xref: /openbmc/qemu/util/qemu-timer.c (revision 5cf3b48094e98c241fb86c5ea27c4c2e6f79a072)
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/osdep.h"
26 #include "qemu/main-loop.h"
27 #include "qemu/timer.h"
28 #include "qemu/lockable.h"
29 #include "sysemu/cpu-timers.h"
30 #include "sysemu/replay.h"
31 #include "sysemu/cpus.h"
32 
33 #ifdef CONFIG_POSIX
34 #include <pthread.h>
35 #endif
36 
37 #ifdef CONFIG_PPOLL
38 #include <poll.h>
39 #endif
40 
41 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
42 #include <sys/prctl.h>
43 #endif
44 
45 /***********************************************************/
46 /* timers */
47 
48 typedef struct QEMUClock {
49     /* We rely on BQL to protect the timerlists */
50     QLIST_HEAD(, QEMUTimerList) timerlists;
51 
52     QEMUClockType type;
53     bool enabled;
54 } QEMUClock;
55 
56 QEMUTimerListGroup main_loop_tlg;
57 static QEMUClock qemu_clocks[QEMU_CLOCK_MAX];
58 
59 /* A QEMUTimerList is a list of timers attached to a clock. More
60  * than one QEMUTimerList can be attached to each clock, for instance
61  * used by different AioContexts / threads. Each clock also has
62  * a list of the QEMUTimerLists associated with it, in order that
63  * reenabling the clock can call all the notifiers.
64  */
65 
66 struct QEMUTimerList {
67     QEMUClock *clock;
68     QemuMutex active_timers_lock;
69     QEMUTimer *active_timers;
70     QLIST_ENTRY(QEMUTimerList) list;
71     QEMUTimerListNotifyCB *notify_cb;
72     void *notify_opaque;
73 
74     /* lightweight method to mark the end of timerlist's running */
75     QemuEvent timers_done_ev;
76 };
77 
78 /**
79  * qemu_clock_ptr:
80  * @type: type of clock
81  *
82  * Translate a clock type into a pointer to QEMUClock object.
83  *
84  * Returns: a pointer to the QEMUClock object
85  */
qemu_clock_ptr(QEMUClockType type)86 static inline QEMUClock *qemu_clock_ptr(QEMUClockType type)
87 {
88     return &qemu_clocks[type];
89 }
90 
timer_expired_ns(QEMUTimer * timer_head,int64_t current_time)91 static bool timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
92 {
93     return timer_head && (timer_head->expire_time <= current_time);
94 }
95 
timerlist_new(QEMUClockType type,QEMUTimerListNotifyCB * cb,void * opaque)96 QEMUTimerList *timerlist_new(QEMUClockType type,
97                              QEMUTimerListNotifyCB *cb,
98                              void *opaque)
99 {
100     QEMUTimerList *timer_list;
101     QEMUClock *clock = qemu_clock_ptr(type);
102 
103     timer_list = g_new0(QEMUTimerList, 1);
104     qemu_event_init(&timer_list->timers_done_ev, true);
105     timer_list->clock = clock;
106     timer_list->notify_cb = cb;
107     timer_list->notify_opaque = opaque;
108     qemu_mutex_init(&timer_list->active_timers_lock);
109     QLIST_INSERT_HEAD(&clock->timerlists, timer_list, list);
110     return timer_list;
111 }
112 
timerlist_free(QEMUTimerList * timer_list)113 void timerlist_free(QEMUTimerList *timer_list)
114 {
115     assert(!timerlist_has_timers(timer_list));
116     if (timer_list->clock) {
117         QLIST_REMOVE(timer_list, list);
118     }
119     qemu_mutex_destroy(&timer_list->active_timers_lock);
120     g_free(timer_list);
121 }
122 
qemu_clock_init(QEMUClockType type,QEMUTimerListNotifyCB * notify_cb)123 static void qemu_clock_init(QEMUClockType type, QEMUTimerListNotifyCB *notify_cb)
