qemu-timer.c 18.8 KB
Newer Older
Paolo Bonzini's avatar
Paolo Bonzini committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
/*
 * QEMU System Emulator
 *
 * Copyright (c) 2003-2008 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "sysemu.h"
#include "net.h"
#include "monitor.h"
#include "console.h"

#include "hw/hw.h"

32 33
#include "qemu-timer.h"

Paolo Bonzini's avatar
Paolo Bonzini committed
34 35 36 37 38 39 40 41 42 43 44 45
#ifdef _WIN32
#include <mmsystem.h>
#endif

/***********************************************************/
/* timers */

#define QEMU_CLOCK_REALTIME 0
#define QEMU_CLOCK_VIRTUAL  1
#define QEMU_CLOCK_HOST     2

struct QEMUClock {
46
    QEMUTimer *active_timers;
47 48 49

    NotifierList reset_notifiers;
    int64_t last;
50 51 52

    int type;
    bool enabled;
Paolo Bonzini's avatar
Paolo Bonzini committed
53 54 55
};

struct QEMUTimer {
56
    int64_t expire_time;	/* in nanoseconds */
57
    QEMUClock *clock;
Paolo Bonzini's avatar
Paolo Bonzini committed
58 59
    QEMUTimerCB *cb;
    void *opaque;
60 61
    QEMUTimer *next;
    int scale;
Paolo Bonzini's avatar
Paolo Bonzini committed
62 63 64 65 66 67
};

struct qemu_alarm_timer {
    char const *name;
    int (*start)(struct qemu_alarm_timer *t);
    void (*stop)(struct qemu_alarm_timer *t);
68
    void (*rearm)(struct qemu_alarm_timer *t, int64_t nearest_delta_ns);
Stefan Weil's avatar
Stefan Weil committed
69 70
#if defined(__linux__)
    timer_t timer;
71
    int fd;
Stefan Weil's avatar
Stefan Weil committed
72 73 74
#elif defined(_WIN32)
    HANDLE timer;
#endif
75 76
    bool expired;
    bool pending;
Paolo Bonzini's avatar
Paolo Bonzini committed
77 78 79 80
};

static struct qemu_alarm_timer *alarm_timer;

81 82 83 84 85
static bool qemu_timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
{
    return timer_head && (timer_head->expire_time <= current_time);
}

86 87
static int64_t qemu_next_alarm_deadline(void)
{
88
    int64_t delta = INT64_MAX;
89 90
    int64_t rtdelta;

91
    if (!use_icount && vm_clock->enabled && vm_clock->active_timers) {
92 93 94
        delta = vm_clock->active_timers->expire_time -
                     qemu_get_clock_ns(vm_clock);
    }
95
    if (host_clock->enabled && host_clock->active_timers) {
96 97 98 99 100 101
        int64_t hdelta = host_clock->active_timers->expire_time -
                 qemu_get_clock_ns(host_clock);
        if (hdelta < delta) {
            delta = hdelta;
        }
    }
102
    if (rt_clock->enabled && rt_clock->active_timers) {
103 104 105 106 107 108 109 110 111 112
        rtdelta = (rt_clock->active_timers->expire_time -
                 qemu_get_clock_ns(rt_clock));
        if (rtdelta < delta) {
            delta = rtdelta;
        }
    }

    return delta;
}

Paolo Bonzini's avatar
Paolo Bonzini committed
113 114
static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)
{
115 116 117
    int64_t nearest_delta_ns = qemu_next_alarm_deadline();
    if (nearest_delta_ns < INT64_MAX) {
        t->rearm(t, nearest_delta_ns);
118
    }
Paolo Bonzini's avatar
Paolo Bonzini committed
119 120
}

121 122
/* TODO: MIN_TIMER_REARM_NS should be optimized */
#define MIN_TIMER_REARM_NS 250000
Paolo Bonzini's avatar
Paolo Bonzini committed
123 124 125

