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"
40 /***********************************************************/
44 QEMUTimer *active_timers;
46 NotifierList reset_notifiers;
54 int64_t expire_time; /* in nanoseconds */
62 struct qemu_alarm_timer {
64 int (*start)(struct qemu_alarm_timer *t);
65 void (*stop)(struct qemu_alarm_timer *t);
66 void (*rearm)(struct qemu_alarm_timer *t, int64_t nearest_delta_ns);
67 #if defined(__linux__)
77 static struct qemu_alarm_timer *alarm_timer;
79 static bool timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
81 return timer_head && (timer_head->expire_time <= current_time);
84 static int64_t qemu_next_alarm_deadline(void)
86 int64_t delta = INT64_MAX;
89 if (!use_icount && vm_clock->enabled && vm_clock->active_timers) {
90 delta = vm_clock->active_timers->expire_time -
91 qemu_get_clock_ns(vm_clock);
93 if (host_clock->enabled && host_clock->active_timers) {
94 int64_t hdelta = host_clock->active_timers->expire_time -
95 qemu_get_clock_ns(host_clock);
100 if (rt_clock->enabled && rt_clock->active_timers) {
101 rtdelta = (rt_clock->active_timers->expire_time -
102 qemu_get_clock_ns(rt_clock));
103 if (rtdelta < delta) {
111 static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)
113 int64_t nearest_delta_ns = qemu_next_alarm_deadline();
114 if (nearest_delta_ns < INT64_MAX) {
115 t->rearm(t, nearest_delta_ns);
119 /* TODO: MIN_TIMER_REARM_NS should be optimized */
120 #define MIN_TIMER_REARM_NS 250000
124 static int mm_start_timer(struct qemu_alarm_timer *t);
125 static void mm_stop_timer(struct qemu_alarm_timer *t);
126 static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
128 static int win32_start_timer(struct qemu_alarm_timer *t);
129 static void win32_stop_timer(struct qemu_alarm_timer *t);
130 static void win32_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
134 static int unix_start_timer(struct qemu_alarm_timer *t);
135 static void unix_stop_timer(struct qemu_alarm_timer *t);
136 static void unix_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
140 static int dynticks_start_timer(struct qemu_alarm_timer *t);
141 static void dynticks_stop_timer(struct qemu_alarm_timer *t);
142 static void dynticks_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
144 #endif /* __linux__ */
148 static struct qemu_alarm_timer alarm_timers[] = {
151 {"dynticks", dynticks_start_timer,
152 dynticks_stop_timer, dynticks_rearm_timer},
154 {"unix", unix_start_timer, unix_stop_timer, unix_rearm_timer},
156 {"mmtimer", mm_start_timer, mm_stop_timer, mm_rearm_timer},
157 {"dynticks", win32_start_timer, win32_stop_timer, win32_rearm_timer},
162 static void show_available_alarms(void)
166 printf("Available alarm timers, in order of precedence:\n");
167 for (i = 0; alarm_timers[i].name; i++)
168 printf("%s\n", alarm_timers[i].name);
171 void configure_alarms(char const *opt)
175 int count = ARRAY_SIZE(alarm_timers) - 1;
178 struct qemu_alarm_timer tmp;
180 if (is_help_option(opt)) {
181 show_available_alarms();
187 /* Reorder the array */
188 name = strtok(arg, ",");
190 for (i = 0; i < count && alarm_timers[i].name; i++) {
191 if (!strcmp(alarm_timers[i].name, name))
196 fprintf(stderr, "Unknown clock %s\n", name);
205 tmp = alarm_timers[i];
206 alarm_timers[i] = alarm_timers[cur];
207 alarm_timers[cur] = tmp;
211 name = strtok(NULL, ",");
217 /* Disable remaining timers */
218 for (i = cur; i < count; i++)
219 alarm_timers[i].name = NULL;
221 show_available_alarms();
228 QEMUClock *host_clock;
230 static QEMUClock *qemu_clock_new(int type)
234 clock = g_malloc0(sizeof(QEMUClock));
236 clock->enabled = true;
237 clock->last = INT64_MIN;
238 notifier_list_init(&clock->reset_notifiers);
242 void qemu_clock_enable(QEMUClock *clock, bool enabled)
244 bool old = clock->enabled;
245 clock->enabled = enabled;
246 if (enabled && !old) {
247 qemu_rearm_alarm_timer(alarm_timer);
251 int64_t qemu_clock_has_timers(QEMUClock *clock)
253 return !!clock->active_timers;
256 int64_t qemu_clock_expired(QEMUClock *clock)
258 return (clock->active_timers &&
259 clock->active_timers->expire_time < qemu_get_clock_ns(clock));
262 int64_t qemu_clock_deadline(QEMUClock *clock)
264 /* To avoid problems with overflow limit this to 2^32. */
265 int64_t delta = INT32_MAX;
267 if (clock->active_timers) {
268 delta = clock->active_timers->expire_time - qemu_get_clock_ns(clock);
277 * As above, but return -1 for no deadline, and do not cap to 2^32
278 * as we know the result is always positive.
