4 * Copyright (c) 2003-2008 Fabrice Bellard
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:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
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
25 #include "sysemu/sysemu.h"
26 #include "monitor/monitor.h"
27 #include "ui/console.h"
31 #include "qemu/timer.h"
44 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
45 #include <sys/prctl.h>
48 /***********************************************************/
52 QEMUTimerList *main_loop_timerlist;
53 QLIST_HEAD(, QEMUTimerList) timerlists;
55 NotifierList reset_notifiers;
62 QEMUTimerListGroup main_loop_tlg;
63 QEMUClock *qemu_clocks[QEMU_CLOCK_MAX];
65 /* A QEMUTimerList is a list of timers attached to a clock. More
66 * than one QEMUTimerList can be attached to each clock, for instance
67 * used by different AioContexts / threads. Each clock also has
68 * a list of the QEMUTimerLists associated with it, in order that
69 * reenabling the clock can call all the notifiers.
72 struct QEMUTimerList {
74 QEMUTimer *active_timers;
75 QLIST_ENTRY(QEMUTimerList) list;
76 QEMUTimerListNotifyCB *notify_cb;
80 struct qemu_alarm_timer {
82 int (*start)(struct qemu_alarm_timer *t);
83 void (*stop)(struct qemu_alarm_timer *t);
84 void (*rearm)(struct qemu_alarm_timer *t, int64_t nearest_delta_ns);
85 #if defined(__linux__)
95 static struct qemu_alarm_timer *alarm_timer;
97 static bool timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
99 return timer_head && (timer_head->expire_time <= current_time);
102 static int64_t qemu_next_alarm_deadline(void)
104 int64_t delta = INT64_MAX;
108 if (!use_icount && vm_clock->enabled &&
109 vm_clock->main_loop_timerlist->active_timers) {
110 delta = vm_clock->main_loop_timerlist->active_timers->expire_time -
111 qemu_get_clock_ns(vm_clock);
113 if (host_clock->enabled &&
114 host_clock->main_loop_timerlist->active_timers) {
115 hdelta = host_clock->main_loop_timerlist->active_timers->expire_time -
116 qemu_get_clock_ns(host_clock);
117 if (hdelta < delta) {
121 if (rt_clock->enabled &&
122 rt_clock->main_loop_timerlist->active_timers) {
123 rtdelta = (rt_clock->main_loop_timerlist->active_timers->expire_time -
124 qemu_get_clock_ns(rt_clock));
125 if (rtdelta < delta) {
133 static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)
135 int64_t nearest_delta_ns = qemu_next_alarm_deadline();
136 if (nearest_delta_ns < INT64_MAX) {
137 t->rearm(t, nearest_delta_ns);
141 /* TODO: MIN_TIMER_REARM_NS should be optimized */
142 #define MIN_TIMER_REARM_NS 250000
146 static int mm_start_timer(struct qemu_alarm_timer *t);
147 static void mm_stop_timer(struct qemu_alarm_timer *t);
148 static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
150 static int win32_start_timer(struct qemu_alarm_timer *t);
151 static void win32_stop_timer(struct qemu_alarm_timer *t);
152 static void win32_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
156 static int unix_start_timer(struct qemu_alarm_timer *t);
157 static void unix_stop_timer(struct qemu_alarm_timer *t);
158 static void unix_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
162 static int dynticks_start_timer(struct qemu_alarm_timer *t);
163 static void dynticks_stop_timer(struct qemu_alarm_timer *t);
164 static void dynticks_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
166 #endif /* __linux__ */
170 static struct qemu_alarm_timer alarm_timers[] = {
173 {"dynticks", dynticks_start_timer,
174 dynticks_stop_timer, dynticks_rearm_timer},
176 {"unix", unix_start_timer, unix_stop_timer, unix_rearm_timer},
178 {"mmtimer", mm_start_timer, mm_stop_timer, mm_rearm_timer},
179 {"dynticks", win32_start_timer, win32_stop_timer, win32_rearm_timer},
184 static void show_available_alarms(void)
188 printf("Available alarm timers, in order of precedence:\n");
189 for (i = 0; alarm_timers[i].name; i++)
190 printf("%s\n", alarm_timers[i].name);
193 void configure_alarms(char const *opt)
197 int count = ARRAY_SIZE(alarm_timers) - 1;
200 struct qemu_alarm_timer tmp;
202 if (is_help_option(opt)) {
203 show_available_alarms();
209 /* Reorder the array */
210 name = strtok(arg, ",");
212 for (i = 0; i < count && alarm_timers[i].name; i++) {
213 if (!strcmp(alarm_timers[i].name, name))
218 fprintf(stderr, "Unknown clock %s\n", name);
227 tmp = alarm_timers[i];
228 alarm_timers[i] = alarm_timers[cur];
229 alarm_timers[cur] = tmp;
233 name = strtok(NULL, ",");
239 /* Disable remaining timers */
240 for (i = cur; i < count; i++)
241 alarm_timers[i].name = NULL;
243 show_available_alarms();
248 static QEMUTimerList *timerlist_new_from_clock(QEMUClock *clock,
249 QEMUTimerListNotifyCB *cb,
252 QEMUTimerList *timer_list;
254 /* Assert if we do not have a clock. If you see this
255 * assertion in means that the clocks have not been
256 * initialised before a timerlist is needed. This
257 * normally happens if an AioContext is used before
258 * init_clocks() is called within main().
