Pi4j genereates lots of threads

I have some doubts using Pi4J.

I’m currently using my Raspberry Pi (Model B) to communicate via USB to my Arduino Uno board. For this purpose I’m using Pi4j, thorugh serial port /dev/ttyACM0

My serial communication code looks like this (this function is executed every 5 minutes)

public DeviceData readData() throws DeviceException{

    try{
        DeviceData data = new DeviceData();

        if (serialPort == null || "".equals(serialPort))
            serialPort = Serial.DEFAULT_COM_PORT;

        serial = SerialFactory.createInstance();
        serial.addListener(
                event -> {
                    // print out the data received to the console
                    String payload;
                    try {
                        payload = event.getAsciiString();
                        LOGGER.debug("Arduino said :" + payload);
                    } catch (IOException ioe) {
                        throw new RuntimeException(ioe);
                    }

                }

        );

        LOGGER.info("Attempting connection to " + serialPort + " , baud rate " + baudRate);

        serial.open(serialPort, baudRate);

        if (serial.isOpen()){
            LOGGER.info("Connected");
            // send request, get data

            LOGGER.debug("Probing");
            serial.write('D');
            Thread.sleep(3000);

            LOGGER.debug("Requesting FREE MEMORY");
            serial.write('F');
            Thread.sleep(1500);

            serial.close();
            SerialFactory.shutdown();

            LOGGER.info("Disconnected");

        }

        return data;

    } catch (IOException e) {
        throw new DeviceException("Error while connecting to device.", e);
    } catch (Exception e) {
        throw new DeviceException("Unexpected error while connecting to device.", e);
    } finally {

    }
}

Even when using both serial.close() and SerialFactory.shutdown(), I can see on Java Mission Control that there are a lot of waiting threads with the same name (pi4j-single-executor-0) and increasing over time.

Is this a memory leak ? Should I reuse SerialFactory object ? Should I also reuse Serial object ?

[savageautomate]

Nevermind on the timing comment … I completely overlooked the sleep you have in the code.

[menazord]

Excellent news, thanks a lot