hw/net: fix mcf_fec driver receiver
[qemu.git] / qemu-timer.c
1 /*
2 * QEMU System Emulator
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25 #include "qemu/main-loop.h"
26 #include "qemu/timer.h"
27
28 #ifdef CONFIG_POSIX
29 #include <pthread.h>
30 #endif
31
32 #ifdef CONFIG_PPOLL
33 #include <poll.h>
34 #endif
35
36 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
37 #include <sys/prctl.h>
38 #endif
39
40 /***********************************************************/
41 /* timers */
42
43 typedef struct QEMUClock {
44 /* We rely on BQL to protect the timerlists */
45 QLIST_HEAD(, QEMUTimerList) timerlists;
46
47 NotifierList reset_notifiers;
48 int64_t last;
49
50 QEMUClockType type;
51 bool enabled;
52 } QEMUClock;
53
54 QEMUTimerListGroup main_loop_tlg;
55 static QEMUClock qemu_clocks[QEMU_CLOCK_MAX];
56
57 /* A QEMUTimerList is a list of timers attached to a clock. More
58 * than one QEMUTimerList can be attached to each clock, for instance
59 * used by different AioContexts / threads. Each clock also has
60 * a list of the QEMUTimerLists associated with it, in order that
61 * reenabling the clock can call all the notifiers.
62 */
63
64 struct QEMUTimerList {
65 QEMUClock *clock;
66 QemuMutex active_timers_lock;
67 QEMUTimer *active_timers;
68 QLIST_ENTRY(QEMUTimerList) list;
69 QEMUTimerListNotifyCB *notify_cb;
70 void *notify_opaque;
71
72 /* lightweight method to mark the end of timerlist's running */
73 QemuEvent timers_done_ev;
74 };
75
76 /**
77 * qemu_clock_ptr:
78 * @type: type of clock
79 *
80 * Translate a clock type into a pointer to QEMUClock object.
81 *
82 * Returns: a pointer to the QEMUClock object
83 */
84 static inline QEMUClock *qemu_clock_ptr(QEMUClockType type)
85 {
86 return &qemu_clocks[type];
87 }
88
89 static bool timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
90 {
91 return timer_head && (timer_head->expire_time <= current_time);
92 }
93
94 QEMUTimerList *timerlist_new(QEMUClockType type,
95 QEMUTimerListNotifyCB *cb,
96 void *opaque)
97 {
98 QEMUTimerList *timer_list;
99 QEMUClock *clock = qemu_clock_ptr(type);
100
101 timer_list = g_malloc0(sizeof(QEMUTimerList));
102 qemu_event_init(&timer_list->timers_done_ev, true);
103 timer_list->clock = clock;
104 timer_list->notify_cb = cb;
105 timer_list->notify_opaque = opaque;
106 qemu_mutex_init(&timer_list->active_timers_lock);
107 QLIST_INSERT_HEAD(&clock->timerlists, timer_list, list);
108 return timer_list;
109 }
110
111 void timerlist_free(QEMUTimerList *timer_list)
112 {
113 assert(!timerlist_has_timers(timer_list));
114 if (timer_list->clock) {
115 QLIST_REMOVE(timer_list, list);
116 }
117 qemu_mutex_destroy(&timer_list->active_timers_lock);
118 g_free(timer_list);
119 }
120
121 static void qemu_clock_init(QEMUClockType type)
122 {
123 QEMUClock *clock = qemu_clock_ptr(type);
124
125 /* Assert that the clock of type TYPE has not been initialized yet. */
126 assert(main_loop_tlg.tl[type] == NULL);
127
128 clock->type = type;
129 clock->enabled = true;
130 clock->last = INT64_MIN;
131 QLIST_INIT(&clock->timerlists);
132 notifier_list_init(&clock->reset_notifiers);
133 main_loop_tlg.tl[type] = timerlist_new(type, NULL, NULL);
134 }
135
136 bool qemu_clock_use_for_deadline(QEMUClockType type)
137 {
138 return !(use_icount && (type == QEMU_CLOCK_VIRTUAL));
139 }
140
141 void qemu_clock_notify(QEMUClockType type)
142 {
143 QEMUTimerList *timer_list;
144 QEMUClock *clock = qemu_clock_ptr(type);
145 QLIST_FOREACH(timer_list, &clock->timerlists, list) {
146 timerlist_notify(timer_list);
147 }
148 }
149
150 /* Disabling the clock will wait for related timerlists to stop
151 * executing qemu_run_timers. Thus, this functions should not
152 * be used from the callback of a timer that is based on @clock.