124 {
125     QEMUClock *clock = qemu_clock_ptr(type);
126 
127     /* Assert that the clock of type TYPE has not been initialized yet. */
128     assert(main_loop_tlg.tl[type] == NULL);
129 
130     clock->type = type;
131     clock->enabled = (type == QEMU_CLOCK_VIRTUAL ? false : true);
132     QLIST_INIT(&clock->timerlists);
133     main_loop_tlg.tl[type] = timerlist_new(type, notify_cb, NULL);
134 }
135 
qemu_clock_use_for_deadline(QEMUClockType type)136 bool qemu_clock_use_for_deadline(QEMUClockType type)
137 {
138     return !(icount_enabled() && (type == QEMU_CLOCK_VIRTUAL));
139 }
140 
qemu_clock_notify(QEMUClockType type)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  */
qemu_clock_enable(QEMUClockType type,bool enabled)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 
timerlist_has_timers(QEMUTimerList * timer_list)172 bool timerlist_has_timers(QEMUTimerList *timer_list)
173 {
174     return !!qatomic_read(&timer_list->active_timers);
175 }
176 
qemu_clock_has_timers(QEMUClockType type)177 bool qemu_clock_has_timers(QEMUClockType type)
178 {
179     return timerlist_has_timers(
180         main_loop_tlg.tl[type]);
181 }
182 
timerlist_expired(QEMUTimerList * timer_list)183 bool timerlist_expired(QEMUTimerList *timer_list)
184 {
185     int64_t expire_time = 0;
186 
187     if (!qatomic_read(&timer_list->active_timers)) {
188         return false;
189     }
190 
191     WITH_QEMU_LOCK_GUARD(&timer_list->active_timers_lock) {
192         if (!timer_list->active_timers) {
193             return false;
194         }
195         expire_time = timer_list->active_timers->expire_time;
196     }
197 
198     return expire_time <= qemu_clock_get_ns(timer_list->clock->type);
199 }
200 
qemu_clock_expired(QEMUClockType type)201 bool qemu_clock_expired(QEMUClockType type)
202 {
203     return timerlist_expired(
204         main_loop_tlg.tl[type]);
205 }
206 
207 /*
208  * As above, but return -1 for no deadline, and do not cap to 2^32
209  * as we know the result is always positive.
210  */
211 
timerlist_deadline_ns(QEMUTimerList * timer_list)212 int64_t timerlist_deadline_ns(QEMUTimerList *timer_list)
213 {
214     int64_t delta;
215     int64_t expire_time = 0;
216 
217     if (!qatomic_read(&timer_list->active_timers)) {
218         return -1;
219     }
220 
221     if (!timer_list->clock->enabled) {
222         return -1;
223     }
224 
225     /* The active timers list may be modified before the caller uses our return
226      * value but ->notify_cb() is called when the deadline changes.  Therefore
227      * the caller should notice the change and there is no race condition.
228      */
229     WITH_QEMU_LOCK_GUARD(&timer_list->active_timers_lock) {
230         if (!timer_list->active_timers) {
231             return -1;
232         }
233         expire_time = timer_list->active_timers->expire_time;
234     }
235 
236     delta = expire_time - qemu_clock_get_ns(timer_list->clock->type);
237 
238     if (delta <= 0) {
239         return 0;
240     }
241 
242     return delta;
243 }
244 
245 /* Calculate the soonest deadline across all timerlists attached
246  * to the clock. This is used for the icount timeout so we
247  * ignore whether or not the clock should be used in deadline
248  * calculations.
