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 "qemu/main-loop.h"
26 #include "qemu/timer.h"
27 #include "sysemu/replay.h"
37 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
38 #include <sys/prctl.h>
41 /***********************************************************/
44 typedef struct QEMUClock
{
45 /* We rely on BQL to protect the timerlists */
46 QLIST_HEAD(, QEMUTimerList
) timerlists
;
48 NotifierList reset_notifiers
;
55 QEMUTimerListGroup main_loop_tlg
;
56 static QEMUClock qemu_clocks
[QEMU_CLOCK_MAX
];
58 /* A QEMUTimerList is a list of timers attached to a clock. More
59 * than one QEMUTimerList can be attached to each clock, for instance
60 * used by different AioContexts / threads. Each clock also has
61 * a list of the QEMUTimerLists associated with it, in order that
62 * reenabling the clock can call all the notifiers.
65 struct QEMUTimerList
{
67 QemuMutex active_timers_lock
;
68 QEMUTimer
*active_timers
;
69 QLIST_ENTRY(QEMUTimerList
) list
;
70 QEMUTimerListNotifyCB
*notify_cb
;
73 /* lightweight method to mark the end of timerlist's running */
74 QemuEvent timers_done_ev
;
79 * @type: type of clock
81 * Translate a clock type into a pointer to QEMUClock object.
83 * Returns: a pointer to the QEMUClock object
85 static inline QEMUClock
*qemu_clock_ptr(QEMUClockType type
)
87 return &qemu_clocks
[type
];
90 static bool timer_expired_ns(QEMUTimer
*timer_head
, int64_t current_time
)
92 return timer_head
&& (timer_head
->expire_time
<= current_time
);
95 QEMUTimerList
*timerlist_new(QEMUClockType type
,
96 QEMUTimerListNotifyCB
*cb
,
99 QEMUTimerList
*timer_list
;
100 QEMUClock
*clock
= qemu_clock_ptr(type
);
102 timer_list
= g_malloc0(sizeof(QEMUTimerList
));
103 qemu_event_init(&timer_list
->timers_done_ev
, true);
104 timer_list
->clock
= clock
;
105 timer_list
->notify_cb
= cb
;
106 timer_list
->notify_opaque
= opaque
;
107 qemu_mutex_init(&timer_list
->active_timers_lock
);
108 QLIST_INSERT_HEAD(&clock
->timerlists
, timer_list
, list
);
112 void timerlist_free(QEMUTimerList
*timer_list
)
114 assert(!timerlist_has_timers(timer_list
));
115 if (timer_list
->clock
) {
116 QLIST_REMOVE(timer_list
, list
);
118 qemu_mutex_destroy(&timer_list
->active_timers_lock
);
122 static void qemu_clock_init(QEMUClockType type
)
124 QEMUClock
*clock
= qemu_clock_ptr(type
);
126 /* Assert that the clock of type TYPE has not been initialized yet. */
127 assert(main_loop_tlg
.tl
[type
] == NULL
);
130 clock
->enabled
= true;
131 clock
->last
= INT64_MIN
;
132 QLIST_INIT(&clock
->timerlists
);
133 notifier_list_init(&clock
->reset_notifiers
);
134 main_loop_tlg
.tl
[type
] = timerlist_new(type
, NULL
, NULL
);
137 bool qemu_clock_use_for_deadline(QEMUClockType type
)
139 return !(use_icount
&& (type
== QEMU_CLOCK_VIRTUAL
));
142 void qemu_clock_notify(QEMUClockType type
)
144 QEMUTimerList
*timer_list
;
145 QEMUClock
*clock
= qemu_clock_ptr(type
);
146 QLIST_FOREACH(timer_list
, &clock
->timerlists
, list
) {
147 timerlist_notify(timer_list
);
151 /* Disabling the clock will wait for related timerlists to stop
152 * executing qemu_run_timers. Thus, this functions should not
153 * be used from the callback of a timer that is based on @clock.
154 * Doing so would cause a deadlock.
156 * Caller should hold BQL.
