qdev: Set the object property's description to the qdev property's.

[qemu.git] / qemu-timer.c

diff --git a/qemu-timer.c b/qemu-timer.c
index 4117addcdef14eab817fe050a6914829ea2f742c..00a5d35c3f64f5c9a65a5ade0e85273e3555e5c0 100644 (file)
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -33,272 +33,319 @@
 #include <pthread.h>
 #endif
 
 #include <pthread.h>
 #endif
 

-#ifdef _WIN32
-#include <mmsystem.h>
+#ifdef CONFIG_PPOLL
+#include <poll.h>
+#endif
+
+#ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
+#include <sys/prctl.h>

 #endif
 
 /***********************************************************/
 /* timers */
 
 #endif
 
 /***********************************************************/
 /* timers */
 

-struct QEMUClock {
-    QEMUTimer *active_timers;
+typedef struct QEMUClock {
+    /* We rely on BQL to protect the timerlists */
+    QLIST_HEAD(, QEMUTimerList) timerlists;

 
     NotifierList reset_notifiers;
     int64_t last;
 
 
     NotifierList reset_notifiers;
     int64_t last;
 

-    int type;
+    QEMUClockType type;

     bool enabled;
     bool enabled;

-};
+} QEMUClock;
+
+QEMUTimerListGroup main_loop_tlg;
+static QEMUClock qemu_clocks[QEMU_CLOCK_MAX];

 
 

-struct QEMUTimer {
-    int64_t expire_time;       /* in nanoseconds */
+/* A QEMUTimerList is a list of timers attached to a clock. More
+ * than one QEMUTimerList can be attached to each clock, for instance
+ * used by different AioContexts / threads. Each clock also has
+ * a list of the QEMUTimerLists associated with it, in order that
+ * reenabling the clock can call all the notifiers.
+ */
+
+struct QEMUTimerList {

     QEMUClock *clock;
     QEMUClock *clock;

-    QEMUTimerCB *cb;
-    void *opaque;
-    QEMUTimer *next;
-    int scale;
-};
+    QemuMutex active_timers_lock;
+    QEMUTimer *active_timers;
+    QLIST_ENTRY(QEMUTimerList) list;
+    QEMUTimerListNotifyCB *notify_cb;
+    void *notify_opaque;

 
 

-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;
+    /* lightweight method to mark the end of timerlist's running */
+    QemuEvent timers_done_ev;

 };
 
 };
 

-static struct qemu_alarm_timer *alarm_timer;
+/**
+ * qemu_clock_ptr:
+ * @type: type of clock
+ *
+ * Translate a clock type into a pointer to QEMUClock object.
+ *
+ * Returns: a pointer to the QEMUClock object
+ */
+static inline QEMUClock *qemu_clock_ptr(QEMUClockType type)
+{
+    return &qemu_clocks[type];
+}

 
 static bool timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
 {
     return timer_head && (timer_head->expire_time <= current_time);
 }
 
 
 static bool 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)
+QEMUTimerList *timerlist_new(QEMUClockType type,
+                             QEMUTimerListNotifyCB *cb,
+                             void *opaque)

 {
 {

-    int64_t delta = INT64_MAX;
-    int64_t rtdelta;
+    QEMUTimerList *timer_list;
+    QEMUClock *clock = qemu_clock_ptr(type);

 
 

-    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;
+    timer_list = g_malloc0(sizeof(QEMUTimerList));
+    qemu_event_init(&timer_list->timers_done_ev, false);
+    timer_list->clock = clock;
+    timer_list->notify_cb = cb;
+    timer_list->notify_opaque = opaque;
+    qemu_mutex_init(&timer_list->active_timers_lock);
+    QLIST_INSERT_HEAD(&clock->timerlists, timer_list, list);
+    return timer_list;

 }
 
 }
 

-static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)
+void timerlist_free(QEMUTimerList *timer_list)

 {
 {

-    int64_t nearest_delta_ns = qemu_next_alarm_deadline();
-    if (nearest_delta_ns < INT64_MAX) {
-        t->rearm(t, nearest_delta_ns);
+    assert(!timerlist_has_timers(timer_list));
+    if (timer_list->clock) {
+        QLIST_REMOVE(timer_list, list);