153 * Doing so would cause a deadlock.
154 *
155 * Caller should hold BQL.
156 */
157 void qemu_clock_enable(QEMUClockType type, bool enabled)
158 {
159 QEMUClock *clock = qemu_clock_ptr(type);
160 QEMUTimerList *tl;
161 bool old = clock->enabled;
162 clock->enabled = enabled;
163 if (enabled && !old) {
164 qemu_clock_notify(type);
165 } else if (!enabled && old) {
166 QLIST_FOREACH(tl, &clock->timerlists, list) {
167 qemu_event_wait(&tl->timers_done_ev);
168 }
169 }
170 }
171
172 bool timerlist_has_timers(QEMUTimerList *timer_list)
173 {
174 return !!timer_list->active_timers;
175 }
176
177 bool qemu_clock_has_timers(QEMUClockType type)
178 {
179 return timerlist_has_timers(
180 main_loop_tlg.tl[type]);
181 }
182
183 bool timerlist_expired(QEMUTimerList *timer_list)
184 {
185 int64_t expire_time;
186
187 qemu_mutex_lock(&timer_list->active_timers_lock);
188 if (!timer_list->active_timers) {
189 qemu_mutex_unlock(&timer_list->active_timers_lock);
190 return false;
191 }
192 expire_time = timer_list->active_timers->expire_time;
193 qemu_mutex_unlock(&timer_list->active_timers_lock);
194
195 return expire_time < qemu_clock_get_ns(timer_list->clock->type);
196 }
197
198 bool qemu_clock_expired(QEMUClockType type)
199 {
200 return timerlist_expired(
201 main_loop_tlg.tl[type]);
202 }
203
204 /*
205 * As above, but return -1 for no deadline, and do not cap to 2^32
206 * as we know the result is always positive.
207 */
208
209 int64_t timerlist_deadline_ns(QEMUTimerList *timer_list)
210 {
211 int64_t delta;
212 int64_t expire_time;
213
214 if (!timer_list->clock->enabled) {
215 return -1;
216 }
217
218 /* The active timers list may be modified before the caller uses our return
219 * value but ->notify_cb() is called when the deadline changes. Therefore
220 * the caller should notice the change and there is no race condition.
221 */
222 qemu_mutex_lock(&timer_list->active_timers_lock);
223 if (!timer_list->active_timers) {
224 qemu_mutex_unlock(&timer_list->active_timers_lock);
225 return -1;
226 }
227 expire_time = timer_list->active_timers->expire_time;
228 qemu_mutex_unlock(&timer_list->active_timers_lock);
229
230 delta = expire_time - qemu_clock_get_ns(timer_list->clock->type);
231
232 if (delta <= 0) {
233 return 0;
234 }
235
236 return delta;
237 }
238
239 /* Calculate the soonest deadline across all timerlists attached
240 * to the clock. This is used for the icount timeout so we
241 * ignore whether or not the clock should be used in deadline
242 * calculations.
