X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=qemu-timer.c;h=eb22e9218bc06f885b922acf543056358663e281;hb=9d324b0e67c2b570df389c1361f591b95a4e4278;hp=ed1763f50149de7a3f29248416d37b98a58f2e7d;hpb=7bf8fbde449600926370f744b2b3d9cc819ca74f;p=mirror_qemu.git

diff --git a/qemu-timer.c b/qemu-timer.c
index ed1763f501..eb22e9218b 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -22,13 +22,12 @@
  * THE SOFTWARE.
  */
 
+#include "qemu/osdep.h"
+#include "qemu/main-loop.h"
+#include "qemu/timer.h"
+#include "sysemu/replay.h"
 #include "sysemu/sysemu.h"
-#include "monitor/monitor.h"
-#include "ui/console.h"
-
-#include "hw/hw.h"
 
-#include "qemu/timer.h"
 #ifdef CONFIG_POSIX
 #include <pthread.h>
 #endif
@@ -44,7 +43,8 @@
 /***********************************************************/
 /* timers */
 
-struct QEMUClock {
+typedef struct QEMUClock {
+    /* We rely on BQL to protect the timerlists */
     QLIST_HEAD(, QEMUTimerList) timerlists;
 
     NotifierList reset_notifiers;
@@ -52,10 +52,10 @@ struct QEMUClock {
 
     QEMUClockType type;
     bool enabled;
-};
+} QEMUClock;
 
 QEMUTimerListGroup main_loop_tlg;
-QEMUClock qemu_clocks[QEMU_CLOCK_MAX];
+static QEMUClock qemu_clocks[QEMU_CLOCK_MAX];
 
 /* A QEMUTimerList is a list of timers attached to a clock. More
  * than one QEMUTimerList can be attached to each clock, for instance
@@ -66,10 +66,14 @@ QEMUClock qemu_clocks[QEMU_CLOCK_MAX];
 
 struct QEMUTimerList {
     QEMUClock *clock;
+    QemuMutex active_timers_lock;
     QEMUTimer *active_timers;
     QLIST_ENTRY(QEMUTimerList) list;
     QEMUTimerListNotifyCB *notify_cb;
     void *notify_opaque;
+
+    /* lightweight method to mark the end of timerlist's running */
+    QemuEvent timers_done_ev;
 };
 
 /**
@@ -80,7 +84,7 @@ struct QEMUTimerList {
  *
  * Returns: a pointer to the QEMUClock object
  */
-QEMUClock *qemu_clock_ptr(QEMUClockType type)
+static inline QEMUClock *qemu_clock_ptr(QEMUClockType type)
 {
     return &qemu_clocks[type];
 }
@@ -98,9 +102,11 @@ QEMUTimerList *timerlist_new(QEMUClockType type,
     QEMUClock *clock = qemu_clock_ptr(type);
 
     timer_list = g_malloc0(sizeof(QEMUTimerList));
+    qemu_event_init(&timer_list->timers_done_ev, true);
     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;
 }
@@ -111,6 +117,7 @@ void timerlist_free(QEMUTimerList *timer_list)
     if (timer_list->clock) {
         QLIST_REMOVE(timer_list, list);
     }
+    qemu_mutex_destroy(&timer_list->active_timers_lock);
     g_free(timer_list);
 }
 
@@ -118,6 +125,9 @@ static void qemu_clock_init(QEMUClockType type)
 {
     QEMUClock *clock = qemu_clock_ptr(type);
 
+    /* Assert that the clock of type TYPE has not been initialized yet. */
+    assert(main_loop_tlg.tl[type] == NULL);
+
     clock->type = type;
     clock->enabled = true;
     clock->last = INT64_MIN;
@@ -140,13 +150,25 @@ void qemu_clock_notify(QEMUClockType type)
     }
 }
 
+/* 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);
+        }
     }
 }
 
@@ -163,9 +185,17 @@ bool qemu_clock_has_timers(QEMUClockType type)
 
 bool timerlist_expired(QEMUTimerList *timer_list)
 {
-    return (timer_list->active_timers &&
-            timer_list->active_timers->expire_time <
-            qemu_clock_get_ns(timer_list->clock->type));
+    int64_t expire_time;
+
+    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);
+
+    return expire_time < qemu_clock_get_ns(timer_list->clock->type);
 }
 
 bool qemu_clock_expired(QEMUClockType type)
@@ -182,13 +212,25 @@ bool qemu_clock_expired(QEMUClockType type)
 int64_t timerlist_deadline_ns(QEMUTimerList *timer_list)
 {
     int64_t delta;
+    int64_t expire_time;
 
-    if (!timer_list->clock->enabled || !timer_list->active_timers) {
+    if (!timer_list->clock->enabled) {
+        return -1;
+    }
+
+    /* 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);
 