262 timer_list = g_malloc0(sizeof(QEMUTimerList));
263 timer_list->clock = clock;
264 timer_list->notify_cb = cb;
265 timer_list->notify_opaque = opaque;
266 QLIST_INSERT_HEAD(&clock->timerlists, timer_list, list);
270 QEMUTimerList *timerlist_new(QEMUClockType type,
271 QEMUTimerListNotifyCB *cb, void *opaque)
273 return timerlist_new_from_clock(qemu_clock_ptr(type), cb, opaque);
276 void timerlist_free(QEMUTimerList *timer_list)
278 assert(!timerlist_has_timers(timer_list));
279 if (timer_list->clock) {
280 QLIST_REMOVE(timer_list, list);
281 if (timer_list->clock->main_loop_timerlist == timer_list) {
282 timer_list->clock->main_loop_timerlist = NULL;
288 static QEMUClock *qemu_clock_new(QEMUClockType type)
292 clock = g_malloc0(sizeof(QEMUClock));
294 clock->enabled = true;
295 clock->last = INT64_MIN;
296 QLIST_INIT(&clock->timerlists);
297 notifier_list_init(&clock->reset_notifiers);
298 clock->main_loop_timerlist = timerlist_new_from_clock(clock, NULL, NULL);
302 bool qemu_clock_use_for_deadline(QEMUClock *clock)
304 return !(use_icount && (clock->type == QEMU_CLOCK_VIRTUAL));
307 void qemu_clock_notify(QEMUClock *clock)
309 QEMUTimerList *timer_list;
310 QLIST_FOREACH(timer_list, &clock->timerlists, list) {
311 timerlist_notify(timer_list);
315 void qemu_clock_enable(QEMUClock *clock, bool enabled)
317 bool old = clock->enabled;
318 clock->enabled = enabled;
319 if (enabled && !old) {
320 qemu_clock_notify(clock);
321 qemu_rearm_alarm_timer(alarm_timer);
325 bool timerlist_has_timers(QEMUTimerList *timer_list)
327 return !!timer_list->active_timers;
330 bool qemu_clock_has_timers(QEMUClock *clock)
332 return timerlist_has_timers(clock->main_loop_timerlist);
335 bool timerlist_expired(QEMUTimerList *timer_list)
337 return (timer_list->active_timers &&
338 timer_list->active_timers->expire_time <
339 qemu_get_clock_ns(timer_list->clock));
342 bool qemu_clock_expired(QEMUClock *clock)
344 return timerlist_expired(clock->main_loop_timerlist);
347 int64_t timerlist_deadline(QEMUTimerList *timer_list)
349 /* To avoid problems with overflow limit this to 2^32. */
350 int64_t delta = INT32_MAX;
352 if (timer_list->clock->enabled && timer_list->active_timers) {
353 delta = timer_list->active_timers->expire_time -
354 qemu_get_clock_ns(timer_list->clock);
362 int64_t qemu_clock_deadline(QEMUClock *clock)
364 return timerlist_deadline(clock->main_loop_timerlist);
368 * As above, but return -1 for no deadline, and do not cap to 2^32
369 * as we know the result is always positive.