243 */
244 int64_t qemu_clock_deadline_ns_all(QEMUClockType type)
245 {
246 int64_t deadline = -1;
247 QEMUTimerList *timer_list;
248 QEMUClock *clock = qemu_clock_ptr(type);
249 QLIST_FOREACH(timer_list, &clock->timerlists, list) {
250 deadline = qemu_soonest_timeout(deadline,
251 timerlist_deadline_ns(timer_list));
252 }
253 return deadline;
254 }
255
256 QEMUClockType timerlist_get_clock(QEMUTimerList *timer_list)
257 {
258 return timer_list->clock->type;
259 }
260
261 QEMUTimerList *qemu_clock_get_main_loop_timerlist(QEMUClockType type)
262 {
263 return main_loop_tlg.tl[type];
264 }
265
266 void timerlist_notify(QEMUTimerList *timer_list)
267 {
268 if (timer_list->notify_cb) {
269 timer_list->notify_cb(timer_list->notify_opaque);
270 } else {
271 qemu_notify_event();
272 }
273 }
274
275 /* Transition function to convert a nanosecond timeout to ms
276 * This is used where a system does not support ppoll
277 */
278 int qemu_timeout_ns_to_ms(int64_t ns)
279 {
280 int64_t ms;
281 if (ns < 0) {
282 return -1;
283 }
284
285 if (!ns) {
286 return 0;
287 }
288
289 /* Always round up, because it's better to wait too long than to wait too
290 * little and effectively busy-wait
291 */
292 ms = (ns + SCALE_MS - 1) / SCALE_MS;
293
294 /* To avoid overflow problems, limit this to 2^31, i.e. approx 25 days */
295 if (ms > (int64_t) INT32_MAX) {
296 ms = INT32_MAX;
297 }
298
299 return (int) ms;
300 }
301
302
303 /* qemu implementation of g_poll which uses a nanosecond timeout but is
304 * otherwise identical to g_poll
305 */
306 int qemu_poll_ns(GPollFD *fds, guint nfds, int64_t timeout)
307 {
308 #ifdef CONFIG_PPOLL
309 if (timeout < 0) {
310 return ppoll((struct pollfd *)fds, nfds, NULL, NULL);
311 } else {
312 struct timespec ts;
313 int64_t tvsec = timeout / 1000000000LL;
314 /* Avoid possibly overflowing and specifying a negative number of
315 * seconds, which would turn a very long timeout into a busy-wait.
316 */
317 if (tvsec > (int64_t)INT32_MAX) {
318 tvsec = INT32_MAX;
319 }
320 ts.tv_sec = tvsec;
321 ts.tv_nsec = timeout % 1000000000LL;
322 return ppoll((struct pollfd *)fds, nfds, &ts, NULL);
323 }
324 #else
325 return g_poll(fds, nfds, qemu_timeout_ns_to_ms(timeout));
326 #endif
327 }
328
329
330 void timer_init_tl(QEMUTimer *ts,
331 QEMUTimerList *timer_list, int scale,
332 QEMUTimerCB *cb, void *opaque)
333 {
334 ts->timer_list = timer_list;
335 ts->cb = cb;
336 ts->opaque = opaque;
337 ts->scale = scale;
338 ts->expire_time = -1;
339 }
340
341 void timer_deinit(QEMUTimer *ts)
342 {
343 assert(ts->expire_time == -1);
344 ts->timer_list = NULL;
345 }
346
347 void timer_free(QEMUTimer *ts)
348 {
349 g_free(ts);
350 }
351
352 static void timer_del_locked(QEMUTimerList *timer_list, QEMUTimer *ts)
353 {
354 QEMUTimer **pt, *t;
355
356 ts->expire_time = -1;
357 pt = &timer_list->active_timers;
358 for(;;) {
359 t = *pt;
360 if (!t)
361 break;
362 if (t == ts) {
363 *pt = t->next;
364 break;
365 }
366 pt = &t->next;
367 }
368 }
369
370 static bool timer_mod_ns_locked(QEMUTimerList *timer_list,
371 QEMUTimer *ts, int64_t expire_time)
372 {
373 QEMUTimer **pt, *t;
374
375 /* add the timer in the sorted list */
376 pt = &timer_list->active_timers;
377 for (;;) {
378 t = *pt;
