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 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
41 #include <sys/prctl.h>
44 /***********************************************************/
47 typedef struct QEMUClock
{
48 /* We rely on BQL to protect the timerlists */
49 QLIST_HEAD(, QEMUTimerList
) timerlists
;
51 NotifierList reset_notifiers
;
58 QEMUTimerListGroup main_loop_tlg
;
59 static QEMUClock qemu_clocks
[QEMU_CLOCK_MAX
];
61 /* A QEMUTimerList is a list of timers attached to a clock. More
62 * than one QEMUTimerList can be attached to each clock, for instance
63 * used by different AioContexts / threads. Each clock also has
64 * a list of the QEMUTimerLists associated with it, in order that
65 * reenabling the clock can call all the notifiers.
68 struct QEMUTimerList
{
70 QemuMutex active_timers_lock
;
71 QEMUTimer
*active_timers
;
72 QLIST_ENTRY(QEMUTimerList
) list
;
73 QEMUTimerListNotifyCB
*notify_cb
;
76 /* lightweight method to mark the end of timerlist's running */
77 QemuEvent timers_done_ev
;
82 * @type: type of clock
84 * Translate a clock type into a pointer to QEMUClock object.
86 * Returns: a pointer to the QEMUClock object
88 static inline QEMUClock
*qemu_clock_ptr(QEMUClockType type
)
90 return &qemu_clocks
[type
];
93 static bool timer_expired_ns(QEMUTimer
*timer_head
, int64_t current_time
)
95 return timer_head
&& (timer_head
->expire_time
<= current_time
);
98 QEMUTimerList
*timerlist_new(QEMUClockType type
,
99 QEMUTimerListNotifyCB
*cb
,
102 QEMUTimerList
*timer_list
;
103 QEMUClock
*clock
= qemu_clock_ptr(type
);
105 timer_list
= g_malloc0(sizeof(QEMUTimerList
));
106 qemu_event_init(&timer_list
->timers_done_ev
, false);
107 timer_list
->clock
= clock
;
108 timer_list
->notify_cb
= cb
;
109 timer_list
->notify_opaque
= opaque
;
110 qemu_mutex_init(&timer_list
->active_timers_lock
);
111 QLIST_INSERT_HEAD(&clock
->timerlists
, timer_list
, list
);
115 void timerlist_free(QEMUTimerList
*timer_list
)
117 assert(!timerlist_has_timers(timer_list
));
118 if (timer_list
->clock
) {
119 QLIST_REMOVE(timer_list
, list
);
121 qemu_mutex_destroy(&timer_list
->active_timers_lock
);
125 static void qemu_clock_init(QEMUClockType type
)
127 QEMUClock
*clock
= qemu_clock_ptr(type
);
129 /* Assert that the clock of type TYPE has not been initialized yet. */
130 assert(main_loop_tlg
.tl
[type
] == NULL
);
133 clock
->enabled
= true;
134 clock
->last
= INT64_MIN
;
135 QLIST_INIT(&clock
->timerlists
);
136 notifier_list_init(&clock
->reset_notifiers
);
137 main_loop_tlg
.tl
[type
] = timerlist_new(type
, NULL
, NULL
);
140 bool qemu_clock_use_for_deadline(QEMUClockType type
)
142 return !(use_icount
&& (type
== QEMU_CLOCK_VIRTUAL
));
145 void qemu_clock_notify(QEMUClockType type
)
147 QEMUTimerList
*timer_list
;
148 QEMUClock
*clock
= qemu_clock_ptr(type
);
149 QLIST_FOREACH(timer_list
, &clock
->timerlists
, list
) {
150 timerlist_notify(timer_list
);
154 /* Disabling the clock will wait for related timerlists to stop
155 * executing qemu_run_timers. Thus, this functions should not
156 * be used from the callback of a timer that is based on @clock.
157 * Doing so would cause a deadlock.
159 * Caller should hold BQL.