#ifdef _WIN32

Stefan Weil's avatar
Stefan Weil committed
126 127
static int mm_start_timer(struct qemu_alarm_timer *t);
static void mm_stop_timer(struct qemu_alarm_timer *t);
128
static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
Stefan Weil's avatar
Stefan Weil committed
129

Paolo Bonzini's avatar
Paolo Bonzini committed
130 131
static int win32_start_timer(struct qemu_alarm_timer *t);
static void win32_stop_timer(struct qemu_alarm_timer *t);
132
static void win32_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
Paolo Bonzini's avatar
Paolo Bonzini committed
133 134 135 136 137

#else

static int unix_start_timer(struct qemu_alarm_timer *t);
static void unix_stop_timer(struct qemu_alarm_timer *t);
138
static void unix_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
Paolo Bonzini's avatar
Paolo Bonzini committed
139 140 141 142 143

#ifdef __linux__

static int dynticks_start_timer(struct qemu_alarm_timer *t);
static void dynticks_stop_timer(struct qemu_alarm_timer *t);
144
static void dynticks_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
Paolo Bonzini's avatar
Paolo Bonzini committed
145 146 147 148 149 150 151 152 153

#endif /* __linux__ */

#endif /* _WIN32 */

static struct qemu_alarm_timer alarm_timers[] = {
#ifndef _WIN32
#ifdef __linux__
    {"dynticks", dynticks_start_timer,
Stefan Weil's avatar
Stefan Weil committed
154
     dynticks_stop_timer, dynticks_rearm_timer},
Paolo Bonzini's avatar
Paolo Bonzini committed
155
#endif
156
    {"unix", unix_start_timer, unix_stop_timer, unix_rearm_timer},
Paolo Bonzini's avatar
Paolo Bonzini committed
157
#else
Paolo Bonzini's avatar
Paolo Bonzini committed
158
    {"mmtimer", mm_start_timer, mm_stop_timer, mm_rearm_timer},
Stefan Weil's avatar
Stefan Weil committed
159
    {"dynticks", win32_start_timer, win32_stop_timer, win32_rearm_timer},
Paolo Bonzini's avatar
Paolo Bonzini committed
160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181
#endif
    {NULL, }
};

static void show_available_alarms(void)
{
    int i;

    printf("Available alarm timers, in order of precedence:\n");
    for (i = 0; alarm_timers[i].name; i++)
        printf("%s\n", alarm_timers[i].name);
}

void configure_alarms(char const *opt)
{
    int i;
    int cur = 0;
    int count = ARRAY_SIZE(alarm_timers) - 1;
    char *arg;
    char *name;
    struct qemu_alarm_timer tmp;

182
    if (is_help_option(opt)) {
Paolo Bonzini's avatar
Paolo Bonzini committed
183 184 185 186
        show_available_alarms();
        exit(0);
    }

187
    arg = g_strdup(opt);
Paolo Bonzini's avatar
Paolo Bonzini committed
188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215

    /* Reorder the array */
    name = strtok(arg, ",");
    while (name) {
        for (i = 0; i < count && alarm_timers[i].name; i++) {
            if (!strcmp(alarm_timers[i].name, name))
                break;
        }

        if (i == count) {
            fprintf(stderr, "Unknown clock %s\n", name);
            goto next;
        }

        if (i < cur)
            /* Ignore */
            goto next;

	/* Swap */
        tmp = alarm_timers[i];
        alarm_timers[i] = alarm_timers[cur];
        alarm_timers[cur] = tmp;

        cur++;
next:
        name = strtok(NULL, ",");
    }

216
    g_free(arg);
Paolo Bonzini's avatar
Paolo Bonzini committed
217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234

    if (cur) {
        /* Disable remaining timers */
        for (i = cur; i < count; i++)
            alarm_timers[i].name = NULL;
    } else {
        show_available_alarms();
        exit(1);
    }
}

