Commit | Line | Data |
---|---|---|
e12489f9 | 1 | /* Asynchronous timers. |
ab422c4d | 2 | Copyright (C) 2000-2013 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> | |
5890e9f7 | 20 | #include <stdio.h> |
0328b6de | 21 | |
898b4c5c DN |
22 | #include "lisp.h" |
23 | #include "syssignal.h" | |
24 | #include "systime.h" | |
25 | #include "blockinput.h" | |
26 | #include "atimer.h" | |
e12489f9 | 27 | #include <unistd.h> |
e12489f9 | 28 | |
e12489f9 GM |
29 | /* Free-list of atimer structures. */ |
30 | ||
31 | static struct atimer *free_atimers; | |
32 | ||
9c2e3e8d GM |
33 | /* List of currently not running timers due to a call to |
34 | lock_atimer. */ | |
35 | ||
36 | static struct atimer *stopped_atimers; | |
37 | ||
e12489f9 GM |
38 | /* List of active atimers, sorted by expiration time. The timer that |
39 | will become ripe next is always at the front of this list. */ | |
40 | ||
41 | static struct atimer *atimers; | |
42 | ||
e26fd2e4 PE |
43 | /* The alarm timer and whether it was properly initialized, if |
44 | POSIX timers are available. */ | |
2b794d69 | 45 | #ifdef HAVE_ITIMERSPEC |
e26fd2e4 PE |
46 | static timer_t alarm_timer; |
47 | static bool alarm_timer_ok; | |
48 | #endif | |
49 | ||
5f351ff1 | 50 | /* Block/unblock SIGALRM. */ |
e12489f9 | 51 | |
2fe28299 PE |
52 | static void |
53 | sigmask_atimers (int how) | |
54 | { | |
55 | sigset_t blocked; | |
56 | sigemptyset (&blocked); | |
57 | sigaddset (&blocked, SIGALRM); | |
58 | pthread_sigmask (how, &blocked, 0); | |
59 | } | |
60 | static void | |
61 | block_atimers (void) | |
62 | { | |
63 | sigmask_atimers (SIG_BLOCK); | |
64 | } | |
65 | static void | |
66 | unblock_atimers (void) | |
67 | { | |
68 | sigmask_atimers (SIG_UNBLOCK); | |
69 | } | |
e12489f9 GM |
70 | |
71 | /* Function prototypes. */ | |
72 | ||
f57e2426 J |
73 | static void set_alarm (void); |
74 | static void schedule_atimer (struct atimer *); | |
75 | static struct atimer *append_atimer_lists (struct atimer *, | |
76 | struct atimer *); | |
e12489f9 GM |
77 | |
78 | /* Start a new atimer of type TYPE. TIME specifies when the timer is | |
79 | ripe. FN is the function to call when the timer fires. | |
80 | CLIENT_DATA is stored in the client_data member of the atimer | |
81 | structure returned and so made available to FN when it is called. | |
82 | ||
83 | If TYPE is ATIMER_ABSOLUTE, TIME is the absolute time at which the | |
84 | timer fires. | |
85 | ||
86 | If TYPE is ATIMER_RELATIVE, the timer is ripe TIME s/us in the | |
87 | future. | |
88 | ||
89 | In both cases, the timer is automatically freed after it has fired. | |
90 | ||
91 | If TYPE is ATIMER_CONTINUOUS, the timer fires every TIME s/us. | |
92 | ||
93 | Value is a pointer to the atimer started. It can be used in calls | |
94 | to cancel_atimer; don't free it yourself. */ | |
95 | ||
96 | struct atimer * | |
3e7d6594 | 97 | start_atimer (enum atimer_type type, EMACS_TIME timestamp, atimer_callback fn, |
e5447b22 | 98 | void *client_data) |
e12489f9 GM |
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 | |
d35af63c PE |
105 | if (EMACS_NSECS (timestamp) != 0 |
106 | && EMACS_SECS (timestamp) < TYPE_MAXIMUM (time_t)) | |
e9a9ae03 | 107 | timestamp = make_emacs_time (EMACS_SECS (timestamp) + 1, 0); |
e12489f9 GM |
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 | |