249  */
qemu_clock_deadline_ns_all(QEMUClockType type,int attr_mask)250 int64_t qemu_clock_deadline_ns_all(QEMUClockType type, int attr_mask)
251 {
252     int64_t deadline = -1;
253     int64_t delta;
254     int64_t expire_time;
255     QEMUTimer *ts;
256     QEMUTimerList *timer_list;
257     QEMUClock *clock = qemu_clock_ptr(type);
258 
259     if (!clock->enabled) {
260         return -1;
261     }
262 
263     QLIST_FOREACH(timer_list, &clock->timerlists, list) {
264         if (!qatomic_read(&timer_list->active_timers)) {
265             continue;
266         }
267         qemu_mutex_lock(&timer_list->active_timers_lock);
268         ts = timer_list->active_timers;
269         /* Skip all external timers */
270         while (ts && (ts->attributes & ~attr_mask)) {
271             ts = ts->next;
272         }
273         if (!ts) {
274             qemu_mutex_unlock(&timer_list->active_timers_lock);
275             continue;
276         }
277         expire_time = ts->expire_time;
278         qemu_mutex_unlock(&timer_list->active_timers_lock);
279 
280         delta = expire_time - qemu_clock_get_ns(type);
281         if (delta <= 0) {
282             delta = 0;
283         }
284         deadline = qemu_soonest_timeout(deadline, delta);
285     }
286     return deadline;
287 }
288 
timerlist_notify(QEMUTimerList * timer_list)289 void timerlist_notify(QEMUTimerList *timer_list)
290 {
291     if (timer_list->notify_cb) {
292         timer_list->notify_cb(timer_list->notify_opaque, timer_list->clock->type);
293     } else {
294         qemu_notify_event();
295     }
296 }
297 
298 /* Transition function to convert a nanosecond timeout to ms
299  * This is used where a system does not support ppoll
300  */
qemu_timeout_ns_to_ms(int64_t ns)301 int qemu_timeout_ns_to_ms(int64_t ns)
302 {
303     int64_t ms;
304     if (ns < 0) {
305         return -1;
306     }
307 
308     if (!ns) {
309         return 0;
310     }
311 
312     /* Always round up, because it's better to wait too long than to wait too
313      * little and effectively busy-wait
314      */
315     ms = DIV_ROUND_UP(ns, SCALE_MS);
316 
317     /* To avoid overflow problems, limit this to 2^31, i.e. approx 25 days */
318     return MIN(ms, INT32_MAX);
319 }
320 
321 
322 /* qemu implementation of g_poll which uses a nanosecond timeout but is
323  * otherwise identical to g_poll
324  */
qemu_poll_ns(GPollFD * fds,guint nfds,int64_t timeout)325 int qemu_poll_ns(GPollFD *fds, guint nfds, int64_t timeout)
326 {
327 #ifdef CONFIG_PPOLL
328     if (timeout < 0) {
329         return ppoll((struct pollfd *)fds, nfds, NULL, NULL);
330     } else {
331         struct timespec ts;
332         int64_t tvsec = timeout / 1000000000LL;
333         /* Avoid possibly overflowing and specifying a negative number of
334          * seconds, which would turn a very long timeout into a busy-wait.
335          */
336         if (tvsec > (int64_t)INT32_MAX) {
337             tvsec = INT32_MAX;
338         }
339         ts.tv_sec = tvsec;
340         ts.tv_nsec = timeout % 1000000000LL;
341         return ppoll((struct pollfd *)fds, nfds, &ts, NULL);
342     }
343 #else
344     return g_poll(fds, nfds, qemu_timeout_ns_to_ms(timeout));
345 #endif
346 }
347 
348 
timer_init_full(QEMUTimer * ts,QEMUTimerListGroup * timer_list_group,QEMUClockType type,int scale,int attributes,QEMUTimerCB * cb,void * opaque)349 void timer_init_full(QEMUTimer *ts,
350                      QEMUTimerListGroup *timer_list_group, QEMUClockType type,
351                      int scale, int attributes,
352                      QEMUTimerCB *cb, void *opaque)
353 {
354     if (!timer_list_group) {
355         timer_list_group = &main_loop_tlg;
356     }
357     ts->timer_list = timer_list_group->tl[type];
358     ts->cb = cb;
359     ts->opaque = opaque;
360     ts->scale = scale;
361     ts->attributes = attributes;
362     ts->expire_time = -1;
363 }
364 
timer_deinit(QEMUTimer * ts)365 void timer_deinit(QEMUTimer *ts)
366 {
367     assert(ts->expire_time == -1);
368     ts->timer_list = NULL;
369 }
370 
timer_del_locked(QEMUTimerList * timer_list,QEMUTimer * ts)371 static void timer_del_locked(QEMUTimerList *timer_list, QEMUTimer *ts)
372 {
373     QEMUTimer **pt, *t;
374 
375     ts->expire_time = -1;
376     pt = &timer_list->active_timers;
377     for(;;) {
378         t = *pt;
379         if (!t)
380             break;
381         if (t == ts) {
382             qatomic_set(pt, t->next);
383             break;
384         }
385         pt = &t->next;
386     }