QEMUClock *rt_clock;
QEMUClock *vm_clock;
QEMUClock *host_clock;

static QEMUClock *qemu_new_clock(int type)
{
    QEMUClock *clock;
235

236
    clock = g_malloc0(sizeof(QEMUClock));
Paolo Bonzini's avatar
Paolo Bonzini committed
237
    clock->type = type;
238
    clock->enabled = true;
239
    clock->last = INT64_MIN;
240
    notifier_list_init(&clock->reset_notifiers);
Paolo Bonzini's avatar
Paolo Bonzini committed
241 242 243
    return clock;
}

244
void qemu_clock_enable(QEMUClock *clock, bool enabled)
Paolo Bonzini's avatar
Paolo Bonzini committed
245
{
246
    bool old = clock->enabled;
Paolo Bonzini's avatar
Paolo Bonzini committed
247
    clock->enabled = enabled;
248 249 250
    if (enabled && !old) {
        qemu_rearm_alarm_timer(alarm_timer);
    }
Paolo Bonzini's avatar
Paolo Bonzini committed
251 252
}

253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277
int64_t qemu_clock_has_timers(QEMUClock *clock)
{
    return !!clock->active_timers;
}

int64_t qemu_clock_expired(QEMUClock *clock)
{
    return (clock->active_timers &&
            clock->active_timers->expire_time < qemu_get_clock_ns(clock));
}

int64_t qemu_clock_deadline(QEMUClock *clock)
{
    /* To avoid problems with overflow limit this to 2^32.  */
    int64_t delta = INT32_MAX;

    if (clock->active_timers) {
        delta = clock->active_timers->expire_time - qemu_get_clock_ns(clock);
    }
    if (delta < 0) {
        delta = 0;
    }
    return delta;
}

278 279
QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
                          QEMUTimerCB *cb, void *opaque)
Paolo Bonzini's avatar
Paolo Bonzini committed
280 281 282
{
    QEMUTimer *ts;

283
    ts = g_malloc0(sizeof(QEMUTimer));
Paolo Bonzini's avatar
Paolo Bonzini committed
284 285 286
    ts->clock = clock;
    ts->cb = cb;
    ts->opaque = opaque;
287
    ts->scale = scale;
Paolo Bonzini's avatar
Paolo Bonzini committed
288 289 290 291 292
    return ts;
}

void qemu_free_timer(QEMUTimer *ts)
{
293
    g_free(ts);
Paolo Bonzini's avatar
Paolo Bonzini committed
294 295 296 297 298 299 300 301 302
}

/* stop a timer, but do not dealloc it */
void qemu_del_timer(QEMUTimer *ts)
{
    QEMUTimer **pt, *t;

    /* NOTE: this code must be signal safe because
       qemu_timer_expired() can be called from a signal. */
303
    pt = &ts->clock->active_timers;
Paolo Bonzini's avatar
Paolo Bonzini committed
304 305 306 307 308 309 310 311 312 313 314 315 316 317
    for(;;) {
        t = *pt;
        if (!t)
            break;
        if (t == ts) {
            *pt = t->next;
            break;
        }
        pt = &t->next;
    }
}

/* modify the current timer so that it will be fired when current_time
   >= expire_time. The corresponding callback will be called. */
318
void qemu_mod_timer_ns(QEMUTimer *ts, int64_t expire_time)
Paolo Bonzini's avatar
Paolo Bonzini committed
319 320 321 322 323 324 325 326
{
    QEMUTimer **pt, *t;

    qemu_del_timer(ts);

    /* add the timer in the sorted list */
    /* NOTE: this code must be signal safe because
       qemu_timer_expired() can be called from a signal. */
327
    pt = &ts->clock->active_timers;
Paolo Bonzini's avatar
Paolo Bonzini committed
328 329
    for(;;) {
        t = *pt;
330
        if (!qemu_timer_expired_ns(t, expire_time)) {
Paolo Bonzini's avatar
Paolo Bonzini committed
331
            break;
332
        }
Paolo Bonzini's avatar
Paolo Bonzini committed
333 334 335 336 337 338 339
        pt = &t->next;
    }
    ts->expire_time = expire_time;
    ts->next = *pt;
    *pt = ts;

