[qemu.git] / qemu-timer.c

/*
 * 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"

#include "qemu-timer.h"

#ifdef _WIN32
#include <mmsystem.h>
#endif

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

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

struct QEMUClock {
    QEMUTimer *active_timers;

    NotifierList reset_notifiers;
    int64_t last;

    int type;
    bool enabled;
};

struct QEMUTimer {
    int64_t expire_time;	/* in nanoseconds */
    QEMUClock *clock;
    QEMUTimerCB *cb;
    void *opaque;
    QEMUTimer *next;
    int scale;
};

struct qemu_alarm_timer {
    char const *name;
    int (*start)(struct qemu_alarm_timer *t);
    void (*stop)(struct qemu_alarm_timer *t);
    void (*rearm)(struct qemu_alarm_timer *t, int64_t nearest_delta_ns);
#if defined(__linux__)
    timer_t timer;
    int fd;
#elif defined(_WIN32)
    HANDLE timer;
#endif
    bool expired;
    bool pending;
};

static struct qemu_alarm_timer *alarm_timer;

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

static int64_t qemu_next_alarm_deadline(void)
{
    int64_t delta = INT64_MAX;
    int64_t rtdelta;

    if (!use_icount && vm_clock->enabled && vm_clock->active_timers) {
        delta = vm_clock->active_timers->expire_time -
                     qemu_get_clock_ns(vm_clock);
    }
    if (host_clock->enabled && host_clock->active_timers) {
        int64_t hdelta = host_clock->active_timers->expire_time -
                 qemu_get_clock_ns(host_clock);
        if (hdelta < delta) {
            delta = hdelta;
        }
    }
    if (rt_clock->enabled && rt_clock->active_timers) {
        rtdelta = (rt_clock->active_timers->expire_time -
                 qemu_get_clock_ns(rt_clock));
        if (rtdelta < delta) {
            delta = rtdelta;
        }
    }

    return delta;
}

static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)
{
    int64_t nearest_delta_ns;
    if (!rt_clock->active_timers &&
        !vm_clock->active_timers &&
        !host_clock->active_timers) {
        return;
    }
    nearest_delta_ns = qemu_next_alarm_deadline();
    t->rearm(t, nearest_delta_ns);
}

/* TODO: MIN_TIMER_REARM_NS should be optimized */
#define MIN_TIMER_REARM_NS 250000

#ifdef _WIN32

static int mm_start_timer(struct qemu_alarm_timer *t);
static void mm_stop_timer(struct qemu_alarm_timer *t);
static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);

static int win32_start_timer(struct qemu_alarm_timer *t);
static void win32_stop_timer(struct qemu_alarm_timer *t);
static void win32_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);

#else

static int unix_start_timer(struct qemu_alarm_timer *t);
static void unix_stop_timer(struct qemu_alarm_timer *t);
static void unix_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);

#ifdef __linux__

static int dynticks_start_timer(struct qemu_alarm_timer *t);
static void dynticks_stop_timer(struct qemu_alarm_timer *t);
static void dynticks_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);

#endif /* __linux__ */

#endif /* _WIN32 */

static struct qemu_alarm_timer alarm_timers[] = {
#ifndef _WIN32
#ifdef __linux__
    {"dynticks", dynticks_start_timer,
     dynticks_stop_timer, dynticks_rearm_timer},
#endif
    {"unix", unix_start_timer, unix_stop_timer, unix_rearm_timer},
#else
    {"mmtimer", mm_start_timer, mm_stop_timer, mm_rearm_timer},
    {"dynticks", win32_start_timer, win32_stop_timer, win32_rearm_timer},
#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;

    if (!strcmp(opt, "?")) {
        show_available_alarms();
        exit(0);
    }

    arg = g_strdup(opt);

    /* 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, ",");
    }

    g_free(arg);

    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;

    clock = g_malloc0(sizeof(QEMUClock));
    clock->type = type;
    clock->enabled = true;
    clock->last = INT64_MIN;
    notifier_list_init(&clock->reset_notifiers);
    return clock;
}

void qemu_clock_enable(QEMUClock *clock, bool enabled)
{
    bool old = clock->enabled;
    clock->enabled = enabled;
    if (enabled && !old) {
        qemu_rearm_alarm_timer(alarm_timer);
    }
}

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;
}

QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
                          QEMUTimerCB *cb, void *opaque)
{
    QEMUTimer *ts;

    ts = g_malloc0(sizeof(QEMUTimer));
    ts->clock = clock;
    ts->cb = cb;
    ts->opaque = opaque;
    ts->scale = scale;
    return ts;
}

void qemu_free_timer(QEMUTimer *ts)
{
    g_free(ts);
}

/* 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. */
    pt = &ts->clock->active_timers;
    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. */
void qemu_mod_timer_ns(QEMUTimer *ts, int64_t expire_time)
{
    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. */
    pt = &ts->clock->active_timers;
    for(;;) {
        t = *pt;
        if (!qemu_timer_expired_ns(t, expire_time)) {
            break;
        }
        pt = &t->next;
    }
    ts->expire_time = expire_time;
    ts->next = *pt;
    *pt = ts;

