[rules-users] multi-threaded deadlock?

[Greg Barton]

Did you do deadlock detection in a tool like jconsole?

--- On Thu, 8/6/09, Charles Binford <Charles.Binford at sun.com> wrote:

> From: Charles Binford <Charles.Binford at sun.com>
> Subject: [rules-users] multi-threaded deadlock?
> To: "Rules Users List" <rules-users at lists.jboss.org>
> Date: Thursday, August 6, 2009, 4:08 PM
> All,
> 
> Drools 4.0.7. 
> 
> I have a single rulebase and three threads running
> stateless sessions
> (each thread has it's own session).  All appears to
> work fine until I
> try to dynamically update the packages in the
> rulebase.  That scenario
> intermittently hangs on an apparent deadlock.  The
> documentation says,
> "Packages can be added and removed at any time...", but
> maybe this
> wasn't assuming a multi-threaded context?
> 
> The stack trace of my three threads is below. 
> - Thread 10 is in the middle if fireAllRules
> - Thread 12 is trying to add facts to its session
> - thread 11 is trying to add a new package to the ruleBase,
> but seems to
> be in some flavor of fireAllRules on the ruleBase even
> though there is
> no session argument in this code path.
> 
> Am I breaking some fundamental drools rule for
> multi-threading?  Do I
> need to lock out other sessions from activity while
> updating packages?
> 
> Thanks
> Charles Binford
> 
> 
> 
> "Thread-10"
> java.lang.Object.wait(Object.java)
> java.lang.Object.wait(Object.java:485)
> org.drools.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:106)
> org.drools.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:195)
> org.drools.common.AbstractWorkingMemory.getFactHandleByIdentity(AbstractWorkingMemory.java:604)
> org.drools.base.DefaultKnowledgeHelper.update(DefaultKnowledgeHelper.java:98)
> com.sun.evtl.pe.customerPolicy.adm.rules.Rule_turn_on_batch_0.consequence(Rule_turn_on_batch_0.java:8)
> com.sun.evtl.pe.customerPolicy.adm.rules.Rule_turn_on_batch_0ConsequenceInvoker.evaluate(Rule_turn_on_batch_0ConsequenceInvoker.java:22)
> org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:554)
> org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:518)
> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:475)
> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:439)
> com.sun.evtl.pe.common.PolicyManager.fireRules(PolicyManager.java:353)
> com.sun.evtl.pe.customerPolicy.adm.rules.ArchiveMgrThrd.fireRules(ArchiveMgrThrd.java:132)
> com.sun.evtl.pe.customerPolicy.adm.rules.ArchiveMgrThrd.runEngine(ArchiveMgrThrd.java:51)
> com.sun.evtl.pe.customerPolicy.adm.msg.PolicyListenerThrd.run(PolicyListenerThrd.java:57)
> java.lang.Thread.run(Thread.java:619)
> 
> 
> 
> "Thread-11"
> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:439)
> org.drools.base.FireAllRulesRuleBaseUpdateListener.beforeRuleBaseUnlocked(FireAllRulesRuleBaseUpdateListener.java:29)
> org.drools.event.RuleBaseEventSupport.fireBeforeRuleBaseUnlocked(RuleBaseEventSupport.java:168)
> org.drools.common.AbstractRuleBase.unlock(AbstractRuleBase.java:361)
> org.drools.common.AbstractRuleBase.addPackage(AbstractRuleBase.java:456)
> com.sun.evtl.pe.common.PolicyManager.addPackage(PolicyManager.java:237)
> com.sun.evtl.pe.customerPolicy.adm.rules.ArchiveMgr.loadNewUserRules(ArchiveMgr.java:170)
> com.sun.evtl.pe.customerPolicy.adm.msg.PolicyListenerThrd.run(PolicyListenerThrd.java:78)
> java.lang.Thread.run(Thread.java:619)
> 
> 
> 
> "Thread-12"
> java.lang.Object.wait(Object.java)
> java.lang.Object.wait(Object.java:485)
> org.drools.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:106)
> org.drools.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:195)
> org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:743)
> org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:704)
> com.sun.evtl.pe.common.PolicyManager.insertSensor(PolicyManager.java:316)
> com.sun.evtl.pe.customerPolicy.adm.rules.ArchiveMgrThrd.assertFacts(ArchiveMgrThrd.java:79)
> com.sun.evtl.pe.customerPolicy.adm.rules.ArchiveMgrThrd.runEngine(ArchiveMgrThrd.java:50)
> com.sun.evtl.pe.customerPolicy.adm.msg.PolicyListenerThrd.run(PolicyListenerThrd.java:57)
> java.lang.Thread.run(Thread.java:619)
> 
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