5 Replies Latest reply on Jul 4, 2012 9:49 AM by devilkazuya99

ConcurrentModificationException when LocalTaskService.complete()

devilkazuya99 Jul 4, 2012 2:52 AM

I am using jbpm 5.1.2 + drools 5.3.0

When I run the code below, SOMETIMES I get the ConcurrentModificationException.

private org.jbpm.task.TaskService localTaskService;
...
localTaskService.complete(task1.getId(), actor, contentData);
...

Here is the exception I encounter.

 java.util.ConcurrentModificationException
     at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
     at java.util.AbstractList$Itr.next(AbstractList.java:343)
     at org.jbpm.task.event.MessagingTaskEventListener.taskCompleted(MessagingTaskEventListener.java:72)
     at org.jbpm.task.event.TaskEventSupport.fireTaskCompleted(TaskEventSupport.java:47)
     at org.jbpm.task.service.TaskServiceSession.postTaskCompleteOperation(TaskServiceSession.java:497)
     at org.jbpm.task.service.TaskServiceSession.taskOperation(TaskServiceSession.java:463)
     at org.jbpm.task.service.local.LocalTaskService.complete(LocalTaskService.java:73)

Q1: Is it a known bug in this version?

Q2: Is it fixed?

Q3: Can bypass it?

1. Re: ConcurrentModificationException when LocalTaskService.complete()

salaboy21 Jul 4, 2012 4:30 AM (in response to devilkazuya99)

This is fixed in master already.
There should be a property inside teh TaskService to set it as local. if you do that, the callbacks will be executed in the same thread avoiding the race condition.
Cheers
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2. Re: ConcurrentModificationException when LocalTaskService.complete()

devilkazuya99 Jul 4, 2012 5:01 AM (in response to salaboy21)

Do you mean this? (set local)
SyncWSHumanTaskHandler syncWSHumanTaskHandler = new SyncWSHumanTaskHandler(localTaskService, ks);
syncWSHumanTaskHandler.setLocal(true);
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3. Re: ConcurrentModificationException when LocalTaskService.complete()

salaboy21 Jul 4, 2012 5:05 AM (in response to devilkazuya99)

Yes sorry, are you using that option in the WorkItemHandler?
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4. Re: ConcurrentModificationException when LocalTaskService.complete()

devilkazuya99 Jul 4, 2012 9:47 AM (in response to salaboy21)

SyncWSHumanTaskHandler syncWSHumanTaskHandler = new SyncWSHumanTaskHandler(localTaskService, ksession);
syncWSHumanTaskHandler.setLocal(true);
ksession.getWorkItemManager().registerWorkItemHandler("Human Task", syncWSHumanTaskHandler);
This is what I did. Am I missing something?
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5. Re: ConcurrentModificationException when LocalTaskService.complete()

devilkazuya99 Jul 4, 2012 9:49 AM (in response to devilkazuya99)

Any different if I do it this way? (Use blank SyncWSHumanTaskHandler constructor)

SyncWSHumanTaskHandler syncWSHumanTaskHandler = new SyncWSHumanTaskHandler(); syncWSHumanTaskHandler.setLocal(true); syncWSHumanTaskHandler.setClient(localTaskService); ksession.getWorkItemManager().registerWorkItemHandler("Human Task", syncWSHumanTaskHandler);
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