379 if (!timer_expired_ns(t, expire_time)) {
380 break;
381 }
382 pt = &t->next;
383 }
384 ts->expire_time = MAX(expire_time, 0);
385 ts->next = *pt;
386 *pt = ts;
387
388 return pt == &timer_list->active_timers;
389 }
390
391 static void timerlist_rearm(QEMUTimerList *timer_list)
392 {
393 /* Interrupt execution to force deadline recalculation. */
394 qemu_clock_warp(timer_list->clock->type);
395 timerlist_notify(timer_list);
396 }
397
398 /* stop a timer, but do not dealloc it */
399 void timer_del(QEMUTimer *ts)
400 {
401 QEMUTimerList *timer_list = ts->timer_list;
402
403 if (timer_list) {
404 qemu_mutex_lock(&timer_list->active_timers_lock);
405 timer_del_locked(timer_list, ts);
406 qemu_mutex_unlock(&timer_list->active_timers_lock);
407 }
408 }
409
410 /* modify the current timer so that it will be fired when current_time
411 >= expire_time. The corresponding callback will be called. */
412 void timer_mod_ns(QEMUTimer *ts, int64_t expire_time)
413 {
414 QEMUTimerList *timer_list = ts->timer_list;
415 bool rearm;
416
417 qemu_mutex_lock(&timer_list->active_timers_lock);
418 timer_del_locked(timer_list, ts);
419 rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
420 qemu_mutex_unlock(&timer_list->active_timers_lock);
421
422 if (rearm) {
423 timerlist_rearm(timer_list);
424 }
425 }
426
427 /* modify the current timer so that it will be fired when current_time
428 >= expire_time or the current deadline, whichever comes earlier.
429 The corresponding callback will be called. */
430 void timer_mod_anticipate_ns(QEMUTimer *ts, int64_t expire_time)
431 {
432 QEMUTimerList *timer_list = ts->timer_list;
433 bool rearm;
434
435 qemu_mutex_lock(&timer_list->active_timers_lock);
436 if (ts->expire_time == -1 || ts->expire_time > expire_time) {
437 if (ts->expire_time != -1) {
438 timer_del_locked(timer_list, ts);
439 }
440 rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
441 } else {
442 rearm = false;
443 }
444 qemu_mutex_unlock(&timer_list->active_timers_lock);
445
446 if (rearm) {
447 timerlist_rearm(timer_list);
448 }
449 }
450
451 void timer_mod(QEMUTimer *ts, int64_t expire_time)
452 {
453 timer_mod_ns(ts, expire_time * ts->scale);
454 }
455
456 void timer_mod_anticipate(QEMUTimer *ts, int64_t expire_time)
457 {
458 timer_mod_anticipate_ns(ts, expire_time * ts->scale);
459 }
460
461 bool timer_pending(QEMUTimer *ts)
462 {
463 return ts->expire_time >= 0;
464 }
465
466 bool timer_expired(QEMUTimer *timer_head, int64_t current_time)
467 {
468 return timer_expired_ns(timer_head, current_time * timer_head->scale);
469 }
470
471 bool timerlist_run_timers(QEMUTimerList *timer_list)
472 {
473 QEMUTimer *ts;
474 int64_t current_time;
475 bool progress = false;
476 QEMUTimerCB *cb;
477 void *opaque;
478
479 qemu_event_reset(&timer_list->timers_done_ev);
480 if (!timer_list->clock->enabled) {
481 goto out;
482 }
483
484 current_time = qemu_clock_get_ns(timer_list->clock->type);
485 for(;;) {
486 qemu_mutex_lock(&timer_list->active_timers_lock);
487 ts = timer_list->active_timers;
488 if (!timer_expired_ns(ts, current_time)) {
489 qemu_mutex_unlock(&timer_list->active_timers_lock);
490 break;
491 }
492
493 /* remove timer from the list before calling the callback */