158 void qemu_clock_enable(QEMUClockType type
, bool enabled
)
160 QEMUClock
*clock
= qemu_clock_ptr(type
);
162 bool old
= clock
->enabled
;
163 clock
->enabled
= enabled
;
164 if (enabled
&& !old
) {
165 qemu_clock_notify(type
);
166 } else if (!enabled
&& old
) {
167 QLIST_FOREACH(tl
, &clock
->timerlists
, list
) {
168 qemu_event_wait(&tl
->timers_done_ev
);
173 bool timerlist_has_timers(QEMUTimerList
*timer_list
)
175 return !!timer_list
->active_timers
;
178 bool qemu_clock_has_timers(QEMUClockType type
)
180 return timerlist_has_timers(
181 main_loop_tlg
.tl
[type
]);
184 bool timerlist_expired(QEMUTimerList
*timer_list
)
188 qemu_mutex_lock(&timer_list
->active_timers_lock
);
189 if (!timer_list
->active_timers
) {
190 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
193 expire_time
= timer_list
->active_timers
->expire_time
;
194 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
196 return expire_time
< qemu_clock_get_ns(timer_list
->clock
->type
);
199 bool qemu_clock_expired(QEMUClockType type
)
201 return timerlist_expired(
202 main_loop_tlg
.tl
[type
]);
206 * As above, but return -1 for no deadline, and do not cap to 2^32
207 * as we know the result is always positive.
210 int64_t timerlist_deadline_ns(QEMUTimerList
*timer_list
)
215 if (!timer_list
->clock
->enabled
) {
219 /* The active timers list may be modified before the caller uses our return
220 * value but ->notify_cb() is called when the deadline changes. Therefore
221 * the caller should notice the change and there is no race condition.
223 qemu_mutex_lock(&timer_list
->active_timers_lock
);
224 if (!timer_list
->active_timers
) {
225 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
228 expire_time
= timer_list
->active_timers
->expire_time
;
229 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
231 delta
= expire_time
- qemu_clock_get_ns(timer_list
->clock
->type
);
240 /* Calculate the soonest deadline across all timerlists attached
241 * to the clock. This is used for the icount timeout so we
242 * ignore whether or not the clock should be used in deadline
245 int64_t qemu_clock_deadline_ns_all(QEMUClockType type
)
247 int64_t deadline
= -1;
248 QEMUTimerList
*timer_list
;
249 QEMUClock
*clock
= qemu_clock_ptr(type
);
250 QLIST_FOREACH(timer_list
, &clock
->timerlists
, list
) {
251 deadline
= qemu_soonest_timeout(deadline
,
252 timerlist_deadline_ns(timer_list
));
257 QEMUClockType
timerlist_get_clock(QEMUTimerList
*timer_list
)
259 return timer_list
->clock
->type
;
262 QEMUTimerList
*qemu_clock_get_main_loop_timerlist(QEMUClockType type
)
264 return main_loop_tlg
.tl
[type
];
267 void timerlist_notify(QEMUTimerList
*timer_list
)
269 if (timer_list
->notify_cb
) {
270 timer_list
->notify_cb(timer_list
->notify_opaque
);
276 /* Transition function to convert a nanosecond timeout to ms
277 * This is used where a system does not support ppoll
279 int qemu_timeout_ns_to_ms(int64_t ns
)
290 /* Always round up, because it's better to wait too long than to wait too
291 * little and effectively busy-wait
293 ms
= (ns
+ SCALE_MS
- 1) / SCALE_MS
;
295 /* To avoid overflow problems, limit this to 2^31, i.e. approx 25 days */
296 if (ms
> (int64_t) INT32_MAX
) {
304 /* qemu implementation of g_poll which uses a nanosecond timeout but is
305 * otherwise identical to g_poll
307 int qemu_poll_ns(GPollFD
*fds
, guint nfds
, int64_t timeout
)
311 return ppoll((struct pollfd
*)fds
, nfds
, NULL
, NULL
);
314 int64_t tvsec
= timeout
/ 1000000000LL;
315 /* Avoid possibly overflowing and specifying a negative number of
316 * seconds, which would turn a very long timeout into a busy-wait.