23f86fce | 118 | t = xmalloc (sizeof *t); |
e12489f9 GM |
119 | |
120 | /* Fill the atimer structure. */ | |
72af86bd | 121 | memset (t, 0, sizeof *t); |
e12489f9 GM |
122 | t->type = type; |
123 | t->fn = fn; | |
124 | t->client_data = client_data; | |
125 | ||
2fe28299 | 126 | block_atimers (); |
e12489f9 GM |
127 | |
128 | /* Compute the timer's expiration time. */ | |
129 | switch (type) | |
130 | { | |
131 | case ATIMER_ABSOLUTE: | |
3e7d6594 | 132 | t->expiration = timestamp; |
e12489f9 | 133 | break; |
177c0ea7 | 134 | |
e12489f9 | 135 | case ATIMER_RELATIVE: |
e9a9ae03 | 136 | t->expiration = add_emacs_time (current_emacs_time (), timestamp); |
e12489f9 | 137 | break; |
177c0ea7 | 138 | |
e12489f9 | 139 | case ATIMER_CONTINUOUS: |
e9a9ae03 | 140 | t->expiration = add_emacs_time (current_emacs_time (), timestamp); |
3e7d6594 | 141 | t->interval = timestamp; |
e12489f9 GM |
142 | break; |
143 | } | |
144 | ||
145 | /* Insert the timer in the list of active atimers. */ | |
146 | schedule_atimer (t); | |
2fe28299 | 147 | unblock_atimers (); |
e12489f9 GM |
148 | |
149 | /* Arrange for a SIGALRM at the time the next atimer is ripe. */ | |
150 | set_alarm (); | |
177c0ea7 | 151 | |
e12489f9 GM |
152 | return t; |
153 | } | |
154 | ||
155 | ||
156 | /* Cancel and free atimer TIMER. */ | |
157 | ||
158 | void | |
971de7fb | 159 | cancel_atimer (struct atimer *timer) |
e12489f9 | 160 | { |
50b1039f | 161 | int i; |
177c0ea7 | 162 | |
2fe28299 | 163 | block_atimers (); |
e12489f9 | 164 | |
50b1039f | 165 | for (i = 0; i < 2; ++i) |
94870977 | 166 | { |
50b1039f GM |
167 | struct atimer *t, *prev; |
168 | struct atimer **list = i ? &stopped_atimers : &atimers; | |
177c0ea7 | 169 | |
94870977 | 170 | /* See if TIMER is active or stopped. */ |
4ab1d4be | 171 | for (t = *list, prev = NULL; t && t != timer; prev = t, t = t->next) |
94870977 GM |
172 | ; |
173 | ||
88dbda51 JB |
174 | /* If it is, take it off its list, and put in on the free-list. |
175 | We don't bother to arrange for setting a different alarm time, | |
176 | since a too early one doesn't hurt. */ | |
94870977 GM |
177 | if (t) |
178 | { | |
179 | if (prev) | |
180 | prev->next = t->next; | |
181 | else | |
182 | *list = t->next; | |
177c0ea7 | 183 | |
94870977 GM |
184 | t->next = free_atimers; |
185 | free_atimers = t; | |
4ab1d4be | 186 | break; |
94870977 | 187 | } |
e12489f9 GM |
188 | } |
189 | ||
2fe28299 | 190 | unblock_atimers (); |
e12489f9 GM |
191 | } |
192 | ||
193 | ||
3e7d6594 | 194 | /* Append two lists of atimers LIST_1 and LIST_2 and return the |
50b1039f GM |
195 | result list. */ |
196 | ||
197 | static struct atimer * | |
3e7d6594 | 198 | append_atimer_lists (struct atimer *list_1, struct atimer *list_2) |
50b1039f | 199 | { |
3e7d6594 PE |
200 | if (list_1 == NULL) |
201 | return list_2; | |
202 | else if (list_2 == NULL) | |
203 | return list_1; | |
50b1039f GM |
204 | else |
205 | { | |
206 | struct atimer *p; | |
177c0ea7 | 207 | |
3e7d6594 | 208 | for (p = list_1; p->next; p = p->next) |
50b1039f | 209 | ; |
3e7d6594 PE |
210 | p->next = list_2; |
211 | return list_1; | |
50b1039f GM |
212 | } |
213 | } | |
214 | ||
215 | ||
216 | /* Stop all timers except timer T. T null means stop all timers. */ | |
9c2e3e8d GM |
217 | |
218 | void | |
971de7fb | 219 | stop_other_atimers (struct atimer *t) |
9c2e3e8d | 220 | { |