372 int64_t timerlist_deadline_ns(QEMUTimerList *timer_list)
376 if (!timer_list->clock->enabled || !timer_list->active_timers) {
380 delta = timer_list->active_timers->expire_time -
381 qemu_get_clock_ns(timer_list->clock);
390 int64_t qemu_clock_deadline_ns(QEMUClock *clock)
392 return timerlist_deadline_ns(clock->main_loop_timerlist);
395 QEMUClock *timerlist_get_clock(QEMUTimerList *timer_list)
397 return timer_list->clock;
400 QEMUTimerList *qemu_clock_get_main_loop_timerlist(QEMUClock *clock)
402 return clock->main_loop_timerlist;
405 void timerlist_notify(QEMUTimerList *timer_list)
407 if (timer_list->notify_cb) {
408 timer_list->notify_cb(timer_list->notify_opaque);
414 /* Transition function to convert a nanosecond timeout to ms
415 * This is used where a system does not support ppoll
417 int qemu_timeout_ns_to_ms(int64_t ns)
428 /* Always round up, because it's better to wait too long than to wait too
429 * little and effectively busy-wait
431 ms = (ns + SCALE_MS - 1) / SCALE_MS;
433 /* To avoid overflow problems, limit this to 2^31, i.e. approx 25 days */
434 if (ms > (int64_t) INT32_MAX) {
442 /* qemu implementation of g_poll which uses a nanosecond timeout but is
443 * otherwise identical to g_poll
445 int qemu_poll_ns(GPollFD *fds, guint nfds, int64_t timeout)
449 return ppoll((struct pollfd *)fds, nfds, NULL, NULL);
452 ts.tv_sec = timeout / 1000000000LL;
453 ts.tv_nsec = timeout % 1000000000LL;
454 return ppoll((struct pollfd *)fds, nfds, &ts, NULL);
457 return g_poll(fds, nfds, qemu_timeout_ns_to_ms(timeout));
462 void timer_init(QEMUTimer *ts,
463 QEMUTimerList *timer_list, int scale,
464 QEMUTimerCB *cb, void *opaque)
466 ts->timer_list = timer_list;
472 QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
473 QEMUTimerCB *cb, void *opaque)
475 return timer_new_tl(clock->main_loop_timerlist,
479 void qemu_free_timer(QEMUTimer *ts)
484 /* stop a timer, but do not dealloc it */
485 void qemu_del_timer(QEMUTimer *ts)
489 /* NOTE: this code must be signal safe because
490 timer_expired() can be called from a signal. */
491 pt = &ts->timer_list->active_timers;
504 /* modify the current timer so that it will be fired when current_time
505 >= expire_time. The corresponding callback will be called. */
506 void qemu_mod_timer_ns(QEMUTimer *ts, int64_t expire_time)
512 /* add the timer in the sorted list */
513 /* NOTE: this code must be signal safe because
514 timer_expired() can be called from a signal. */
515 pt = &ts->timer_list->active_timers;
518 if (!timer_expired_ns(t, expire_time)) {
523 ts->expire_time = expire_time;
527 /* Rearm if necessary */
528 if (pt == &ts->timer_list->active_timers) {
529 if (!alarm_timer->pending) {
530 qemu_rearm_alarm_timer(alarm_timer);
532 /* Interrupt execution to force deadline recalculation. */
533 qemu_clock_warp(ts->timer_list->clock);
534 timerlist_notify(ts->timer_list);
538 void qemu_mod_timer(QEMUTimer *ts, int64_t expire_time)
540 qemu_mod_timer_ns(ts, expire_time * ts->scale);
543 bool timer_pending(QEMUTimer *ts)
546 for (t = ts->timer_list->active_timers; t != NULL; t = t->next) {
554 bool timer_expired(QEMUTimer *timer_head, int64_t current_time)
556 return timer_expired_ns(timer_head, current_time * timer_head->scale);
559 bool timerlist_run_timers(QEMUTimerList *timer_list)
562 int64_t current_time;
563 bool progress = false;
565 if (!timer_list->clock->enabled) {
569 current_time = qemu_get_clock_ns(timer_list->clock);
571 ts = timer_list->active_timers;
572 if (!timer_expired_ns(ts, current_time)) {
575 /* remove timer from the list before calling the callback */
576 timer_list->active_timers = ts->next;
579 /* run the callback (the timer list can be modified) */
586 bool qemu_run_timers(QEMUClock *clock)
588 return timerlist_run_timers(clock->main_loop_timerlist);