161 void qemu_clock_enable(QEMUClockType type
, bool enabled
)
163 QEMUClock
*clock
= qemu_clock_ptr(type
);
165 bool old
= clock
->enabled
;
166 clock
->enabled
= enabled
;
167 if (enabled
&& !old
) {
168 qemu_clock_notify(type
);
169 } else if (!enabled
&& old
) {
170 QLIST_FOREACH(tl
, &clock
->timerlists
, list
) {
171 qemu_event_wait(&tl
->timers_done_ev
);
176 bool timerlist_has_timers(QEMUTimerList
*timer_list
)
178 return !!timer_list
->active_timers
;
181 bool qemu_clock_has_timers(QEMUClockType type
)
183 return timerlist_has_timers(
184 main_loop_tlg
.tl
[type
]);
187 bool timerlist_expired(QEMUTimerList
*timer_list
)
191 qemu_mutex_lock(&timer_list
->active_timers_lock
);
192 if (!timer_list
->active_timers
) {
193 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
196 expire_time
= timer_list
->active_timers
->expire_time
;
197 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
199 return expire_time
< qemu_clock_get_ns(timer_list
->clock
->type
);
202 bool qemu_clock_expired(QEMUClockType type
)
204 return timerlist_expired(
205 main_loop_tlg
.tl
[type
]);
209 * As above, but return -1 for no deadline, and do not cap to 2^32
210 * as we know the result is always positive.
213 int64_t timerlist_deadline_ns(QEMUTimerList
*timer_list
)
218 if (!timer_list
->clock
->enabled
) {
222 /* The active timers list may be modified before the caller uses our return
223 * value but ->notify_cb() is called when the deadline changes. Therefore
224 * the caller should notice the change and there is no race condition.
226 qemu_mutex_lock(&timer_list
->active_timers_lock
);
227 if (!timer_list
->active_timers
) {
228 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
231 expire_time
= timer_list
->active_timers
->expire_time
;
232 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
234 delta
= expire_time
- qemu_clock_get_ns(timer_list
->clock
->type
);
243 /* Calculate the soonest deadline across all timerlists attached
244 * to the clock. This is used for the icount timeout so we
245 * ignore whether or not the clock should be used in deadline
248 int64_t qemu_clock_deadline_ns_all(QEMUClockType type
)
250 int64_t deadline
= -1;
251 QEMUTimerList
*timer_list
;
252 QEMUClock
*clock
= qemu_clock_ptr(type
);
253 QLIST_FOREACH(timer_list
, &clock
->timerlists
, list
) {
254 deadline
= qemu_soonest_timeout(deadline
,
255 timerlist_deadline_ns(timer_list
));
260 QEMUClockType
timerlist_get_clock(QEMUTimerList
*timer_list
)
262 return timer_list
->clock
->type
;
265 QEMUTimerList
*qemu_clock_get_main_loop_timerlist(QEMUClockType type
)
267 return main_loop_tlg
.tl
[type
];
270 void timerlist_notify(QEMUTimerList
*timer_list
)
272 if (timer_list
->notify_cb
) {
273 timer_list
->notify_cb(timer_list
->notify_opaque
);
279 /* Transition function to convert a nanosecond timeout to ms
280 * This is used where a system does not support ppoll
282 int qemu_timeout_ns_to_ms(int64_t ns
)
293 /* Always round up, because it's better to wait too long than to wait too
294 * little and effectively busy-wait
296 ms
= (ns
+ SCALE_MS
- 1) / SCALE_MS
;
298 /* To avoid overflow problems, limit this to 2^31, i.e. approx 25 days */
299 if (ms
> (int64_t) INT32_MAX
) {
307 /* qemu implementation of g_poll which uses a nanosecond timeout but is
308 * otherwise identical to g_poll
310 int qemu_poll_ns(GPollFD
*fds
, guint nfds
, int64_t timeout
)
314 return ppoll((struct pollfd
*)fds
, nfds
, NULL
, NULL
);
317 int64_t tvsec
= timeout
/ 1000000000LL;
318 /* Avoid possibly overflowing and specifying a negative number of
319 * seconds, which would turn a very long timeout into a busy-wait.