387 }
388 
timer_mod_ns_locked(QEMUTimerList * timer_list,QEMUTimer * ts,int64_t expire_time)389 static bool timer_mod_ns_locked(QEMUTimerList *timer_list,
390                                 QEMUTimer *ts, int64_t expire_time)
391 {
392     QEMUTimer **pt, *t;
393 
394     /* add the timer in the sorted list */
395     pt = &timer_list->active_timers;
396     for (;;) {
397         t = *pt;
398         if (!timer_expired_ns(t, expire_time)) {
399             break;
400         }
401         pt = &t->next;
402     }
403     ts->expire_time = MAX(expire_time, 0);
404     ts->next = *pt;
405     qatomic_set(pt, ts);
406 
407     return pt == &timer_list->active_timers;
408 }
409 
timerlist_rearm(QEMUTimerList * timer_list)410 static void timerlist_rearm(QEMUTimerList *timer_list)
411 {
412     timerlist_notify(timer_list);
413 }
414 
415 /* stop a timer, but do not dealloc it */
timer_del(QEMUTimer * ts)416 void timer_del(QEMUTimer *ts)
417 {
418     QEMUTimerList *timer_list = ts->timer_list;
419 
420     if (timer_list) {
421         qemu_mutex_lock(&timer_list->active_timers_lock);
422         timer_del_locked(timer_list, ts);
423         qemu_mutex_unlock(&timer_list->active_timers_lock);
424     }
425 }
426 
427 /* modify the current timer so that it will be fired when current_time
428    >= expire_time. The corresponding callback will be called. */
timer_mod_ns(QEMUTimer * ts,int64_t expire_time)429 void timer_mod_ns(QEMUTimer *ts, int64_t expire_time)
430 {
431     QEMUTimerList *timer_list = ts->timer_list;
432     bool rearm;
433 
434     qemu_mutex_lock(&timer_list->active_timers_lock);
435     timer_del_locked(timer_list, ts);
436     rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
437     qemu_mutex_unlock(&timer_list->active_timers_lock);
438 
439     if (rearm) {
440         timerlist_rearm(timer_list);
441     }
442 }
443 
444 /* modify the current timer so that it will be fired when current_time
445    >= expire_time or the current deadline, whichever comes earlier.
446    The corresponding callback will be called. */
timer_mod_anticipate_ns(QEMUTimer * ts,int64_t expire_time)447 void timer_mod_anticipate_ns(QEMUTimer *ts, int64_t expire_time)
448 {
449     QEMUTimerList *timer_list = ts->timer_list;
450     bool rearm = false;
451 
452     WITH_QEMU_LOCK_GUARD(&timer_list->active_timers_lock) {
453         if (ts->expire_time == -1 || ts->expire_time > expire_time) {
454             if (ts->expire_time != -1) {
455                 timer_del_locked(timer_list, ts);
456             }
457             rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
458         } else {
459             rearm = false;
460         }
461     }
462     if (rearm) {
463         timerlist_rearm(timer_list);
464     }
465 }
466 
timer_mod(QEMUTimer * ts,int64_t expire_time)467 void timer_mod(QEMUTimer *ts, int64_t expire_time)
468 {
469     timer_mod_ns(ts, expire_time * ts->scale);
470 }
471 
timer_mod_anticipate(QEMUTimer * ts,int64_t expire_time)472 void timer_mod_anticipate(QEMUTimer *ts, int64_t expire_time)
473 {
474     timer_mod_anticipate_ns(ts, expire_time * ts->scale);
475 }
476 
timer_pending(QEMUTimer * ts)477 bool timer_pending(QEMUTimer *ts)
478 {
479     return ts->expire_time >= 0;
480 }
481 
timer_expired(QEMUTimer * timer_head,int64_t current_time)482 bool timer_expired(QEMUTimer *timer_head, int64_t current_time)
483 {
484     return timer_expired_ns(timer_head, current_time * timer_head->scale);
485 }
486 
timerlist_run_timers(QEMUTimerList * timer_list)487 bool timerlist_run_timers(QEMUTimerList *timer_list)
488 {
489     QEMUTimer *ts;
490     int64_t current_time;
491     bool progress = false;
492     QEMUTimerCB *cb;
493     void *opaque;
494 
495     if (!qatomic_read(&timer_list->active_timers)) {
496         return false;
497     }
498 
499     qemu_event_reset(&timer_list->timers_done_ev);
500     if (!timer_list->clock->enabled) {
501         goto out;
502     }
503 
504     switch (timer_list->clock->type) {
505     case QEMU_CLOCK_REALTIME:
506         break;
507     default:
508     case QEMU_CLOCK_VIRTUAL:
509         break;
510     case QEMU_CLOCK_HOST:
511         if (!replay_checkpoint(CHECKPOINT_CLOCK_HOST)) {
512             goto out;
513         }
514         break;
515     case QEMU_CLOCK_VIRTUAL_RT:
516         if (!replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL_RT)) {
517             goto out;
518         }
519         break;
520     }
521 
522     /*
523      * Extract expired timers from active timers list and process them.
