Commit | Line | Data |
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e12489f9 | 1 | /* Asynchronous timers. |
ba318903 | 2 | Copyright (C) 2000-2014 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 * | |
43aac990 PE |
97 | start_atimer (enum atimer_type type, struct timespec timestamp, |
98 | atimer_callback fn, 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 | |
43aac990 PE |
105 | if (timestamp.tv_nsec != 0 && timestamp.tv_sec < TYPE_MAXIMUM (time_t)) |
106 | timestamp = make_timespec (timestamp.tv_sec + 1, 0); | |
e12489f9 GM |
107 | #endif /* not HAVE_SETITIMER */ |
108 | ||
109 | /* Get an atimer structure from the free-list, or allocate | |
110 | a new one. */ | |
111 | if (free_atimers) | |
112 | { | |
113 | t = free_atimers; | |
114 | free_atimers = t->next; | |
115 | } | |
116 | else | |
23f86fce | 117 | t = xmalloc (sizeof *t); |
e12489f9 GM |
118 | |
119 | /* Fill the atimer structure. */ | |
72af86bd | 120 | memset (t, 0, sizeof *t); |
e12489f9 GM |
121 | t->type = type; |
122 | t->fn = fn; | |
123 | t->client_data = client_data; | |
124 | ||
2fe28299 | 125 | block_atimers (); |
e12489f9 GM |
126 | |
127 | /* Compute the timer's expiration time. */ | |
128 | switch (type) | |
129 | { | |
130 | case ATIMER_ABSOLUTE: | |
3e7d6594 | 131 | t->expiration = timestamp; |
e12489f9 | 132 | break; |
177c0ea7 | 133 | |
e12489f9 | 134 | case ATIMER_RELATIVE: |
43aac990 | 135 | t->expiration = timespec_add (current_timespec (), timestamp); |
e12489f9 | 136 | break; |
177c0ea7 | 137 | |
e12489f9 | 138 | case ATIMER_CONTINUOUS: |
43aac990 | 139 | t->expiration = timespec_add (current_timespec (), timestamp); |
3e7d6594 | 140 | t->interval = timestamp; |
e12489f9 GM |
141 | break; |
142 | } | |
143 | ||
144 | /* Insert the timer in the list of active atimers. */ | |
145 | schedule_atimer (t); | |
2fe28299 | 146 | unblock_atimers (); |
e12489f9 GM |
147 | |
148 | /* Arrange for a SIGALRM at the time the next atimer is ripe. */ | |
149 | set_alarm (); | |
177c0ea7 | 150 | |
e12489f9 GM |
151 | return t; |
152 | } | |
153 | ||
154 | ||
155 | /* Cancel and free atimer TIMER. */ | |
156 | ||
157 | void | |
971de7fb | 158 | cancel_atimer (struct atimer *timer) |
e12489f9 | 159 | { |
50b1039f | 160 | int i; |
177c0ea7 | 161 | |
2fe28299 | 162 | block_atimers (); |
e12489f9 | 163 | |
50b1039f | 164 | for (i = 0; i < 2; ++i) |
94870977 | 165 | { |
50b1039f GM |
166 | struct atimer *t, *prev; |
167 | struct atimer **list = i ? &stopped_atimers : &atimers; | |
177c0ea7 | 168 | |
94870977 | 169 | /* See if TIMER is active or stopped. */ |
4ab1d4be | 170 | for (t = *list, prev = NULL; t && t != timer; prev = t, t = t->next) |
94870977 GM |
171 | ; |
172 | ||
88dbda51 JB |
173 | /* If it is, take it off its list, and put in on the free-list. |
174 | We don't bother to arrange for setting a different alarm time, | |
175 | since a too early one doesn't hurt. */ | |
94870977 GM |
176 | if (t) |
177 | { | |
178 | if (prev) | |
179 | prev->next = t->next; | |
180 | else | |
181 | *list = t->next; | |
177c0ea7 | 182 | |
94870977 GM |
183 | t->next = free_atimers; |
184 | free_atimers = t; | |
4ab1d4be | 185 | break; |
94870977 | 186 | } |
e12489f9 GM |
187 | } |
188 | ||
2fe28299 | 189 | unblock_atimers (); |
e12489f9 GM |
190 | } |
191 | ||
192 | ||
3e7d6594 | 193 | /* Append two lists of atimers LIST_1 and LIST_2 and return the |
50b1039f GM |
194 | result list. */ |
195 | ||
196 | static struct atimer * | |
3e7d6594 | 197 | append_atimer_lists (struct atimer *list_1, struct atimer *list_2) |
