php man page for event_add

EVENT_ADD(3)								 1							      EVENT_ADD(3)

event_add - Add an event to the set of monitored events

SYNOPSIS
       bool event_add (resource  $event, [int  $timeout = -1])

DESCRIPTION
       event_add(3) schedules the execution of the $event when the event specified in event_set(3) occurs or in at least the time specified by the
       $timeout argument. If $timeout was not specified, not  timeout  is  set.  The  $event  must  be	already  initalized  by  event_set(3)  and
       event_base_set(3) functions. If the $event already has a timeout set, it is replaced by the new one.

PARAMETERS
	      o $event
		- Valid event resource.

	      o $timeout
		- Optional timeout (in microseconds).

RETURN VALUES
       event_add(3) returns TRUE on success or FALSE on error.

PHP Documentation Group 													      EVENT_ADD(3)