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monitor: Split MonitorQAPIEventConf off MonitorQAPIEventState 

In preparation of turning monitor_qapi_event_state[] into a hash table
for finer grained throttling.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444921716-9511-5-git-send-email-armbru@redhat.com>
This commit is contained in:
Markus Armbruster 2015-10-15 17:08:33 +02:00
parent 1824c41a62
commit b9b03ab0d4
1 changed files with 38 additions and 42 deletions
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80
monitor.c
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@ -182,11 +182,14 @@ typedef struct {
*/
typedef struct MonitorQAPIEventState {
QAPIEvent event; /* Event being tracked */
int64_t rate; /* Minimum time (in ns) between two events */
QEMUTimer *timer; /* Timer for handling delayed events */
QDict *qdict; /* Delayed event (if any) */
} MonitorQAPIEventState;
typedef struct {
int64_t rate; /* Minimum time (in ns) between two events */
} MonitorQAPIEventConf;
struct Monitor {
CharDriverState *chr;
int reset_seen;
@ -437,6 +440,16 @@ static void monitor_protocol_emitter(Monitor *mon, QObject *data,
}
static MonitorQAPIEventConf monitor_qapi_event_conf[QAPI_EVENT_MAX] = {
/* Limit guest-triggerable events to 1 per second */
[QAPI_EVENT_RTC_CHANGE] = { 1000 * SCALE_MS },
[QAPI_EVENT_WATCHDOG] = { 1000 * SCALE_MS },
[QAPI_EVENT_BALLOON_CHANGE] = { 1000 * SCALE_MS },
[QAPI_EVENT_QUORUM_REPORT_BAD] = { 1000 * SCALE_MS },
[QAPI_EVENT_QUORUM_FAILURE] = { 1000 * SCALE_MS },
[QAPI_EVENT_VSERPORT_CHANGE] = { 1000 * SCALE_MS },
};
static MonitorQAPIEventState monitor_qapi_event_state[QAPI_EVENT_MAX];
/*
@ -462,21 +475,23 @@ static void monitor_qapi_event_emit(QAPIEvent event, QDict *qdict)
static void
monitor_qapi_event_queue(QAPIEvent event, QDict *qdict, Error **errp)
{
MonitorQAPIEventConf *evconf;
MonitorQAPIEventState *evstate;
assert(event < QAPI_EVENT_MAX);
evconf = &monitor_qapi_event_conf[event];
evstate = &monitor_qapi_event_state[event];
trace_monitor_protocol_event_queue(event, qdict, evstate->rate);
trace_monitor_protocol_event_queue(event, qdict, evconf->rate);
qemu_mutex_lock(&monitor_lock);
if (!evstate->rate) {
if (!evconf->rate) {
/* Unthrottled event */
monitor_qapi_event_emit(event, qdict);
} else {
if (timer_pending(evstate->timer)) {
/*
* Timer is pending for (at least) evstate->rate ns after
* Timer is pending for (at least) evconf->rate ns after
* last send. Store event for sending when timer fires,
* replacing a prior stored event if any.
*/
@ -485,15 +500,15 @@ monitor_qapi_event_queue(QAPIEvent event, QDict *qdict, Error **errp)
QINCREF(evstate->qdict);
} else {
/*
* Last send was (at least) evstate->rate ns ago.
* Last send was (at least) evconf->rate ns ago.
* Send immediately, and arm the timer to call
* monitor_qapi_event_handler() in evstate->rate ns. Any
* monitor_qapi_event_handler() in evconf->rate ns. Any
* events arriving before then will be delayed until then.
*/
int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
monitor_qapi_event_emit(event, qdict);
timer_mod_ns(evstate->timer, now + evstate->rate);
timer_mod_ns(evstate->timer, now + evconf->rate);
}
}
@ -501,13 +516,14 @@ monitor_qapi_event_queue(QAPIEvent event, QDict *qdict, Error **errp)
}
/*
* This function runs evstate->rate ns after sending a throttled
* This function runs evconf->rate ns after sending a throttled
* event.
* If another event has since been stored, send it.
*/
static void monitor_qapi_event_handler(void *opaque)
{
MonitorQAPIEventState *evstate = opaque;
MonitorQAPIEventConf *evconf = &monitor_qapi_event_conf[evstate->event];
trace_monitor_protocol_event_handler(evstate->event, evstate->qdict);
qemu_mutex_lock(&monitor_lock);
@ -518,47 +534,27 @@ static void monitor_qapi_event_handler(void *opaque)
monitor_qapi_event_emit(evstate->event, evstate->qdict);
QDECREF(evstate->qdict);
evstate->qdict = NULL;
timer_mod_ns(evstate->timer, now + evstate->rate);
timer_mod_ns(evstate->timer, now + evconf->rate);
}
qemu_mutex_unlock(&monitor_lock);
}
/*
* @event: the event ID to be limited
* @rate: the rate limit in milliseconds
*
* Sets a rate limit on a particular event, so no
* more than 1 event will be emitted within @rate
* milliseconds
*/
static void
monitor_qapi_event_throttle(QAPIEvent event, int64_t rate)
{
MonitorQAPIEventState *evstate;
assert(event < QAPI_EVENT_MAX);
evstate = &(monitor_qapi_event_state[event]);
trace_monitor_protocol_event_throttle(event, rate);
evstate->event = event;
assert(rate * SCALE_MS <= INT64_MAX);
evstate->rate = rate * SCALE_MS;
evstate->qdict = NULL;
evstate->timer = timer_new_ns(QEMU_CLOCK_REALTIME,
monitor_qapi_event_handler,
evstate);
}
static void monitor_qapi_event_init(void)
{
/* Limit guest-triggerable events to 1 per second */
monitor_qapi_event_throttle(QAPI_EVENT_RTC_CHANGE, 1000);
monitor_qapi_event_throttle(QAPI_EVENT_WATCHDOG, 1000);
monitor_qapi_event_throttle(QAPI_EVENT_BALLOON_CHANGE, 1000);
monitor_qapi_event_throttle(QAPI_EVENT_QUORUM_REPORT_BAD, 1000);
monitor_qapi_event_throttle(QAPI_EVENT_QUORUM_FAILURE, 1000);
monitor_qapi_event_throttle(QAPI_EVENT_VSERPORT_CHANGE, 1000);
int i;
MonitorQAPIEventState *evstate;
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);
}
}
qmp_event_set_func_emit(monitor_qapi_event_queue);
}