IllegalStateException in xtext rule engine when using getThingStatusInfo() inside a lambda

[cweitkamp (Christoph Weitkamp)]

I am experiencing the following ISE when using the getThingStatusInfo() action in one of my rules inside a lambda. Without finding a solution for it I finally decides to post it here and ask for help. Any ideas?

import org.eclipse.xtext.xbase.lib.Functions

val Functions$Function1<String, String> getThingStatus = [ String thingUID |
    val thingStatusInfo = getThingStatusInfo(thingUID)
    if( thingStatusInfo === null ) {
        "OFFLINE"
    } else {
        thingStatusInfo.getStatus().toString()
    }
]

rule "My Thing - Thing Status changed"
when
    Thing "my:thing:uid" changed
then
    try {
        myItem.postUpdate(getThingStatus.apply("my:thing:uid"))
    } catch(Exception e) {
        logError("thing-status", "Exception: {}", e)
    }
end

2019-01-08 21:22:30.356 [ERROR] [.smarthome.model.script.thing-status] - Exception: {}
java.lang.IllegalStateException: null
        at org.eclipse.xtext.xbase.typesystem.references.UnboundTypeReference.doCopyInto(UnboundTypeReference.java:677) ~[?:?]
        at org.eclipse.xtext.xbase.typesystem.references.UnboundTypeReference.copyInto(UnboundTypeReference.java:433) ~[?:?]
        at org.eclipse.xtext.xbase.typesystem.internal.ResolvedTypes.toOwnedReference(ResolvedTypes.java:599) ~[?:?]
        at org.eclipse.xtext.xbase.typesystem.internal.ResolvedTypes.getExpectedType(ResolvedTypes.java:622) ~[?:?]
        at org.eclipse.xtext.xbase.typesystem.internal.ForwardingResolvedTypes.getExpectedType(ForwardingResolvedTypes.java:90) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.internalEvaluate(XbaseInterpreter.java:205) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter._doEvaluate(XbaseInterpreter.java:447) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.doEvaluate(XbaseInterpreter.java:228) ~[?:?]
        at org.eclipse.smarthome.model.script.interpreter.ScriptInterpreter.doEvaluate(ScriptInterpreter.java:226) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.internalEvaluate(XbaseInterpreter.java:204) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter._doEvaluate(XbaseInterpreter.java:464) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.doEvaluate(XbaseInterpreter.java:244) ~[?:?]
        at org.eclipse.smarthome.model.script.interpreter.ScriptInterpreter.doEvaluate(ScriptInterpreter.java:226) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.internalEvaluate(XbaseInterpreter.java:204) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter._doEvaluate(XbaseInterpreter.java:447) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.doEvaluate(XbaseInterpreter.java:228) ~[?:?]
        at org.eclipse.smarthome.model.script.interpreter.ScriptInterpreter.doEvaluate(ScriptInterpreter.java:226) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.internalEvaluate(XbaseInterpreter.java:204) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.evaluate(XbaseInterpreter.java:190) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.ClosureInvocationHandler.doInvoke(ClosureInvocationHandler.java:46) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.AbstractClosureInvocationHandler.invoke(AbstractClosureInvocationHandler.java:29) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.invokeOperation(XbaseInterpreter.java:1079) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.invokeOperation(XbaseInterpreter.java:1061) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter._invokeFeature(XbaseInterpreter.java:1047) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.invokeFeature(XbaseInterpreter.java:992) ~[?:?]
        at org.eclipse.smarthome.model.script.interpreter.ScriptInterpreter.invokeFeature(ScriptInterpreter.java:151) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter._doEvaluate(XbaseInterpreter.java:772) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.doEvaluate(XbaseInterpreter.java:220) ~[?:?]
        at org.eclipse.smarthome.model.script.interpreter.ScriptInterpreter.doEvaluate(ScriptInterpreter.java:226) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.internalEvaluate(XbaseInterpreter.java:204) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.evaluateArgumentExpressions(XbaseInterpreter.java:1116) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter._invokeFeature(XbaseInterpreter.java:1046) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.invokeFeature(XbaseInterpreter.java:992) ~[?:?]
        at org.eclipse.smarthome.model.script.interpreter.ScriptInterpreter.invokeFeature(ScriptInterpreter.java:151) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter._doEvaluate(XbaseInterpreter.java:772) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.doEvaluate(XbaseInterpreter.java:220) ~[?:?]
        at org.eclipse.smarthome.model.script.interpreter.ScriptInterpreter.doEvaluate(ScriptInterpreter.java:226) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.internalEvaluate(XbaseInterpreter.java:204) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter._doEvaluate(XbaseInterpreter.java:447) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.doEvaluate(XbaseInterpreter.java:228) ~[?:?]
        at org.eclipse.smarthome.model.script.interpreter.ScriptInterpreter.doEvaluate(ScriptInterpreter.java:226) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.internalEvaluate(XbaseInterpreter.java:204) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter._doEvaluate(XbaseInterpreter.java:626) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.doEvaluate(XbaseInterpreter.java:260) ~[?:?]
        at org.eclipse.smarthome.model.script.interpreter.ScriptInterpreter.doEvaluate(ScriptInterpreter.java:226) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.internalEvaluate(XbaseInterpreter.java:204) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter._doEvaluate(XbaseInterpreter.java:447) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.doEvaluate(XbaseInterpreter.java:228) ~[?:?]
        at org.eclipse.smarthome.model.script.interpreter.ScriptInterpreter.doEvaluate(ScriptInterpreter.java:226) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.internalEvaluate(XbaseInterpreter.java:204) ~[?:?]
        at org.eclipse.xtext.xbase.interpreter.impl.XbaseInterpreter.evaluate(XbaseInterpreter.java:190) ~[?:?]
        at org.eclipse.smarthome.model.script.runtime.internal.engine.ScriptImpl.execute(ScriptImpl.java:82) ~[?:?]
        at org.eclipse.smarthome.model.rule.runtime.internal.engine.RuleEngineImpl.lambda$2(RuleEngineImpl.java:341) ~[?:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:?]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:?]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) [?:?]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) [?:?]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:?]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:?]
        at java.lang.Thread.run(Thread.java:748) [?:?]