524      *
525      * In rr mode we need "filtered" checkpointing for virtual clock.  The
526      * checkpoint must be recorded/replayed before processing any non-EXTERNAL timer,
527      * and that must only be done once since the clock value stays the same. Because
528      * non-EXTERNAL timers may appear in the timers list while it being processed,
529      * the checkpoint can be issued at a time until no timers are left and we are
530      * done".
531      */
532     current_time = qemu_clock_get_ns(timer_list->clock->type);
533     qemu_mutex_lock(&timer_list->active_timers_lock);
534     while ((ts = timer_list->active_timers)) {
535         if (!timer_expired_ns(ts, current_time)) {
536             /* No expired timers left.  The checkpoint can be skipped
537              * if no timers fired or they were all external.
538              */
539             break;
540         }
541         /* Checkpoint for virtual clock is redundant in cases where
542          * it's being triggered with only non-EXTERNAL timers, because
543          * these timers don't change guest state directly.
544          */
545         if (replay_mode != REPLAY_MODE_NONE
546             && timer_list->clock->type == QEMU_CLOCK_VIRTUAL
547             && !(ts->attributes & QEMU_TIMER_ATTR_EXTERNAL)
548             && !replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL)) {
549             qemu_mutex_unlock(&timer_list->active_timers_lock);
550             goto out;
551         }
552 
553         /* remove timer from the list before calling the callback */
554         timer_list->active_timers = ts->next;
555         ts->next = NULL;
556         ts->expire_time = -1;
557         cb = ts->cb;
558         opaque = ts->opaque;
559 
560         /* run the callback (the timer list can be modified) */
561         qemu_mutex_unlock(&timer_list->active_timers_lock);
562         cb(opaque);
563         qemu_mutex_lock(&timer_list->active_timers_lock);
564 
565         progress = true;
566     }
567     qemu_mutex_unlock(&timer_list->active_timers_lock);
568 
569 out:
570     qemu_event_set(&timer_list->timers_done_ev);
571     return progress;
572 }
573 
qemu_clock_run_timers(QEMUClockType type)574 bool qemu_clock_run_timers(QEMUClockType type)
575 {
576     return timerlist_run_timers(main_loop_tlg.tl[type]);
577 }
578 
timerlistgroup_init(QEMUTimerListGroup * tlg,QEMUTimerListNotifyCB * cb,void * opaque)579 void timerlistgroup_init(QEMUTimerListGroup *tlg,
580                          QEMUTimerListNotifyCB *cb, void *opaque)
581 {
582     QEMUClockType type;
583     for (type = 0; type < QEMU_CLOCK_MAX; type++) {
584         tlg->tl[type] = timerlist_new(type, cb, opaque);
585     }
586 }
587 
timerlistgroup_deinit(QEMUTimerListGroup * tlg)588 void timerlistgroup_deinit(QEMUTimerListGroup *tlg)
589 {
590     QEMUClockType type;
591     for (type = 0; type < QEMU_CLOCK_MAX; type++) {
592         timerlist_free(tlg->tl[type]);
593     }
594 }
595 
timerlistgroup_run_timers(QEMUTimerListGroup * tlg)596 bool timerlistgroup_run_timers(QEMUTimerListGroup *tlg)
597 {
598     QEMUClockType type;
599     bool progress = false;
600     for (type = 0; type < QEMU_CLOCK_MAX; type++) {
601         progress |= timerlist_run_timers(tlg->tl[type]);
602     }
603     return progress;
604 }
605 
