jBPM 4.1 takeTask() race condition

[scollyp]

See original user forum thread: http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4265708

One correction to my original post is that I'm getting a JbpmException. The StaleObjectStateException is produced but not allowed to propagate.

My company has a legacy workflow system that lets users click a "Get Next Task" button. The system then decides which task they should get based on task priority, user skill level, phase of the moon, etc. Once that's decided, the system puts it on the user's personal task list. The key is that this all happens atomically inside the database, so two users never end up with the same task.

What would it take to accomplish this with jBPM? Opinion on how valuable this would be to the overall user base?

Thanks
Scott

[jbarrez]

Should be easy to do by just writing a service method that does a query/assignment with the jBPM API.

If you then get a staleObjectException, you know someone else has taken the task just before you.

[kukeltje]

I think this should become part of the API so a nice message can be returned like ' task has been taken by someone else' Users should not be bothered with low level SOE.

[jbarrez]

Good suggestion.

My only concern is that it would be required in several different places with different error messages. Perhaps an interceptor that catches SOEs and wraps them in a jBPMException can do it in a generic way and is already sufficient?