root / qemu-timer.c @ 7267c094
History | View | Annotate | Download (31.9 kB)
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 "sysemu.h" |
26 |
#include "net.h" |
27 |
#include "monitor.h" |
28 |
#include "console.h" |
29 |
|
30 |
#include "hw/hw.h" |
31 |
|
32 |
#include <unistd.h> |
33 |
#include <fcntl.h> |
34 |
#include <time.h> |
35 |
#include <errno.h> |
36 |
#include <sys/time.h> |
37 |
#include <signal.h> |
38 |
#ifdef __FreeBSD__
|
39 |
#include <sys/param.h> |
40 |
#endif
|
41 |
|
42 |
#ifdef _WIN32
|
43 |
#include <windows.h> |
44 |
#include <mmsystem.h> |
45 |
#endif
|
46 |
|
47 |
#include "qemu-timer.h" |
48 |
|
49 |
/* Conversion factor from emulated instructions to virtual clock ticks. */
|
50 |
int icount_time_shift;
|
51 |
/* Arbitrarily pick 1MIPS as the minimum allowable speed. */
|
52 |
#define MAX_ICOUNT_SHIFT 10 |
53 |
/* Compensate for varying guest execution speed. */
|
54 |
int64_t qemu_icount_bias; |
55 |
static QEMUTimer *icount_rt_timer;
|
56 |
static QEMUTimer *icount_vm_timer;
|
57 |
|
58 |
/***********************************************************/
|
59 |
/* guest cycle counter */
|
60 |
|
61 |
typedef struct TimersState { |
62 |
int64_t cpu_ticks_prev; |
63 |
int64_t cpu_ticks_offset; |
64 |
int64_t cpu_clock_offset; |
65 |
int32_t cpu_ticks_enabled; |
66 |
int64_t dummy; |
67 |
} TimersState; |
68 |
|
69 |
TimersState timers_state; |
70 |
|
71 |
/* return the host CPU cycle counter and handle stop/restart */
|
72 |
int64_t cpu_get_ticks(void)
|
73 |
{ |
74 |
if (use_icount) {
|
75 |
return cpu_get_icount();
|
76 |
} |
77 |
if (!timers_state.cpu_ticks_enabled) {
|
78 |
return timers_state.cpu_ticks_offset;
|
79 |
} else {
|
80 |
int64_t ticks; |
81 |
ticks = cpu_get_real_ticks(); |
82 |
if (timers_state.cpu_ticks_prev > ticks) {
|
83 |
/* Note: non increasing ticks may happen if the host uses
|
84 |
software suspend */
|
85 |
timers_state.cpu_ticks_offset += timers_state.cpu_ticks_prev - ticks; |
86 |
} |
87 |
timers_state.cpu_ticks_prev = ticks; |
88 |
return ticks + timers_state.cpu_ticks_offset;
|
89 |
} |
90 |
} |
91 |
|
92 |
/* return the host CPU monotonic timer and handle stop/restart */
|
93 |
static int64_t cpu_get_clock(void) |
94 |
{ |
95 |
int64_t ti; |
96 |
if (!timers_state.cpu_ticks_enabled) {
|
97 |
return timers_state.cpu_clock_offset;
|
98 |
} else {
|
99 |
ti = get_clock(); |
100 |
return ti + timers_state.cpu_clock_offset;
|
101 |
} |
102 |
} |
103 |
|
104 |
#ifndef CONFIG_IOTHREAD
|
105 |
static int64_t qemu_icount_delta(void) |
106 |
{ |
107 |
if (!use_icount) {
|
108 |
return 5000 * (int64_t) 1000000; |
109 |
} else if (use_icount == 1) { |
110 |
/* When not using an adaptive execution frequency
|
111 |
we tend to get badly out of sync with real time,
|
112 |
so just delay for a reasonable amount of time. */
|
113 |
return 0; |
114 |
} else {
|
115 |
return cpu_get_icount() - cpu_get_clock();
|
116 |
} |
117 |
} |
118 |
#endif
|
119 |
|
120 |
/* enable cpu_get_ticks() */
|
121 |
void cpu_enable_ticks(void) |
122 |
{ |
123 |
if (!timers_state.cpu_ticks_enabled) {
|
124 |
timers_state.cpu_ticks_offset -= cpu_get_real_ticks(); |
125 |
timers_state.cpu_clock_offset -= get_clock(); |
126 |
timers_state.cpu_ticks_enabled = 1;
|
127 |
} |
128 |
} |
129 |
|
130 |
/* disable cpu_get_ticks() : the clock is stopped. You must not call
|
131 |
cpu_get_ticks() after that. */
|
132 |
void cpu_disable_ticks(void) |
133 |
{ |
134 |
if (timers_state.cpu_ticks_enabled) {
|
135 |
timers_state.cpu_ticks_offset = cpu_get_ticks(); |
136 |
timers_state.cpu_clock_offset = cpu_get_clock(); |
137 |
timers_state.cpu_ticks_enabled = 0;
|
138 |
} |
139 |
} |
140 |
|
141 |
/***********************************************************/
|
142 |
/* timers */
|
143 |
|
144 |
#define QEMU_CLOCK_REALTIME 0 |
145 |
#define QEMU_CLOCK_VIRTUAL 1 |
146 |
#define QEMU_CLOCK_HOST 2 |
147 |
|
148 |
struct QEMUClock {
|
149 |
int type;
|
150 |
int enabled;
|
151 |
|
152 |
QEMUTimer *warp_timer; |
153 |
|
154 |
NotifierList reset_notifiers; |
155 |
int64_t last; |
156 |
}; |
157 |
|
158 |
struct QEMUTimer {
|
159 |
QEMUClock *clock; |
160 |
int64_t expire_time; /* in nanoseconds */
|
161 |
int scale;
|
162 |
QEMUTimerCB *cb; |
163 |
void *opaque;
|
164 |
struct QEMUTimer *next;
|
165 |
}; |
166 |
|
167 |
struct qemu_alarm_timer {
|
168 |
char const *name; |
169 |
int (*start)(struct qemu_alarm_timer *t); |
170 |
void (*stop)(struct qemu_alarm_timer *t); |
171 |
void (*rearm)(struct qemu_alarm_timer *t); |
172 |
#if defined(__linux__)
|
173 |
int fd;
|
174 |
timer_t timer; |
175 |
#elif defined(_WIN32)
|
176 |
HANDLE timer; |
177 |
#endif
|
178 |
char expired;
|
179 |
char pending;
|
180 |
}; |
181 |
|
182 |
static struct qemu_alarm_timer *alarm_timer; |
