 | } | |
140 | ||
141 | ||
142 | /* Cancel and free atimer TIMER. */ | |
143 | ||
144 | void | |
971de7fb | 145 | cancel_atimer (struct atimer *timer) |
e12489f9 | 146 | { |
50b1039f | 147 | int i; |
177c0ea7 | 148 | |
e12489f9 GM |
149 | BLOCK_ATIMERS; |
150 | ||
50b1039f | 151 | for (i = 0; i < 2; ++i) |
94870977 | 152 | { |
50b1039f GM |
153 | struct atimer *t, *prev; |
154 | struct atimer **list = i ? &stopped_atimers : &atimers; | |
177c0ea7 | 155 | |
94870977 | 156 | /* See if TIMER is active or stopped. */ |
4ab1d4be | 157 | for (t = *list, prev = NULL; t && t != timer; prev = t, t = t->next) |
94870977 GM |
158 | ; |
159 | ||
88dbda51 JB |
160 | /* If it is, take it off its list, and put in on the free-list. |
161 | We don't bother to arrange for setting a different alarm time, | |
162 | since a too early one doesn't hurt. */ | |
94870977 GM |
163 | if (t) |
164 | { | |
165 | if (prev) | |
166 | prev->next = t->next; | |
167 | else | |
168 | *list = t->next; | |
177c0ea7 | 169 | |
94870977 GM |
170 | t->next = free_atimers; |
171 | free_atimers = t; | |
4ab1d4be | 172 | break; |
94870977 | 173 | } |
e12489f9 GM |
174 | } |
175 | ||
176 | UNBLOCK_ATIMERS; | |
177 | } | |
178 | ||
179 | ||
3e7d6594 | 180 | /* Append two lists of atimers LIST_1 and LIST_2 and return the |
50b1039f GM |
181 | result list. */ |
182 | ||
183 | static struct atimer * | |
3e7d6594 | 184 | append_atimer_lists (struct atimer *list_1, struct atimer *list_2) |
50b1039f | 185 | { |
3e7d6594 PE |
186 | if (list_1 == NULL) |
187 | return list_2; | |
188 | else if (list_2 == NULL) | |
189 | return list_1; | |
50b1039f GM |
190 | else |
191 | { | |
192 | struct atimer *p; | |
177c0ea7 | 193 | |
3e7d6594 | 194 | for (p = list_1; p->next; p = p->next) |
50b1039f | 195 | ; |
3e7d6594 PE |
196 | p->next = list_2; |
197 | return list_1; | |
50b1039f GM |
198 | } |
199 | } | |
200 | ||
201 | ||
202 | /* Stop all timers except timer T. T null means stop all timers. */ | |
9c2e3e8d GM |
203 | |
204 | void | |
971de7fb | 205 | stop_other_atimers (struct atimer *t) |
9c2e3e8d GM |
206 | { |
207 | BLOCK_ATIMERS; | |
177c0ea7 | 208 | |
9c2e3e8d GM |
209 | if (t) |
210 | { | |
2503c8b1 | 211 | struct atimer *p, *prev; |
177c0ea7 | 212 | |
2503c8b1 | 213 | /* See if T is active. */ |
96013ba9 | 214 | for (p = atimers, prev = NULL; p && p != t; prev = p, p = p->next) |
2503c8b1 GM |
215 | ; |
216 | ||
217 | if (p == t) | |
218 | { | |
219 | if (prev) | |
220 | prev->next = t->next; | |
221 | else | |
222 | atimers = t->next; | |
223 | t->next = NULL; | |
224 | } | |
225 | else | |
226 | /* T is not active. Let's handle this like T == 0. */ | |
227 | t = NULL; | |
9c2e3e8d | 228 | } |
177c0ea7 | 229 | |
50b1039f | 230 | stopped_atimers = append_atimer_lists (atimers, stopped_atimers); |
9c2e3e8d GM |
231 | atimers = t; |
232 | UNBLOCK_ATIMERS; | |
233 | } | |
234 | ||
235 | ||
236 | /* Run all timers again, if some have been stopped with a call to | |