    /* Rearm if necessary  */
340
    if (pt == &ts->clock->active_timers) {
Paolo Bonzini's avatar
Paolo Bonzini committed
341 342 343 344
        if (!alarm_timer->pending) {
            qemu_rearm_alarm_timer(alarm_timer);
        }
        /* Interrupt execution to force deadline recalculation.  */
345 346
        qemu_clock_warp(ts->clock);
        if (use_icount) {
Paolo Bonzini's avatar
Paolo Bonzini committed
347
            qemu_notify_event();
348
        }
Paolo Bonzini's avatar
Paolo Bonzini committed
349 350 351
    }
}

352 353 354 355 356
void qemu_mod_timer(QEMUTimer *ts, int64_t expire_time)
{
    qemu_mod_timer_ns(ts, expire_time * ts->scale);
}

357
bool qemu_timer_pending(QEMUTimer *ts)
Paolo Bonzini's avatar
Paolo Bonzini committed
358 359
{
    QEMUTimer *t;
360
    for (t = ts->clock->active_timers; t != NULL; t = t->next) {
361 362 363
        if (t == ts) {
            return true;
        }
Paolo Bonzini's avatar
Paolo Bonzini committed
364
    }
365
    return false;
Paolo Bonzini's avatar
Paolo Bonzini committed
366 367
}

368
bool qemu_timer_expired(QEMUTimer *timer_head, int64_t current_time)
Paolo Bonzini's avatar
Paolo Bonzini committed
369
{
370
    return qemu_timer_expired_ns(timer_head, current_time * timer_head->scale);
Paolo Bonzini's avatar
Paolo Bonzini committed
371 372
}

Paolo Bonzini's avatar
Paolo Bonzini committed
373
void qemu_run_timers(QEMUClock *clock)
Paolo Bonzini's avatar
Paolo Bonzini committed
374
{
375
    QEMUTimer *ts;
Paolo Bonzini's avatar
Paolo Bonzini committed
376 377 378 379 380
    int64_t current_time;
   
    if (!clock->enabled)
        return;

381
    current_time = qemu_get_clock_ns(clock);
Paolo Bonzini's avatar
Paolo Bonzini committed
382
    for(;;) {
383
        ts = clock->active_timers;
384
        if (!qemu_timer_expired_ns(ts, current_time)) {
Paolo Bonzini's avatar
Paolo Bonzini committed
385
            break;
386
        }
Paolo Bonzini's avatar
Paolo Bonzini committed
387
        /* remove timer from the list before calling the callback */
388
        clock->active_timers = ts->next;
Paolo Bonzini's avatar
Paolo Bonzini committed
389 390 391 392 393 394 395 396 397
        ts->next = NULL;

        /* run the callback (the timer list can be modified) */
        ts->cb(ts->opaque);
    }
}

int64_t qemu_get_clock_ns(QEMUClock *clock)
{
398 399
    int64_t now, last;

Paolo Bonzini's avatar
Paolo Bonzini committed
400 401 402 403 404 405 406 407 408 409 410
    switch(clock->type) {
    case QEMU_CLOCK_REALTIME:
        return get_clock();
    default:
    case QEMU_CLOCK_VIRTUAL:
        if (use_icount) {
            return cpu_get_icount();
        } else {
            return cpu_get_clock();
        }
    case QEMU_CLOCK_HOST:
411 412 413 414 415 416 417
        now = get_clock_realtime();
        last = clock->last;
        clock->last = now;
        if (now < last) {
            notifier_list_notify(&clock->reset_notifiers, &now);
        }
        return now;
Paolo Bonzini's avatar
Paolo Bonzini committed
418 419 420
    }
}

421 422 423 424 425 426 427
void qemu_register_clock_reset_notifier(QEMUClock *clock, Notifier *notifier)
{
    notifier_list_add(&clock->reset_notifiers, notifier);
}

void qemu_unregister_clock_reset_notifier(QEMUClock *clock, Notifier *notifier)
{
Paolo Bonzini's avatar
Paolo Bonzini committed
428
    notifier_remove(notifier);
429 430
}

