[Pellet-users] Exception "cannot stop timer"

[Paul Hsueh-Min Chang]

Dear Pellet developers,

Lately, my program begin running into exceptions like this:

java.lang.UnsupportedOperationException: Cannot stop timer 'cloneABox'
which is not started!

where 'cloneABox' can be something else. I would like to provide to some
sample code but the exception can appear in many places. It seems to be
a thread-related problem, but it sometimes appears even when I use a
single thread.

Could you please give me some hints about what the problem might be, and
how it might be avoided?

Many thanks,
Hsueh-Min

p.s. here is a sample stacktrace, using Pellet 1.5.0:

java.lang.UnsupportedOperationException: Cannot stop timer 'cloneABox'
which is not started!
    at org.mindswap.pellet.utils.Timer.stop(Timer.java:139)
    at org.mindswap.pellet.ABox.<init>(ABox.java:389)
    at org.mindswap.pellet.ABox.copy(ABox.java:428)
    at org.mindswap.pellet.ABox.isConsistent(ABox.java:1652)
    at org.mindswap.pellet.ABox.isType(ABox.java:1169)
    at org.mindswap.pellet.KnowledgeBase.retrieve(KnowledgeBase.java:3436)
    at
org.mindswap.pellet.KnowledgeBase.getInstances(KnowledgeBase.java:2710)
    at
org.mindswap.pellet.jena.PelletInfGraph.instanceIterator(PelletInfGraph.java:878)
    at
org.mindswap.pellet.jena.PelletInfGraph.findInABox(PelletInfGraph.java:372)
    at
org.mindswap.pellet.jena.PelletInfGraph.findWithContinuation(PelletInfGraph.java:209)
    at
com.hp.hpl.jena.reasoner.BaseInfGraph.graphBaseFind(BaseInfGraph.java:344)
    at com.hp.hpl.jena.graph.impl.GraphBase.find(GraphBase.java:246)
    at
com.hp.hpl.jena.graph.query.SimpleQueryHandler.subjectsFor(SimpleQueryHandler.java:60)
    at
com.hp.hpl.jena.graph.query.SimpleQueryHandler.subjectsFor(SimpleQueryHandler.java:44)
    at
com.hp.hpl.jena.rdf.model.impl.ModelCom.listSubjectsFor(ModelCom.java:1037)
    at
com.hp.hpl.jena.rdf.model.impl.ModelCom.listSubjectsWithProperty(ModelCom.java:1048)
    at org.airpg.npc.StateUnit.getInstances(StateUnit.java:316)
.....