-    delta = timer_list->active_timers->expire_time -
-        qemu_clock_get_ns(timer_list->clock->type);
+    delta = expire_time - qemu_clock_get_ns(timer_list->clock->type);
 
     if (delta <= 0) {
         return 0;
@@ -250,7 +292,7 @@ int qemu_timeout_ns_to_ms(int64_t ns)
     /* 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;
+    ms = DIV_ROUND_UP(ns, SCALE_MS);
 
     /* To avoid overflow problems, limit this to 2^31, i.e. approx 25 days */
     if (ms > (int64_t) INT32_MAX) {
@@ -271,7 +313,14 @@ int qemu_poll_ns(GPollFD *fds, guint nfds, int64_t timeout)
         return ppoll((struct pollfd *)fds, nfds, NULL, NULL);
     } else {
         struct timespec ts;
-        ts.tv_sec = timeout / 1000000000LL;
+        int64_t tvsec = timeout / 1000000000LL;
+        /* Avoid possibly overflowing and specifying a negative number of
+         * seconds, which would turn a very long timeout into a busy-wait.
+         */
+        if (tvsec > (int64_t)INT32_MAX) {
+            tvsec = INT32_MAX;
+        }
+        ts.tv_sec = tvsec;
         ts.tv_nsec = timeout % 1000000000LL;
         return ppoll((struct pollfd *)fds, nfds, &ts, NULL);
     }
@@ -281,21 +330,21 @@ int qemu_poll_ns(GPollFD *fds, guint nfds, int64_t timeout)
 }
 
 
-void timer_init(QEMUTimer *ts,
-                QEMUTimerList *timer_list, int scale,
-                QEMUTimerCB *cb, void *opaque)
+void timer_init_tl(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->expire_time = -1;
 }
 
-QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
-                          QEMUTimerCB *cb, void *opaque)
+void timer_deinit(QEMUTimer *ts)
 {
-    return timer_new_tl(main_loop_tlg.tl[clock->type],
-                     scale, cb, opaque);
+    assert(ts->expire_time == -1);
+    ts->timer_list = NULL;
 }
 
 void timer_free(QEMUTimer *ts)
@@ -303,14 +352,12 @@ void timer_free(QEMUTimer *ts)
     g_free(ts);
 }
 
-/* stop a timer, but do not dealloc it */
-void timer_del(QEMUTimer *ts)
+static void timer_del_locked(QEMUTimerList *timer_list, QEMUTimer *ts)
 {
     QEMUTimer **pt, *t;
 
-    /* NOTE: this code must be signal safe because
-       timer_expired() can be called from a signal. */
-    pt = &ts->timer_list->active_timers;
+    ts->expire_time = -1;
+    pt = &timer_list->active_timers;
     for(;;) {
         t = *pt;
         if (!t)
@@ -323,34 +370,86 @@ void timer_del(QEMUTimer *ts)
     }
 }
 
-/* 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)
+static bool timer_mod_ns_locked(QEMUTimerList *timer_list,
+                                QEMUTimer *ts, int64_t expire_time)
 {
     QEMUTimer **pt, *t;
 
-    timer_del(ts);
-
     /* 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->timer_list->active_timers;
-    for(;;) {
+    pt = &timer_list->active_timers;
+    for (;;) {
         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;
 
-    /* Rearm if necessary  */
-    if (pt == &ts->timer_list->active_timers) {
-        /* Interrupt execution to force deadline recalculation.  */
-        qemu_clock_warp(ts->timer_list->clock->type);
-        timerlist_notify(ts->timer_list);
+    return pt == &timer_list->active_timers;
+}
+
+static void timerlist_rearm(QEMUTimerList *timer_list)
+{
+    /* Interrupt execution to force deadline recalculation.  */
+    if (timer_list->clock->type == QEMU_CLOCK_VIRTUAL) {
+        qemu_start_warp_timer();
+    }
+    timerlist_notify(timer_list);
+}
+
+/* stop a timer, but do not dealloc it */
+void timer_del(QEMUTimer *ts)
+{
+    QEMUTimerList *timer_list = ts->timer_list;
+
+    if (timer_list) {
+        qemu_mutex_lock(&timer_list->active_timers_lock);
+        timer_del_locked(timer_list, ts);
+        qemu_mutex_unlock(&timer_list->active_timers_lock);
+    }
+}
+
+/* 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)
+{
+    QEMUTimerList *timer_list = ts->timer_list;
+    bool rearm;
+
+    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);
+
+    if (rearm) {
+        timerlist_rearm(timer_list);
+    }
+}
+
+/* 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)
+{
+    QEMUTimerList *timer_list = ts->timer_list;
+    bool rearm;
+
+    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);
+        }
+        rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
+    } else {
+        rearm = false;
+    }
+    qemu_mutex_unlock(&timer_list->active_timers_lock);
+
+    if (rearm) {
+        timerlist_rearm(timer_list);
     }
 }
 
