public Event get_next_double_cpu() {
        Event out = null;
        double min = Double.MAX_VALUE;
        if (tempoCPU1 < min) {
            min = tempoCPU1;
            out = Event.CPU1;
        }
        if (tempoCPU2 < min) {
            min = tempoCPU2;
            out = Event.CPU2;
        }
        if (tempoArrivo < min) {
            min = tempoArrivo;
            out = Event.ARRIVAL;
        }
        if (tempoIO < min)
            out = Event.IO;
        return out;
    }