183 |
|
184 |
static bool qemu_timer_expired_ns(QEMUTimer *timer_head, int64_t current_time) |
185 |
{ |
186 |
return timer_head && (timer_head->expire_time <= current_time);
|
187 |
} |
188 |
|
189 |
int qemu_alarm_pending(void) |
190 |
{ |
191 |
return alarm_timer->pending;
|
192 |
} |
193 |
|
194 |
static inline int alarm_has_dynticks(struct qemu_alarm_timer *t) |
195 |
{ |
196 |
return !!t->rearm;
|
197 |
} |
198 |
|
199 |
static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t) |
200 |
{ |
201 |
if (!alarm_has_dynticks(t))
|
202 |
return;
|
203 |
|
204 |
t->rearm(t); |
205 |
} |
206 |
|
207 |
/* TODO: MIN_TIMER_REARM_NS should be optimized */
|
208 |
#define MIN_TIMER_REARM_NS 250000 |
209 |
|
210 |
#ifdef _WIN32
|
211 |
|
212 |
static int mm_start_timer(struct qemu_alarm_timer *t); |
213 |
static void mm_stop_timer(struct qemu_alarm_timer *t); |
214 |
static void mm_rearm_timer(struct qemu_alarm_timer *t); |
215 |
|
216 |
static int win32_start_timer(struct qemu_alarm_timer *t); |
217 |
static void win32_stop_timer(struct qemu_alarm_timer *t); |
218 |
static void win32_rearm_timer(struct qemu_alarm_timer *t); |
219 |
|
220 |
#else
|
221 |
|
222 |
static int unix_start_timer(struct qemu_alarm_timer *t); |
223 |
static void unix_stop_timer(struct qemu_alarm_timer *t); |
224 |
static void unix_rearm_timer(struct qemu_alarm_timer *t); |
225 |
|
226 |
#ifdef __linux__
|
227 |
|
228 |
static int dynticks_start_timer(struct qemu_alarm_timer *t); |
229 |
static void dynticks_stop_timer(struct qemu_alarm_timer *t); |
230 |
static void dynticks_rearm_timer(struct qemu_alarm_timer *t); |
231 |
|
232 |
#endif /* __linux__ */ |
233 |
|
234 |
#endif /* _WIN32 */ |
235 |
|
236 |
/* Correlation between real and virtual time is always going to be
|
237 |
fairly approximate, so ignore small variation.
|
238 |
When the guest is idle real and virtual time will be aligned in
|
239 |
the IO wait loop. */
|
240 |
#define ICOUNT_WOBBLE (get_ticks_per_sec() / 10) |
241 |
|
242 |
static void icount_adjust(void) |
243 |
{ |
244 |
int64_t cur_time; |
245 |
int64_t cur_icount; |
246 |
int64_t delta; |
247 |
static int64_t last_delta;
|
248 |
/* If the VM is not running, then do nothing. */
|
249 |
if (!vm_running)
|
250 |
return;
|
251 |
|
252 |
cur_time = cpu_get_clock(); |
253 |
cur_icount = qemu_get_clock_ns(vm_clock); |
254 |
delta = cur_icount - cur_time; |
255 |
/* FIXME: This is a very crude algorithm, somewhat prone to oscillation. */
|
256 |
if (delta > 0 |
257 |
&& last_delta + ICOUNT_WOBBLE < delta * 2
|
258 |
&& icount_time_shift > 0) {
|
259 |
/* The guest is getting too far ahead. Slow time down. */
|
260 |
icount_time_shift--; |
261 |
} |
262 |
if (delta < 0 |
263 |
&& last_delta - ICOUNT_WOBBLE > delta * 2
|
264 |
&& icount_time_shift < MAX_ICOUNT_SHIFT) { |
265 |
/* The guest is getting too far behind. Speed time up. */
|
266 |
icount_time_shift++; |
267 |
} |
268 |
last_delta = delta; |
269 |
qemu_icount_bias = cur_icount - (qemu_icount << icount_time_shift); |
270 |
} |
271 |
|
272 |
static void icount_adjust_rt(void * opaque) |
273 |
{ |
274 |
qemu_mod_timer(icount_rt_timer, |
275 |
qemu_get_clock_ms(rt_clock) + 1000);
|
276 |
icount_adjust(); |
277 |
} |
278 |
|
279 |
static void icount_adjust_vm(void * opaque) |
280 |
{ |
281 |
qemu_mod_timer(icount_vm_timer, |
282 |
qemu_get_clock_ns(vm_clock) + get_ticks_per_sec() / 10);
|
283 |
icount_adjust(); |
284 |
} |
285 |
|
286 |
int64_t qemu_icount_round(int64_t count) |
287 |
{ |
288 |
return (count + (1 << icount_time_shift) - 1) >> icount_time_shift; |
289 |
} |
290 |
|
291 |
static struct qemu_alarm_timer alarm_timers[] = { |
292 |
#ifndef _WIN32
|
293 |
#ifdef __linux__
|
294 |
{"dynticks", dynticks_start_timer,
|
295 |
dynticks_stop_timer, dynticks_rearm_timer}, |
296 |
#endif
|
297 |
{"unix", unix_start_timer, unix_stop_timer, unix_rearm_timer},
|
298 |
#else
|
299 |
{"mmtimer", mm_start_timer, mm_stop_timer, NULL}, |
300 |
{"mmtimer2", mm_start_timer, mm_stop_timer, mm_rearm_timer},
|
301 |
{"dynticks", win32_start_timer, win32_stop_timer, win32_rearm_timer},
|
302 |
{"win32", win32_start_timer, win32_stop_timer, NULL}, |
303 |
#endif
|
304 |
{NULL, }
|
305 |
}; |
306 |
|
307 |
static void show_available_alarms(void) |
308 |
{ |
309 |
int i;
|
310 |
|
311 |
printf("Available alarm timers, in order of precedence:\n");
|
312 |
for (i = 0; alarm_timers[i].name; i++) |
313 |
printf("%s\n", alarm_timers[i].name);
|
314 |
} |
315 |
|
316 |
void configure_alarms(char const *opt) |
317 |
{ |
318 |
int i;
|
319 |
int cur = 0; |
320 |
int count = ARRAY_SIZE(alarm_timers) - 1; |
321 |
char *arg;
|
322 |
char *name;
|
323 |
struct qemu_alarm_timer tmp;
|
324 |
|
325 |
if (!strcmp(opt, "?")) { |