    /* Rearm if necessary  */
    if (pt == &ts->clock->active_timers) {
        if (!alarm_timer->pending) {
            qemu_rearm_alarm_timer(alarm_timer);
        }
        /* Interrupt execution to force deadline recalculation.  */
        qemu_clock_warp(ts->clock);
        if (use_icount) {
            qemu_notify_event();
        }
    }
}

void qemu_mod_timer(QEMUTimer *ts, int64_t expire_time)
{
    qemu_mod_timer_ns(ts, expire_time * ts->scale);
}

bool qemu_timer_pending(QEMUTimer *ts)
{
    QEMUTimer *t;
    for (t = ts->clock->active_timers; t != NULL; t = t->next) {
        if (t == ts) {
            return true;
        }
    }
    return false;
}

bool qemu_timer_expired(QEMUTimer *timer_head, int64_t current_time)
{
    return qemu_timer_expired_ns(timer_head, current_time * timer_head->scale);
}

void qemu_run_timers(QEMUClock *clock)
{
    QEMUTimer **ptimer_head, *ts;
    int64_t current_time;
   
    if (!clock->enabled)
        return;

    current_time = qemu_get_clock_ns(clock);
    ptimer_head = &clock->active_timers;
    for(;;) {
        ts = *ptimer_head;
        if (!qemu_timer_expired_ns(ts, current_time)) {
            break;
        }
        /* remove timer from the list before calling the callback */
        *ptimer_head = ts->next;
        ts->next = NULL;

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

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

    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:
        now = get_clock_realtime();
        last = clock->last;
        clock->last = now;
        if (now < last) {
            notifier_list_notify(&clock->reset_notifiers, &now);
        }
        return now;
    }
}

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)
{
    notifier_remove(notifier);
}

void init_clocks(void)
{
    rt_clock = qemu_new_clock(QEMU_CLOCK_REALTIME);
    vm_clock = qemu_new_clock(QEMU_CLOCK_VIRTUAL);
    host_clock = qemu_new_clock(QEMU_CLOCK_HOST);
}

uint64_t qemu_timer_expire_time_ns(QEMUTimer *ts)
{
    return qemu_timer_pending(ts) ? ts->expire_time : -1;
}

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

    /* vm time timers */
    qemu_run_timers(vm_clock);
    qemu_run_timers(rt_clock);
    qemu_run_timers(host_clock);

    /* rearm timer, if not periodic */
    if (alarm_timer->expired) {
        alarm_timer->expired = false;
        qemu_rearm_alarm_timer(alarm_timer);
    }
}

#ifdef _WIN32
static void CALLBACK host_alarm_handler(PVOID lpParam, BOOLEAN unused)
#else
static void host_alarm_handler(int host_signum)
#endif
{
    struct qemu_alarm_timer *t = alarm_timer;
    if (!t)
	return;

    t->expired = true;
    t->pending = true;
    qemu_notify_event();
}

#if defined(__linux__)

#include "compatfd.h"

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;
#ifdef SIGEV_THREAD_ID
    if (qemu_signalfd_available()) {
        ev.sigev_notify = SIGEV_THREAD_ID;
        ev._sigev_un._tid = qemu_get_thread_id();
    }
#endif /* SIGEV_THREAD_ID */
    ev.sigev_signo = SIGALRM;

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

    t->timer = host_timer;

    return 0;
}

static void dynticks_stop_timer(struct qemu_alarm_timer *t)
{
    timer_t host_timer = t->timer;

    timer_delete(host_timer);
}

static void dynticks_rearm_timer(struct qemu_alarm_timer *t,
                                 int64_t nearest_delta_ns)
{
    timer_t host_timer = t->timer;
    struct itimerspec timeout;
    int64_t current_ns;

    if (nearest_delta_ns < MIN_TIMER_REARM_NS)
        nearest_delta_ns = MIN_TIMER_REARM_NS;

    /* check whether a timer is already running */
    if (timer_gettime(host_timer, &timeout)) {
        perror("gettime");
        fprintf(stderr, "Internal timer error: aborting\n");
        exit(1);
    }
    current_ns = timeout.it_value.tv_sec * 1000000000LL + timeout.it_value.tv_nsec;
    if (current_ns && current_ns <= nearest_delta_ns)
        return;

    timeout.it_interval.tv_sec = 0;
    timeout.it_interval.tv_nsec = 0; /* 0 for one-shot timer */
    timeout.it_value.tv_sec =  nearest_delta_ns / 1000000000;
    timeout.it_value.tv_nsec = nearest_delta_ns % 1000000000;
    if (timer_settime(host_timer, 0 /* RELATIVE */, &timeout, NULL)) {
        perror("settime");
        fprintf(stderr, "Internal timer error: aborting\n");
        exit(1);
    }
}