2fe28299 | 221 | block_atimers (); |
177c0ea7 | 222 | |
9c2e3e8d GM |
223 | if (t) |
224 | { | |
2503c8b1 | 225 | struct atimer *p, *prev; |
177c0ea7 | 226 | |
2503c8b1 | 227 | /* See if T is active. */ |
96013ba9 | 228 | for (p = atimers, prev = NULL; p && p != t; prev = p, p = p->next) |
2503c8b1 GM |
229 | ; |
230 | ||
231 | if (p == t) | |
232 | { | |
233 | if (prev) | |
234 | prev->next = t->next; | |
235 | else | |
236 | atimers = t->next; | |
237 | t->next = NULL; | |
238 | } | |
239 | else | |
240 | /* T is not active. Let's handle this like T == 0. */ | |
241 | t = NULL; | |
9c2e3e8d | 242 | } |
177c0ea7 | 243 | |
50b1039f | 244 | stopped_atimers = append_atimer_lists (atimers, stopped_atimers); |
9c2e3e8d | 245 | atimers = t; |
2fe28299 | 246 | unblock_atimers (); |
9c2e3e8d GM |
247 | } |
248 | ||
249 | ||
250 | /* Run all timers again, if some have been stopped with a call to | |
251 | stop_other_atimers. */ | |
252 | ||
e192d7d3 | 253 | static void |
971de7fb | 254 | run_all_atimers (void) |
9c2e3e8d GM |
255 | { |
256 | if (stopped_atimers) | |
257 | { | |
258 | struct atimer *t = atimers; | |
50b1039f | 259 | struct atimer *next; |
177c0ea7 | 260 | |
2fe28299 | 261 | block_atimers (); |
9c2e3e8d GM |
262 | atimers = stopped_atimers; |
263 | stopped_atimers = NULL; | |
177c0ea7 | 264 | |
50b1039f GM |
265 | while (t) |
266 | { | |
267 | next = t->next; | |
268 | schedule_atimer (t); | |
269 | t = next; | |
270 | } | |
177c0ea7 | 271 | |
2fe28299 | 272 | unblock_atimers (); |
9c2e3e8d GM |
273 | } |
274 | } | |
275 | ||
276 | ||
e192d7d3 | 277 | /* A version of run_all_atimers suitable for a record_unwind_protect. */ |
9c2e3e8d GM |
278 | |
279 | Lisp_Object | |
971de7fb | 280 | unwind_stop_other_atimers (Lisp_Object dummy) |
9c2e3e8d GM |
281 | { |
282 | run_all_atimers (); | |
283 | return Qnil; | |
284 | } | |
285 | ||
286 | ||
e12489f9 GM |
287 | /* Arrange for a SIGALRM to arrive when the next timer is ripe. */ |
288 | ||
289 | static void | |
971de7fb | 290 | set_alarm (void) |
e12489f9 | 291 | { |
e12489f9 GM |
292 | if (atimers) |
293 | { | |
e12489f9 GM |
294 | #ifdef HAVE_SETITIMER |
295 | struct itimerval it; | |
296 | #endif | |
e26fd2e4 | 297 | EMACS_TIME now, interval; |
e12489f9 | 298 | |
2b794d69 | 299 | #ifdef HAVE_ITIMERSPEC |
e26fd2e4 PE |
300 | if (alarm_timer_ok) |
301 | { | |
302 | struct itimerspec ispec; | |
303 | ispec.it_value = atimers->expiration; | |
304 | ispec.it_interval.tv_sec = ispec.it_interval.tv_nsec = 0; | |
305 | if (timer_settime (alarm_timer, 0, &ispec, 0) == 0) | |
306 | return; | |
307 | } | |
308 | #endif | |
e12489f9 | 309 | |
e26fd2e4 PE |
310 | /* Determine interval till the next timer is ripe. |
311 | Don't set the interval to 0; this disables the timer. */ | |
312 | now = current_emacs_time (); | |
313 | interval = (EMACS_TIME_LE (atimers->expiration, now) | |
314 | ? make_emacs_time (0, 1000 * 1000) | |
315 | : sub_emacs_time (atimers->expiration, now)); | |
d35af63c PE |
316 | |
317 | #ifdef HAVE_SETITIMER | |
177c0ea7 | 318 | |
72af86bd | 319 | memset (&it, 0, sizeof it); |
e9a9ae03 | 320 | it.it_value = make_timeval (interval); |
e12489f9 GM |
321 | setitimer (ITIMER_REAL, &it, 0); |
322 | #else /* not HAVE_SETITIMER */ | |
e9a9ae03 | 323 | alarm (max (EMACS_SECS (interval), 1)); |
e12489f9 GM |
324 | #endif /* not HAVE_SETITIMER */ |