     }
     }

+    qemu_mutex_destroy(&timer_list->active_timers_lock);
+    g_free(timer_list);

 }
 
 }
 

-/* 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);
+static void qemu_clock_init(QEMUClockType type)
+{
+    QEMUClock *clock = qemu_clock_ptr(type);

 
 

-#ifdef __linux__
+    /* Assert that the clock of type TYPE has not been initialized yet. */
+    assert(main_loop_tlg.tl[type] == NULL);

 
 

-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);
+    clock->type = type;
+    clock->enabled = true;
+    clock->last = INT64_MIN;
+    QLIST_INIT(&clock->timerlists);
+    notifier_list_init(&clock->reset_notifiers);
+    main_loop_tlg.tl[type] = timerlist_new(type, NULL, NULL);
+}

 
 

-#endif /* __linux__ */
+bool qemu_clock_use_for_deadline(QEMUClockType type)
+{
+    return !(use_icount && (type == QEMU_CLOCK_VIRTUAL));
+}

 
 

-#endif /* _WIN32 */
+void qemu_clock_notify(QEMUClockType type)
+{
+    QEMUTimerList *timer_list;
+    QEMUClock *clock = qemu_clock_ptr(type);
+    QLIST_FOREACH(timer_list, &clock->timerlists, list) {
+        timerlist_notify(timer_list);
+    }
+}

 
 

-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, }
-};
+/* Disabling the clock will wait for related timerlists to stop
+ * executing qemu_run_timers.  Thus, this functions should not
+ * be used from the callback of a timer that is based on @clock.
+ * Doing so would cause a deadlock.
+ *
+ * Caller should hold BQL.
+ */
+void qemu_clock_enable(QEMUClockType type, bool enabled)
+{
+    QEMUClock *clock = qemu_clock_ptr(type);
+    QEMUTimerList *tl;
+    bool old = clock->enabled;
+    clock->enabled = enabled;
+    if (enabled && !old) {
+        qemu_clock_notify(type);
+    } else if (!enabled && old) {
+        QLIST_FOREACH(tl, &clock->timerlists, list) {
+            qemu_event_wait(&tl->timers_done_ev);
+        }
+    }
+}

 
 

-static void show_available_alarms(void)
+bool timerlist_has_timers(QEMUTimerList *timer_list)

 {
 {

-    int i;
+    return !!timer_list->active_timers;
+}

 
 

-    printf("Available alarm timers, in order of precedence:\n");
-    for (i = 0; alarm_timers[i].name; i++)
-        printf("%s\n", alarm_timers[i].name);
+bool qemu_clock_has_timers(QEMUClockType type)
+{
+    return timerlist_has_timers(
+        main_loop_tlg.tl[type]);

 }
 
 }
 

-void configure_alarms(char const *opt)
+bool timerlist_expired(QEMUTimerList *timer_list)

 {
 {

-    int i;
-    int cur = 0;
-    int count = ARRAY_SIZE(alarm_timers) - 1;
-    char *arg;
-    char *name;
-    struct qemu_alarm_timer tmp;
+    int64_t expire_time;

 
 

-    if (is_help_option(opt)) {
-        show_available_alarms();
-        exit(0);
+    qemu_mutex_lock(&timer_list->active_timers_lock);
+    if (!timer_list->active_timers) {
+        qemu_mutex_unlock(&timer_list->active_timers_lock);
+        return false;

     }
     }

+    expire_time = timer_list->active_timers->expire_time;
+    qemu_mutex_unlock(&timer_list->active_timers_lock);

 
 

-    arg = g_strdup(opt);
+    return expire_time < qemu_clock_get_ns(timer_list->clock->type);
+}

 
 

-    /* 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;
-        }
+bool qemu_clock_expired(QEMUClockType type)
+{
+    return timerlist_expired(
+        main_loop_tlg.tl[type]);
+}

 
 

-        if (i == count) {
-            fprintf(stderr, "Unknown clock %s\n", name);
-            goto next;
-        }
+/*
+ * As above, but return -1 for no deadline, and do not cap to 2^32
+ * as we know the result is always positive.
+ */

 
 