timerlistgroup_deadline_ns(QEMUTimerListGroup * tlg)606 int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup *tlg)
607 {
608     int64_t deadline = -1;
609     QEMUClockType type;
610     for (type = 0; type < QEMU_CLOCK_MAX; type++) {
611         if (qemu_clock_use_for_deadline(type)) {
612             deadline = qemu_soonest_timeout(deadline,
613                                             timerlist_deadline_ns(tlg->tl[type]));
614         }
615     }
616     return deadline;
617 }
618 
qemu_clock_get_ns(QEMUClockType type)619 int64_t qemu_clock_get_ns(QEMUClockType type)
620 {
621     switch (type) {
622     case QEMU_CLOCK_REALTIME:
623         return get_clock();
624     default:
625     case QEMU_CLOCK_VIRTUAL:
626         return cpus_get_virtual_clock();
627     case QEMU_CLOCK_HOST:
628         return REPLAY_CLOCK(REPLAY_CLOCK_HOST, get_clock_realtime());
629     case QEMU_CLOCK_VIRTUAL_RT:
630         return REPLAY_CLOCK(REPLAY_CLOCK_VIRTUAL_RT, cpu_get_clock());
631     }
632 }
633 
qemu_virtual_clock_set_ns(int64_t time)634 static void qemu_virtual_clock_set_ns(int64_t time)
635 {
636     return cpus_set_virtual_clock(time);
637 }
638 
init_clocks(QEMUTimerListNotifyCB * notify_cb)639 void init_clocks(QEMUTimerListNotifyCB *notify_cb)
640 {
641     QEMUClockType type;
642     for (type = 0; type < QEMU_CLOCK_MAX; type++) {
643         qemu_clock_init(type, notify_cb);
644     }
645 
646 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
647     prctl(PR_SET_TIMERSLACK, 1, 0, 0, 0);
648 #endif
649 }
650 
timer_expire_time_ns(QEMUTimer * ts)651 uint64_t timer_expire_time_ns(QEMUTimer *ts)
652 {
653     return timer_pending(ts) ? ts->expire_time : -1;
654 }
655 
qemu_clock_run_all_timers(void)656 bool qemu_clock_run_all_timers(void)
657 {
658     bool progress = false;
659     QEMUClockType type;
660 
661     for (type = 0; type < QEMU_CLOCK_MAX; type++) {
662         if (qemu_clock_use_for_deadline(type)) {
663             progress |= qemu_clock_run_timers(type);
664         }
665     }
666 
667     return progress;
668 }
669 
qemu_clock_advance_virtual_time(int64_t dest)670 int64_t qemu_clock_advance_virtual_time(int64_t dest)
671 {
672     int64_t clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
673     AioContext *aio_context;
674     int64_t deadline;
675 
676     aio_context = qemu_get_aio_context();
677 
678     deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL,
679                                                       QEMU_TIMER_ATTR_ALL);
680     /*
681      * A deadline of < 0 indicates this timer is not enabled, so we
682      * won't get far trying to run it forward.
683      */
684     while (deadline >= 0 && clock < dest) {
685         int64_t warp = qemu_soonest_timeout(dest - clock, deadline);
686 
687         qemu_virtual_clock_set_ns(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + warp);
688 
689         qemu_clock_run_timers(QEMU_CLOCK_VIRTUAL);
690         timerlist_run_timers(aio_context->tlg.tl[QEMU_CLOCK_VIRTUAL]);
691         clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
692 
693         deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL,
694                                               QEMU_TIMER_ATTR_ALL);
695     }
696     qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
697 
698     return clock;
699 }
700