50b1039f | 198 | { |
3e7d6594 PE |
199 | if (list_1 == NULL) |
200 | return list_2; | |
201 | else if (list_2 == NULL) | |
202 | return list_1; | |
50b1039f GM |
203 | else |
204 | { | |
205 | struct atimer *p; | |
177c0ea7 | 206 | |
3e7d6594 | 207 | for (p = list_1; p->next; p = p->next) |
50b1039f | 208 | ; |
3e7d6594 PE |
209 | p->next = list_2; |
210 | return list_1; | |
50b1039f GM |
211 | } |
212 | } | |
213 | ||
214 | ||
215 | /* Stop all timers except timer T. T null means stop all timers. */ | |
9c2e3e8d GM |
216 | |
217 | void | |
971de7fb | 218 | stop_other_atimers (struct atimer *t) |
9c2e3e8d | 219 | { |
2fe28299 | 220 | block_atimers (); |
177c0ea7 | 221 | |
9c2e3e8d GM |
222 | if (t) |
223 | { | |
2503c8b1 | 224 | struct atimer *p, *prev; |
177c0ea7 | 225 | |
2503c8b1 | 226 | /* See if T is active. */ |
96013ba9 | 227 | for (p = atimers, prev = NULL; p && p != t; prev = p, p = p->next) |
2503c8b1 GM |
228 | ; |
229 | ||
230 | if (p == t) | |
231 | { | |
232 | if (prev) | |
233 | prev->next = t->next; | |
234 | else | |
235 | atimers = t->next; | |
236 | t->next = NULL; | |
237 | } | |
238 | else | |
239 | /* T is not active. Let's handle this like T == 0. */ | |
240 | t = NULL; | |
9c2e3e8d | 241 | } |
177c0ea7 | 242 | |
50b1039f | 243 | stopped_atimers = append_atimer_lists (atimers, stopped_atimers); |
9c2e3e8d | 244 | atimers = t; |
2fe28299 | 245 | unblock_atimers (); |
9c2e3e8d GM |
246 | } |
247 | ||
248 | ||
249 | /* Run all timers again, if some have been stopped with a call to | |
250 | stop_other_atimers. */ | |
251 | ||
27e498e6 | 252 | void |
971de7fb | 253 | run_all_atimers (void) |
9c2e3e8d GM |
254 | { |
255 | if (stopped_atimers) | |
256 | { | |
257 | struct atimer *t = atimers; | |
50b1039f | 258 | struct atimer *next; |
177c0ea7 | 259 | |
2fe28299 | 260 | block_atimers (); |
9c2e3e8d GM |
261 | atimers = stopped_atimers; |
262 | stopped_atimers = NULL; | |
177c0ea7 | 263 | |
50b1039f GM |
264 | while (t) |
265 | { | |
266 | next = t->next; | |
267 | schedule_atimer (t); | |
268 | t = next; | |
269 | } | |
177c0ea7 | 270 | |
2fe28299 | 271 | unblock_atimers (); |
9c2e3e8d GM |
272 | } |
273 | } | |
274 | ||
275 | ||
e12489f9 GM |
276 | /* Arrange for a SIGALRM to arrive when the next timer is ripe. */ |
277 | ||
278 | static void | |
971de7fb | 279 | set_alarm (void) |
e12489f9 | 280 | { |
e12489f9 GM |
281 | if (atimers) |
282 | { | |
e12489f9 GM |
283 | #ifdef HAVE_SETITIMER |
284 | struct itimerval it; | |
285 | #endif | |
43aac990 | 286 | struct timespec now, interval; |
e12489f9 | 287 | |
2b794d69 | 288 | #ifdef HAVE_ITIMERSPEC |
e26fd2e4 PE |
289 | if (alarm_timer_ok) |
290 | { | |
291 | struct itimerspec ispec; | |
292 | ispec.it_value = atimers->expiration; | |
293 | ispec.it_interval.tv_sec = ispec.it_interval.tv_nsec = 0; | |
294 | if (timer_settime (alarm_timer, 0, &ispec, 0) == 0) | |
295 | return; | |
296 | } | |
297 | #endif | |
e12489f9 | 298 | |
e26fd2e4 PE |
299 | /* Determine interval till the next timer is ripe. |
300 | Don't set the interval to 0; this disables the timer. */ | |
43aac990 PE |
301 | now = current_timespec (); |
302 | interval = (timespec_cmp (atimers->expiration, now) <= 0 | |
303 | ? make_timespec (0, 1000 * 1000) | |
304 | : timespec_sub (atimers->expiration, now)); | |
d35af63c PE |
305 | |
306 | #ifdef HAVE_SETITIMER | |
177c0ea7 | 307 | |
72af86bd | 308 | memset (&it, 0, sizeof it); |
e9a9ae03 | 309 | it.it_value = make_timeval (interval); |
e12489f9 GM |