Paolo Bonzini's avatar
Paolo Bonzini committed
431 432
void init_clocks(void)
{
433 434 435 436 437
    if (!rt_clock) {
        rt_clock = qemu_new_clock(QEMU_CLOCK_REALTIME);
        vm_clock = qemu_new_clock(QEMU_CLOCK_VIRTUAL);
        host_clock = qemu_new_clock(QEMU_CLOCK_HOST);
    }
Paolo Bonzini's avatar
Paolo Bonzini committed
438 439
}

440
uint64_t qemu_timer_expire_time_ns(QEMUTimer *ts)
Paolo Bonzini's avatar
Paolo Bonzini committed
441
{
442
    return qemu_timer_pending(ts) ? ts->expire_time : -1;
Paolo Bonzini's avatar
Paolo Bonzini committed
443 444 445 446
}

void qemu_run_all_timers(void)
{
447
    alarm_timer->pending = false;
448

449 450 451 452 453
    /* vm time timers */
    qemu_run_timers(vm_clock);
    qemu_run_timers(rt_clock);
    qemu_run_timers(host_clock);

Paolo Bonzini's avatar
Paolo Bonzini committed
454 455
    /* rearm timer, if not periodic */
    if (alarm_timer->expired) {
456
        alarm_timer->expired = false;
Paolo Bonzini's avatar
Paolo Bonzini committed
457 458 459 460 461
        qemu_rearm_alarm_timer(alarm_timer);
    }
}

#ifdef _WIN32
Paolo Bonzini's avatar
Paolo Bonzini committed
462
static void CALLBACK host_alarm_handler(PVOID lpParam, BOOLEAN unused)
Paolo Bonzini's avatar
Paolo Bonzini committed
463 464 465 466 467 468 469 470
#else
static void host_alarm_handler(int host_signum)
#endif
{
    struct qemu_alarm_timer *t = alarm_timer;
    if (!t)
	return;

471 472 473
    t->expired = true;
    t->pending = true;
    qemu_notify_event();
Paolo Bonzini's avatar
Paolo Bonzini committed
474 475
}

476 477
#if defined(__linux__)

478 479
#include "compatfd.h"

Paolo Bonzini's avatar
Paolo Bonzini committed
480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498
static int dynticks_start_timer(struct qemu_alarm_timer *t)
{
    struct sigevent ev;
    timer_t host_timer;
    struct sigaction act;

    sigfillset(&act.sa_mask);
    act.sa_flags = 0;
    act.sa_handler = host_alarm_handler;

    sigaction(SIGALRM, &act, NULL);

    /* 
     * Initialize ev struct to 0 to avoid valgrind complaining
     * about uninitialized data in timer_create call
     */
    memset(&ev, 0, sizeof(ev));
    ev.sigev_value.sival_int = 0;
    ev.sigev_notify = SIGEV_SIGNAL;
499
#ifdef CONFIG_SIGEV_THREAD_ID
500 501 502 503
    if (qemu_signalfd_available()) {
        ev.sigev_notify = SIGEV_THREAD_ID;
        ev._sigev_un._tid = qemu_get_thread_id();
    }
504
#endif /* CONFIG_SIGEV_THREAD_ID */
Paolo Bonzini's avatar
Paolo Bonzini committed
505 506 507 508 509 510 511
    ev.sigev_signo = SIGALRM;

    if (timer_create(CLOCK_REALTIME, &ev, &host_timer)) {
        perror("timer_create");
        return -1;
    }

