RuleNetworkEvaluator infinite loop when doUpdatesReorderLeftMemory is called ---------------------------------------------------------------------------- Key: DROOLS-766 URL: https://issues.jboss.org/browse/DROOLS-766 Project: Drools Issue Type: Bug Components: core engine Affects Versions: 6.2.0.Final Reporter: Juan Carlos Garcia Assignee: Mario Fusco Attachments: infiniteLoopReproducer.jar, infiniteLoopReproducer_src.jar We are migrating our system to use drools 6.2.0.Final from 6.0.1.Final and one of our testcase which actually simulate several complex scenario is making drools (6.2.0.Final) going into an endless loop, while the same works fine in 6.0.1.Final. I took a thread dump and it seems stuck: {code} at org.drools.core.phreak.RuleNetworkEvaluator.doUpdatesReorderLeftMemory(RuleNetworkEvaluator.java:795) {code} While debugging the source code this is what i got: # LeftTupleMemory ltm = bm.getLeftTupleMemory(); ** LeftTupleMemory is a LeftTupleList # leftTuple.getStagedNext(); ** Always return the same object instance(leftTuple is a JoinNodeLeftTuple type), hence the loop never ends. Unfortunately i cannot provide the DRL files + domain classes involve and don't know if it would be even possible for me right now to recreate the same testcase without leaking internal information from the company i work for. ThreadDump {code} "Attach Listener" daemon prio=10 tid=0x00007fdb74001000 nid=0x88c waiting on condition [0x0000000000000000] java.lang.Thread.State: RUNNABLE "drools-worker-2" daemon prio=10 tid=0x00007fdb54003000 nid=0x803 waiting on condition [0x00007fdb9b7cc000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x0000000783f213f0> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186) at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2043) at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442) at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1068) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745) "pool-3-thread-1" prio=10 tid=0x00007fdba46de000 nid=0x764 waiting on condition [0x00007fdb9bbd6000] java.lang.Thread.State: TIMED_WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x0000000783eba160> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:226) at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2082) at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:1090) at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:807) at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1068) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745) "Service Thread" daemon prio=10 tid=0x00007fdba40ad800 nid=0x754 runnable [0x0000000000000000] java.lang.Thread.State: RUNNABLE "C2 CompilerThread1" daemon prio=10 tid=0x00007fdba40ab000 nid=0x753 waiting on condition [0x0000000000000000] java.lang.Thread.State: RUNNABLE "C2 CompilerThread0" daemon prio=10 tid=0x00007fdba40a8000 nid=0x752 waiting on condition [0x0000000000000000] java.lang.Thread.State: RUNNABLE "JDWP Command Reader" daemon prio=10 tid=0x00007fdb68001000 nid=0x74e runnable [0x0000000000000000] java.lang.Thread.State: RUNNABLE "JDWP Event Helper Thread" daemon prio=10 tid=0x00007fdba40a6000 nid=0x74d runnable [0x0000000000000000] java.lang.Thread.State: RUNNABLE "JDWP Transport Listener: dt_socket" daemon prio=10 tid=0x00007fdba40a2800 nid=0x74c runnable [0x0000000000000000] java.lang.Thread.State: RUNNABLE "Signal Dispatcher" daemon prio=10 tid=0x00007fdba4094800 nid=0x74b runnable [0x0000000000000000] java.lang.Thread.State: RUNNABLE "Finalizer" daemon prio=10 tid=0x00007fdba4074800 nid=0x74a in Object.wait() [0x00007fdba0cfb000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x00000007838824e0> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:135) - locked <0x00000007838824e0> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:151) at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:209) "Reference Handler" daemon prio=10 tid=0x00007fdba4072800 nid=0x749 in Object.wait() [0x00007fdba0dfc000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x00000007838820a0> (a java.lang.ref.Reference$Lock) at java.lang.Object.wait(Object.java:503) at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:133) - locked <0x00000007838820a0> (a java.lang.ref.Reference$Lock) "main" prio=10 tid=0x00007fdba400e800 nid=0x743 runnable [0x00007fdbad9a8000] java.lang.Thread.State: RUNNABLE at org.drools.core.phreak.RuleNetworkEvaluator.doUpdatesReorderLeftMemory(RuleNetworkEvaluator.java:795) at org.drools.core.phreak.PhreakJoinNode.doNode(PhreakJoinNode.java:38) at org.drools.core.phreak.RuleNetworkEvaluator.switchOnDoBetaNode(RuleNetworkEvaluator.java:547) at org.drools.core.phreak.RuleNetworkEvaluator.evalBetaNode(RuleNetworkEvaluator.java:533) at org.drools.core.phreak.RuleNetworkEvaluator.innerEval(RuleNetworkEvaluator.java:334) at org.drools.core.phreak.RuleNetworkEvaluator.outerEval(RuleNetworkEvaluator.java:161) at org.drools.core.phreak.RuleNetworkEvaluator.evaluateNetwork(RuleNetworkEvaluator.java:116) at org.drools.core.phreak.RuleExecutor.reEvaluateNetwork(RuleExecutor.java:235) - locked <0x0000000783f2da90> (a org.drools.core.phreak.RuleExecutor) at org.drools.core.phreak.RuleExecutor.evaluateNetworkAndFire(RuleExecutor.java:106) - locked <0x0000000783f2da90> (a org.drools.core.phreak.RuleExecutor) at org.drools.core.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:1016) at org.drools.core.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1302) at org.drools.core.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:1289) at org.drools.core.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:1262) at org.drools.core.command.runtime.rule.FireAllRulesCommand.execute(FireAllRulesCommand.java:109) at org.drools.core.command.runtime.rule.FireAllRulesCommand.execute(FireAllRulesCommand.java:34) at org.drools.core.command.runtime.BatchExecutionCommandImpl.execute(BatchExecutionCommandImpl.java:155) at org.drools.core.command.runtime.BatchExecutionCommandImpl.execute(BatchExecutionCommandImpl.java:76) at org.drools.core.impl.StatefulKnowledgeSessionImpl.execute(StatefulKnowledgeSessionImpl.java:723) at org.drools.core.impl.StatefulKnowledgeSessionImpl.execute(StatefulKnowledgeSessionImpl.java:697) {code}