[vzorglub (Vincent Regaud)]

import org.eclipse.xtext.xbase.lib.Functions

val Functions$Function1<String, String> getThingStatus = [ String thingUID |
    val thingStatusInfo = getThingStatusInfo(thingUID)
    if( thingStatusInfo === null ) {
        "OFFLINE"
    } else {
        thingStatusInfo.getStatus().toString()
    }
]

1. You shouldn’t need the import

2. In the docs example:

var thingStatusInfo = getThingStatusInfo("zwave:device:c5155aa4:node2")

Change your val to var

That’s all I can suggest

[cweitkamp (Christoph Weitkamp)]

Thanks for your hints, I will try them but I do not assume they will help me to prevent the ISE.

On thing I forgot to mention: In general the rule plus lambda are working fine. The ISE occurs randomly two or three times a day. I use this setup to check the status for nearly 150 different things. It is kind of hard to reproduce.

[vzorglub (Vincent Regaud)]

Maybe a short 50ms sleep in the lamdba?

[rossko57]

Bit late to this party … but it cropped up in another thread.

Lambda / functions are not thread safe. I found out the hard way when working on my own thing-error-handling DSL code that Thing changes can come in very rapid succession, and need careful queuing. I’d be pretty sure this is a concurrency issue.

In my case I was forced to come up with a method of communicating from one rule to another. Using an Item is obvious - using a command maybe not as obvious, but does allow for really rapid fire data transfers that do not step on each others toes. Item state cannot be trusted as it is shared. openHABs own event bus manages queuing for us.

I would say to rewrite your function as a rule that works with incoming command to a shared String Item.
Rewrite your thing-change catcher rule(s) to send info as command.

More detail here -

Modbus error management in openHAB

This is a more developed solution to automatically disable failed Modbus Things, and re-enable periodically to attempt recovery. There are two parts to it. But first, create a dummy Item to use as a communication tool between the rules // catcher for Modbus Poller Thing status changes String MBpollerChanged "Failed Modbus UID [%s]" <tools> {autoupdate="false", expire="20m,state= "} I send commands here, rather than state updates, so that a flurry of incidents in quick succession will be hand…