#endif /* defined(__linux__) */

#if !defined(_WIN32)

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);
    return 0;
}

static void unix_rearm_timer(struct qemu_alarm_timer *t,
                             int64_t nearest_delta_ns)
{
    struct itimerval itv;
    int err;

    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);
    }
}

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

static MMRESULT mm_timer;
static TIMECAPS mm_tc;

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;
    }
    t->expired = true;
    t->pending = true;
    qemu_notify_event();
}

static int mm_start_timer(struct qemu_alarm_timer *t)
{
    timeGetDevCaps(&mm_tc, sizeof(mm_tc));

    timeBeginPeriod(mm_tc.wPeriodMin);

    mm_timer = timeSetEvent(mm_tc.wPeriodMin,   /* interval (ms) */
                            mm_tc.wPeriodMin,   /* resolution */
                            mm_alarm_handler,   /* function */
                            (DWORD_PTR)t,       /* parameter */
                            TIME_ONESHOT | TIME_CALLBACK_FUNCTION);

    if (!mm_timer) {
        fprintf(stderr, "Failed to initialize win32 alarm timer\n");
        timeEndPeriod(mm_tc.wPeriodMin);
        return -1;
    }

    return 0;
}

static void mm_stop_timer(struct qemu_alarm_timer *t)
{
    timeKillEvent(mm_timer);
    timeEndPeriod(mm_tc.wPeriodMin);
}

static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta)
{
    int64_t nearest_delta_ms = delta / 1000000;
    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;
    }

    timeKillEvent(mm_timer);
    mm_timer = timeSetEvent((UINT)nearest_delta_ms,
                            mm_tc.wPeriodMin,
                            mm_alarm_handler,
                            (DWORD_PTR)t,
                            TIME_ONESHOT | TIME_CALLBACK_FUNCTION);

    if (!mm_timer) {
        fprintf(stderr, "Failed to re-arm win32 alarm timer\n");
        timeEndPeriod(mm_tc.wPeriodMin);
        exit(1);
    }
}

static int win32_start_timer(struct qemu_alarm_timer *t)
{
    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,
                          3600000,
                          WT_EXECUTEINTIMERTHREAD);

    if (!success) {
        fprintf(stderr, "Failed to initialize win32 alarm timer: %ld\n",
                GetLastError());
        return -1;
    }

    t->timer = hTimer;
    return 0;
}

static void win32_stop_timer(struct qemu_alarm_timer *t)
{
    HANDLE hTimer = t->timer;

    if (hTimer) {
        DeleteTimerQueueTimer(NULL, hTimer, NULL);
    }
}

static void win32_rearm_timer(struct qemu_alarm_timer *t,
                              int64_t nearest_delta_ns)
{
    HANDLE hTimer = t->timer;
    int64_t nearest_delta_ms;
    BOOLEAN success;

    nearest_delta_ms = nearest_delta_ns / 1000000;
    if (nearest_delta_ms < 1) {
        nearest_delta_ms = 1;
    }
    /* ULONG_MAX can be 32 bit */
    if (nearest_delta_ms > ULONG_MAX) {
        nearest_delta_ms = ULONG_MAX;
    }
    success = ChangeTimerQueueTimer(NULL,
                                    hTimer,
                                    (unsigned long) nearest_delta_ms,
                                    3600000);

    if (!success) {
        fprintf(stderr, "Failed to rearm win32 alarm timer: %ld\n",
                GetLastError());
        exit(-1);
    }

}

#endif /* _WIN32 */

static void quit_timers(void)
{
    struct qemu_alarm_timer *t = alarm_timer;
    alarm_timer = NULL;
    t->stop(t);
}

int init_timer_alarm(void)
{
    struct qemu_alarm_timer *t = NULL;
    int i, err = -1;

    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;
    }

    /* first event is at time 0 */
    atexit(quit_timers);
    t->pending = true;
    alarm_timer = t;

    return 0;