Stefan Weil's avatar
Stefan Weil committed
512
    t->timer = host_timer;
Paolo Bonzini's avatar
Paolo Bonzini committed
513 514 515 516 517 518

    return 0;
}

static void dynticks_stop_timer(struct qemu_alarm_timer *t)
{
Stefan Weil's avatar
Stefan Weil committed
519
    timer_t host_timer = t->timer;
Paolo Bonzini's avatar
Paolo Bonzini committed
520 521 522 523

    timer_delete(host_timer);
}

524 525
static void dynticks_rearm_timer(struct qemu_alarm_timer *t,
                                 int64_t nearest_delta_ns)
Paolo Bonzini's avatar
Paolo Bonzini committed
526
{
Stefan Weil's avatar
Stefan Weil committed
527
    timer_t host_timer = t->timer;
Paolo Bonzini's avatar
Paolo Bonzini committed
528
    struct itimerspec timeout;
529
    int64_t current_ns;
Paolo Bonzini's avatar
Paolo Bonzini committed
530

531 532
    if (nearest_delta_ns < MIN_TIMER_REARM_NS)
        nearest_delta_ns = MIN_TIMER_REARM_NS;
Paolo Bonzini's avatar
Paolo Bonzini committed
533 534 535 536 537 538 539

    /* check whether a timer is already running */
    if (timer_gettime(host_timer, &timeout)) {
        perror("gettime");
        fprintf(stderr, "Internal timer error: aborting\n");
        exit(1);
    }
540 541
    current_ns = timeout.it_value.tv_sec * 1000000000LL + timeout.it_value.tv_nsec;
    if (current_ns && current_ns <= nearest_delta_ns)
Paolo Bonzini's avatar
Paolo Bonzini committed
542 543 544 545
        return;

    timeout.it_interval.tv_sec = 0;
    timeout.it_interval.tv_nsec = 0; /* 0 for one-shot timer */
546 547
    timeout.it_value.tv_sec =  nearest_delta_ns / 1000000000;
    timeout.it_value.tv_nsec = nearest_delta_ns % 1000000000;
Paolo Bonzini's avatar
Paolo Bonzini committed
548 549 550 551 552 553 554 555 556
    if (timer_settime(host_timer, 0 /* RELATIVE */, &timeout, NULL)) {
        perror("settime");
        fprintf(stderr, "Internal timer error: aborting\n");
        exit(1);
    }
}

#endif /* defined(__linux__) */

557 558
#if !defined(_WIN32)

Paolo Bonzini's avatar
Paolo Bonzini committed
559 560 561 562 563 564 565 566 567 568
static int unix_start_timer(struct qemu_alarm_timer *t)
{
    struct sigaction act;

    /* timer signal */
    sigfillset(&act.sa_mask);
    act.sa_flags = 0;
    act.sa_handler = host_alarm_handler;

    sigaction(SIGALRM, &act, NULL);
569 570
    return 0;
}
Paolo Bonzini's avatar
Paolo Bonzini committed
571

572 573
static void unix_rearm_timer(struct qemu_alarm_timer *t,
                             int64_t nearest_delta_ns)
574 575 576
{
    struct itimerval itv;
    int err;
Paolo Bonzini's avatar
Paolo Bonzini committed
577

578 579 580 581 582 583 584 585 586 587 588 589 590
    if (nearest_delta_ns < MIN_TIMER_REARM_NS)
        nearest_delta_ns = MIN_TIMER_REARM_NS;

    itv.it_interval.tv_sec = 0;
    itv.it_interval.tv_usec = 0; /* 0 for one-shot timer */
    itv.it_value.tv_sec =  nearest_delta_ns / 1000000000;
    itv.it_value.tv_usec = (nearest_delta_ns % 1000000000) / 1000;
    err = setitimer(ITIMER_REAL, &itv, NULL);
    if (err) {
        perror("setitimer");
        fprintf(stderr, "Internal timer error: aborting\n");
        exit(1);
    }
Paolo Bonzini's avatar
Paolo Bonzini committed
591 592 593 594 595 596 597 598 599 600 601 602 603 604 605
}

static void unix_stop_timer(struct qemu_alarm_timer *t)
{
    struct itimerval itv;