326 |
show_available_alarms(); |
327 |
exit(0);
|
328 |
} |
329 |
|
330 |
arg = g_strdup(opt); |
331 |
|
332 |
/* Reorder the array */
|
333 |
name = strtok(arg, ",");
|
334 |
while (name) {
|
335 |
for (i = 0; i < count && alarm_timers[i].name; i++) { |
336 |
if (!strcmp(alarm_timers[i].name, name))
|
337 |
break;
|
338 |
} |
339 |
|
340 |
if (i == count) {
|
341 |
fprintf(stderr, "Unknown clock %s\n", name);
|
342 |
goto next;
|
343 |
} |
344 |
|
345 |
if (i < cur)
|
346 |
/* Ignore */
|
347 |
goto next;
|
348 |
|
349 |
/* Swap */
|
350 |
tmp = alarm_timers[i]; |
351 |
alarm_timers[i] = alarm_timers[cur]; |
352 |
alarm_timers[cur] = tmp; |
353 |
|
354 |
cur++; |
355 |
next:
|
356 |
name = strtok(NULL, ","); |
357 |
} |
358 |
|
359 |
g_free(arg); |
360 |
|
361 |
if (cur) {
|
362 |
/* Disable remaining timers */
|
363 |
for (i = cur; i < count; i++)
|
364 |
alarm_timers[i].name = NULL;
|
365 |
} else {
|
366 |
show_available_alarms(); |
367 |
exit(1);
|
368 |
} |
369 |
} |
370 |
|
371 |
#define QEMU_NUM_CLOCKS 3 |
372 |
|
373 |
QEMUClock *rt_clock; |
374 |
QEMUClock *vm_clock; |
375 |
QEMUClock *host_clock; |
376 |
|
377 |
static QEMUTimer *active_timers[QEMU_NUM_CLOCKS];
|
378 |
|
379 |
static QEMUClock *qemu_new_clock(int type) |
380 |
{ |
381 |
QEMUClock *clock; |
382 |
|
383 |
clock = g_malloc0(sizeof(QEMUClock));
|
384 |
clock->type = type; |
385 |
clock->enabled = 1;
|
386 |
notifier_list_init(&clock->reset_notifiers); |
387 |
/* required to detect & report backward jumps */
|
388 |
if (type == QEMU_CLOCK_HOST) {
|
389 |
clock->last = get_clock_realtime(); |
390 |
} |
391 |
return clock;
|
392 |
} |
393 |
|
394 |
void qemu_clock_enable(QEMUClock *clock, int enabled) |
395 |
{ |
396 |
clock->enabled = enabled; |
397 |
} |
398 |
|
399 |
static int64_t vm_clock_warp_start;
|
400 |
|
401 |
static void icount_warp_rt(void *opaque) |
402 |
{ |
403 |
if (vm_clock_warp_start == -1) { |
404 |
return;
|
405 |
} |
406 |
|
407 |
if (vm_running) {
|
408 |
int64_t clock = qemu_get_clock_ns(rt_clock); |
409 |
int64_t warp_delta = clock - vm_clock_warp_start; |
410 |
if (use_icount == 1) { |
411 |
qemu_icount_bias += warp_delta; |
412 |
} else {
|
413 |
/*
|
414 |
* In adaptive mode, do not let the vm_clock run too
|
415 |
* far ahead of real time.
|
416 |
*/
|
417 |
int64_t cur_time = cpu_get_clock(); |
418 |
int64_t cur_icount = qemu_get_clock_ns(vm_clock); |
419 |
int64_t delta = cur_time - cur_icount; |
420 |
qemu_icount_bias += MIN(warp_delta, delta); |
421 |
} |
422 |
if (qemu_timer_expired(active_timers[QEMU_CLOCK_VIRTUAL],
|
423 |
qemu_get_clock_ns(vm_clock))) { |
424 |
qemu_notify_event(); |
425 |
} |
426 |
} |
427 |
vm_clock_warp_start = -1;
|
428 |
} |
429 |
|
430 |
void qemu_clock_warp(QEMUClock *clock)
|
431 |
{ |
432 |
int64_t deadline; |
433 |
|
434 |
if (!clock->warp_timer) {
|
435 |
return;
|
436 |
} |
437 |
|
438 |
/*
|
439 |
* There are too many global variables to make the "warp" behavior
|
440 |
* applicable to other clocks. But a clock argument removes the
|
441 |
* need for if statements all over the place.
|
442 |
*/
|
443 |
assert(clock == vm_clock); |
444 |
|
445 |
/*
|
446 |
* If the CPUs have been sleeping, advance the vm_clock timer now. This
|
447 |
* ensures that the deadline for the timer is computed correctly below.
|
448 |
* This also makes sure that the insn counter is synchronized before the
|
449 |
* CPU starts running, in case the CPU is woken by an event other than
|
450 |
* the earliest vm_clock timer.
|
451 |
*/
|
452 |
icount_warp_rt(NULL);
|
453 |
if (!all_cpu_threads_idle() || !active_timers[clock->type]) {
|
454 |
qemu_del_timer(clock->warp_timer); |
455 |
return;
|
456 |
} |
457 |
|
458 |
vm_clock_warp_start = qemu_get_clock_ns(rt_clock); |
459 |
deadline = qemu_next_icount_deadline(); |
460 |
if (deadline > 0) { |
461 |
/*
|
462 |
* Ensure the vm_clock proceeds even when the virtual CPU goes to
|
463 |
* sleep. Otherwise, the CPU might be waiting for a future timer
|
464 |
* interrupt to wake it up, but the interrupt never comes because
|
465 |
* the vCPU isn't running any insns and thus doesn't advance the
|
466 |
* vm_clock.
|
467 |
*
|
468 |
* An extreme solution for this problem would be to never let VCPUs
|
469 |
* sleep in icount mode if there is a pending vm_clock timer; rather
|
470 |
* time could just advance to the next vm_clock event. Instead, we
|
471 |
* do stop VCPUs and only advance vm_clock after some "real" time,
|
472 |
* (related to the time left until the next event) has passed. This
|
473 |
* rt_clock timer will do this. This avoids that the warps are too
|
474 |
* visible externally---for example, you will not be sending network
|
475 |
* packets continously instead of every 100ms.