fail:
    return err;
}
Commit	Line	Data
	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 "qemu-timer.h"
	33
	34	#ifdef _WIN32
	35	#include <mmsystem.h>
	36	#endif
	37
	38	/***********************************************************/
	39	/* timers */
	40
	41	#define QEMU_CLOCK_REALTIME 0
	42	#define QEMU_CLOCK_VIRTUAL 1
	43	#define QEMU_CLOCK_HOST 2
	44
	45	struct QEMUClock {
	46	QEMUTimer *active_timers;
	47
	48	NotifierList reset_notifiers;
	49	int64_t last;
	50
	51	int type;
	52	bool enabled;
	53	};
	54
	55	struct QEMUTimer {
	56	int64_t expire_time; /* in nanoseconds */
	57	QEMUClock *clock;
	58	QEMUTimerCB *cb;
	59	void *opaque;
	60	QEMUTimer *next;
	61	int scale;
	62	};
	63
	64	struct qemu_alarm_timer {
	65	char const *name;
	66	int (start)(struct qemu_alarm_timer t);
	67	void (stop)(struct qemu_alarm_timer t);
	68	void (rearm)(struct qemu_alarm_timer t, int64_t nearest_delta_ns);
	69	#if defined(__linux__)
	70	timer_t timer;
	71	int fd;
	72	#elif defined(_WIN32)
	73	HANDLE timer;
	74	#endif
	75	bool expired;
	76	bool pending;
	77	};
	78
	79	static struct qemu_alarm_timer *alarm_timer;
	80
	81	static bool qemu_timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
	82	{
	83	return timer_head && (timer_head->expire_time <= current_time);
	84	}
	85
	86	static int64_t qemu_next_alarm_deadline(void)
	87	{
	88	int64_t delta = INT64_MAX;
	89	int64_t rtdelta;
	90
	91	if (!use_icount && vm_clock->enabled && vm_clock->active_timers) {
	92	delta = vm_clock->active_timers->expire_time -
	93	qemu_get_clock_ns(vm_clock);
	94	}
	95	if (host_clock->enabled && host_clock->active_timers) {
	96	int64_t hdelta = host_clock->active_timers->expire_time -
	97	qemu_get_clock_ns(host_clock);
	98	if (hdelta < delta) {
	99	delta = hdelta;
	100	}
	101	}
	102	if (rt_clock->enabled && rt_clock->active_timers) {
	103	rtdelta = (rt_clock->active_timers->expire_time -
	104	qemu_get_clock_ns(rt_clock));
	105	if (rtdelta < delta) {
	106	delta = rtdelta;
	107	}
	108	}
	109
	110	return delta;
	111	}
	112
	113	static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)
	114	{
	115	int64_t nearest_delta_ns;
	116	if (!rt_clock->active_timers &&
	117	!vm_clock->active_timers &&
	118	!host_clock->active_timers) {
	119	return;
	120	}
	121	nearest_delta_ns = qemu_next_alarm_deadline();
	122	t->rearm(t, nearest_delta_ns);
	123	}
	124
	125	/* TODO: MIN_TIMER_REARM_NS should be optimized */
	126	#define MIN_TIMER_REARM_NS 250000
	127
	128	#ifdef _WIN32
	129
	130	static int mm_start_timer(struct qemu_alarm_timer *t);
	131	static void mm_stop_timer(struct qemu_alarm_timer *t);
	132	static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
	133
	134	static int win32_start_timer(struct qemu_alarm_timer *t);
	135	static void win32_stop_timer(struct qemu_alarm_timer *t);
	136	static void win32_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
	137
	138	#else
	139
	140	static int unix_start_timer(struct qemu_alarm_timer *t);
	141	static void unix_stop_timer(struct qemu_alarm_timer *t);
	142	static void unix_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
	143
	144	#ifdef __linux__
	145
	146	static int dynticks_start_timer(struct qemu_alarm_timer *t);
	147	static void dynticks_stop_timer(struct qemu_alarm_timer *t);
	148	static void dynticks_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
	149
	150	#endif /* __linux__ */
	151
	152	#endif /* _WIN32 */
	153
	154	static struct qemu_alarm_timer alarm_timers[] = {
	155	#ifndef _WIN32
	156	#ifdef __linux__
	157	{"dynticks", dynticks_start_timer,
	158	dynticks_stop_timer, dynticks_rearm_timer},
	159	#endif
	160	{"unix", unix_start_timer, unix_stop_timer, unix_rearm_timer},
	161	#else
	162	{"mmtimer", mm_start_timer, mm_stop_timer, mm_rearm_timer},