-        if (i < cur)
-            /* Ignore */
-            goto next;
+int64_t timerlist_deadline_ns(QEMUTimerList *timer_list)
+{
+    int64_t delta;
+    int64_t expire_time;

 
 

-       /* Swap */
-        tmp = alarm_timers[i];
-        alarm_timers[i] = alarm_timers[cur];
-        alarm_timers[cur] = tmp;
+    if (!timer_list->clock->enabled) {
+        return -1;
+    }

 
 

-        cur++;
-next:
-        name = strtok(NULL, ",");
+    /* The active timers list may be modified before the caller uses our return
+     * value but ->notify_cb() is called when the deadline changes.  Therefore
+     * the caller should notice the change and there is no race condition.
+     */
+    qemu_mutex_lock(&timer_list->active_timers_lock);
+    if (!timer_list->active_timers) {
+        qemu_mutex_unlock(&timer_list->active_timers_lock);
+        return -1;

     }
     }

+    expire_time = timer_list->active_timers->expire_time;
+    qemu_mutex_unlock(&timer_list->active_timers_lock);

 
 

-    g_free(arg);
+    delta = expire_time - qemu_clock_get_ns(timer_list->clock->type);

 
 

-    if (cur) {
-        /* Disable remaining timers */
-        for (i = cur; i < count; i++)
-            alarm_timers[i].name = NULL;
-    } else {
-        show_available_alarms();
-        exit(1);
+    if (delta <= 0) {
+        return 0;

     }
     }

-}

 
 

-QEMUClock *rt_clock;
-QEMUClock *vm_clock;
-QEMUClock *host_clock;
+    return delta;
+}

 
 

-static QEMUClock *qemu_clock_new(int type)
+/* Calculate the soonest deadline across all timerlists attached
+ * to the clock. This is used for the icount timeout so we
+ * ignore whether or not the clock should be used in deadline
+ * calculations.
+ */
+int64_t qemu_clock_deadline_ns_all(QEMUClockType 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;
+    int64_t deadline = -1;
+    QEMUTimerList *timer_list;
+    QEMUClock *clock = qemu_clock_ptr(type);
+    QLIST_FOREACH(timer_list, &clock->timerlists, list) {
+        deadline = qemu_soonest_timeout(deadline,
+                                        timerlist_deadline_ns(timer_list));
+    }
+    return deadline;

 }
 
 }
 

-void qemu_clock_enable(QEMUClock *clock, bool enabled)
+QEMUClockType timerlist_get_clock(QEMUTimerList *timer_list)

 {
 {

-    bool old = clock->enabled;
-    clock->enabled = enabled;
-    if (enabled && !old) {
-        qemu_rearm_alarm_timer(alarm_timer);
-    }
+    return timer_list->clock->type;

 }
 
 }
 

-int64_t qemu_clock_has_timers(QEMUClock *clock)
+QEMUTimerList *qemu_clock_get_main_loop_timerlist(QEMUClockType type)

 {
 {

-    return !!clock->active_timers;
+    return main_loop_tlg.tl[type];

 }
 
 }
 

-int64_t qemu_clock_expired(QEMUClock *clock)
+void timerlist_notify(QEMUTimerList *timer_list)

 {
 {

-    return (clock->active_timers &&
-            clock->active_timers->expire_time < qemu_get_clock_ns(clock));
+    if (timer_list->notify_cb) {
+        timer_list->notify_cb(timer_list->notify_opaque);
+    } else {
+        qemu_notify_event();
+    }

 }
 
 }
 

-int64_t qemu_clock_deadline(QEMUClock *clock)
+/* Transition function to convert a nanosecond timeout to ms
+ * This is used where a system does not support ppoll
+ */
+int qemu_timeout_ns_to_ms(int64_t ns)

 {
 {

-    /* To avoid problems with overflow limit this to 2^32.  */
-    int64_t delta = INT32_MAX;
+    int64_t ms;
+    if (ns < 0) {
+        return -1;
+    }

 
 

-    if (clock->active_timers) {
-        delta = clock->active_timers->expire_time - qemu_get_clock_ns(clock);
+    if (!ns) {
+        return 0;