|
476 |
*/
|
477 |
qemu_mod_timer(clock->warp_timer, vm_clock_warp_start + deadline); |
478 |
} else {
|
479 |
qemu_notify_event(); |
480 |
} |
481 |
} |
482 |
|
483 |
QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
|
484 |
QEMUTimerCB *cb, void *opaque)
|
485 |
{ |
486 |
QEMUTimer *ts; |
487 |
|
488 |
ts = g_malloc0(sizeof(QEMUTimer));
|
489 |
ts->clock = clock; |
490 |
ts->cb = cb; |
491 |
ts->opaque = opaque; |
492 |
ts->scale = scale; |
493 |
return ts;
|
494 |
} |
495 |
|
496 |
void qemu_free_timer(QEMUTimer *ts)
|
497 |
{ |
498 |
g_free(ts); |
499 |
} |
500 |
|
501 |
/* stop a timer, but do not dealloc it */
|
502 |
void qemu_del_timer(QEMUTimer *ts)
|
503 |
{ |
504 |
QEMUTimer **pt, *t; |
505 |
|
506 |
/* NOTE: this code must be signal safe because
|
507 |
qemu_timer_expired() can be called from a signal. */
|
508 |
pt = &active_timers[ts->clock->type]; |
509 |
for(;;) {
|
510 |
t = *pt; |
511 |
if (!t)
|
512 |
break;
|
513 |
if (t == ts) {
|
514 |
*pt = t->next; |
515 |
break;
|
516 |
} |
517 |
pt = &t->next; |
518 |
} |
519 |
} |
520 |
|
521 |
/* modify the current timer so that it will be fired when current_time
|
522 |
>= expire_time. The corresponding callback will be called. */
|
523 |
static void qemu_mod_timer_ns(QEMUTimer *ts, int64_t expire_time) |
524 |
{ |
525 |
QEMUTimer **pt, *t; |
526 |
|
527 |
qemu_del_timer(ts); |
528 |
|
529 |
/* add the timer in the sorted list */
|
530 |
/* NOTE: this code must be signal safe because
|
531 |
qemu_timer_expired() can be called from a signal. */
|
532 |
pt = &active_timers[ts->clock->type]; |
533 |
for(;;) {
|
534 |
t = *pt; |
535 |
if (!qemu_timer_expired_ns(t, expire_time)) {
|
536 |
break;
|
537 |
} |
538 |
pt = &t->next; |
539 |
} |
540 |
ts->expire_time = expire_time; |
541 |
ts->next = *pt; |
542 |
*pt = ts; |
543 |
|
544 |
/* Rearm if necessary */
|
545 |
if (pt == &active_timers[ts->clock->type]) {
|
546 |
if (!alarm_timer->pending) {
|
547 |
qemu_rearm_alarm_timer(alarm_timer); |
548 |
} |
549 |
/* Interrupt execution to force deadline recalculation. */
|
550 |
qemu_clock_warp(ts->clock); |
551 |
if (use_icount) {
|
552 |
qemu_notify_event(); |
553 |
} |
554 |
} |
555 |
} |
556 |
|
557 |
/* modify the current timer so that it will be fired when current_time
|
558 |
>= expire_time. The corresponding callback will be called. */
|
559 |
void qemu_mod_timer(QEMUTimer *ts, int64_t expire_time)
|
560 |
{ |
561 |
qemu_mod_timer_ns(ts, expire_time * ts->scale); |
562 |
} |
563 |
|
564 |
int qemu_timer_pending(QEMUTimer *ts)
|
565 |
{ |
566 |
QEMUTimer *t; |
567 |
for(t = active_timers[ts->clock->type]; t != NULL; t = t->next) { |
568 |
if (t == ts)
|
569 |
return 1; |
570 |
} |
571 |
return 0; |
572 |
} |
573 |
|
574 |
int qemu_timer_expired(QEMUTimer *timer_head, int64_t current_time)
|
575 |
{ |
576 |
return qemu_timer_expired_ns(timer_head, current_time * timer_head->scale);
|
577 |
} |
578 |
|
579 |
static void qemu_run_timers(QEMUClock *clock) |
580 |
{ |
581 |
QEMUTimer **ptimer_head, *ts; |
582 |
int64_t current_time; |
583 |
|
584 |
if (!clock->enabled)
|
585 |
return;
|
586 |
|
587 |
current_time = qemu_get_clock_ns(clock); |
588 |
ptimer_head = &active_timers[clock->type]; |
589 |
for(;;) {
|
590 |
ts = *ptimer_head; |
591 |
if (!qemu_timer_expired_ns(ts, current_time)) {
|
592 |
break;
|
593 |
} |
594 |
/* remove timer from the list before calling the callback */
|
595 |
*ptimer_head = ts->next; |
596 |
ts->next = NULL;
|
597 |
|
598 |
/* run the callback (the timer list can be modified) */
|
599 |
ts->cb(ts->opaque); |
600 |
} |
601 |
} |
602 |
|
603 |
int64_t qemu_get_clock_ns(QEMUClock *clock) |
604 |
{ |
605 |
int64_t now, last; |
606 |
|
607 |
switch(clock->type) {
|
608 |
case QEMU_CLOCK_REALTIME:
|
609 |
return get_clock();
|
610 |
default:
|
611 |
case QEMU_CLOCK_VIRTUAL:
|
612 |
if (use_icount) {
|
613 |
return cpu_get_icount();
|
614 |
} else {
|
615 |
return cpu_get_clock();
|
616 |
} |
617 |
case QEMU_CLOCK_HOST:
|
618 |
now = get_clock_realtime(); |
619 |
last = clock->last; |
620 |
clock->last = now; |
621 |
if (now < last) {
|
622 |
notifier_list_notify(&clock->reset_notifiers, &now); |
623 |
} |
624 |
return now;
|
625 |
} |
626 |
} |
627 |
|
628 |
void qemu_register_clock_reset_notifier(QEMUClock *clock, Notifier *notifier)
|
629 |
{ |
630 |
notifier_list_add(&clock->reset_notifiers, notifier); |