    memset(&itv, 0, sizeof(itv));
    setitimer(ITIMER_REAL, &itv, NULL);
}

#endif /* !defined(_WIN32) */


#ifdef _WIN32

Stefan Weil's avatar
Stefan Weil committed
606
static MMRESULT mm_timer;
607
static TIMECAPS mm_tc;
Stefan Weil's avatar
Stefan Weil committed
608 609 610 611 612 613 614 615 616

static void CALLBACK mm_alarm_handler(UINT uTimerID, UINT uMsg,
                                      DWORD_PTR dwUser, DWORD_PTR dw1,
                                      DWORD_PTR dw2)
{
    struct qemu_alarm_timer *t = alarm_timer;
    if (!t) {
        return;
    }
617 618 619
    t->expired = true;
    t->pending = true;
    qemu_notify_event();
Stefan Weil's avatar
Stefan Weil committed
620 621 622 623
}

static int mm_start_timer(struct qemu_alarm_timer *t)
{
624
    timeGetDevCaps(&mm_tc, sizeof(mm_tc));
Stefan Weil's avatar
Stefan Weil committed
625

626
    timeBeginPeriod(mm_tc.wPeriodMin);
Stefan Weil's avatar
Stefan Weil committed
627

628 629
    mm_timer = timeSetEvent(mm_tc.wPeriodMin,   /* interval (ms) */
                            mm_tc.wPeriodMin,   /* resolution */
Stefan Weil's avatar
Stefan Weil committed
630 631
                            mm_alarm_handler,   /* function */
                            (DWORD_PTR)t,       /* parameter */
632
                            TIME_ONESHOT | TIME_CALLBACK_FUNCTION);
Stefan Weil's avatar
Stefan Weil committed
633 634

    if (!mm_timer) {
635
        fprintf(stderr, "Failed to initialize win32 alarm timer\n");
636
        timeEndPeriod(mm_tc.wPeriodMin);
Stefan Weil's avatar
Stefan Weil committed
637 638 639 640 641 642 643 644 645
        return -1;
    }

    return 0;
}

static void mm_stop_timer(struct qemu_alarm_timer *t)
{
    timeKillEvent(mm_timer);
646
    timeEndPeriod(mm_tc.wPeriodMin);
Stefan Weil's avatar
Stefan Weil committed
647 648
}

649
static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta)
Stefan Weil's avatar
Stefan Weil committed
650
{
651
    int64_t nearest_delta_ms = delta / 1000000;
652 653 654 655
    if (nearest_delta_ms < mm_tc.wPeriodMin) {
        nearest_delta_ms = mm_tc.wPeriodMin;
    } else if (nearest_delta_ms > mm_tc.wPeriodMax) {
        nearest_delta_ms = mm_tc.wPeriodMax;
656
    }
657 658

    timeKillEvent(mm_timer);
659 660
    mm_timer = timeSetEvent((UINT)nearest_delta_ms,
                            mm_tc.wPeriodMin,
Stefan Weil's avatar
Stefan Weil committed
661 662 663 664 665
                            mm_alarm_handler,
                            (DWORD_PTR)t,
                            TIME_ONESHOT | TIME_CALLBACK_FUNCTION);

    if (!mm_timer) {
666
        fprintf(stderr, "Failed to re-arm win32 alarm timer\n");
667
        timeEndPeriod(mm_tc.wPeriodMin);
Stefan Weil's avatar
Stefan Weil committed
668 669 670 671
        exit(1);
    }
}

Paolo Bonzini's avatar
Paolo Bonzini committed
672 673
static int win32_start_timer(struct qemu_alarm_timer *t)
{
Paolo Bonzini's avatar
Paolo Bonzini committed
674 675 676 677 678 679 680 681 682 683 684 685
    HANDLE hTimer;
    BOOLEAN success;

