Disconnecting USB device causes Java to exit with 2.5

[robnielsen]

I'm trying improve how the Insteon binding handles reconnects. During my testing of the PLM which uses a USB port, Java exits with no error in the following situation on Linux

1. disconnect a working USB device, this causes a IOException to get thrown
2. close the IO streams associated with the device
3. open the USB device

This causes Java to exit in gnu.io.CommPortIdentifier.open():

throw new gnu.io.PortInUseException(
	native_psmisc_report_owner(PortName));

With nrjavaserial-3.14.0.jar, this is line 474 in CommPortIdentifier.java.

It appears that Java is crashing while trying to call the native method native_psmisc_report_owner.

This appears to be the same as https://code.google.com/archive/p/nrjavaserial/issues/27

[wborn]

I've created NeuronRobotics/nrjavaserial#180 for this recently.

[robnielsen]

@wborn, this might be different. Here's the code:

SerialPortIdentifier spi = serialPortManager.getIdentifier(devName);
if (spi == null) {
    logger.warn("{} is not a valid serial port.", devName);
    return false;
}

port = spi.open(appName, 1000);

I created NeuronRobotics/nrjavaserial#181 for this issue.

[wborn]

Did you also test using nrjavaserial 5.1+?
It has several fixes when USB devices are unplugged.

[wborn]

I've created a reversioned nrjavaserial 5.1.1 bundle that can also be easily used with OH 2.5.x.
See: openhab/org.openhab.binding.zwave#1332 (comment).

[robnielsen]

@wborn, I gave 5.1.1 a try and it still crashes. I renamed the old library by appending .old:

$ ls -l runtime/system/org/openhab/nrjavaserial/3.15.0.OH2/*
-rw-r--r-- 1 rob rob 728329 May 22 08:17 runtime/system/org/openhab/nrjavaserial/3.15.0.OH2/nrjavaserial-3.15.0.OH2.jar
-rw-r--r-- 1 rob rob 748907 May 20 05:28 runtime/system/org/openhab/nrjavaserial/3.15.0.OH2/nrjavaserial-3.15.0.OH2.jar.old
$ unzip -l runtime/system/org/openhab/nrjavaserial/3.15.0.OH2/nrjavaserial-3.15.0.OH2.jar
Archive:  runtime/system/org/openhab/nrjavaserial/3.15.0.OH2/nrjavaserial-3.15.0.OH2.jar
  Length      Date    Time    Name
---------  ---------- -----   ----
        0  2020-05-09 13:09   META-INF/
     1237  2020-05-15 01:31   META-INF/MANIFEST.MF
        0  2020-05-09 13:09   com/

[robnielsen]

This should be fixed in nrjavaserial 5.2.0.

[wborn]

It doesn't seem to fix the other issue NeuronRobotics/nrjavaserial#180.
At least the whole JVM doesn't exit now which is certainly an improvement. 😉

[robnielsen]

@wborn, let me know if you have a reversioned bundle like you have above for 5.1.1. If so, I'll give it a try.

[wborn]

I've reversioned 5.2.1 in this nrjavaserial-3.15.0.OH2.jar.

[robnielsen]

This is fixed with 5.2.1

[wborn]

That's certainly nice! There's still NeuronRobotics/nrjavaserial#111 that may cause the library fail to reconnect after the device has been unplugged for a while and you then reconnect it. 🙁

[robnielsen]

@wborn,
Java is no longer crashing, but the library still isn't working correctly either. On disconnect, the following code:

SerialPortIdentifier spi = serialPortManager.getIdentifier(devName);
if (spi == null) {
    logger.warn("{} is not a valid serial port.", devName);
    return false;
}

spi is false. It should be true.

[robnielsen]

I tried calling serialPortManager.getIdentifier(devName) once, and started to get the PortInUseException. But this created a new issue, the PortInUseException continued to get thrown after the device is plugged back in.

[wborn]

Let's close this since the original issue is fixed with nrjavaserial 5.2.1.

If you have more nrjavaserial related issues, please create issues for these in the nrjavaserial issue tracker. That way they will be fixed sooner because the nrjavaserial maintainers don't look for issues in their library in this tracker. 😉