HashTableIterator of AbstractHashTable is not Thread Safe

public static class HashTableIterator has a shared state that gets inconsistent when multiple threads work on the getting the next entity:

public Object next() {
if ( this.entry != null )

{ PART 1 >> this.entry = this.entry.getNext(); }

// if no entry keep skipping rows until we come to the end, or find one that is populated
while ( this.entry == null && ++this.row < this.length )

{ PART II >> this.entry = this.table[this.row]; }

return this.entry;
}

In "PART 1", the race condition causes "this.entry" be NULL in "this.entry.getNext()", and throws the exception below.

In "PART 2", the race condition causes inconsistent state of "this.row", and throws multiple exceptions, but mostly the one that is described in: https://jira.jboss.org/browse/JBRULES-2794

java.util.concurrent.ExecutionException: org.drools.RuntimeDroolsException: Unexpected exception executing action org.drools.reteoo.ReteooWorkingMemory$WorkingMemoryReteAssertAction@1ff323
at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:222)
at java.util.concurrent.FutureTask.get(FutureTask.java:83)
at org.custom.workflow.stress.test.WorkflowStressTest.shouldRunFlow(WorkflowStressTest.java:49)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:82)
at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:240)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:180)
at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:94)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:192)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:64)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:115)
Caused by: org.drools.RuntimeDroolsException: Unexpected exception executing action org.drools.reteoo.ReteooWorkingMemory$WorkingMemoryReteAssertAction@1ff323
at org.drools.common.AbstractWorkingMemory.executeQueuedActions(AbstractWorkingMemory.java:1473)
at org.drools.common.AbstractWorkingMemory.startProcess(AbstractWorkingMemory.java:1631)
at org.drools.impl.StatefulKnowledgeSessionImpl.startProcess(StatefulKnowledgeSessionImpl.java:318)
at org.drools.command.runtime.process.StartProcessCommand.execute(StartProcessCommand.java:99)
at org.drools.command.runtime.process.StartProcessCommand.execute(StartProcessCommand.java:38)
at org.drools.persistence.session.SingleSessionCommandService.execute(SingleSessionCommandService.java:285)
at org.drools.command.impl.CommandBasedStatefulKnowledgeSession.startProcess(CommandBasedStatefulKnowledgeSession.java:193)
at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:191)
at org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint(Cglib2AopProxy.java:692)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:625)
at org.custom.workflow.stress.test.WorkflowRunner.call(WorkflowRunner.java:38)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
at org.drools.core.util.AbstractHashTable$HashTableIterator.next(AbstractHashTable.java:312)
at org.drools.reteoo.EntryPointNode.updateSink(EntryPointNode.java:323)
at org.drools.reteoo.ObjectTypeNode.attach(ObjectTypeNode.java:303)
at org.drools.reteoo.builder.PatternBuilder.attachObjectTypeNode(PatternBuilder.java:257)
at org.drools.reteoo.ClassObjectTypeConf.<init>(ClassObjectTypeConf.java:92)
at org.drools.common.ObjectTypeConfigurationRegistry.getObjectTypeConf(ObjectTypeConfigurationRegistry.java:68)
at org.drools.reteoo.Rete.assertObject(Rete.java:111)
at org.drools.reteoo.ReteooRuleBase.assertObject(ReteooRuleBase.java:280)
at org.drools.reteoo.ReteooWorkingMemory$WorkingMemoryReteAssertAction.execute(ReteooWorkingMemory.java:360)
at org.drools.common.AbstractWorkingMemory.executeQueuedActions(AbstractWorkingMemory.java:1471)
... 24 more