310 | setitimer (ITIMER_REAL, &it, 0); |
311 | #else /* not HAVE_SETITIMER */ | |
43aac990 | 312 | alarm (max (interval.tv_sec, 1)); |
e12489f9 GM |
313 | #endif /* not HAVE_SETITIMER */ |
314 | } | |
315 | } | |
316 | ||
317 | ||
318 | /* Insert timer T into the list of active atimers `atimers', keeping | |
319 | the list sorted by expiration time. T must not be in this list | |
320 | already. */ | |
321 | ||
322 | static void | |
971de7fb | 323 | schedule_atimer (struct atimer *t) |
e12489f9 GM |
324 | { |
325 | struct atimer *a = atimers, *prev = NULL; | |
326 | ||
327 | /* Look for the first atimer that is ripe after T. */ | |
43aac990 | 328 | while (a && timespec_cmp (a->expiration, t->expiration) < 0) |
e12489f9 GM |
329 | prev = a, a = a->next; |
330 | ||
331 | /* Insert T in front of the atimer found, if any. */ | |
332 | if (prev) | |
333 | prev->next = t; | |
334 | else | |
335 | atimers = t; | |
177c0ea7 | 336 | |
e12489f9 GM |
337 | t->next = a; |
338 | } | |
339 | ||
170c80be | 340 | static void |
971de7fb | 341 | run_timers (void) |
e12489f9 | 342 | { |
43aac990 | 343 | struct timespec now = current_timespec (); |
177c0ea7 | 344 | |
43aac990 | 345 | while (atimers && timespec_cmp (atimers->expiration, now) <= 0) |
e12489f9 | 346 | { |
4d7e6e51 | 347 | struct atimer *t = atimers; |
e12489f9 GM |
348 | atimers = atimers->next; |
349 | t->fn (t); | |
177c0ea7 | 350 | |
e12489f9 GM |
351 | if (t->type == ATIMER_CONTINUOUS) |
352 | { | |
43aac990 | 353 | t->expiration = timespec_add (now, t->interval); |
e12489f9 GM |
354 | schedule_atimer (t); |
355 | } | |
356 | else | |
357 | { | |
358 | t->next = free_atimers; | |
359 | free_atimers = t; | |
360 | } | |
e12489f9 | 361 | } |
177c0ea7 | 362 | |
4d7e6e51 | 363 | set_alarm (); |
e12489f9 GM |
364 | } |
365 | ||
366 | ||
170c80be JD |
367 | /* Signal handler for SIGALRM. SIGNO is the signal number, i.e. |
368 | SIGALRM. */ | |
369 | ||
20ef56db PE |
370 | static void |
371 | handle_alarm_signal (int sig) | |
170c80be | 372 | { |
325530de | 373 | pending_signals = 1; |
170c80be JD |
374 | } |
375 | ||
376 | ||
4d7e6e51 | 377 | /* Do pending timers. */ |
e12489f9 GM |
378 | |
379 | void | |
971de7fb | 380 | do_pending_atimers (void) |
e12489f9 | 381 | { |
4d7e6e51 | 382 | if (atimers) |
e12489f9 | 383 | { |
2fe28299 | 384 | block_atimers (); |
170c80be | 385 | run_timers (); |
2fe28299 | 386 | unblock_atimers (); |
e12489f9 GM |
387 | } |
388 | } | |
389 | ||
390 | ||
391 | /* Turn alarms on/off. This seems to be temporarily necessary on | |
392 | some systems like HPUX (see process.c). */ | |
393 | ||
394 | void | |
b1bb8011 | 395 | turn_on_atimers (bool on) |
e12489f9 GM |
396 | { |
397 | if (on) | |
4d7e6e51 | 398 | set_alarm (); |
e12489f9 GM |
399 | else |
400 | alarm (0); | |
401 | } | |
402 | ||
403 | ||
404 | void | |
971de7fb | 405 | init_atimer (void) |
e12489f9 | 406 | { |
2fe28299 | 407 | struct sigaction action; |
2b794d69 | 408 | #ifdef HAVE_ITIMERSPEC |
e26fd2e4 PE |
409 | struct sigevent sigev; |
410 | sigev.sigev_notify = SIGEV_SIGNAL; | |
411 | sigev.sigev_signo = SIGALRM; | |
412 | sigev.sigev_value.sival_ptr = &alarm_timer; | |
413 | alarm_timer_ok = timer_create (CLOCK_REALTIME, &sigev, &alarm_timer) == 0; | |
414 | #endif | |
bcdf96ba | 415 | free_atimers = stopped_atimers = atimers = NULL; |
325530de | 416 | /* pending_signals is initialized in init_keyboard.*/ |
4d7e6e51 | 417 | emacs_sigaction_init (&action, handle_alarm_signal); |
2fe28299 | 418 | sigaction (SIGALRM, &action, 0); |
e12489f9 | 419 | } |