     }
     }

-    if (delta < 0) {
-        delta = 0;
+
+    /* Always round up, because it's better to wait too long than to wait too
+     * little and effectively busy-wait
+     */
+    ms = (ns + SCALE_MS - 1) / SCALE_MS;
+
+    /* To avoid overflow problems, limit this to 2^31, i.e. approx 25 days */
+    if (ms > (int64_t) INT32_MAX) {
+        ms = INT32_MAX;

     }
     }

-    return delta;
+
+    return (int) ms;

 }
 
 }
 

-QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
-                          QEMUTimerCB *cb, void *opaque)
+
+/* qemu implementation of g_poll which uses a nanosecond timeout but is
+ * otherwise identical to g_poll
+ */
+int qemu_poll_ns(GPollFD *fds, guint nfds, int64_t timeout)

 {
 {

-    QEMUTimer *ts;
+#ifdef CONFIG_PPOLL
+    if (timeout < 0) {
+        return ppoll((struct pollfd *)fds, nfds, NULL, NULL);
+    } else {
+        struct timespec ts;
+        ts.tv_sec = timeout / 1000000000LL;
+        ts.tv_nsec = timeout % 1000000000LL;
+        return ppoll((struct pollfd *)fds, nfds, &ts, NULL);
+    }
+#else
+    return g_poll(fds, nfds, qemu_timeout_ns_to_ms(timeout));
+#endif
+}
+

 
 

-    ts = g_malloc0(sizeof(QEMUTimer));
-    ts->clock = clock;
+void timer_init(QEMUTimer *ts,
+                QEMUTimerList *timer_list, int scale,
+                QEMUTimerCB *cb, void *opaque)
+{
+    ts->timer_list = timer_list;

     ts->cb = cb;
     ts->opaque = opaque;
     ts->scale = scale;
     ts->cb = cb;
     ts->opaque = opaque;
     ts->scale = scale;

-    return ts;
+    ts->expire_time = -1;

 }
 
 }
 

-void qemu_free_timer(QEMUTimer *ts)
+void timer_free(QEMUTimer *ts)

 {
     g_free(ts);
 }
 
 {
     g_free(ts);
 }
 

-/* stop a timer, but do not dealloc it */
-void qemu_del_timer(QEMUTimer *ts)
+static void timer_del_locked(QEMUTimerList *timer_list, QEMUTimer *ts)

 {
     QEMUTimer **pt, *t;
 
 {
     QEMUTimer **pt, *t;
 

-    /* NOTE: this code must be signal safe because
-       timer_expired() can be called from a signal. */
-    pt = &ts->clock->active_timers;
+    ts->expire_time = -1;
+    pt = &timer_list->active_timers;

     for(;;) {
         t = *pt;
         if (!t)
     for(;;) {
         t = *pt;
         if (!t)


@@ -311,466 +358,255 @@ void qemu_del_timer(QEMUTimer *ts)
     }
 }
 
     }
 }
 

-/* 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)
+static bool timer_mod_ns_locked(QEMUTimerList *timer_list,
+                                QEMUTimer *ts, int64_t expire_time)

 {
     QEMUTimer **pt, *t;
 
 {
     QEMUTimer **pt, *t;
 

-    qemu_del_timer(ts);
-

     /* add the timer in the sorted list */
     /* add the timer in the sorted list */

-    /* NOTE: this code must be signal safe because
-       timer_expired() can be called from a signal. */
-    pt = &ts->clock->active_timers;
-    for(;;) {
+    pt = &timer_list->active_timers;
+    for (;;) {

         t = *pt;
         if (!timer_expired_ns(t, expire_time)) {
             break;
         }
         pt = &t->next;
     }
         t = *pt;
         if (!timer_expired_ns(t, expire_time)) {
             break;
         }
         pt = &t->next;
     }

-    ts->expire_time = expire_time;
+    ts->expire_time = MAX(expire_time, 0);

     ts->next = *pt;
     *pt = ts;
 
     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();
-        }
-    }
+    return pt == &timer_list->active_timers;

 }
 
 }
 

-void qemu_mod_timer(QEMUTimer *ts, int64_t expire_time)
+static void timerlist_rearm(QEMUTimerList *timer_list)

