private void processEvent(Sim_event ev) {
        Object data = null;
        data = ev.get_data();       // get the event's data

        if (data != null && data instanceof Gridlet) {
        	Gridlet gl = (Gridlet)data;
        	completedJobs.add(gl);
        }
        else {
            // handle ping request
            if (ev.get_tag() == GridSimTags.INFOPKT_SUBMIT) {
                processPingRequest(ev);
            }
        }
    }