Bug 995078
| Summary: | Deadlock between AbstractWorkingMemory and DefaultAgenda | ||
|---|---|---|---|
| Product: | [JBoss] JBoss Enterprise BRMS Platform 5 | Reporter: | Mario Fusco <mfusco> |
| Component: | BRE (Expert, Fusion) | Assignee: | Mario Fusco <mfusco> |
| Status: | VERIFIED --- | QA Contact: | |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | BRMS 5.3.1 | CC: | nwallace |
| Target Milestone: | GA | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | Bug | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | |||
| Bug Blocks: | 986451 | ||
Verified on 5.3.1.BRMS-P04. |
I experienced a deadlock when running in STREAM mode and using negative patterns with temporal constraints. When the rule gets fired by the installed timer job and at the same time another thread is firing rules, a deadlock can occur: 1. [rule firing thread] StatefulKnowledgeSessionImpl.execute(StatefulKnowledgeSessionImpl.java:820) acquires lock in AbstractWorkingMemory 2. [timer-thread] DefaultAgenda.fireActivation() call of synchronized method 3. [rule firing thread] DefaultAgenda.fireActivation() synchronized method, wait for other thread to exit synchornized method 4. [timer-thread] AbstractWorkingMemory.getGlobal() tries to access a global, tries to acquire lock in AbstractWorkingMemory which is held by the other thread --> Deadlock Excerpt from thread dump: "http-thread-pool-8082(374)": at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1264) waiting to lock <0x00007f50407e4950> (a org.drools.common.DefaultAgenda) at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:1221) at org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1456) at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:710) at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:679) at org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:234) at org.drools.command.runtime.rule.FireAllRulesCommand.execute(FireAllRulesCommand.java:102) at org.drools.command.runtime.rule.FireAllRulesCommand.execute(FireAllRulesCommand.java:32) at org.drools.command.runtime.BatchExecutionCommandImpl.execute(BatchExecutionCommandImpl.java:155) at org.drools.command.runtime.BatchExecutionCommandImpl.execute(BatchExecutionCommandImpl.java:76) at org.drools.impl.StatefulKnowledgeSessionImpl.execute(StatefulKnowledgeSessionImpl.java:821) "pool-4251-thread-1": at sun.misc.Unsafe.park(Native Method) parking to wait for 0x00007f503fc71a20> (a java.util.concurrent.locks.ReentrantLock$NonfairSync) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:158) at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:747) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:778) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1114) at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:186) at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:262) at org.drools.common.AbstractWorkingMemory.getGlobal(AbstractWorkingMemory.java:634) at myrules.Rule_ruleWithTimeout_ece4a3c9fc2741a4ab97a92b77611203DefaultConsequenceInvokerGenerated.evaluate(Unknown Source) at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1287) locked <0x00007f50407e4950> (a org.drools.common.DefaultAgenda) at org.drools.common.DefaultAgenda.fireTimedActivation(DefaultAgenda.java:1344) locked <0x00007f50407e4950> (a org.drools.common.DefaultAgenda) at org.drools.common.Scheduler$ActivationTimerJob.execute(Scheduler.java:83)