 {
 {

-    qemu_mod_timer_ns(ts, expire_time * ts->scale);
+    /* Interrupt execution to force deadline recalculation.  */
+    qemu_clock_warp(timer_list->clock->type);
+    timerlist_notify(timer_list);

 }
 
 }
 

-bool timer_pending(QEMUTimer *ts)
+/* stop a timer, but do not dealloc it */
+void timer_del(QEMUTimer *ts)

 {
 {

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

 
 

-bool timer_expired(QEMUTimer *timer_head, int64_t current_time)
-{
-    return timer_expired_ns(timer_head, current_time * timer_head->scale);
+    qemu_mutex_lock(&timer_list->active_timers_lock);
+    timer_del_locked(timer_list, ts);
+    qemu_mutex_unlock(&timer_list->active_timers_lock);

 }
 
 }
 

-void qemu_run_timers(QEMUClock *clock)
+/* modify the current timer so that it will be fired when current_time
+   >= expire_time. The corresponding callback will be called. */
+void timer_mod_ns(QEMUTimer *ts, int64_t expire_time)

 {
 {

-    QEMUTimer *ts;
-    int64_t current_time;
-   
-    if (!clock->enabled)
-        return;
+    QEMUTimerList *timer_list = ts->timer_list;
+    bool rearm;

 
 

-    current_time = qemu_get_clock_ns(clock);
-    for(;;) {
-        ts = clock->active_timers;
-        if (!timer_expired_ns(ts, current_time)) {
-            break;
-        }
-        /* remove timer from the list before calling the callback */
-        clock->active_timers = ts->next;
-        ts->next = NULL;
+    qemu_mutex_lock(&timer_list->active_timers_lock);
+    timer_del_locked(timer_list, ts);
+    rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
+    qemu_mutex_unlock(&timer_list->active_timers_lock);

 
 

-        /* run the callback (the timer list can be modified) */
-        ts->cb(ts->opaque);
+    if (rearm) {
+        timerlist_rearm(timer_list);

     }
 }
 
     }
 }
 

-int64_t qemu_get_clock_ns(QEMUClock *clock)
+/* modify the current timer so that it will be fired when current_time
+   >= expire_time or the current deadline, whichever comes earlier.
+   The corresponding callback will be called. */
+void timer_mod_anticipate_ns(QEMUTimer *ts, int64_t expire_time)

 {
 {

-    int64_t now, last;
+    QEMUTimerList *timer_list = ts->timer_list;
+    bool rearm;

 
 

-    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();
+    qemu_mutex_lock(&timer_list->active_timers_lock);
+    if (ts->expire_time == -1 || ts->expire_time > expire_time) {
+        if (ts->expire_time != -1) {
+            timer_del_locked(timer_list, ts);

         }
         }

-    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;
+        rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
+    } else {
+        rearm = false;

     }
     }

-}
+    qemu_mutex_unlock(&timer_list->active_timers_lock);

 
 

-void qemu_register_clock_reset_notifier(QEMUClock *clock, Notifier *notifier)
-{
-    notifier_list_add(&clock->reset_notifiers, notifier);
+    if (rearm) {
+        timerlist_rearm(timer_list);
+    }

 }
 
 }
 

-void qemu_unregister_clock_reset_notifier(QEMUClock *clock, Notifier *notifier)
+void timer_mod(QEMUTimer *ts, int64_t expire_time)

 {
 {

-    notifier_remove(notifier);
+    timer_mod_ns(ts, expire_time * ts->scale);

 }
 
 }
 

-void init_clocks(void)
+void timer_mod_anticipate(QEMUTimer *ts, int64_t expire_time)

 {
 {

-    if (!rt_clock) {
-        rt_clock = qemu_clock_new(QEMU_CLOCK_REALTIME);
-        vm_clock = qemu_clock_new(QEMU_CLOCK_VIRTUAL);
-        host_clock = qemu_clock_new(QEMU_CLOCK_HOST);
-    }
+    timer_mod_anticipate_ns(ts, expire_time * ts->scale);

 }
 
 }
 

-uint64_t timer_expire_time_ns(QEMUTimer *ts)
-{
-    return timer_pending(ts) ? ts->expire_time : -1;
-}
-
-void qemu_run_all_timers(void)
+bool timer_pending(QEMUTimer *ts)

