Commit a24712af authored by Markus Armbruster's avatar Markus Armbruster
Browse files

monitor: Turn monitor_qapi_event_state[] into a hash table 



In preparation of finer grained throttling.

Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Message-Id: <1444921716-9511-6-git-send-email-armbru@redhat.com>
parent 8681dffa

monitor.c

+37 −16
Original line number Diff line number Diff line
@@ -450,7 +450,7 @@ static MonitorQAPIEventConf monitor_qapi_event_conf[QAPI_EVENT_MAX] = { 
    [QAPI_EVENT_VSERPORT_CHANGE]   = { 1000 * SCALE_MS },

};



static MonitorQAPIEventState monitor_qapi_event_state[QAPI_EVENT_MAX];

GHashTable *monitor_qapi_event_state;



/*

 * Emits the event to every monitor instance, @event is only used for trace
@@ -468,6 +468,8 @@ static void monitor_qapi_event_emit(QAPIEvent event, QDict *qdict) 
    }

}



static void monitor_qapi_event_handler(void *opaque);



/*

 * Queue a new event for emission to Monitor instances,

 * applying any rate limiting if required.
@@ -480,7 +482,6 @@ monitor_qapi_event_queue(QAPIEvent event, QDict *qdict, Error **errp) 


    assert(event < QAPI_EVENT_MAX);

    evconf = &monitor_qapi_event_conf[event];

    evstate = &monitor_qapi_event_state[event];

    trace_monitor_protocol_event_queue(event, qdict, evconf->rate);



    qemu_mutex_lock(&monitor_lock);
@@ -489,7 +490,12 @@ monitor_qapi_event_queue(QAPIEvent event, QDict *qdict, Error **errp) 
        /* Unthrottled event */

        monitor_qapi_event_emit(event, qdict);

    } else {

        if (timer_pending(evstate->timer)) {

        MonitorQAPIEventState key = { .event = event };



        evstate = g_hash_table_lookup(monitor_qapi_event_state, &key);

        assert(!evstate || timer_pending(evstate->timer));



        if (evstate) {

            /*

             * Timer is pending for (at least) evconf->rate ns after

             * last send.  Store event for sending when timer fires,
@@ -508,6 +514,14 @@ monitor_qapi_event_queue(QAPIEvent event, QDict *qdict, Error **errp) 
            int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);



            monitor_qapi_event_emit(event, qdict);



            evstate = g_new(MonitorQAPIEventState, 1);

            evstate->event = event;

            evstate->qdict = NULL;

            evstate->timer = timer_new_ns(QEMU_CLOCK_REALTIME,

                                          monitor_qapi_event_handler,

                                          evstate);

            g_hash_table_add(monitor_qapi_event_state, evstate);

            timer_mod_ns(evstate->timer, now + evconf->rate);

        }

    }
@@ -535,27 +549,34 @@ static void monitor_qapi_event_handler(void *opaque) 
        QDECREF(evstate->qdict);

        evstate->qdict = NULL;

        timer_mod_ns(evstate->timer, now + evconf->rate);

    } else {

        g_hash_table_remove(monitor_qapi_event_state, evstate);

        timer_free(evstate->timer);

        g_free(evstate);

    }



    qemu_mutex_unlock(&monitor_lock);

}



static void monitor_qapi_event_init(void)

static unsigned int qapi_event_throttle_hash(const void *key)

{

    int i;

    MonitorQAPIEventState *evstate;

    const MonitorQAPIEventState *evstate = key;



    for (i = 0; i < QAPI_EVENT_MAX; i++) {

        if (monitor_qapi_event_conf[i].rate) {

            evstate = &monitor_qapi_event_state[i];

            evstate->event = i;

            evstate->qdict = NULL;

            evstate->timer = timer_new_ns(QEMU_CLOCK_REALTIME,

                                          monitor_qapi_event_handler,

                                          evstate);

    return evstate->event * 255;

}



static gboolean qapi_event_throttle_equal(const void *a, const void *b)

{

    const MonitorQAPIEventState *eva = a;

    const MonitorQAPIEventState *evb = b;



    return eva->event == evb->event;

}



static void monitor_qapi_event_init(void)

{

    monitor_qapi_event_state = g_hash_table_new(qapi_event_throttle_hash,

                                                qapi_event_throttle_equal);

    qmp_event_set_func_emit(monitor_qapi_event_queue);

}