494 timer_list->active_timers = ts->next;
495 ts->next = NULL;
496 ts->expire_time = -1;
497 cb = ts->cb;
498 opaque = ts->opaque;
499 qemu_mutex_unlock(&timer_list->active_timers_lock);
500
501 /* run the callback (the timer list can be modified) */
502 cb(opaque);
503 progress = true;
504 }
505
506 out:
507 qemu_event_set(&timer_list->timers_done_ev);
508 return progress;
509 }
510
511 bool qemu_clock_run_timers(QEMUClockType type)
512 {
513 return timerlist_run_timers(main_loop_tlg.tl[type]);
514 }
515
516 void timerlistgroup_init(QEMUTimerListGroup *tlg,
517 QEMUTimerListNotifyCB *cb, void *opaque)
518 {
519 QEMUClockType type;
520 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
521 tlg->tl[type] = timerlist_new(type, cb, opaque);
522 }
523 }
524
525 void timerlistgroup_deinit(QEMUTimerListGroup *tlg)
526 {
527 QEMUClockType type;
528 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
529 timerlist_free(tlg->tl[type]);
530 }
531 }
532
533 bool timerlistgroup_run_timers(QEMUTimerListGroup *tlg)
534 {
535 QEMUClockType type;
536 bool progress = false;
537 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
538 progress |= timerlist_run_timers(tlg->tl[type]);
539 }
540 return progress;
541 }
542
543 int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup *tlg)
544 {
545 int64_t deadline = -1;
546 QEMUClockType type;
547 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
548 if (qemu_clock_use_for_deadline(tlg->tl[type]->clock->type)) {
549 deadline = qemu_soonest_timeout(deadline,
550 timerlist_deadline_ns(
551 tlg->tl[type]));
552 }
553 }
554 return deadline;
555 }
556
557 int64_t qemu_clock_get_ns(QEMUClockType type)
558 {
559 int64_t now, last;
560 QEMUClock *clock = qemu_clock_ptr(type);
561
562 switch (type) {
563 case QEMU_CLOCK_REALTIME:
564 return get_clock();
565 default:
566 case QEMU_CLOCK_VIRTUAL:
567 if (use_icount) {
568 return cpu_get_icount();
569 } else {
570 return cpu_get_clock();
571 }
572 case QEMU_CLOCK_HOST:
573 now = get_clock_realtime();
574 last = clock->last;
575 clock->last = now;
576 if (now < last || now > (last + get_max_clock_jump())) {
577 notifier_list_notify(&clock->reset_notifiers, &now);
578 }
579 return now;
580 case QEMU_CLOCK_VIRTUAL_RT:
581 return cpu_get_clock();
582 }
583 }
584
585 void qemu_clock_register_reset_notifier(QEMUClockType type,
586 Notifier *notifier)
587 {
588 QEMUClock *clock = qemu_clock_ptr(type);
589 notifier_list_add(&clock->reset_notifiers, notifier);
590 }
591
592 void qemu_clock_unregister_reset_notifier(QEMUClockType type,
593 Notifier *notifier)
594 {
595 notifier_remove(notifier);
596 }
597
598 void init_clocks(void)
599 {
600 QEMUClockType type;
601 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
602 qemu_clock_init(type);
603 }
604
605 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
606 prctl(PR_SET_TIMERSLACK, 1, 0, 0, 0);
607 #endif
608 }
609
610 uint64_t timer_expire_time_ns(QEMUTimer *ts)
611 {
612 return timer_pending(ts) ? ts->expire_time : -1;
613 }
614
615 bool qemu_clock_run_all_timers(void)
616 {
617 bool progress = false;
618 QEMUClockType type;
619
620 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
621 progress |= qemu_clock_run_timers(type);
622 }
623
624 return progress;
625 }