	163	{"dynticks", win32_start_timer, win32_stop_timer, win32_rearm_timer},
	164	#endif
	165	{NULL, }
	166	};
	167
	168	static void show_available_alarms(void)
	169	{
	170	int i;
	171
	172	printf("Available alarm timers, in order of precedence:\n");
	173	for (i = 0; alarm_timers[i].name; i++)
	174	printf("%s\n", alarm_timers[i].name);
	175	}
	176
	177	void configure_alarms(char const *opt)
	178	{
	179	int i;
	180	int cur = 0;
	181	int count = ARRAY_SIZE(alarm_timers) - 1;
	182	char *arg;
	183	char *name;
	184	struct qemu_alarm_timer tmp;
	185
	186	if (!strcmp(opt, "?")) {
	187	show_available_alarms();
	188	exit(0);
	189	}
	190
	191	arg = g_strdup(opt);
	192
	193	/* Reorder the array */
	194	name = strtok(arg, ",");
	195	while (name) {
	196	for (i = 0; i < count && alarm_timers[i].name; i++) {
	197	if (!strcmp(alarm_timers[i].name, name))
	198	break;
	199	}
	200
	201	if (i == count) {
	202	fprintf(stderr, "Unknown clock %s\n", name);
	203	goto next;
	204	}
	205
	206	if (i < cur)
	207	/* Ignore */
	208	goto next;
	209
	210	/* Swap */
	211	tmp = alarm_timers[i];
	212	alarm_timers[i] = alarm_timers[cur];
	213	alarm_timers[cur] = tmp;
	214
	215	cur++;
	216	next:
	217	name = strtok(NULL, ",");
	218	}
	219
	220	g_free(arg);
	221
	222	if (cur) {
	223	/* Disable remaining timers */
	224	for (i = cur; i < count; i++)
	225	alarm_timers[i].name = NULL;
	226	} else {
	227	show_available_alarms();
	228	exit(1);
	229	}
	230	}
	231
	232	QEMUClock *rt_clock;
	233	QEMUClock *vm_clock;
	234	QEMUClock *host_clock;
	235
	236	static QEMUClock *qemu_new_clock(int type)
	237	{
	238	QEMUClock *clock;
	239
	240	clock = g_malloc0(sizeof(QEMUClock));
	241	clock->type = type;
	242	clock->enabled = true;
	243	clock->last = INT64_MIN;
	244	notifier_list_init(&clock->reset_notifiers);
	245	return clock;
	246	}
	247
	248	void qemu_clock_enable(QEMUClock *clock, bool enabled)
	249	{
	250	bool old = clock->enabled;
	251	clock->enabled = enabled;
	252	if (enabled && !old) {
	253	qemu_rearm_alarm_timer(alarm_timer);
	254	}
	255	}
	256
	257	int64_t qemu_clock_has_timers(QEMUClock *clock)
	258	{
	259	return !!clock->active_timers;
	260	}
	261
	262	int64_t qemu_clock_expired(QEMUClock *clock)
	263	{
	264	return (clock->active_timers &&
	265	clock->active_timers->expire_time < qemu_get_clock_ns(clock));
	266	}
	267
	268	int64_t qemu_clock_deadline(QEMUClock *clock)
	269	{
	270	/* To avoid problems with overflow limit this to 2^32. */
	271	int64_t delta = INT32_MAX;
	272
	273	if (clock->active_timers) {
	274	delta = clock->active_timers->expire_time - qemu_get_clock_ns(clock);
	275	}
	276	if (delta < 0) {
	277	delta = 0;
	278	}
	279	return delta;
	280	}
	281
	282	QEMUTimer qemu_new_timer(QEMUClock clock, int scale,
	283	QEMUTimerCB cb, void opaque)
	284	{
	285	QEMUTimer *ts;
	286
	287	ts = g_malloc0(sizeof(QEMUTimer));
	288	ts->clock = clock;
	289	ts->cb = cb;
	290	ts->opaque = opaque;
	291	ts->scale = scale;
	292	return ts;
	293	}
	294
	295	void qemu_free_timer(QEMUTimer *ts)
	296	{
	297	g_free(ts);
	298	}
	299
	300	/* stop a timer, but do not dealloc it */
	301	void qemu_del_timer(QEMUTimer *ts)
	302	{
	303	QEMUTimer *pt, t;
	304
	305	/* NOTE: this code must be signal safe because
	306	qemu_timer_expired() can be called from a signal. */
	307	pt = &ts->clock->active_timers;
	308	for(;;) {
	309	t = *pt;
	310	if (!t)
	311	break;
	312	if (t == ts) {
	313	*pt = t->next;
	314	break;
	315	}
	316	pt = &t->next;
	317	}
	318	}
	319
	320	/* modify the current timer so that it will be fired when current_time
	321	>= expire_time. The corresponding callback will be called. */
	322	void qemu_mod_timer_ns(QEMUTimer *ts, int64_t expire_time)
	323	{
	324	QEMUTimer *pt, t;
	325
	326	qemu_del_timer(ts);
	327
	328	/* add the timer in the sorted list */