 {
 {

-    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);
-    }
+    return ts->expire_time >= 0;

 }
 
 }
 

-#ifdef _WIN32
-static void CALLBACK host_alarm_handler(PVOID lpParam, BOOLEAN unused)
-#else
-static void host_alarm_handler(int host_signum)
-#endif
+bool timer_expired(QEMUTimer *timer_head, int64_t current_time)

 {
 {

-    struct qemu_alarm_timer *t = alarm_timer;
-    if (!t)
-       return;
-
-    t->expired = true;
-    t->pending = true;
-    qemu_notify_event();
+    return timer_expired_ns(timer_head, current_time * timer_head->scale);

 }
 
 }
 

-#if defined(__linux__)
-
-#include "qemu/compatfd.h"
-
-static int dynticks_start_timer(struct qemu_alarm_timer *t)
+bool timerlist_run_timers(QEMUTimerList *timer_list)

 {
 {

-    struct sigevent ev;
-    timer_t host_timer;
-    struct sigaction act;
+    QEMUTimer *ts;
+    int64_t current_time;
+    bool progress = false;
+    QEMUTimerCB *cb;
+    void *opaque;

 
 

-    sigfillset(&act.sa_mask);
-    act.sa_flags = 0;
-    act.sa_handler = host_alarm_handler;
+    qemu_event_reset(&timer_list->timers_done_ev);
+    if (!timer_list->clock->enabled) {
+        goto out;
+    }

 
 

-    sigaction(SIGALRM, &act, NULL);
+    current_time = qemu_clock_get_ns(timer_list->clock->type);
+    for(;;) {
+        qemu_mutex_lock(&timer_list->active_timers_lock);
+        ts = timer_list->active_timers;
+        if (!timer_expired_ns(ts, current_time)) {
+            qemu_mutex_unlock(&timer_list->active_timers_lock);
+            break;
+        }

 
 

-    /* 
-     * 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 CONFIG_SIGEV_THREAD_ID
-    if (qemu_signalfd_available()) {
-        ev.sigev_notify = SIGEV_THREAD_ID;
-        ev._sigev_un._tid = qemu_get_thread_id();
-    }
-#endif /* CONFIG_SIGEV_THREAD_ID */
-    ev.sigev_signo = SIGALRM;
+        /* remove timer from the list before calling the callback */
+        timer_list->active_timers = ts->next;
+        ts->next = NULL;
+        ts->expire_time = -1;
+        cb = ts->cb;
+        opaque = ts->opaque;
+        qemu_mutex_unlock(&timer_list->active_timers_lock);

 
 

-    if (timer_create(CLOCK_REALTIME, &ev, &host_timer)) {
-        perror("timer_create");
-        return -1;
+        /* run the callback (the timer list can be modified) */
+        cb(opaque);
+        progress = true;

     }
 
     }
 

-    t->timer = host_timer;
-
-    return 0;
+out:
+    qemu_event_set(&timer_list->timers_done_ev);
+    return progress;

 }
 
 }
 

-static void dynticks_stop_timer(struct qemu_alarm_timer *t)
+bool qemu_clock_run_timers(QEMUClockType type)

 {
 {

-    timer_t host_timer = t->timer;
-
-    timer_delete(host_timer);
+    return timerlist_run_timers(main_loop_tlg.tl[type]);

 }
 
 }
 

-static void dynticks_rearm_timer(struct qemu_alarm_timer *t,
-                                 int64_t nearest_delta_ns)
+void timerlistgroup_init(QEMUTimerListGroup *tlg,
+                         QEMUTimerListNotifyCB *cb, void *opaque)

 {
 {

-    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);
+    QEMUClockType type;
+    for (type = 0; type < QEMU_CLOCK_MAX; type++) {
+        tlg->tl[type] = timerlist_new(type, cb, opaque);

     }
     }

-    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)
+void timerlistgroup_deinit(QEMUTimerListGroup *tlg)

 {
 {

-    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);
+    QEMUClockType type;
+    for (type = 0; type < QEMU_CLOCK_MAX; type++) {
+        timerlist_free(tlg->tl[type]);