318 if (tvsec
> (int64_t)INT32_MAX
) {
322 ts
.tv_nsec
= timeout
% 1000000000LL;
323 return ppoll((struct pollfd
*)fds
, nfds
, &ts
, NULL
);
326 return g_poll(fds
, nfds
, qemu_timeout_ns_to_ms(timeout
));
331 void timer_init_tl(QEMUTimer
*ts
,
332 QEMUTimerList
*timer_list
, int scale
,
333 QEMUTimerCB
*cb
, void *opaque
)
335 ts
->timer_list
= timer_list
;
339 ts
->expire_time
= -1;
342 void timer_deinit(QEMUTimer
*ts
)
344 assert(ts
->expire_time
== -1);
345 ts
->timer_list
= NULL
;
348 void timer_free(QEMUTimer
*ts
)
353 static void timer_del_locked(QEMUTimerList
*timer_list
, QEMUTimer
*ts
)
357 ts
->expire_time
= -1;
358 pt
= &timer_list
->active_timers
;
371 static bool timer_mod_ns_locked(QEMUTimerList
*timer_list
,
372 QEMUTimer
*ts
, int64_t expire_time
)
376 /* add the timer in the sorted list */
377 pt
= &timer_list
->active_timers
;
380 if (!timer_expired_ns(t
, expire_time
)) {
385 ts
->expire_time
= MAX(expire_time
, 0);
389 return pt
== &timer_list
->active_timers
;
392 static void timerlist_rearm(QEMUTimerList
*timer_list
)
394 /* Interrupt execution to force deadline recalculation. */
395 qemu_clock_warp(timer_list
->clock
->type
);
396 timerlist_notify(timer_list
);
399 /* stop a timer, but do not dealloc it */
400 void timer_del(QEMUTimer
*ts
)
402 QEMUTimerList
*timer_list
= ts
->timer_list
;
405 qemu_mutex_lock(&timer_list
->active_timers_lock
);
406 timer_del_locked(timer_list
, ts
);
407 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
411 /* modify the current timer so that it will be fired when current_time
412 >= expire_time. The corresponding callback will be called. */
413 void timer_mod_ns(QEMUTimer
*ts
, int64_t expire_time
)
415 QEMUTimerList
*timer_list
= ts
->timer_list
;
418 qemu_mutex_lock(&timer_list
->active_timers_lock
);
419 timer_del_locked(timer_list
, ts
);
420 rearm
= timer_mod_ns_locked(timer_list
, ts
, expire_time
);
421 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
424 timerlist_rearm(timer_list
);
428 /* modify the current timer so that it will be fired when current_time
429 >= expire_time or the current deadline, whichever comes earlier.
430 The corresponding callback will be called. */
431 void timer_mod_anticipate_ns(QEMUTimer
*ts
, int64_t expire_time
)
433 QEMUTimerList
*timer_list
= ts
->timer_list
;
436 qemu_mutex_lock(&timer_list
->active_timers_lock
);
437 if (ts
->expire_time
== -1 || ts
->expire_time
> expire_time
) {
438 if (ts
->expire_time
!= -1) {
439 timer_del_locked(timer_list
, ts
);
441 rearm
= timer_mod_ns_locked(timer_list
, ts
, expire_time
);
445 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
448 timerlist_rearm(timer_list
);
452 void timer_mod(QEMUTimer
*ts
, int64_t expire_time
)
454 timer_mod_ns(ts
, expire_time
* ts
->scale
);
457 void timer_mod_anticipate(QEMUTimer
*ts
, int64_t expire_time
)
459 timer_mod_anticipate_ns(ts
, expire_time
* ts
->scale
);
462 bool timer_pending(QEMUTimer
*ts
)
464 return ts
->expire_time
>= 0;
467 bool timer_expired(QEMUTimer
*timer_head
, int64_t current_time
)
469 return timer_expired_ns(timer_head
, current_time