	329	/* NOTE: this code must be signal safe because
	330	qemu_timer_expired() can be called from a signal. */
	331	pt = &ts->clock->active_timers;
	332	for(;;) {
	333	t = *pt;
	334	if (!qemu_timer_expired_ns(t, expire_time)) {
	335	break;
	336	}
	337	pt = &t->next;
	338	}
	339	ts->expire_time = expire_time;
	340	ts->next = *pt;
	341	*pt = ts;
	342
	343	/* Rearm if necessary */
	344	if (pt == &ts->clock->active_timers) {
	345	if (!alarm_timer->pending) {
	346	qemu_rearm_alarm_timer(alarm_timer);
	347	}
	348	/* Interrupt execution to force deadline recalculation. */
	349	qemu_clock_warp(ts->clock);
	350	if (use_icount) {
	351	qemu_notify_event();
	352	}
	353	}
	354	}
	355
	356	void qemu_mod_timer(QEMUTimer *ts, int64_t expire_time)
	357	{
	358	qemu_mod_timer_ns(ts, expire_time * ts->scale);
	359	}
	360
	361	bool qemu_timer_pending(QEMUTimer *ts)
	362	{
	363	QEMUTimer *t;
	364	for (t = ts->clock->active_timers; t != NULL; t = t->next) {
	365	if (t == ts) {
	366	return true;
	367	}
	368	}
	369	return false;
	370	}
	371
	372	bool qemu_timer_expired(QEMUTimer *timer_head, int64_t current_time)
	373	{
	374	return qemu_timer_expired_ns(timer_head, current_time * timer_head->scale);
	375	}
	376
	377	void qemu_run_timers(QEMUClock *clock)
	378	{
	379	QEMUTimer *ptimer_head, ts;
	380	int64_t current_time;
	381
	382	if (!clock->enabled)
	383	return;
	384
	385	current_time = qemu_get_clock_ns(clock);
	386	ptimer_head = &clock->active_timers;
	387	for(;;) {
	388	ts = *ptimer_head;
	389	if (!qemu_timer_expired_ns(ts, current_time)) {
	390	break;
	391	}
	392	/* remove timer from the list before calling the callback */
	393	*ptimer_head = ts->next;
	394	ts->next = NULL;
	395
	396	/* run the callback (the timer list can be modified) */
	397	ts->cb(ts->opaque);
	398	}
	399	}
	400
	401	int64_t qemu_get_clock_ns(QEMUClock *clock)
	402	{
	403	int64_t now, last;
	404
	405	switch(clock->type) {
	406	case QEMU_CLOCK_REALTIME:
	407	return get_clock();
	408	default:
	409	case QEMU_CLOCK_VIRTUAL:
	410	if (use_icount) {
	411	return cpu_get_icount();
	412	} else {
	413	return cpu_get_clock();
	414	}
	415	case QEMU_CLOCK_HOST:
	416	now = get_clock_realtime();
	417	last = clock->last;
	418	clock->last = now;
	419	if (now < last) {
	420	notifier_list_notify(&clock->reset_notifiers, &now);
	421	}
	422	return now;
	423	}
	424	}
	425
	426	void qemu_register_clock_reset_notifier(QEMUClock clock, Notifier notifier)
	427	{
	428	notifier_list_add(&clock->reset_notifiers, notifier);
	429	}
	430
	431	void qemu_unregister_clock_reset_notifier(QEMUClock clock, Notifier notifier)
	432	{
	433	notifier_remove(notifier);
	434	}
	435
	436	void init_clocks(void)
	437	{
	438	rt_clock = qemu_new_clock(QEMU_CLOCK_REALTIME);
	439	vm_clock = qemu_new_clock(QEMU_CLOCK_VIRTUAL);
	440	host_clock = qemu_new_clock(QEMU_CLOCK_HOST);
	441	}
	442
	443	uint64_t qemu_timer_expire_time_ns(QEMUTimer *ts)
	444	{
	445	return qemu_timer_pending(ts) ? ts->expire_time : -1;
	446	}
	447
	448	void qemu_run_all_timers(void)
	449	{
	450	alarm_timer->pending = false;
	451
	452	/* vm time timers */
	453	qemu_run_timers(vm_clock);
	454	qemu_run_timers(rt_clock);
	455	qemu_run_timers(host_clock);
	456
	457	/* rearm timer, if not periodic */
	458	if (alarm_timer->expired) {
	459	alarm_timer->expired = false;
	460	qemu_rearm_alarm_timer(alarm_timer);
	461	}
	462	}
	463
	464	#ifdef _WIN32
	465	static void CALLBACK host_alarm_handler(PVOID lpParam, BOOLEAN unused)
	466	#else
	467	static void host_alarm_handler(int host_signum)
	468	#endif
	469	{
	470	struct qemu_alarm_timer *t = alarm_timer;
	471	if (!t)
	472	return;
	473
	474	t->expired = true;
	475	t->pending = true;
	476	qemu_notify_event();
	477	}
	478
	479	#if defined(__linux__)