     }
 }
 
     }
 }
 

-static void unix_stop_timer(struct qemu_alarm_timer *t)
+bool timerlistgroup_run_timers(QEMUTimerListGroup *tlg)

 {
 {

-    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;
+    QEMUClockType type;
+    bool progress = false;
+    for (type = 0; type < QEMU_CLOCK_MAX; type++) {
+        progress |= timerlist_run_timers(tlg->tl[type]);

     }
     }

-    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));
-    return 0;
+    return progress;

 }
 
 }
 

-static void mm_stop_timer(struct qemu_alarm_timer *t)
+int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup *tlg)

 {
 {

-    if (mm_timer) {
-        timeKillEvent(mm_timer);
+    int64_t deadline = -1;
+    QEMUClockType type;
+    for (type = 0; type < QEMU_CLOCK_MAX; type++) {
+        if (qemu_clock_use_for_deadline(tlg->tl[type]->clock->type)) {
+            deadline = qemu_soonest_timeout(deadline,
+                                            timerlist_deadline_ns(
+                                                tlg->tl[type]));
+        }

     }
     }

+    return deadline;

 }
 
 }
 

-static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta)
+int64_t qemu_clock_get_ns(QEMUClockType type)

 {
 {

-    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;
-    }
+    int64_t now, last;
+    QEMUClock *clock = qemu_clock_ptr(type);

 
 

-    if (mm_timer) {
-        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);
+    switch (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;

     }
 }
 
     }
 }
 

-static int win32_start_timer(struct qemu_alarm_timer *t)
+void qemu_clock_register_reset_notifier(QEMUClockType type,
+                                        Notifier *notifier)

 {
 {

-    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;
+    QEMUClock *clock = qemu_clock_ptr(type);
+    notifier_list_add(&clock->reset_notifiers, notifier);

 }
 
 }
 

-static void win32_stop_timer(struct qemu_alarm_timer *t)
+void qemu_clock_unregister_reset_notifier(QEMUClockType type,
+                                          Notifier *notifier)

 {
 {

-    HANDLE hTimer = t->timer;
-
-    if (hTimer) {
-        DeleteTimerQueueTimer(NULL, hTimer, NULL);
-    }
+    notifier_remove(notifier);

 }
 
 }
 

-static void win32_rearm_timer(struct qemu_alarm_timer *t,
-                              int64_t nearest_delta_ns)
+void init_clocks(void)

 {
 {

-    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);
+    QEMUClockType type;
+    for (type = 0; type < QEMU_CLOCK_MAX; type++) {
+        qemu_clock_init(type);

     }
 
     }
 

+#ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
+    prctl(PR_SET_TIMERSLACK, 1, 0, 0, 0);
+#endif

 }
 
 }
 

-#endif /* _WIN32 */
-
-static void quit_timers(void)
-{
-    struct qemu_alarm_timer *t = alarm_timer;
-    alarm_timer = NULL;
-    t->stop(t);
-}
-
-#ifdef CONFIG_POSIX
-static void reinit_timers(void)
+uint64_t timer_expire_time_ns(QEMUTimer *ts)

 {
 {

-    struct qemu_alarm_timer *t = alarm_timer;
-    t->stop(t);
-    if (t->start(t)) {
-        fprintf(stderr, "Internal timer error: aborting\n");
-        exit(1);
-    }
-    qemu_rearm_alarm_timer(t);
+    return timer_pending(ts) ? ts->expire_time : -1;

 }
 }

-#endif /* CONFIG_POSIX */

 
 

-int init_timer_alarm(void)
+bool qemu_clock_run_all_timers(void)

 {
 {

-    struct qemu_alarm_timer *t = NULL;
-    int i, err = -1;
-
-    if (alarm_timer) {
-        return 0;
-    }
+    bool progress = false;
+    QEMUClockType type;

 
 

-    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;
+    for (type = 0; type < QEMU_CLOCK_MAX; type++) {
+        progress |= qemu_clock_run_timers(type);

     }
 
     }
 

-    atexit(quit_timers);
-#ifdef CONFIG_POSIX
-    pthread_atfork(NULL, NULL, reinit_timers);
-#endif
-    alarm_timer = t;
-    return 0;
-
-fail:
-    return err;
+    return progress;

 }
 }

-