(PECL libevent >= 0.0.5)
event_priority_set — Assign a priority to an event.
$event
, int $priority
)
Assign a priority to the event.
eventValid event resource.
priorityPriority level. Cannot be less than zero and cannot exceed maximum priority level of the event base (see event_base_priority_init()).
成功时返回 TRUE， 或者在失败时返回 FALSE。