* timer_head
->scale
);
472 bool timerlist_run_timers(QEMUTimerList
*timer_list
)
475 int64_t current_time
;
476 bool progress
= false;
480 qemu_event_reset(&timer_list
->timers_done_ev
);
481 if (!timer_list
->clock
->enabled
) {
485 current_time
= qemu_clock_get_ns(timer_list
->clock
->type
);
487 qemu_mutex_lock(&timer_list
->active_timers_lock
);
488 ts
= timer_list
->active_timers
;
489 if (!timer_expired_ns(ts
, current_time
)) {
490 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
494 /* remove timer from the list before calling the callback */
495 timer_list
->active_timers
= ts
->next
;
497 ts
->expire_time
= -1;
500 qemu_mutex_unlock(&timer_list
->active_timers_lock
);
502 /* run the callback (the timer list can be modified) */
508 qemu_event_set(&timer_list
->timers_done_ev
);
512 bool qemu_clock_run_timers(QEMUClockType type
)
514 return timerlist_run_timers(main_loop_tlg
.tl
[type
]);
517 void timerlistgroup_init(QEMUTimerListGroup
*tlg
,
518 QEMUTimerListNotifyCB
*cb
, void *opaque
)
521 for (type
= 0; type
< QEMU_CLOCK_MAX
; type
++) {
522 tlg
->tl
[type
] = timerlist_new(type
, cb
, opaque
);
526 void timerlistgroup_deinit(QEMUTimerListGroup
*tlg
)
529 for (type
= 0; type
< QEMU_CLOCK_MAX
; type
++) {
530 timerlist_free(tlg
->tl
[type
]);
534 bool timerlistgroup_run_timers(QEMUTimerListGroup
*tlg
)
537 bool progress
= false;
538 for (type
= 0; type
< QEMU_CLOCK_MAX
; type
++) {
539 progress
|= timerlist_run_timers(tlg
->tl
[type
]);
544 int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup
*tlg
)
546 int64_t deadline
= -1;
548 for (type
= 0; type
< QEMU_CLOCK_MAX
; type
++) {
549 if (qemu_clock_use_for_deadline(tlg
->tl
[type
]->clock
->type
)) {
550 deadline
= qemu_soonest_timeout(deadline
,
551 timerlist_deadline_ns(
558 int64_t qemu_clock_get_ns(QEMUClockType type
)
561 QEMUClock
*clock
= qemu_clock_ptr(type
);
564 case QEMU_CLOCK_REALTIME
:
567 case QEMU_CLOCK_VIRTUAL
:
569 return cpu_get_icount();
571 return cpu_get_clock();
573 case QEMU_CLOCK_HOST
:
574 now
= REPLAY_CLOCK(REPLAY_CLOCK_HOST
, get_clock_realtime());
577 if ((now
< last
|| now
> (last
+ get_max_clock_jump()))
578 && replay_mode
== REPLAY_MODE_NONE
) {
579 notifier_list_notify(&clock
->reset_notifiers
, &now
);
582 case QEMU_CLOCK_VIRTUAL_RT
:
583 return REPLAY_CLOCK(REPLAY_CLOCK_VIRTUAL_RT
, cpu_get_clock());
587 void qemu_clock_register_reset_notifier(QEMUClockType type
,
590 QEMUClock
*clock
= qemu_clock_ptr(type
);
591 notifier_list_add(&clock
->reset_notifiers
, notifier
);
594 void qemu_clock_unregister_reset_notifier(QEMUClockType type
,
597 notifier_remove(notifier
);
600 void init_clocks(void)
603 for (type
= 0; type
< QEMU_CLOCK_MAX
; type
++) {
604 qemu_clock_init(type
);
607 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
608 prctl(PR_SET_TIMERSLACK
, 1, 0, 0, 0);
612 uint64_t timer_expire_time_ns(QEMUTimer
*ts
)
614 return timer_pending(ts
) ? ts
->expire_time
: -1;
617 bool qemu_clock_run_all_timers(void)
619 bool progress
= false;
622 for (type
= 0; type
< QEMU_CLOCK_MAX
; type
++) {
623 progress
|= qemu_clock_run_timers(type
);