The function event_add() schedules the execution of the ev event when the
event specified in event_assign()/event_new() occurs, or when the time
specified in timeout has elapesed. If atimeout is NULL, no timeout
occurs and the function will only be
called if a matching event occurs. The event in the
ev argument must be already initialized by event_assign() or event_new()
and may not be used
in calls to event_assign() until it is no longer pending.
If the event in the ev argument already has a scheduled timeout, calling
event_add() replaces the old timeout with the new one, or clears the old
timeout if the timeout argument is NULL.
@param ev an event initialized via event_set()
@param timeout the maximum amount of time to wait for the event, or NULL
to wait forever
@return 0 if successful, or -1 if an error occurred
@see event_del(), event_assign(), event_new()
Add an event to the set of pending events.
The function event_add() schedules the execution of the ev event when the event specified in event_assign()/event_new() occurs, or when the time specified in timeout has elapesed. If atimeout is NULL, no timeout occurs and the function will only be called if a matching event occurs. The event in the ev argument must be already initialized by event_assign() or event_new() and may not be used in calls to event_assign() until it is no longer pending.
If the event in the ev argument already has a scheduled timeout, calling event_add() replaces the old timeout with the new one, or clears the old timeout if the timeout argument is NULL.
@param ev an event initialized via event_set() @param timeout the maximum amount of time to wait for the event, or NULL to wait forever @return 0 if successful, or -1 if an error occurred @see event_del(), event_assign(), event_new()