237 | stop_other_atimers. */ | |
238 | ||
e192d7d3 | 239 | static void |
971de7fb | 240 | run_all_atimers (void) |
9c2e3e8d GM |
241 | { |
242 | if (stopped_atimers) | |
243 | { | |
244 | struct atimer *t = atimers; | |
50b1039f | 245 | struct atimer *next; |
177c0ea7 | 246 | |
9c2e3e8d GM |
247 | BLOCK_ATIMERS; |
248 | atimers = stopped_atimers; | |
249 | stopped_atimers = NULL; | |
177c0ea7 | 250 | |
50b1039f GM |
251 | while (t) |
252 | { | |
253 | next = t->next; | |
254 | schedule_atimer (t); | |
255 | t = next; | |
256 | } | |
177c0ea7 | 257 | |
9c2e3e8d GM |
258 | UNBLOCK_ATIMERS; |
259 | } | |
260 | } | |
261 | ||
262 | ||
e192d7d3 | 263 | /* A version of run_all_atimers suitable for a record_unwind_protect. */ |
9c2e3e8d GM |
264 | |
265 | Lisp_Object | |
971de7fb | 266 | unwind_stop_other_atimers (Lisp_Object dummy) |
9c2e3e8d GM |
267 | { |
268 | run_all_atimers (); | |
269 | return Qnil; | |
270 | } | |
271 | ||
272 | ||
e12489f9 GM |
273 | /* Arrange for a SIGALRM to arrive when the next timer is ripe. */ |
274 | ||
275 | static void | |
971de7fb | 276 | set_alarm (void) |
e12489f9 | 277 | { |
e12489f9 GM |
278 | if (atimers) |
279 | { | |
e12489f9 GM |
280 | #ifdef HAVE_SETITIMER |
281 | struct itimerval it; | |
282 | #endif | |
283 | ||
284 | /* Determine s/us till the next timer is ripe. */ | |
e9a9ae03 | 285 | EMACS_TIME now = current_emacs_time (); |
e12489f9 | 286 | |
e12489f9 | 287 | /* Don't set the interval to 0; this disables the timer. */ |
e9a9ae03 PE |
288 | EMACS_TIME interval = (EMACS_TIME_LE (atimers->expiration, now) |
289 | ? make_emacs_time (0, 1000 * 1000) | |
290 | : sub_emacs_time (atimers->expiration, now)); | |
d35af63c PE |
291 | |
292 | #ifdef HAVE_SETITIMER | |
177c0ea7 | 293 | |
72af86bd | 294 | memset (&it, 0, sizeof it); |
e9a9ae03 | 295 | it.it_value = make_timeval (interval); |
e12489f9 GM |
296 | setitimer (ITIMER_REAL, &it, 0); |
297 | #else /* not HAVE_SETITIMER */ | |
e9a9ae03 | 298 | alarm (max (EMACS_SECS (interval), 1)); |
e12489f9 GM |
299 | #endif /* not HAVE_SETITIMER */ |
300 | } | |
301 | } | |
302 | ||
303 | ||
304 | /* Insert timer T into the list of active atimers `atimers', keeping | |
305 | the list sorted by expiration time. T must not be in this list | |
306 | already. */ | |
307 | ||
308 | static void | |
971de7fb | 309 | schedule_atimer (struct atimer *t) |
e12489f9 GM |
310 | { |
311 | struct atimer *a = atimers, *prev = NULL; | |
312 | ||
313 | /* Look for the first atimer that is ripe after T. */ | |
314 | while (a && EMACS_TIME_GT (t->expiration, a->expiration)) | |
315 | prev = a, a = a->next; | |
316 | ||
317 | /* Insert T in front of the atimer found, if any. */ | |
318 | if (prev) | |
319 | prev->next = t; | |
320 | else | |
321 | atimers = t; | |
177c0ea7 | 322 | |
e12489f9 GM |
323 | t->next = a; |
324 | } | |
325 | ||
170c80be | 326 | static void |
971de7fb | 327 | run_timers (void) |
e12489f9 GM |
328 | { |