325 | } | |
326 | } | |
327 | ||
328 | ||
329 | /* Insert timer T into the list of active atimers `atimers', keeping | |
330 | the list sorted by expiration time. T must not be in this list | |
331 | already. */ | |
332 | ||
333 | static void | |
971de7fb | 334 | schedule_atimer (struct atimer *t) |
e12489f9 GM |
335 | { |
336 | struct atimer *a = atimers, *prev = NULL; | |
337 | ||
338 | /* Look for the first atimer that is ripe after T. */ | |
954b166e | 339 | while (a && EMACS_TIME_LT (a->expiration, t->expiration)) |
e12489f9 GM |
340 | prev = a, a = a->next; |
341 | ||
342 | /* Insert T in front of the atimer found, if any. */ | |
343 | if (prev) | |
344 | prev->next = t; | |
345 | else | |
346 | atimers = t; | |
177c0ea7 | 347 | |
e12489f9 GM |
348 | t->next = a; |
349 | } | |
350 | ||
170c80be | 351 | static void |
971de7fb | 352 | run_timers (void) |
e12489f9 | 353 | { |
4d7e6e51 | 354 | EMACS_TIME now = current_emacs_time (); |
177c0ea7 | 355 | |
4d7e6e51 | 356 | while (atimers && EMACS_TIME_LE (atimers->expiration, now)) |
e12489f9 | 357 | { |
4d7e6e51 | 358 | struct atimer *t = atimers; |
e12489f9 GM |
359 | atimers = atimers->next; |
360 | t->fn (t); | |
177c0ea7 | 361 | |
e12489f9 GM |
362 | if (t->type == ATIMER_CONTINUOUS) |
363 | { | |
e9a9ae03 | 364 | t->expiration = add_emacs_time (now, t->interval); |
e12489f9 GM |
365 | schedule_atimer (t); |
366 | } | |
367 | else | |
368 | { | |
369 | t->next = free_atimers; | |
370 | free_atimers = t; | |
371 | } | |
e12489f9 | 372 | } |
177c0ea7 | 373 | |
4d7e6e51 | 374 | set_alarm (); |
e12489f9 GM |
375 | } |
376 | ||
377 | ||
170c80be JD |
378 | /* Signal handler for SIGALRM. SIGNO is the signal number, i.e. |
379 | SIGALRM. */ | |
380 | ||
20ef56db PE |
381 | static void |
382 | handle_alarm_signal (int sig) | |
170c80be | 383 | { |
325530de | 384 | pending_signals = 1; |
170c80be JD |
385 | } |
386 | ||
387 | ||
4d7e6e51 | 388 | /* Do pending timers. */ |
e12489f9 GM |
389 | |
390 | void | |
971de7fb | 391 | do_pending_atimers (void) |
e12489f9 | 392 | { |
4d7e6e51 | 393 | if (atimers) |
e12489f9 | 394 | { |
2fe28299 | 395 | block_atimers (); |
170c80be | 396 | run_timers (); |
2fe28299 | 397 | unblock_atimers (); |
e12489f9 GM |
398 | } |
399 | } | |
400 | ||
401 | ||
402 | /* Turn alarms on/off. This seems to be temporarily necessary on | |
403 | some systems like HPUX (see process.c). */ | |
404 | ||
405 | void | |
b1bb8011 | 406 | turn_on_atimers (bool on) |
e12489f9 GM |
407 | { |
408 | if (on) | |
4d7e6e51 | 409 | set_alarm (); |
e12489f9 GM |
410 | else |
411 | alarm (0); | |
412 | } | |
413 | ||
414 | ||
415 | void | |
971de7fb | 416 | init_atimer (void) |
e12489f9 | 417 | { |
2fe28299 | 418 | struct sigaction action; |
2b794d69 | 419 | #ifdef HAVE_ITIMERSPEC |
e26fd2e4 PE |
420 | struct sigevent sigev; |
421 | sigev.sigev_notify = SIGEV_SIGNAL; | |
422 | sigev.sigev_signo = SIGALRM; | |
423 | sigev.sigev_value.sival_ptr = &alarm_timer; | |
424 | alarm_timer_ok = timer_create (CLOCK_REALTIME, &sigev, &alarm_timer) == 0; | |
425 | #endif | |
bcdf96ba | 426 | free_atimers = stopped_atimers = atimers = NULL; |
325530de | 427 | /* pending_signals is initialized in init_keyboard.*/ |
4d7e6e51 | 428 | emacs_sigaction_init (&action, handle_alarm_signal); |
2fe28299 | 429 | sigaction (SIGALRM, &action, 0); |
e12489f9 | 430 | } |