591 void timerlistgroup_init(QEMUTimerListGroup *tlg,
592 QEMUTimerListNotifyCB *cb, void *opaque)
595 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
596 tlg->tl[type] = timerlist_new(type, cb, opaque);
600 void timerlistgroup_deinit(QEMUTimerListGroup *tlg)
603 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
604 timerlist_free(tlg->tl[type]);
608 bool timerlistgroup_run_timers(QEMUTimerListGroup *tlg)
611 bool progress = false;
612 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
613 progress |= timerlist_run_timers(tlg->tl[type]);
618 int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup *tlg)
620 int64_t deadline = -1;
622 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
623 if (qemu_clock_use_for_deadline(tlg->tl[type]->clock)) {
624 deadline = qemu_soonest_timeout(deadline,
625 timerlist_deadline_ns(
632 int64_t qemu_get_clock_ns(QEMUClock *clock)
636 switch(clock->type) {
637 case QEMU_CLOCK_REALTIME:
640 case QEMU_CLOCK_VIRTUAL:
642 return cpu_get_icount();
644 return cpu_get_clock();
646 case QEMU_CLOCK_HOST:
647 now = get_clock_realtime();
651 notifier_list_notify(&clock->reset_notifiers, &now);
657 void qemu_register_clock_reset_notifier(QEMUClock *clock, Notifier *notifier)
659 notifier_list_add(&clock->reset_notifiers, notifier);
662 void qemu_unregister_clock_reset_notifier(QEMUClock *clock, Notifier *notifier)
664 notifier_remove(notifier);
667 void init_clocks(void)
670 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
671 if (!qemu_clocks[type]) {
672 qemu_clocks[type] = qemu_clock_new(type);
673 main_loop_tlg.tl[type] = qemu_clocks[type]->main_loop_timerlist;
677 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
678 prctl(PR_SET_TIMERSLACK, 1, 0, 0, 0);
682 uint64_t timer_expire_time_ns(QEMUTimer *ts)
684 return timer_pending(ts) ? ts->expire_time : -1;
687 bool qemu_run_all_timers(void)
689 bool progress = false;
690 alarm_timer->pending = false;
694 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
695 progress |= qemu_run_timers(qemu_clock_ptr(type));
698 /* rearm timer, if not periodic */
699 if (alarm_timer->expired) {
700 alarm_timer->expired = false;
701 qemu_rearm_alarm_timer(alarm_timer);
708 static void CALLBACK host_alarm_handler(PVOID lpParam, BOOLEAN unused)
710 static void host_alarm_handler(int host_signum)
713 struct qemu_alarm_timer *t = alarm_timer;
722 #if defined(__linux__)
724 #include "qemu/compatfd.h"
726 static int dynticks_start_timer(struct qemu_alarm_timer *t)
730 struct sigaction act;
732 sigfillset(&act.sa_mask);
734 act.sa_handler = host_alarm_handler;
736 sigaction(SIGALRM, &act, NULL);
739 * Initialize ev struct to 0 to avoid valgrind complaining
740 * about uninitialized data in timer_create call
742 memset(&ev, 0, sizeof(ev));
743 ev.sigev_value.sival_int = 0;
744 ev.sigev_notify = SIGEV_SIGNAL;
745 #ifdef CONFIG_SIGEV_THREAD_ID
746 if (qemu_signalfd_available()) {
747 ev.sigev_notify = SIGEV_THREAD_ID;
748 ev._sigev_un._tid = qemu_get_thread_id();
750 #endif /* CONFIG_SIGEV_THREAD_ID */
751 ev.sigev_signo = SIGALRM;
753 if (timer_create(CLOCK_REALTIME, &ev, &host_timer)) {
754 perror("timer_create");
758 t->timer = host_timer;
763 static void dynticks_stop_timer(struct qemu_alarm_timer *t)
765 timer_t host_timer = t->timer;
767 timer_delete(host_timer);
770 static void dynticks_rearm_timer(struct qemu_alarm_timer *t,
771 int64_t nearest_delta_ns)
773 timer_t host_timer = t->timer;
774 struct itimerspec timeout;
777 if (nearest_delta_ns < MIN_TIMER_REARM_NS)
778 nearest_delta_ns = MIN_TIMER_REARM_NS;
780 /* check whether a timer is already running */
781 if (timer_gettime(host_timer, &timeout)) {
783 fprintf(stderr, "Internal timer error: aborting\n");
786 current_ns = timeout.it_value.tv_sec * 1000000000LL + timeout.it_value.tv_nsec;
787 if (current_ns && current_ns <= nearest_delta_ns)
