[jboss-jira] [JBoss JIRA] (DROOLS-2313) Bad synchronization of ClassAwareObjectStore list of concreteStores can cause ConcurrentModificationException or ArrayIndexOutOfBoundsException while getting session objects

[Donatien RIVIERE (JIRA)]

     [ https://issues.jboss.org/browse/DROOLS-2313?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Donatien RIVIERE updated DROOLS-2313:
-------------------------------------
    Description: 
If a thread requests for session objects (using kieSession.getObjects() with or without filters) while another one is inserting objects of different classes, there is a chance that a new ConcretObjectStore is added to the concreteStores list at the same time and cause concurrent exception.

Example when using kieSession.getObjects().*iterator()* :

{noformat}
Exception in thread "QueryingThread" java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)
	at java.util.ArrayList$Itr.next(ArrayList.java:851)
	at org.drools.core.common.ClassAwareObjectStore$CompositeObjectIterator.fetchNextIterator(ClassAwareObjectStore.java:556)
	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.nextIterator(ClassAwareObjectStore.java:513)
	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.fetchNext(ClassAwareObjectStore.java:499)
	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.<init>(ClassAwareObjectStore.java:494)
	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.<init>(ClassAwareObjectStore.java:487)
	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.<init>(ClassAwareObjectStore.java:478)
	at org.drools.core.common.ClassAwareObjectStore$CompositeObjectIterator.<init>(ClassAwareObjectStore.java:546)
	at org.drools.core.common.ClassAwareObjectStore$CompositeObjectIterator.<init>(ClassAwareObjectStore.java:544)
	at org.drools.core.common.ClassAwareObjectStore.iterateObjects(ClassAwareObjectStore.java:186)
	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.iterator(StatefulKnowledgeSessionImpl.java:679)
	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.toArray(StatefulKnowledgeSessionImpl.java:710)
	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.toArray(StatefulKnowledgeSessionImpl.java:695)
	at ft.drools.KieSessionConcurrentTest.lambda$0(KieSessionConcurrentTest.java:125)
{noformat}


Example when using kieSession.getObjects().*toArray()* :

{noformat}
Exception in thread "QueryingThread" java.lang.ArrayIndexOutOfBoundsException: 1
	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.toArray(StatefulKnowledgeSessionImpl.java:711)
	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.toArray(StatefulKnowledgeSessionImpl.java:695)
	at ft.drools.KieSessionConcurrentTest.lambda$0(KieSessionConcurrentTest.java:125)
{noformat}


  was:
If a thread requests for session objects (using kieSession.getObjects() with or without filters) while another one is inserting objects of different classes, there is a chance that a new ConcretObjectStore is added to the concreteStores list and cause concurrent exception.

Example when using kieSession.getObjects().*iterator()* :


{noformat}
Exception in thread "QueryingThread" java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)
	at java.util.ArrayList$Itr.next(ArrayList.java:851)
	at org.drools.core.common.ClassAwareObjectStore$CompositeObjectIterator.fetchNextIterator(ClassAwareObjectStore.java:556)
	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.nextIterator(ClassAwareObjectStore.java:513)
	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.fetchNext(ClassAwareObjectStore.java:499)
	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.<init>(ClassAwareObjectStore.java:494)
	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.<init>(ClassAwareObjectStore.java:487)
	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.<init>(ClassAwareObjectStore.java:478)
	at org.drools.core.common.ClassAwareObjectStore$CompositeObjectIterator.<init>(ClassAwareObjectStore.java:546)
	at org.drools.core.common.ClassAwareObjectStore$CompositeObjectIterator.<init>(ClassAwareObjectStore.java:544)
	at org.drools.core.common.ClassAwareObjectStore.iterateObjects(ClassAwareObjectStore.java:186)
	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.iterator(StatefulKnowledgeSessionImpl.java:679)
	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.toArray(StatefulKnowledgeSessionImpl.java:710)
	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.toArray(StatefulKnowledgeSessionImpl.java:695)
	at ft.drools.KieSessionConcurrentTest.lambda$0(KieSessionConcurrentTest.java:125)
{noformat}


Example when using kieSession.getObjects().*toArray()* :

{noformat}
Exception in thread "QueryingThread" java.lang.ArrayIndexOutOfBoundsException: 1
	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.toArray(StatefulKnowledgeSessionImpl.java:711)
	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.toArray(StatefulKnowledgeSessionImpl.java:695)
	at ft.drools.KieSessionConcurrentTest.lambda$0(KieSessionConcurrentTest.java:125)
{noformat}




> Bad synchronization of ClassAwareObjectStore list of concreteStores can cause ConcurrentModificationException or ArrayIndexOutOfBoundsException while getting session objects
> -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: DROOLS-2313
>                 URL: https://issues.jboss.org/browse/DROOLS-2313
>             Project: Drools
>          Issue Type: Bug
>          Components: core engine
>    Affects Versions: 7.5.0.Final, 7.6.0.Final
>            Reporter: Donatien RIVIERE
>            Assignee: Mario Fusco
>         Attachments: KieSessionConcurrentTest.java
>
>
> If a thread requests for session objects (using kieSession.getObjects() with or without filters) while another one is inserting objects of different classes, there is a chance that a new ConcretObjectStore is added to the concreteStores list at the same time and cause concurrent exception.
> Example when using kieSession.getObjects().*iterator()* :
> {noformat}
> Exception in thread "QueryingThread" java.util.ConcurrentModificationException
> 	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)
> 	at java.util.ArrayList$Itr.next(ArrayList.java:851)
> 	at org.drools.core.common.ClassAwareObjectStore$CompositeObjectIterator.fetchNextIterator(ClassAwareObjectStore.java:556)
> 	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.nextIterator(ClassAwareObjectStore.java:513)
> 	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.fetchNext(ClassAwareObjectStore.java:499)
> 	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.<init>(ClassAwareObjectStore.java:494)
> 	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.<init>(ClassAwareObjectStore.java:487)
> 	at org.drools.core.common.ClassAwareObjectStore$AbstractCompositeIterator.<init>(ClassAwareObjectStore.java:478)
> 	at org.drools.core.common.ClassAwareObjectStore$CompositeObjectIterator.<init>(ClassAwareObjectStore.java:546)
> 	at org.drools.core.common.ClassAwareObjectStore$CompositeObjectIterator.<init>(ClassAwareObjectStore.java:544)
> 	at org.drools.core.common.ClassAwareObjectStore.iterateObjects(ClassAwareObjectStore.java:186)
> 	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.iterator(StatefulKnowledgeSessionImpl.java:679)
> 	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.toArray(StatefulKnowledgeSessionImpl.java:710)
> 	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.toArray(StatefulKnowledgeSessionImpl.java:695)
> 	at ft.drools.KieSessionConcurrentTest.lambda$0(KieSessionConcurrentTest.java:125)
> {noformat}
> Example when using kieSession.getObjects().*toArray()* :
> {noformat}
> Exception in thread "QueryingThread" java.lang.ArrayIndexOutOfBoundsException: 1
> 	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.toArray(StatefulKnowledgeSessionImpl.java:711)
> 	at org.drools.core.impl.StatefulKnowledgeSessionImpl$ObjectStoreWrapper.toArray(StatefulKnowledgeSessionImpl.java:695)
> 	at ft.drools.KieSessionConcurrentTest.lambda$0(KieSessionConcurrentTest.java:125)
> {noformat}



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