private void writeByte() {
            synchronized(fifoLock) {
                if (!closed && !fifo.isEmpty()) {
                    try {
                        output.write(fifo.remove());
                        //output.flush();
                    } catch (IOException ex) {
                        Logger.getLogger(ProcessData.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }
            }
        }