790 timeout.it_interval.tv_sec = 0;
791 timeout.it_interval.tv_nsec = 0; /* 0 for one-shot timer */
792 timeout.it_value.tv_sec = nearest_delta_ns / 1000000000;
793 timeout.it_value.tv_nsec = nearest_delta_ns % 1000000000;
794 if (timer_settime(host_timer, 0 /* RELATIVE */, &timeout, NULL)) {
796 fprintf(stderr, "Internal timer error: aborting\n");
801 #endif /* defined(__linux__) */
805 static int unix_start_timer(struct qemu_alarm_timer *t)
807 struct sigaction act;
810 sigfillset(&act.sa_mask);
812 act.sa_handler = host_alarm_handler;
814 sigaction(SIGALRM, &act, NULL);
818 static void unix_rearm_timer(struct qemu_alarm_timer *t,
819 int64_t nearest_delta_ns)
821 struct itimerval itv;
824 if (nearest_delta_ns < MIN_TIMER_REARM_NS)
825 nearest_delta_ns = MIN_TIMER_REARM_NS;
827 itv.it_interval.tv_sec = 0;
828 itv.it_interval.tv_usec = 0; /* 0 for one-shot timer */
829 itv.it_value.tv_sec = nearest_delta_ns / 1000000000;
830 itv.it_value.tv_usec = (nearest_delta_ns % 1000000000) / 1000;
831 err = setitimer(ITIMER_REAL, &itv, NULL);
834 fprintf(stderr, "Internal timer error: aborting\n");
839 static void unix_stop_timer(struct qemu_alarm_timer *t)
841 struct itimerval itv;
843 memset(&itv, 0, sizeof(itv));
844 setitimer(ITIMER_REAL, &itv, NULL);
847 #endif /* !defined(_WIN32) */
852 static MMRESULT mm_timer;
853 static TIMECAPS mm_tc;
855 static void CALLBACK mm_alarm_handler(UINT uTimerID, UINT uMsg,
856 DWORD_PTR dwUser, DWORD_PTR dw1,
859 struct qemu_alarm_timer *t = alarm_timer;
868 static int mm_start_timer(struct qemu_alarm_timer *t)
870 timeGetDevCaps(&mm_tc, sizeof(mm_tc));
874 static void mm_stop_timer(struct qemu_alarm_timer *t)
877 timeKillEvent(mm_timer);
881 static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta)
883 int64_t nearest_delta_ms = delta / 1000000;
884 if (nearest_delta_ms < mm_tc.wPeriodMin) {
885 nearest_delta_ms = mm_tc.wPeriodMin;
886 } else if (nearest_delta_ms > mm_tc.wPeriodMax) {
887 nearest_delta_ms = mm_tc.wPeriodMax;
891 timeKillEvent(mm_timer);
893 mm_timer = timeSetEvent((UINT)nearest_delta_ms,
897 TIME_ONESHOT | TIME_CALLBACK_FUNCTION);
900 fprintf(stderr, "Failed to re-arm win32 alarm timer\n");
901 timeEndPeriod(mm_tc.wPeriodMin);
906 static int win32_start_timer(struct qemu_alarm_timer *t)
911 /* If you call ChangeTimerQueueTimer on a one-shot timer (its period
912 is zero) that has already expired, the timer is not updated. Since
913 creating a new timer is relatively expensive, set a bogus one-hour
914 interval in the dynticks case. */
915 success = CreateTimerQueueTimer(&hTimer,
921 WT_EXECUTEINTIMERTHREAD);
924 fprintf(stderr, "Failed to initialize win32 alarm timer: %ld\n",
933 static void win32_stop_timer(struct qemu_alarm_timer *t)
935 HANDLE hTimer = t->timer;
938 DeleteTimerQueueTimer(NULL, hTimer, NULL);
942 static void win32_rearm_timer(struct qemu_alarm_timer *t,
943 int64_t nearest_delta_ns)
945 HANDLE hTimer = t->timer;
946 int64_t nearest_delta_ms;
949 nearest_delta_ms = nearest_delta_ns / 1000000;
950 if (nearest_delta_ms < 1) {
951 nearest_delta_ms = 1;
953 /* ULONG_MAX can be 32 bit */
954 if (nearest_delta_ms > ULONG_MAX) {
955 nearest_delta_ms = ULONG_MAX;
957 success = ChangeTimerQueueTimer(NULL,
959 (unsigned long) nearest_delta_ms,
963 fprintf(stderr, "Failed to rearm win32 alarm timer: %ld\n",
972 static void quit_timers(void)
974 struct qemu_alarm_timer *t = alarm_timer;
980 static void reinit_timers(void)
982 struct qemu_alarm_timer *t = alarm_timer;
985 fprintf(stderr, "Internal timer error: aborting\n");
988 qemu_rearm_alarm_timer(t);
990 #endif /* CONFIG_POSIX */
992 int init_timer_alarm(void)
994 struct qemu_alarm_timer *t = NULL;
1001 for (i = 0; alarm_timers[i].name; i++) {
1002 t = &alarm_timers[i];
1014 atexit(quit_timers);
1016 pthread_atfork(NULL, NULL, reinit_timers);