631 |
} |
632 |
|
633 |
void qemu_unregister_clock_reset_notifier(QEMUClock *clock, Notifier *notifier)
|
634 |
{ |
635 |
notifier_list_remove(&clock->reset_notifiers, notifier); |
636 |
} |
637 |
|
638 |
void init_clocks(void) |
639 |
{ |
640 |
rt_clock = qemu_new_clock(QEMU_CLOCK_REALTIME); |
641 |
vm_clock = qemu_new_clock(QEMU_CLOCK_VIRTUAL); |
642 |
host_clock = qemu_new_clock(QEMU_CLOCK_HOST); |
643 |
|
644 |
rtc_clock = host_clock; |
645 |
} |
646 |
|
647 |
/* save a timer */
|
648 |
void qemu_put_timer(QEMUFile *f, QEMUTimer *ts)
|
649 |
{ |
650 |
uint64_t expire_time; |
651 |
|
652 |
if (qemu_timer_pending(ts)) {
|
653 |
expire_time = ts->expire_time; |
654 |
} else {
|
655 |
expire_time = -1;
|
656 |
} |
657 |
qemu_put_be64(f, expire_time); |
658 |
} |
659 |
|
660 |
void qemu_get_timer(QEMUFile *f, QEMUTimer *ts)
|
661 |
{ |
662 |
uint64_t expire_time; |
663 |
|
664 |
expire_time = qemu_get_be64(f); |
665 |
if (expire_time != -1) { |
666 |
qemu_mod_timer_ns(ts, expire_time); |
667 |
} else {
|
668 |
qemu_del_timer(ts); |
669 |
} |
670 |
} |
671 |
|
672 |
static const VMStateDescription vmstate_timers = { |
673 |
.name = "timer",
|
674 |
.version_id = 2,
|
675 |
.minimum_version_id = 1,
|
676 |
.minimum_version_id_old = 1,
|
677 |
.fields = (VMStateField []) { |
678 |
VMSTATE_INT64(cpu_ticks_offset, TimersState), |
679 |
VMSTATE_INT64(dummy, TimersState), |
680 |
VMSTATE_INT64_V(cpu_clock_offset, TimersState, 2),
|
681 |
VMSTATE_END_OF_LIST() |
682 |
} |
683 |
}; |
684 |
|
685 |
void configure_icount(const char *option) |
686 |
{ |
687 |
vmstate_register(NULL, 0, &vmstate_timers, &timers_state); |
688 |
if (!option)
|
689 |
return;
|
690 |
|
691 |
#ifdef CONFIG_IOTHREAD
|
692 |
vm_clock->warp_timer = qemu_new_timer_ns(rt_clock, icount_warp_rt, NULL);
|
693 |
#endif
|
694 |
|
695 |
if (strcmp(option, "auto") != 0) { |
696 |
icount_time_shift = strtol(option, NULL, 0); |
697 |
use_icount = 1;
|
698 |
return;
|
699 |
} |
700 |
|
701 |
use_icount = 2;
|
702 |
|
703 |
/* 125MIPS seems a reasonable initial guess at the guest speed.
|
704 |
It will be corrected fairly quickly anyway. */
|
705 |
icount_time_shift = 3;
|
706 |
|
707 |
/* Have both realtime and virtual time triggers for speed adjustment.
|
708 |
The realtime trigger catches emulated time passing too slowly,
|
709 |
the virtual time trigger catches emulated time passing too fast.
|
710 |
Realtime triggers occur even when idle, so use them less frequently
|
711 |
than VM triggers. */
|
712 |
icount_rt_timer = qemu_new_timer_ms(rt_clock, icount_adjust_rt, NULL);
|
713 |
qemu_mod_timer(icount_rt_timer, |
714 |
qemu_get_clock_ms(rt_clock) + 1000);
|
715 |
icount_vm_timer = qemu_new_timer_ns(vm_clock, icount_adjust_vm, NULL);
|
716 |
qemu_mod_timer(icount_vm_timer, |
717 |
qemu_get_clock_ns(vm_clock) + get_ticks_per_sec() / 10);
|
718 |
} |
719 |
|
720 |
void qemu_run_all_timers(void) |
721 |
{ |
722 |
alarm_timer->pending = 0;
|
723 |
|
724 |
/* rearm timer, if not periodic */
|
725 |
if (alarm_timer->expired) {
|
726 |
alarm_timer->expired = 0;
|
727 |
qemu_rearm_alarm_timer(alarm_timer); |
728 |
} |
729 |
|
730 |
/* vm time timers */
|
731 |
if (vm_running) {
|
732 |
qemu_run_timers(vm_clock); |
733 |
} |
734 |
|
735 |
qemu_run_timers(rt_clock); |
736 |
qemu_run_timers(host_clock); |
737 |
} |
738 |
|
739 |
static int64_t qemu_next_alarm_deadline(void); |
740 |
|
741 |
#ifdef _WIN32
|
742 |
static void CALLBACK host_alarm_handler(PVOID lpParam, BOOLEAN unused) |
743 |
#else
|
744 |
static void host_alarm_handler(int host_signum) |
745 |
#endif
|
746 |
{ |
747 |
struct qemu_alarm_timer *t = alarm_timer;
|
748 |
if (!t)
|
749 |
return;
|
750 |
|
751 |
#if 0
|
752 |
#define DISP_FREQ 1000
|
753 |
{
|
754 |
static int64_t delta_min = INT64_MAX;
|
755 |
static int64_t delta_max, delta_cum, last_clock, delta, ti;
|
756 |
static int count;
|
757 |
ti = qemu_get_clock_ns(vm_clock);
|
758 |
if (last_clock != 0) {
|
759 |
delta = ti - last_clock;
|
760 |
if (delta < delta_min)
|
761 |
delta_min = delta;
|
762 |
if (delta > delta_max)
|
763 |
delta_max = delta;
|
764 |
delta_cum += delta;
|
765 |
if (++count == DISP_FREQ) {
|
766 |
printf("timer: min=%" PRId64 " us max=%" PRId64 " us avg=%" PRId64 " us avg_freq=%0.3f Hz\n",
|
767 |
muldiv64(delta_min, 1000000, get_ticks_per_sec()),
|
768 |