	480
	481	#include "compatfd.h"
	482
	483	static int dynticks_start_timer(struct qemu_alarm_timer *t)
	484	{
	485	struct sigevent ev;
	486	timer_t host_timer;
	487	struct sigaction act;
	488
	489	sigfillset(&act.sa_mask);
	490	act.sa_flags = 0;
	491	act.sa_handler = host_alarm_handler;
	492
	493	sigaction(SIGALRM, &act, NULL);
	494
	495	/*
	496	* Initialize ev struct to 0 to avoid valgrind complaining
	497	* about uninitialized data in timer_create call
	498	*/
	499	memset(&ev, 0, sizeof(ev));
	500	ev.sigev_value.sival_int = 0;
	501	ev.sigev_notify = SIGEV_SIGNAL;
	502	#ifdef SIGEV_THREAD_ID
	503	if (qemu_signalfd_available()) {
	504	ev.sigev_notify = SIGEV_THREAD_ID;
	505	ev._sigev_un._tid = qemu_get_thread_id();
	506	}
	507	#endif /* SIGEV_THREAD_ID */
	508	ev.sigev_signo = SIGALRM;
	509
	510	if (timer_create(CLOCK_REALTIME, &ev, &host_timer)) {
	511	perror("timer_create");
	512	return -1;
	513	}
	514
	515	t->timer = host_timer;
	516
	517	return 0;
	518	}
	519
	520	static void dynticks_stop_timer(struct qemu_alarm_timer *t)
	521	{
	522	timer_t host_timer = t->timer;
	523
	524	timer_delete(host_timer);
	525	}
	526
	527	static void dynticks_rearm_timer(struct qemu_alarm_timer *t,
	528	int64_t nearest_delta_ns)
	529	{
	530	timer_t host_timer = t->timer;
	531	struct itimerspec timeout;
	532	int64_t current_ns;
	533
	534	if (nearest_delta_ns < MIN_TIMER_REARM_NS)
	535	nearest_delta_ns = MIN_TIMER_REARM_NS;
	536
	537	/* check whether a timer is already running */
	538	if (timer_gettime(host_timer, &timeout)) {
	539	perror("gettime");
	540	fprintf(stderr, "Internal timer error: aborting\n");
	541	exit(1);
	542	}
	543	current_ns = timeout.it_value.tv_sec * 1000000000LL + timeout.it_value.tv_nsec;
	544	if (current_ns && current_ns <= nearest_delta_ns)
	545	return;
	546
	547	timeout.it_interval.tv_sec = 0;
	548	timeout.it_interval.tv_nsec = 0; /* 0 for one-shot timer */
	549	timeout.it_value.tv_sec = nearest_delta_ns / 1000000000;
	550	timeout.it_value.tv_nsec = nearest_delta_ns % 1000000000;
	551	if (timer_settime(host_timer, 0 /* RELATIVE */, &timeout, NULL)) {
	552	perror("settime");
	553	fprintf(stderr, "Internal timer error: aborting\n");
	554	exit(1);
	555	}
	556	}
	557
	558	#endif /* defined(__linux__) */
	559
	560	#if !defined(_WIN32)
	561
	562	static int unix_start_timer(struct qemu_alarm_timer *t)
	563	{
	564	struct sigaction act;
	565
	566	/* timer signal */
	567	sigfillset(&act.sa_mask);
	568	act.sa_flags = 0;
	569	act.sa_handler = host_alarm_handler;
	570
	571	sigaction(SIGALRM, &act, NULL);
	572	return 0;
	573	}
	574
	575	static void unix_rearm_timer(struct qemu_alarm_timer *t,
	576	int64_t nearest_delta_ns)
	577	{
	578	struct itimerval itv;
	579	int err;
	580
	581	if (nearest_delta_ns < MIN_TIMER_REARM_NS)
	582	nearest_delta_ns = MIN_TIMER_REARM_NS;
	583
	584	itv.it_interval.tv_sec = 0;
	585	itv.it_interval.tv_usec = 0; /* 0 for one-shot timer */
	586	itv.it_value.tv_sec = nearest_delta_ns / 1000000000;
	587	itv.it_value.tv_usec = (nearest_delta_ns % 1000000000) / 1000;
	588	err = setitimer(ITIMER_REAL, &itv, NULL);
	589	if (err) {
	590	perror("setitimer");
	591	fprintf(stderr, "Internal timer error: aborting\n");
	592	exit(1);
	593	}
	594	}
	595
	596	static void unix_stop_timer(struct qemu_alarm_timer *t)
	597	{
	598	struct itimerval itv;
	599
	600	memset(&itv, 0, sizeof(itv));
	601	setitimer(ITIMER_REAL, &itv, NULL);
	602	}
	603
	604	#endif /* !defined(_WIN32) */
	605
	606
	607	#ifdef _WIN32
	608
	609	static MMRESULT mm_timer;
	610	static TIMECAPS mm_tc;
	611
	612	static void CALLBACK mm_alarm_handler(UINT uTimerID, UINT uMsg,
	613	DWORD_PTR dwUser, DWORD_PTR dw1,
	614	DWORD_PTR dw2)
	615	{
	616	struct qemu_alarm_timer *t = alarm_timer;
	617	if (!t) {
	618	return;
