说明

Prepares the timer event to be used in event_add(). The event is prepared to call the function specified by the callback when the event timeout elapses.

After initializing the event, use event_base_set() to associate the event with its event base.

In case of matching event, these three arguments are passed to the callback function:

fd

Signal number or resource indicating the stream.

events

A flag indicating the event. This will always be EV_TIMEOUT for timer events.

arg

Optional parameter, previously passed to event_timer_set() as arg.