muldiv64(delta_max, 1000000, get_ticks_per_sec()),
|
769 |
muldiv64(delta_cum, 1000000 / DISP_FREQ, get_ticks_per_sec()),
|
770 |
(double)get_ticks_per_sec() / ((double)delta_cum / DISP_FREQ));
|
771 |
count = 0;
|
772 |
delta_min = INT64_MAX;
|
773 |
delta_max = 0;
|
774 |
delta_cum = 0;
|
775 |
}
|
776 |
}
|
777 |
last_clock = ti;
|
778 |
}
|
779 |
#endif
|
780 |
if (alarm_has_dynticks(t) ||
|
781 |
qemu_next_alarm_deadline () <= 0) {
|
782 |
t->expired = alarm_has_dynticks(t); |
783 |
t->pending = 1;
|
784 |
qemu_notify_event(); |
785 |
} |
786 |
} |
787 |
|
788 |
int64_t qemu_next_icount_deadline(void)
|
789 |
{ |
790 |
/* To avoid problems with overflow limit this to 2^32. */
|
791 |
int64_t delta = INT32_MAX; |
792 |
|
793 |
assert(use_icount); |
794 |
if (active_timers[QEMU_CLOCK_VIRTUAL]) {
|
795 |
delta = active_timers[QEMU_CLOCK_VIRTUAL]->expire_time - |
796 |
qemu_get_clock_ns(vm_clock); |
797 |
} |
798 |
|
799 |
if (delta < 0) |
800 |
delta = 0;
|
801 |
|
802 |
return delta;
|
803 |
} |
804 |
|
805 |
static int64_t qemu_next_alarm_deadline(void) |
806 |
{ |
807 |
int64_t delta; |
808 |
int64_t rtdelta; |
809 |
|
810 |
if (!use_icount && active_timers[QEMU_CLOCK_VIRTUAL]) {
|
811 |
delta = active_timers[QEMU_CLOCK_VIRTUAL]->expire_time - |
812 |
qemu_get_clock_ns(vm_clock); |
813 |
} else {
|
814 |
delta = INT32_MAX; |
815 |
} |
816 |
if (active_timers[QEMU_CLOCK_HOST]) {
|
817 |
int64_t hdelta = active_timers[QEMU_CLOCK_HOST]->expire_time - |
818 |
qemu_get_clock_ns(host_clock); |
819 |
if (hdelta < delta)
|
820 |
delta = hdelta; |
821 |
} |
822 |
if (active_timers[QEMU_CLOCK_REALTIME]) {
|
823 |
rtdelta = (active_timers[QEMU_CLOCK_REALTIME]->expire_time - |
824 |
qemu_get_clock_ns(rt_clock)); |
825 |
if (rtdelta < delta)
|
826 |
delta = rtdelta; |
827 |
} |
828 |
|
829 |
return delta;
|
830 |
} |
831 |
|
832 |
#if defined(__linux__)
|
833 |
|
834 |
#include "compatfd.h" |
835 |
|
836 |
static int dynticks_start_timer(struct qemu_alarm_timer *t) |
837 |
{ |
838 |
struct sigevent ev;
|
839 |
timer_t host_timer; |
840 |
struct sigaction act;
|
841 |
|
842 |
sigfillset(&act.sa_mask); |
843 |
act.sa_flags = 0;
|
844 |
act.sa_handler = host_alarm_handler; |
845 |
|
846 |
sigaction(SIGALRM, &act, NULL);
|
847 |
|
848 |
/*
|
849 |
* Initialize ev struct to 0 to avoid valgrind complaining
|
850 |
* about uninitialized data in timer_create call
|
851 |
*/
|
852 |
memset(&ev, 0, sizeof(ev)); |
853 |
ev.sigev_value.sival_int = 0;
|
854 |
ev.sigev_notify = SIGEV_SIGNAL; |
855 |
#ifdef SIGEV_THREAD_ID
|
856 |
if (qemu_signalfd_available()) {
|
857 |
ev.sigev_notify = SIGEV_THREAD_ID; |
858 |
ev._sigev_un._tid = qemu_get_thread_id(); |
859 |
} |
860 |
#endif /* SIGEV_THREAD_ID */ |
861 |
ev.sigev_signo = SIGALRM; |
862 |
|
863 |
if (timer_create(CLOCK_REALTIME, &ev, &host_timer)) {
|
864 |
perror("timer_create");
|
865 |
|
866 |
/* disable dynticks */
|
867 |
fprintf(stderr, "Dynamic Ticks disabled\n");
|
868 |
|
869 |
return -1; |
870 |
} |
871 |
|
872 |
t->timer = host_timer; |
873 |
|
874 |
return 0; |
875 |
} |
876 |
|
877 |
static void dynticks_stop_timer(struct qemu_alarm_timer *t) |
878 |
{ |
879 |
timer_t host_timer = t->timer; |
880 |
|
881 |
timer_delete(host_timer); |
882 |
} |
883 |
|
884 |
static void dynticks_rearm_timer(struct qemu_alarm_timer *t) |
885 |
{ |
886 |
timer_t host_timer = t->timer; |
887 |
struct itimerspec timeout;
|
888 |
int64_t nearest_delta_ns = INT64_MAX; |
889 |
int64_t current_ns; |
890 |
|
891 |
assert(alarm_has_dynticks(t)); |
892 |
if (!active_timers[QEMU_CLOCK_REALTIME] &&
|
893 |
!active_timers[QEMU_CLOCK_VIRTUAL] && |
894 |
!active_timers[QEMU_CLOCK_HOST]) |
895 |
return;
|
896 |
|
897 |
nearest_delta_ns = qemu_next_alarm_deadline(); |
898 |
if (nearest_delta_ns < MIN_TIMER_REARM_NS)
|
899 |
nearest_delta_ns = MIN_TIMER_REARM_NS; |
900 |
|
901 |
/* check whether a timer is already running */
|
902 |
if (timer_gettime(host_timer, &timeout)) {
|
903 |
perror("gettime");
|
904 |
fprintf(stderr, "Internal timer error: aborting\n");
|
905 |
exit(1);
|
906 |
} |
907 |
current_ns = timeout.it_value.tv_sec * 1000000000LL + timeout.it_value.tv_nsec;
|
908 |
if (current_ns && current_ns <= nearest_delta_ns)
|
909 |
return;
|
910 |
|
911 |
timeout.it_interval.tv_sec = 0;
|
912 |
timeout.it_interval.tv_nsec = 0; /* 0 for one-shot timer */ |
913 |