@@ -359,15 +458,14 @@ void timer_mod(QEMUTimer *ts, int64_t expire_time)
     timer_mod_ns(ts, expire_time * ts->scale);
 }
 
+void timer_mod_anticipate(QEMUTimer *ts, int64_t expire_time)
+{
+    timer_mod_anticipate_ns(ts, expire_time * ts->scale);
+}
+
 bool timer_pending(QEMUTimer *ts)
 {
-    QEMUTimer *t;
-    for (t = ts->timer_list->active_timers; t != NULL; t = t->next) {
-        if (t == ts) {
-            return true;
-        }
-    }
-    return false;
+    return ts->expire_time >= 0;
 }
 
 bool timer_expired(QEMUTimer *timer_head, int64_t current_time)
@@ -380,25 +478,59 @@ bool timerlist_run_timers(QEMUTimerList *timer_list)
     QEMUTimer *ts;
     int64_t current_time;
     bool progress = false;
-   
-    if (!timer_list->clock->enabled) {
-        return progress;
+    QEMUTimerCB *cb;
+    void *opaque;
+
+    qemu_event_reset(&timer_list->timers_done_ev);
+    if (!timer_list->clock->enabled || !timer_list->active_timers) {
+        goto out;
+    }
+
+    switch (timer_list->clock->type) {
+    case QEMU_CLOCK_REALTIME:
+        break;
+    default:
+    case QEMU_CLOCK_VIRTUAL:
+        if (!replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL)) {
+            goto out;
+        }
+        break;
+    case QEMU_CLOCK_HOST:
+        if (!replay_checkpoint(CHECKPOINT_CLOCK_HOST)) {
+            goto out;
+        }
+        break;
+    case QEMU_CLOCK_VIRTUAL_RT:
+        if (!replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL_RT)) {
+            goto out;
+        }
+        break;
     }
 
     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;
         }
+
         /* 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);
 
         /* run the callback (the timer list can be modified) */
-        ts->cb(ts->opaque);
+        cb(opaque);
         progress = true;
     }
+
+out:
+    qemu_event_set(&timer_list->timers_done_ev);
     return progress;
 }
 
@@ -407,11 +539,6 @@ bool qemu_clock_run_timers(QEMUClockType type)
     return timerlist_run_timers(main_loop_tlg.tl[type]);
 }
 
-bool qemu_run_timers(QEMUClock *clock)
-{
-    return qemu_clock_run_timers(clock->type);
-}
-
 void timerlistgroup_init(QEMUTimerListGroup *tlg,
                          QEMUTimerListNotifyCB *cb, void *opaque)
 {
@@ -443,11 +570,17 @@ int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup *tlg)
 {
     int64_t deadline = -1;
     QEMUClockType type;
+    bool play = replay_mode == REPLAY_MODE_PLAY;
     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]));
+        if (qemu_clock_use_for_deadline(type)) {
+            if (!play || type == QEMU_CLOCK_REALTIME) {
+                deadline = qemu_soonest_timeout(deadline,
+                                                timerlist_deadline_ns(tlg->tl[type]));
+            } else {
+                /* Read clock from the replay file and
+                   do not calculate the deadline, based on virtual clock. */
+                qemu_clock_get_ns(type);
+            }
         }
     }
     return deadline;
@@ -469,21 +602,18 @@ int64_t qemu_clock_get_ns(QEMUClockType type)
             return cpu_get_clock();
         }
     case QEMU_CLOCK_HOST:
-        now = get_clock_realtime();
+        now = REPLAY_CLOCK(REPLAY_CLOCK_HOST, get_clock_realtime());
         last = clock->last;
         clock->last = now;
-        if (now < last) {
+        if (now < last || now > (last + get_max_clock_jump())) {
             notifier_list_notify(&clock->reset_notifiers, &now);
         }
         return now;
+    case QEMU_CLOCK_VIRTUAL_RT:
+        return REPLAY_CLOCK(REPLAY_CLOCK_VIRTUAL_RT, cpu_get_clock());
     }
 }
 
-int64_t qemu_get_clock_ns(QEMUClock *clock)
-{
-    return qemu_clock_get_ns(clock->type);
-}
-
 void qemu_clock_register_reset_notifier(QEMUClockType type,
                                         Notifier *notifier)
 {
@@ -497,18 +627,6 @@ void qemu_clock_unregister_reset_notifier(QEMUClockType type,
     notifier_remove(notifier);
 }
 
-void qemu_register_clock_reset_notifier(QEMUClock *clock,
-                                        Notifier *notifier)
-{
-    qemu_clock_register_reset_notifier(clock->type, notifier);
-}
-
-void qemu_unregister_clock_reset_notifier(QEMUClock *clock,
-                                          Notifier *notifier)
-{
-    qemu_clock_unregister_reset_notifier(clock->type, notifier);
-}
-
 void init_clocks(void)
 {
     QEMUClockType type;