329 | EMACS_TIME now; | |
177c0ea7 | 330 | |
e12489f9 GM |
331 | while (atimers |
332 | && (pending_atimers = interrupt_input_blocked) == 0 | |
e9a9ae03 | 333 | && (now = current_emacs_time (), |
d35af63c | 334 | EMACS_TIME_LE (atimers->expiration, now))) |
e12489f9 GM |
335 | { |
336 | struct atimer *t; | |
177c0ea7 | 337 | |
e12489f9 GM |
338 | t = atimers; |
339 | atimers = atimers->next; | |
340 | t->fn (t); | |
177c0ea7 | 341 | |
e12489f9 GM |
342 | if (t->type == ATIMER_CONTINUOUS) |
343 | { | |
e9a9ae03 | 344 | t->expiration = add_emacs_time (now, t->interval); |
e12489f9 GM |
345 | schedule_atimer (t); |
346 | } | |
347 | else | |
348 | { | |
349 | t->next = free_atimers; | |
350 | free_atimers = t; | |
351 | } | |
e12489f9 | 352 | } |
177c0ea7 | 353 | |
6bbbda87 CY |
354 | if (! atimers) |
355 | pending_atimers = 0; | |
356 | ||
07a1e794 | 357 | #ifdef SYNC_INPUT |
325530de CY |
358 | if (pending_atimers) |
359 | pending_signals = 1; | |
360 | else | |
361 | { | |
362 | pending_signals = interrupt_input_pending; | |
363 | set_alarm (); | |
364 | } | |
07a1e794 JB |
365 | #else |
366 | if (! pending_atimers) | |
367 | set_alarm (); | |
368 | #endif | |
e12489f9 GM |
369 | } |
370 | ||
371 | ||
170c80be JD |
372 | /* Signal handler for SIGALRM. SIGNO is the signal number, i.e. |
373 | SIGALRM. */ | |
374 | ||
20ef56db PE |
375 | static void |
376 | handle_alarm_signal (int sig) | |
170c80be JD |
377 | { |
378 | pending_atimers = 1; | |
07a1e794 | 379 | #ifdef SYNC_INPUT |
325530de | 380 | pending_signals = 1; |
07a1e794 | 381 | #else |
170c80be JD |
382 | run_timers (); |
383 | #endif | |
384 | } | |
385 | ||
20ef56db PE |
386 | static void |
387 | deliver_alarm_signal (int sig) | |
388 | { | |
389 | handle_on_main_thread (sig, handle_alarm_signal); | |
390 | } | |
391 | ||
170c80be | 392 | |
20ef56db | 393 | /* Call alarm signal handler for pending timers. */ |
e12489f9 GM |
394 | |
395 | void | |
971de7fb | 396 | do_pending_atimers (void) |
e12489f9 GM |
397 | { |
398 | if (pending_atimers) | |
399 | { | |
400 | BLOCK_ATIMERS; | |
170c80be | 401 | run_timers (); |
e12489f9 GM |
402 | UNBLOCK_ATIMERS; |
403 | } | |
404 | } | |
405 | ||
406 | ||
407 | /* Turn alarms on/off. This seems to be temporarily necessary on | |
408 | some systems like HPUX (see process.c). */ | |
409 | ||
410 | void | |
b1bb8011 | 411 | turn_on_atimers (bool on) |
e12489f9 GM |
412 | { |
413 | if (on) | |
414 | { | |
20ef56db | 415 | signal (SIGALRM, deliver_alarm_signal); |
e12489f9 GM |
416 | set_alarm (); |
417 | } | |
418 | else | |
419 | alarm (0); | |
420 | } | |
421 | ||
422 | ||
423 | void | |
971de7fb | 424 | init_atimer (void) |
e12489f9 | 425 | { |
bcdf96ba | 426 | free_atimers = stopped_atimers = atimers = NULL; |
e12489f9 | 427 | pending_atimers = 0; |
325530de | 428 | /* pending_signals is initialized in init_keyboard.*/ |
20ef56db | 429 | signal (SIGALRM, deliver_alarm_signal); |
e12489f9 | 430 | } |