timeout.it_value.tv_sec = nearest_delta_ns / 1000000000;
|
914 |
timeout.it_value.tv_nsec = nearest_delta_ns % 1000000000;
|
915 |
if (timer_settime(host_timer, 0 /* RELATIVE */, &timeout, NULL)) { |
916 |
perror("settime");
|
917 |
fprintf(stderr, "Internal timer error: aborting\n");
|
918 |
exit(1);
|
919 |
} |
920 |
} |
921 |
|
922 |
#endif /* defined(__linux__) */ |
923 |
|
924 |
#if !defined(_WIN32)
|
925 |
|
926 |
static int unix_start_timer(struct qemu_alarm_timer *t) |
927 |
{ |
928 |
struct sigaction act;
|
929 |
|
930 |
/* timer signal */
|
931 |
sigfillset(&act.sa_mask); |
932 |
act.sa_flags = 0;
|
933 |
act.sa_handler = host_alarm_handler; |
934 |
|
935 |
sigaction(SIGALRM, &act, NULL);
|
936 |
return 0; |
937 |
} |
938 |
|
939 |
static void unix_rearm_timer(struct qemu_alarm_timer *t) |
940 |
{ |
941 |
struct itimerval itv;
|
942 |
int64_t nearest_delta_ns = INT64_MAX; |
943 |
int err;
|
944 |
|
945 |
assert(alarm_has_dynticks(t)); |
946 |
if (!active_timers[QEMU_CLOCK_REALTIME] &&
|
947 |
!active_timers[QEMU_CLOCK_VIRTUAL] && |
948 |
!active_timers[QEMU_CLOCK_HOST]) |
949 |
return;
|
950 |
|
951 |
nearest_delta_ns = qemu_next_alarm_deadline(); |
952 |
if (nearest_delta_ns < MIN_TIMER_REARM_NS)
|
953 |
nearest_delta_ns = MIN_TIMER_REARM_NS; |
954 |
|
955 |
itv.it_interval.tv_sec = 0;
|
956 |
itv.it_interval.tv_usec = 0; /* 0 for one-shot timer */ |
957 |
itv.it_value.tv_sec = nearest_delta_ns / 1000000000;
|
958 |
itv.it_value.tv_usec = (nearest_delta_ns % 1000000000) / 1000; |
959 |
err = setitimer(ITIMER_REAL, &itv, NULL);
|
960 |
if (err) {
|
961 |
perror("setitimer");
|
962 |
fprintf(stderr, "Internal timer error: aborting\n");
|
963 |
exit(1);
|
964 |
} |
965 |
} |
966 |
|
967 |
static void unix_stop_timer(struct qemu_alarm_timer *t) |
968 |
{ |
969 |
struct itimerval itv;
|
970 |
|
971 |
memset(&itv, 0, sizeof(itv)); |
972 |
setitimer(ITIMER_REAL, &itv, NULL);
|
973 |
} |
974 |
|
975 |
#endif /* !defined(_WIN32) */ |
976 |
|
977 |
|
978 |
#ifdef _WIN32
|
979 |
|
980 |
static MMRESULT mm_timer;
|
981 |
static unsigned mm_period; |
982 |
|
983 |
static void CALLBACK mm_alarm_handler(UINT uTimerID, UINT uMsg, |
984 |
DWORD_PTR dwUser, DWORD_PTR dw1, |
985 |
DWORD_PTR dw2) |
986 |
{ |
987 |
struct qemu_alarm_timer *t = alarm_timer;
|
988 |
if (!t) {
|
989 |
return;
|
990 |
} |
991 |
if (alarm_has_dynticks(t) || qemu_next_alarm_deadline() <= 0) { |
992 |
t->expired = alarm_has_dynticks(t); |
993 |
t->pending = 1;
|
994 |
qemu_notify_event(); |
995 |
} |
996 |
} |
997 |
|
998 |
static int mm_start_timer(struct qemu_alarm_timer *t) |
999 |
{ |
1000 |
TIMECAPS tc; |
1001 |
UINT flags; |
1002 |
|
1003 |
memset(&tc, 0, sizeof(tc)); |
1004 |
timeGetDevCaps(&tc, sizeof(tc));
|
1005 |
|
1006 |
mm_period = tc.wPeriodMin; |
1007 |
timeBeginPeriod(mm_period); |
1008 |
|
1009 |
flags = TIME_CALLBACK_FUNCTION; |
1010 |
if (alarm_has_dynticks(t)) {
|
1011 |
flags |= TIME_ONESHOT; |
1012 |
} else {
|
1013 |
flags |= TIME_PERIODIC; |
1014 |
} |
1015 |
|
1016 |
mm_timer = timeSetEvent(1, /* interval (ms) */ |
1017 |
mm_period, /* resolution */
|
1018 |
mm_alarm_handler, /* function */
|
1019 |
(DWORD_PTR)t, /* parameter */
|
1020 |
flags); |
1021 |
|
1022 |
if (!mm_timer) {
|
1023 |
fprintf(stderr, "Failed to initialize win32 alarm timer: %ld\n",
|
1024 |
GetLastError()); |
1025 |
timeEndPeriod(mm_period); |
1026 |
return -1; |
1027 |
} |
1028 |
|
1029 |
return 0; |
1030 |
} |
1031 |
|
1032 |
static void mm_stop_timer(struct qemu_alarm_timer *t) |
1033 |
{ |
1034 |
timeKillEvent(mm_timer); |
1035 |
timeEndPeriod(mm_period); |
1036 |
} |
1037 |
|
1038 |
static void mm_rearm_timer(struct qemu_alarm_timer *t) |
1039 |
{ |
1040 |
int nearest_delta_ms;
|
1041 |
|
1042 |
assert(alarm_has_dynticks(t)); |
1043 |
if (!active_timers[QEMU_CLOCK_REALTIME] &&
|
1044 |
!active_timers[QEMU_CLOCK_VIRTUAL] && |
1045 |
!active_timers[QEMU_CLOCK_HOST]) { |
1046 |
return;
|
1047 |
} |
1048 |
|
1049 |
timeKillEvent(mm_timer); |
1050 |
|
1051 |
nearest_delta_ms = (qemu_next_alarm_deadline() + 999999) / 1000000; |
1052 |
if (nearest_delta_ms < 1) { |
1053 |
nearest_delta_ms = 1;
|
1054 |
} |
1055 |
mm_timer = timeSetEvent(nearest_delta_ms, |
1056 |
mm_period, |
1057 |
mm_alarm_handler, |
1058 |
(DWORD_PTR)t, |
1059 |
TIME_ONESHOT | TIME_CALLBACK_FUNCTION); |
1060 |
|
1061 |
if (!mm_timer) {
|
1062 |