321 if (tvsec
> (int64_t)INT32_MAX
) {
325 ts
.tv_nsec
= timeout
% 1000000000LL;
326 return ppoll((struct pollfd
*)fds
, nfds
, &ts
, NULL
);
329 return g_poll(fds
, nfds
, qemu_timeout_ns_to_ms(timeout
));
334 void timer_init(QEMUTimer
*ts
,
335 QEMUTimerList
*timer_list
, int scale
,
336 QEMUTimerCB
*cb
, void *opaque
)
338 ts
->timer_list
= timer_list
;
342 ts
->expire_time
= -1;
345 void timer_free(QEMUTimer
*ts
)
350 static void timer_del_locked(QEMUTimerList
*timer_list
, QEMUTimer
*ts
)
354 ts
->expire_time
= -1;
355 pt
= &timer_list
->active_timers
;
368 static bool timer_mod_ns_locked(QEMUTimerList
*timer_list
,
369 QEMUTimer
*ts
, int64_t expire_time
)
373 /* add the timer in the sorted list */
374 pt
= &timer_list
->active_timers
;
377 if (!timer_expired_ns(t
, expire_time
)) {
382 ts
->expire_time
= MAX(expire_time
, 0);
386 return pt
== &timer_list
->active_timers
;
389 static void timerlist_rearm(QEMUTimerList
*timer_list
)
391 /* Interrupt execution to force deadline recalculation. */
392 qemu_clock_warp(timer_list
->clock
->type
);
393 timerlist_notify(timer_list
);
396 /* stop a timer, but do not dealloc it */
397 void timer_del(QEMUTimer
*ts
)
399 QEMUTimerList
*timer_list
= ts
->timer_list
;
401 qemu_mutex_lock(&timer_list
->active_timers_lock
);
402 timer_del_locked(timer_list
, ts
);
403 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
406 /* modify the current timer so that it will be fired when current_time
407 >= expire_time. The corresponding callback will be called. */
408 void timer_mod_ns(QEMUTimer
*ts
, int64_t expire_time
)
410 QEMUTimerList
*timer_list
= ts
->timer_list
;
413 qemu_mutex_lock(&timer_list
->active_timers_lock
);
414 timer_del_locked(timer_list
, ts
);
415 rearm
= timer_mod_ns_locked(timer_list
, ts
, expire_time
);
416 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
419 timerlist_rearm(timer_list
);
423 /* modify the current timer so that it will be fired when current_time
424 >= expire_time or the current deadline, whichever comes earlier.