281 int64_t qemu_clock_deadline_ns(QEMUClock *clock)
285 if (!clock->enabled || !clock->active_timers) {
289 delta = clock->active_timers->expire_time - qemu_get_clock_ns(clock);
298 /* Transition function to convert a nanosecond timeout to ms
299 * This is used where a system does not support ppoll
301 int qemu_timeout_ns_to_ms(int64_t ns)
312 /* Always round up, because it's better to wait too long than to wait too
313 * little and effectively busy-wait
315 ms = (ns + SCALE_MS - 1) / SCALE_MS;
317 /* To avoid overflow problems, limit this to 2^31, i.e. approx 25 days */
318 if (ms > (int64_t) INT32_MAX) {
326 QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
327 QEMUTimerCB *cb, void *opaque)
331 ts = g_malloc0(sizeof(QEMUTimer));
339 void qemu_free_timer(QEMUTimer *ts)
344 /* stop a timer, but do not dealloc it */
345 void qemu_del_timer(QEMUTimer *ts)
349 /* NOTE: this code must be signal safe because
350 timer_expired() can be called from a signal. */
351 pt = &ts->clock->active_timers;
364 /* modify the current timer so that it will be fired when current_time
365 >= expire_time. The corresponding callback will be called. */
366 void qemu_mod_timer_ns(QEMUTimer *ts, int64_t expire_time)
372 /* add the timer in the sorted list */
373 /* NOTE: this code must be signal safe because
374 timer_expired() can be called from a signal. */
375 pt = &ts->clock->active_timers;
378 if (!timer_expired_ns(t, expire_time)) {
383 ts->expire_time = expire_time;
387 /* Rearm if necessary */
388 if (pt == &ts->clock->active_timers) {
389 if (!alarm_timer->pending) {
390 qemu_rearm_alarm_timer(alarm_timer);
392 /* Interrupt execution to force deadline recalculation. */
393 qemu_clock_warp(ts->clock);
400 void qemu_mod_timer(QEMUTimer *ts, int64_t expire_time)
402 qemu_mod_timer_ns(ts, expire_time * ts->scale);
405 bool timer_pending(QEMUTimer *ts)
408 for (t = ts->clock->active_timers; t != NULL; t = t->next) {
416 bool timer_expired(QEMUTimer *timer_head, int64_t current_time)
418 return timer_expired_ns(timer_head, current_time * timer_head->scale);
421 void qemu_run_timers(QEMUClock *clock)
424 int64_t current_time;
429 current_time = qemu_get_clock_ns(clock);
431 ts = clock->active_timers;
432 if (!timer_expired_ns(ts, current_time)) {
435 /* remove timer from the list before calling the callback */
436 clock->active_timers = ts->next;
439 /* run the callback (the timer list can be modified) */
444 int64_t qemu_get_clock_ns(QEMUClock *clock)
448 switch(clock->type) {
449 case QEMU_CLOCK_REALTIME:
452 case QEMU_CLOCK_VIRTUAL:
454 return cpu_get_icount();
456 return cpu_get_clock();
458 case QEMU_CLOCK_HOST:
459 now = get_clock_realtime();
463 notifier_list_notify(&clock->reset_notifiers, &now);
469 void qemu_register_clock_reset_notifier(QEMUClock *clock, Notifier *notifier)
471 notifier_list_add(&clock->reset_notifiers, notifier);
474 void qemu_unregister_clock_reset_notifier(QEMUClock *clock, Notifier *notifier)
476 notifier_remove(notifier);
479 void init_clocks(void)