fprintf(stderr, "Failed to re-arm win32 alarm timer %ld\n",
|
1063 |
GetLastError()); |
1064 |
|
1065 |
timeEndPeriod(mm_period); |
1066 |
exit(1);
|
1067 |
} |
1068 |
} |
1069 |
|
1070 |
static int win32_start_timer(struct qemu_alarm_timer *t) |
1071 |
{ |
1072 |
HANDLE hTimer; |
1073 |
BOOLEAN success; |
1074 |
|
1075 |
/* If you call ChangeTimerQueueTimer on a one-shot timer (its period
|
1076 |
is zero) that has already expired, the timer is not updated. Since
|
1077 |
creating a new timer is relatively expensive, set a bogus one-hour
|
1078 |
interval in the dynticks case. */
|
1079 |
success = CreateTimerQueueTimer(&hTimer, |
1080 |
NULL,
|
1081 |
host_alarm_handler, |
1082 |
t, |
1083 |
1,
|
1084 |
alarm_has_dynticks(t) ? 3600000 : 1, |
1085 |
WT_EXECUTEINTIMERTHREAD); |
1086 |
|
1087 |
if (!success) {
|
1088 |
fprintf(stderr, "Failed to initialize win32 alarm timer: %ld\n",
|
1089 |
GetLastError()); |
1090 |
return -1; |
1091 |
} |
1092 |
|
1093 |
t->timer = hTimer; |
1094 |
return 0; |
1095 |
} |
1096 |
|
1097 |
static void win32_stop_timer(struct qemu_alarm_timer *t) |
1098 |
{ |
1099 |
HANDLE hTimer = t->timer; |
1100 |
|
1101 |
if (hTimer) {
|
1102 |
DeleteTimerQueueTimer(NULL, hTimer, NULL); |
1103 |
} |
1104 |
} |
1105 |
|
1106 |
static void win32_rearm_timer(struct qemu_alarm_timer *t) |
1107 |
{ |
1108 |
HANDLE hTimer = t->timer; |
1109 |
int nearest_delta_ms;
|
1110 |
BOOLEAN success; |
1111 |
|
1112 |
assert(alarm_has_dynticks(t)); |
1113 |
if (!active_timers[QEMU_CLOCK_REALTIME] &&
|
1114 |
!active_timers[QEMU_CLOCK_VIRTUAL] && |
1115 |
!active_timers[QEMU_CLOCK_HOST]) |
1116 |
return;
|
1117 |
|
1118 |
nearest_delta_ms = (qemu_next_alarm_deadline() + 999999) / 1000000; |
1119 |
if (nearest_delta_ms < 1) { |
1120 |
nearest_delta_ms = 1;
|
1121 |
} |
1122 |
success = ChangeTimerQueueTimer(NULL,
|
1123 |
hTimer, |
1124 |
nearest_delta_ms, |
1125 |
3600000);
|
1126 |
|
1127 |
if (!success) {
|
1128 |
fprintf(stderr, "Failed to rearm win32 alarm timer: %ld\n",
|
1129 |
GetLastError()); |
1130 |
exit(-1);
|
1131 |
} |
1132 |
|
1133 |
} |
1134 |
|
1135 |
#endif /* _WIN32 */ |
1136 |
|
1137 |
static void alarm_timer_on_change_state_rearm(void *opaque, int running, int reason) |
1138 |
{ |
1139 |
if (running)
|
1140 |
qemu_rearm_alarm_timer((struct qemu_alarm_timer *) opaque);
|
1141 |
} |
1142 |
|
1143 |
int init_timer_alarm(void) |
1144 |
{ |
1145 |
struct qemu_alarm_timer *t = NULL; |
1146 |
int i, err = -1; |
1147 |
|
1148 |
for (i = 0; alarm_timers[i].name; i++) { |
1149 |
t = &alarm_timers[i]; |
1150 |
|
1151 |
err = t->start(t); |
1152 |
if (!err)
|
1153 |
break;
|
1154 |
} |
1155 |
|
1156 |
if (err) {
|
1157 |
err = -ENOENT; |
1158 |
goto fail;
|
1159 |
} |
1160 |
|
1161 |
/* first event is at time 0 */
|
1162 |
t->pending = 1;
|
1163 |
alarm_timer = t; |
1164 |
qemu_add_vm_change_state_handler(alarm_timer_on_change_state_rearm, t); |
1165 |
|
1166 |
return 0; |
1167 |
|
1168 |
fail:
|
1169 |
return err;
|
1170 |
} |
1171 |
|
1172 |
void quit_timers(void) |
1173 |
{ |
1174 |
struct qemu_alarm_timer *t = alarm_timer;
|
1175 |
alarm_timer = NULL;
|
1176 |
t->stop(t); |
1177 |
} |
1178 |
|
1179 |
int qemu_calculate_timeout(void) |
1180 |
{ |
1181 |
#ifndef CONFIG_IOTHREAD
|
1182 |
int timeout;
|
1183 |
|
1184 |
if (!vm_running)
|
1185 |
timeout = 5000;
|
1186 |
else {
|
1187 |
/* XXX: use timeout computed from timers */
|
1188 |
int64_t add; |
1189 |
int64_t delta; |
1190 |
/* Advance virtual time to the next event. */
|
1191 |
delta = qemu_icount_delta(); |
1192 |
if (delta > 0) { |
1193 |
/* If virtual time is ahead of real time then just
|
1194 |
wait for IO. */
|
1195 |
timeout = (delta + 999999) / 1000000; |
1196 |
} else {
|
1197 |
/* Wait for either IO to occur or the next
|
1198 |
timer event. */
|
1199 |
add = qemu_next_icount_deadline(); |
1200 |
/* We advance the timer before checking for IO.
|
1201 |
Limit the amount we advance so that early IO
|
1202 |
activity won't get the guest too far ahead. */
|
1203 |
if (add > 10000000) |
1204 |
add = 10000000;
|
1205 |
delta += add; |
1206 |
qemu_icount += qemu_icount_round (add); |
1207 |
timeout = delta / 1000000;
|
1208 |
if (timeout < 0) |
1209 |
timeout = 0;
|
1210 |
} |
1211 |
} |
1212 |
|
1213 |
return timeout;
|
1214 |
#else /* CONFIG_IOTHREAD */ |
1215 |
return 1000; |
1216 |
#endif
|
1217 |
} |
1218 |
|