425 The corresponding callback will be called. */
426 void timer_mod_anticipate_ns(QEMUTimer
*ts
, int64_t expire_time
)
428 QEMUTimerList
*timer_list
= ts
->timer_list
;
431 qemu_mutex_lock(&timer_list
->active_timers_lock
);
432 if (ts
->expire_time
== -1 || ts
->expire_time
> expire_time
) {
433 if (ts
->expire_time
!= -1) {
434 timer_del_locked(timer_list
, ts
);
436 rearm
= timer_mod_ns_locked(timer_list
, ts
, expire_time
);
440 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
443 timerlist_rearm(timer_list
);
447 void timer_mod(QEMUTimer
*ts
, int64_t expire_time
)
449 timer_mod_ns(ts
, expire_time
* ts
->scale
);
452 void timer_mod_anticipate(QEMUTimer
*ts
, int64_t expire_time
)
454 timer_mod_anticipate_ns(ts
, expire_time
* ts
->scale
);
457 bool timer_pending(QEMUTimer
*ts
)
459 return ts
->expire_time
>= 0;
462 bool timer_expired(QEMUTimer
*timer_head
, int64_t current_time
)
464 return timer_expired_ns(timer_head
, current_time
* timer_head
->scale
);
467 bool timerlist_run_timers(QEMUTimerList
*timer_list
)
470 int64_t current_time
;
471 bool progress
= false;
475 qemu_event_reset(&timer_list
->timers_done_ev
);
476 if (!timer_list
->clock
->enabled
) {
480 current_time
= qemu_clock_get_ns(timer_list
->clock
->type
);
482 qemu_mutex_lock(&timer_list
->active_timers_lock
);
483 ts
= timer_list
->active_timers
;
484 if (!timer_expired_ns(ts
, current_time
)) {
485 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
489 /* remove timer from the list before calling the callback */
490 timer_list
->active_timers
= ts
->next
;
492 ts
->expire_time
= -1;
495 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
497 /* run the callback (the timer list can be modified) */
503 qemu_event_set(&timer_list
->timers_done_ev
);
507 bool qemu_clock_run_timers(QEMUClockType type
)
509 return timerlist_run_timers(main_loop_tlg
.tl
[type
]);
512 void timerlistgroup_init(QEMUTimerListGroup
*tlg
,
513 QEMUTimerListNotifyCB
*cb
, void *opaque
)
516 for (type
= 0; type
< QEMU_CLOCK_MAX
; type
++) {
517 tlg
->tl
[type
] = timerlist_new(type
, cb
, opaque
);
521 void timerlistgroup_deinit(QEMUTimerListGroup
*tlg
)
524 for (type
= 0; type
< QEMU_CLOCK_MAX
; type
++) {
525 timerlist_free(tlg
->tl
[type
]);
529 bool timerlistgroup_run_timers(QEMUTimerListGroup
*tlg
)
532 bool progress
= false;
533 for (type
= 0; type
< QEMU_CLOCK_MAX
; type
++) {
534 progress
|= timerlist_run_timers(tlg
->tl
[type
]);
539 int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup
*tlg
)
541 int64_t deadline
= -1;
543 for (type
= 0; type
< QEMU_CLOCK_MAX
; type
++) {
544 if (qemu_clock_use_for_deadline(tlg
->tl
[type
]->clock
->type
)) {
545 deadline
= qemu_soonest_timeout(deadline
,
546 timerlist_deadline_ns(
553 int64_t qemu_clock_get_ns(QEMUClockType type
)
556 QEMUClock
*clock
= qemu_clock_ptr(type
);
559 case QEMU_CLOCK_REALTIME
:
562 case QEMU_CLOCK_VIRTUAL
:
564 return cpu_get_icount();
566 return cpu_get_clock();
568 case QEMU_CLOCK_HOST
:
569 now
= get_clock_realtime();
573 notifier_list_notify(&clock
->reset_notifiers
, &now
);
576 case QEMU_CLOCK_VIRTUAL_RT
:
577 return cpu_get_clock();
581 void qemu_clock_register_reset_notifier(QEMUClockType type
,
584 QEMUClock
*clock
= qemu_clock_ptr(type
);
585 notifier_list_add(&clock
->reset_notifiers
, notifier
);
588 void qemu_clock_unregister_reset_notifier(QEMUClockType type
,
591 notifier_remove(notifier
);
594 void init_clocks(void)
597 for (type
= 0; type
< QEMU_CLOCK_MAX
; type
++) {
598 qemu_clock_init(type
);
601 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
602 prctl(PR_SET_TIMERSLACK
, 1, 0, 0, 0);
606 uint64_t timer_expire_time_ns(QEMUTimer
*ts
)
608 return timer_pending(ts
) ? ts
->expire_time
: -1;
611 bool qemu_clock_run_all_timers(void)
613 bool progress
= false;
616 for (type
= 0; type
< QEMU_CLOCK_MAX
; type
++) {
617 progress
|= qemu_clock_run_timers(type
);