Add access to max event count stats

This commit provides an interface for accessing and resetting the maximum
number of events in a given period.  This information provides better insight
into event queue pressure.
This commit is contained in:
Andrew Sweeney 2013-12-30 14:06:20 -05:00
parent ccf432b912
commit 5173bef50f
3 changed files with 62 additions and 2 deletions

View File

@ -224,10 +224,16 @@ struct event_base {
/** Number of virtual events */
int virtual_event_count;
/** Maximum number of virtual events active */
int virtual_event_count_max;
/** Number of total events added to this event_base */
int event_count;
/** Maximum number of total events added to this event_base */
int event_count_max;
/** Number of total events active in this event_base */
int event_count_active;
/** Maximum number of total events active in this event_base */
int event_count_active_max;
/** Set if we should terminate the loop once we're done processing
* events. */

46
event.c
View File

@ -1204,6 +1204,36 @@ event_base_get_num_events(struct event_base *base, unsigned int type)
return r;
}
int
event_base_get_max_events(struct event_base *base, unsigned int type, int clear)
{
int r = 0;
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
if (type & EVENT_BASE_COUNT_ACTIVE) {
r += base->event_count_active_max;
if (clear)
base->event_count_active_max = 0;
}
if (type & EVENT_BASE_COUNT_VIRTUAL) {
r += base->virtual_event_count_max;
if (clear)
base->virtual_event_count_max = 0;
}
if (type & EVENT_BASE_COUNT_ADDED) {
r += base->event_count_max;
if (clear)
base->event_count_max = 0;
}
EVBASE_RELEASE_LOCK(base, th_base_lock);
return r;
}
/* Returns true iff we're currently watching any events. */
static int
event_haveevents(struct event_base *base)
@ -3026,14 +3056,23 @@ timeout_process(struct event_base *base)
#if (EVLIST_INTERNAL >> 4) != 1
#error "Mismatch for value of EVLIST_INTERNAL"
#endif
#ifndef MAX
#define MAX(a,b) (((a)>(b))?(a):(b))
#endif
#define MAX_EVENT_COUNT(var, v) var = MAX(var, v)
/* These are a fancy way to spell
if (flags & EVLIST_INTERNAL)
base->event_count--/++;
*/
#define DECR_EVENT_COUNT(base,flags) \
((base)->event_count -= (~((flags) >> 4) & 1))
#define INCR_EVENT_COUNT(base,flags) \
((base)->event_count += (~((flags) >> 4) & 1))
#define INCR_EVENT_COUNT(base,flags) do { \
((base)->event_count += (~((flags) >> 4) & 1)); \
MAX_EVENT_COUNT((base)->event_count_max, (base)->event_count_max); \
} while (0)
static void
event_queue_remove_inserted(struct event_base *base, struct event *ev)
@ -3203,6 +3242,7 @@ event_queue_insert_active(struct event_base *base, struct event_callback *evcb)
evcb->evcb_flags |= EVLIST_ACTIVE;
base->event_count_active++;
MAX_EVENT_COUNT(base->event_count_active_max, base->event_count_active);
EVUTIL_ASSERT(evcb->evcb_pri < base->nactivequeues);
TAILQ_INSERT_TAIL(&base->activequeues[evcb->evcb_pri],
evcb, evcb_active_next);
@ -3220,6 +3260,7 @@ event_queue_insert_active_later(struct event_base *base, struct event_callback *
INCR_EVENT_COUNT(base, evcb->evcb_flags);
evcb->evcb_flags |= EVLIST_ACTIVE_LATER;
base->event_count_active++;
MAX_EVENT_COUNT(base->event_count_active_max, base->event_count_active);
EVUTIL_ASSERT(evcb->evcb_pri < base->nactivequeues);
TAILQ_INSERT_TAIL(&base->active_later_queue, evcb, evcb_active_next);
}
@ -3637,6 +3678,7 @@ event_base_add_virtual_(struct event_base *base)
{
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
base->virtual_event_count++;
MAX_EVENT_COUNT(base->virtual_event_count_max, base->virtual_event_count);
EVBASE_RELEASE_LOCK(base, th_base_lock);
}

View File

@ -424,6 +424,18 @@ const char **event_get_supported_methods(void);
*/
int event_base_get_num_events(struct event_base *, unsigned int);
/**
Get the maximum number of events in a given event_base as specified in the
flags.
@param eb the event_base structure returned by event_base_new()
@param flags a bitwise combination of the kinds of events to aggregate
counts for
@param clear option used to reset the maximum count.
@return the number of events specified in the flags
*/
int event_base_get_max_events(struct event_base *, unsigned int, int);
/**
Allocates a new event configuration object.