[jboss-jira] [JBoss JIRA] Resolved: (JBRULES-2346) insert: ConcurrentModificationException on iterate of ObjectTypeConfigurationRegistry#typeConfMap.

insert: ConcurrentModificationException on iterate of ObjectTypeConfigurationRegistry#typeConfMap. -------------------------------------------------------------------------------------------------- Key: JBRULES-2346 URL: https://jira.jboss.org/browse/JBRULES-2346 Project: Drools Issue Type: Bug Security Level: Public(Everyone can see) Components: drools-core Affects Versions: 5.0.1.FINAL Reporter: Olexandr Demura Assignee: Edson Tirelli Fix For: 5.1.0.CR1 Attachments: ClassFieldAccessorCache.java, EntryPointNode.java, JBRULES-2346.diff, JBRULES-2346.patch, ObjectTypeConfigurationRegistry.java Very rare exception occurs in multi-threaded environment, each thread processes series of rule evaluations with recreation of StatefulSession after each: java.util.ConcurrentModificationException at java.util.HashMap$HashIterator.nextEntry(HashMap.java:1091) at java.util.HashMap$ValueIterator.next(HashMap.java:1122) at org.drools.reteoo.EntryPointNode.updateSink(EntryPointNode.java:285) at org.drools.reteoo.ObjectTypeNode.attach(ObjectTypeNode.java:279) at org.drools.reteoo.builder.PatternBuilder.attachObjectTypeNode(PatternBuilder.java:234) at org.drools.reteoo.ClassObjectTypeConf.<init>(ClassObjectTypeConf.java:93) at org.drools.common.ObjectTypeConfigurationRegistry.getObjectTypeConf(ObjectTypeConfigurationRegistry.java:58) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:849) at org.drools.base.DefaultKnowledgeHelper.insert(DefaultKnowledgeHelper.java:114) at org.drools.base.DefaultKnowledgeHelper.insert(DefaultKnowledgeHelper.java:108) Problem is caused by cyclic dependency. ObjectTypeConfigurationRegistry#getObjectTypeConf(EntryPoint, Object) creates ClassObjectTypeConf to put into ObjectTypeConfigurationRegistry#typeConfMap, creation code relies on EntryPointNode#updateSink(ObjectSink, PropagationContext, InternalWorkingMemory), which iterates on ObjectTypeConfigurationRegistry#typeConfMap. I can't reproduce it on 5.1.0.M1 now, but because of rare reproduction. Source looks like have this bug yet. Used workaround for it: EntryPointNode#updateSink(ObjectSink, PropagationContext, InternalWorkingMemory) iterates on copy of ObjectTypeConfigurationRegistry#typeConfMap: for ( ObjectTypeConf objectTypeConf : wmEntryPoint.getObjectTypeConfigurationRegistry().values() ) { -> for ( ObjectTypeConf objectTypeConf : new ArrayList<ObjectTypeConf>( new wmEntryPoint.getObjectTypeConfigurationRegistry().values() )) {