482 rt_clock = qemu_clock_new(QEMU_CLOCK_REALTIME);
483 vm_clock = qemu_clock_new(QEMU_CLOCK_VIRTUAL);
484 host_clock = qemu_clock_new(QEMU_CLOCK_HOST);
488 uint64_t timer_expire_time_ns(QEMUTimer *ts)
490 return timer_pending(ts) ? ts->expire_time : -1;
493 void qemu_run_all_timers(void)
495 alarm_timer->pending = false;
498 qemu_run_timers(vm_clock);
499 qemu_run_timers(rt_clock);
500 qemu_run_timers(host_clock);
502 /* rearm timer, if not periodic */
503 if (alarm_timer->expired) {
504 alarm_timer->expired = false;
505 qemu_rearm_alarm_timer(alarm_timer);
510 static void CALLBACK host_alarm_handler(PVOID lpParam, BOOLEAN unused)
512 static void host_alarm_handler(int host_signum)
515 struct qemu_alarm_timer *t = alarm_timer;
524 #if defined(__linux__)
526 #include "qemu/compatfd.h"
528 static int dynticks_start_timer(struct qemu_alarm_timer *t)
532 struct sigaction act;
534 sigfillset(&act.sa_mask);
536 act.sa_handler = host_alarm_handler;
538 sigaction(SIGALRM, &act, NULL);
541 * Initialize ev struct to 0 to avoid valgrind complaining
542 * about uninitialized data in timer_create call
544 memset(&ev, 0, sizeof(ev));
545 ev.sigev_value.sival_int = 0;
546 ev.sigev_notify = SIGEV_SIGNAL;
547 #ifdef CONFIG_SIGEV_THREAD_ID
548 if (qemu_signalfd_available()) {
549 ev.sigev_notify = SIGEV_THREAD_ID;
550 ev._sigev_un._tid = qemu_get_thread_id();
552 #endif /* CONFIG_SIGEV_THREAD_ID */
553 ev.sigev_signo = SIGALRM;
555 if (timer_create(CLOCK_REALTIME, &ev, &host_timer)) {
556 perror("timer_create");
560 t->timer = host_timer;
565 static void dynticks_stop_timer(struct qemu_alarm_timer *t)
567 timer_t host_timer = t->timer;
569 timer_delete(host_timer);
572 static void dynticks_rearm_timer(struct qemu_alarm_timer *t,
573 int64_t nearest_delta_ns)
575 timer_t host_timer = t->timer;
576 struct itimerspec timeout;
579 if (nearest_delta_ns < MIN_TIMER_REARM_NS)
580 nearest_delta_ns = MIN_TIMER_REARM_NS;
582 /* check whether a timer is already running */
583 if (timer_gettime(host_timer, &timeout)) {
585 fprintf(stderr, "Internal timer error: aborting\n");
588 current_ns = timeout.it_value.tv_sec * 1000000000LL + timeout.it_value.tv_nsec;
589 if (current_ns && current_ns <= nearest_delta_ns)
592 timeout.it_interval.tv_sec = 0;
593 timeout.it_interval.tv_nsec = 0; /* 0 for one-shot timer */
594 timeout.it_value.tv_sec = nearest_delta_ns / 1000000000;
595 timeout.it_value.tv_nsec = nearest_delta_ns % 1000000000;
596 if (timer_settime(host_timer, 0 /* RELATIVE */, &timeout, NULL)) {
598 fprintf(stderr, "Internal timer error: aborting\n");
603 #endif /* defined(__linux__) */
607 static int unix_start_timer(struct qemu_alarm_timer *t)
609 struct sigaction act;
612 sigfillset(&act.sa_mask);
614 act.sa_handler = host_alarm_handler;
616 sigaction(SIGALRM, &act, NULL);
620 static void unix_rearm_timer(struct qemu_alarm_timer *t,
621 int64_t nearest_delta_ns)
623 struct itimerval itv;
626 if (nearest_delta_ns < MIN_TIMER_REARM_NS)
627 nearest_delta_ns = MIN_TIMER_REARM_NS;