	619	}
	620	t->expired = true;
	621	t->pending = true;
	622	qemu_notify_event();
	623	}
	624
	625	static int mm_start_timer(struct qemu_alarm_timer *t)
	626	{
	627	timeGetDevCaps(&mm_tc, sizeof(mm_tc));
	628
	629	timeBeginPeriod(mm_tc.wPeriodMin);
	630
	631	mm_timer = timeSetEvent(mm_tc.wPeriodMin, /* interval (ms) */
	632	mm_tc.wPeriodMin, /* resolution */
	633	mm_alarm_handler, /* function */
	634	(DWORD_PTR)t, /* parameter */
	635	TIME_ONESHOT \| TIME_CALLBACK_FUNCTION);
	636
	637	if (!mm_timer) {
	638	fprintf(stderr, "Failed to initialize win32 alarm timer\n");
	639	timeEndPeriod(mm_tc.wPeriodMin);
	640	return -1;
	641	}
	642
	643	return 0;
	644	}
	645
	646	static void mm_stop_timer(struct qemu_alarm_timer *t)
	647	{
	648	timeKillEvent(mm_timer);
	649	timeEndPeriod(mm_tc.wPeriodMin);
	650	}
	651
	652	static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta)
	653	{
	654	int64_t nearest_delta_ms = delta / 1000000;
	655	if (nearest_delta_ms < mm_tc.wPeriodMin) {
	656	nearest_delta_ms = mm_tc.wPeriodMin;
	657	} else if (nearest_delta_ms > mm_tc.wPeriodMax) {
	658	nearest_delta_ms = mm_tc.wPeriodMax;
	659	}
	660
	661	timeKillEvent(mm_timer);
	662	mm_timer = timeSetEvent((UINT)nearest_delta_ms,
	663	mm_tc.wPeriodMin,
	664	mm_alarm_handler,
	665	(DWORD_PTR)t,
	666	TIME_ONESHOT \| TIME_CALLBACK_FUNCTION);
	667
	668	if (!mm_timer) {
	669	fprintf(stderr, "Failed to re-arm win32 alarm timer\n");
	670	timeEndPeriod(mm_tc.wPeriodMin);
	671	exit(1);
	672	}
	673	}
	674
	675	static int win32_start_timer(struct qemu_alarm_timer *t)
	676	{
	677	HANDLE hTimer;
	678	BOOLEAN success;
	679
	680	/* If you call ChangeTimerQueueTimer on a one-shot timer (its period
	681	is zero) that has already expired, the timer is not updated. Since
	682	creating a new timer is relatively expensive, set a bogus one-hour
	683	interval in the dynticks case. */
	684	success = CreateTimerQueueTimer(&hTimer,
	685	NULL,
	686	host_alarm_handler,
	687	t,
	688	1,
	689	3600000,
	690	WT_EXECUTEINTIMERTHREAD);
	691
	692	if (!success) {
	693	fprintf(stderr, "Failed to initialize win32 alarm timer: %ld\n",
	694	GetLastError());
	695	return -1;
	696	}
	697
	698	t->timer = hTimer;
	699	return 0;
	700	}
	701
	702	static void win32_stop_timer(struct qemu_alarm_timer *t)
	703	{
	704	HANDLE hTimer = t->timer;
	705
	706	if (hTimer) {
	707	DeleteTimerQueueTimer(NULL, hTimer, NULL);
	708	}
	709	}
	710
	711	static void win32_rearm_timer(struct qemu_alarm_timer *t,
	712	int64_t nearest_delta_ns)
	713	{
	714	HANDLE hTimer = t->timer;
	715	int64_t nearest_delta_ms;
	716	BOOLEAN success;
	717
	718	nearest_delta_ms = nearest_delta_ns / 1000000;
	719	if (nearest_delta_ms < 1) {
	720	nearest_delta_ms = 1;
	721	}
	722	/* ULONG_MAX can be 32 bit */
	723	if (nearest_delta_ms > ULONG_MAX) {
	724	nearest_delta_ms = ULONG_MAX;
	725	}
	726	success = ChangeTimerQueueTimer(NULL,
	727	hTimer,
	728	(unsigned long) nearest_delta_ms,
	729	3600000);
	730
	731	if (!success) {
	732	fprintf(stderr, "Failed to rearm win32 alarm timer: %ld\n",
	733	GetLastError());
	734	exit(-1);
	735	}
	736
	737	}
	738
	739	#endif /* _WIN32 */
	740
	741	static void quit_timers(void)
	742	{
	743	struct qemu_alarm_timer *t = alarm_timer;
	744	alarm_timer = NULL;
	745	t->stop(t);
	746	}
	747
	748	int init_timer_alarm(void)
	749	{
	750	struct qemu_alarm_timer *t = NULL;
	751	int i, err = -1;
	752
	753	for (i = 0; alarm_timers[i].name; i++) {
	754	t = &alarm_timers[i];
	755
	756	err = t->start(t);
	757	if (!err)
	758	break;
	759	}
	760
	761	if (err) {
	762	err = -ENOENT;
	763	goto fail;
	764	}
	765
	766	/* first event is at time 0 */
	767	atexit(quit_timers);
	768	t->pending = true;
	769	alarm_timer = t;
	770
	771	return 0;
	772
	773	fail:
	774	return err;
	775	}
	776