    /* If you call ChangeTimerQueueTimer on a one-shot timer (its period
       is zero) that has already expired, the timer is not updated.  Since
       creating a new timer is relatively expensive, set a bogus one-hour
       interval in the dynticks case.  */
    success = CreateTimerQueueTimer(&hTimer,
                          NULL,
                          host_alarm_handler,
                          t,
                          1,
686
                          3600000,
Paolo Bonzini's avatar
Paolo Bonzini committed
687 688 689
                          WT_EXECUTEINTIMERTHREAD);

    if (!success) {
Paolo Bonzini's avatar
Paolo Bonzini committed
690 691 692 693 694
        fprintf(stderr, "Failed to initialize win32 alarm timer: %ld\n",
                GetLastError());
        return -1;
    }

Stefan Weil's avatar
Stefan Weil committed
695
    t->timer = hTimer;
Paolo Bonzini's avatar
Paolo Bonzini committed
696 697 698 699 700
    return 0;
}

static void win32_stop_timer(struct qemu_alarm_timer *t)
{
Stefan Weil's avatar
Stefan Weil committed
701
    HANDLE hTimer = t->timer;
Paolo Bonzini's avatar
Paolo Bonzini committed
702

Paolo Bonzini's avatar
Paolo Bonzini committed
703 704 705
    if (hTimer) {
        DeleteTimerQueueTimer(NULL, hTimer, NULL);
    }
Paolo Bonzini's avatar
Paolo Bonzini committed
706 707
}

708 709
static void win32_rearm_timer(struct qemu_alarm_timer *t,
                              int64_t nearest_delta_ns)
Paolo Bonzini's avatar
Paolo Bonzini committed
710
{
Stefan Weil's avatar
Stefan Weil committed
711
    HANDLE hTimer = t->timer;
712
    int64_t nearest_delta_ms;
Paolo Bonzini's avatar
Paolo Bonzini committed
713
    BOOLEAN success;
Paolo Bonzini's avatar
Paolo Bonzini committed
714

715
    nearest_delta_ms = nearest_delta_ns / 1000000;
716 717 718
    if (nearest_delta_ms < 1) {
        nearest_delta_ms = 1;
    }
719 720 721 722
    /* ULONG_MAX can be 32 bit */
    if (nearest_delta_ms > ULONG_MAX) {
        nearest_delta_ms = ULONG_MAX;
    }
Paolo Bonzini's avatar
Paolo Bonzini committed
723 724
    success = ChangeTimerQueueTimer(NULL,
                                    hTimer,
725
                                    (unsigned long) nearest_delta_ms,
Paolo Bonzini's avatar
Paolo Bonzini committed
726
                                    3600000);
Paolo Bonzini's avatar
Paolo Bonzini committed
727

Paolo Bonzini's avatar
Paolo Bonzini committed
728 729 730 731
    if (!success) {
        fprintf(stderr, "Failed to rearm win32 alarm timer: %ld\n",
                GetLastError());
        exit(-1);
Paolo Bonzini's avatar
Paolo Bonzini committed
732
    }
Paolo Bonzini's avatar
Paolo Bonzini committed
733

Paolo Bonzini's avatar
Paolo Bonzini committed
734 735 736 737
}

#endif /* _WIN32 */

738 739 740 741 742 743 744
static void quit_timers(void)
{
    struct qemu_alarm_timer *t = alarm_timer;
    alarm_timer = NULL;
    t->stop(t);
}

Paolo Bonzini's avatar
Paolo Bonzini committed
745 746 747 748 749
int init_timer_alarm(void)
{
    struct qemu_alarm_timer *t = NULL;
    int i, err = -1;

750 751 752 753
    if (alarm_timer) {
        return 0;
    }

Paolo Bonzini's avatar
Paolo Bonzini committed
754 755 756 757 758 759 760 761 762 763 764 765 766
    for (i = 0; alarm_timers[i].name; i++) {
        t = &alarm_timers[i];

        err = t->start(t);
        if (!err)
            break;
    }

    if (err) {
        err = -ENOENT;
        goto fail;
    }

767
    atexit(quit_timers);
Paolo Bonzini's avatar
Paolo Bonzini committed
768 769 770 771 772 773 774
    alarm_timer = t;
    return 0;

fail:
    return err;
}