629 itv.it_interval.tv_sec = 0;
630 itv.it_interval.tv_usec = 0; /* 0 for one-shot timer */
631 itv.it_value.tv_sec = nearest_delta_ns / 1000000000;
632 itv.it_value.tv_usec = (nearest_delta_ns % 1000000000) / 1000;
633 err = setitimer(ITIMER_REAL, &itv, NULL);
636 fprintf(stderr, "Internal timer error: aborting\n");
641 static void unix_stop_timer(struct qemu_alarm_timer *t)
643 struct itimerval itv;
645 memset(&itv, 0, sizeof(itv));
646 setitimer(ITIMER_REAL, &itv, NULL);
649 #endif /* !defined(_WIN32) */
654 static MMRESULT mm_timer;
655 static TIMECAPS mm_tc;
657 static void CALLBACK mm_alarm_handler(UINT uTimerID, UINT uMsg,
658 DWORD_PTR dwUser, DWORD_PTR dw1,
661 struct qemu_alarm_timer *t = alarm_timer;
670 static int mm_start_timer(struct qemu_alarm_timer *t)
672 timeGetDevCaps(&mm_tc, sizeof(mm_tc));
676 static void mm_stop_timer(struct qemu_alarm_timer *t)
679 timeKillEvent(mm_timer);
683 static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta)
685 int64_t nearest_delta_ms = delta / 1000000;
686 if (nearest_delta_ms < mm_tc.wPeriodMin) {
687 nearest_delta_ms = mm_tc.wPeriodMin;
688 } else if (nearest_delta_ms > mm_tc.wPeriodMax) {
689 nearest_delta_ms = mm_tc.wPeriodMax;
693 timeKillEvent(mm_timer);
695 mm_timer = timeSetEvent((UINT)nearest_delta_ms,
699 TIME_ONESHOT | TIME_CALLBACK_FUNCTION);
702 fprintf(stderr, "Failed to re-arm win32 alarm timer\n");
703 timeEndPeriod(mm_tc.wPeriodMin);
708 static int win32_start_timer(struct qemu_alarm_timer *t)
713 /* If you call ChangeTimerQueueTimer on a one-shot timer (its period
714 is zero) that has already expired, the timer is not updated. Since
715 creating a new timer is relatively expensive, set a bogus one-hour
716 interval in the dynticks case. */
717 success = CreateTimerQueueTimer(&hTimer,
723 WT_EXECUTEINTIMERTHREAD);
726 fprintf(stderr, "Failed to initialize win32 alarm timer: %ld\n",
735 static void win32_stop_timer(struct qemu_alarm_timer *t)
737 HANDLE hTimer = t->timer;
740 DeleteTimerQueueTimer(NULL, hTimer, NULL);
744 static void win32_rearm_timer(struct qemu_alarm_timer *t,
745 int64_t nearest_delta_ns)
747 HANDLE hTimer = t->timer;
748 int64_t nearest_delta_ms;
751 nearest_delta_ms = nearest_delta_ns / 1000000;
752 if (nearest_delta_ms < 1) {
753 nearest_delta_ms = 1;
755 /* ULONG_MAX can be 32 bit */
756 if (nearest_delta_ms > ULONG_MAX) {
757 nearest_delta_ms = ULONG_MAX;
759 success = ChangeTimerQueueTimer(NULL,
761 (unsigned long) nearest_delta_ms,
765 fprintf(stderr, "Failed to rearm win32 alarm timer: %ld\n",
774 static void quit_timers(void)
776 struct qemu_alarm_timer *t = alarm_timer;
782 static void reinit_timers(void)
784 struct qemu_alarm_timer *t = alarm_timer;
787 fprintf(stderr, "Internal timer error: aborting\n");
790 qemu_rearm_alarm_timer(t);
792 #endif /* CONFIG_POSIX */
794 int init_timer_alarm(void)
796 struct qemu_alarm_timer *t = NULL;
803 for (i = 0; alarm_timers[i].name; i++) {
804 t = &alarm_timers[i];
818 pthread_atfork(NULL, NULL, reinit_timers);