...as well as: http://jira.jboss.com/jira/browse/JBJMX-38
I hope you don't think this is a useless rant... ;^) Has there been any indications that Sun will *ever* try to address this bug? I see that these issues have been accepted as bugs, but that was over 2 years ago (and 2 major VM versions ago...) and it's unclear whether they have *any* intention of actually doing anything about it... (i.e. the number of votes it's gotten certainly has't moved them...) Also, in regards to the attempted workaround in JBoss 3.2.3. I don't believe the fix will work in all cases. For example: Suppose there are threads T1, T2 & T3 and that T1 is using UCL1 and T2 and T3 are using UCL2. Now suppose T1 and T2 enter into loadClass(...) of UCL1 and UCL2 respectively (hence obtaining their locks). Now if T3 needs to load a class with UCL2 it will be blocked in the VM before even getting into UCL2 loadClass (or loadClassInternal for that matter because it seems the VM obtains the CL lock even before calling into loadClassInternal...). If UCL1 and UCL2 need to delegate to each other in T1 and T2, then it's possible for UCL2 to give up its lock thereby allowing T3 to acquire the lock and have the VM throw the ClassCircularityError (if T2 was in the middle of loading class Foo that T3 was also trying to load before it was blocked...). T3 is then an "innocent bystander" in this scenario. I believe the attempted fix assumes that the CCE occurs within the context of a UCL.loadClass(...) reentrant call. We have been plagued by random ClassCircularityErrors at startup of our server (we've used versions 3.0.8 and 3.2.3) and having evaluated the UCL code and the attempted workarounds to the VM bug, I believe the above scenario is a likely explaination. Do this assessment sound correct? If so, then I'm not sure that anything can be done about this at the UCL level as it seems there's always the possibility for an innocent bystander thread to get a CCE before the UCL has even been entered. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3860837#3860837 Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=3860837 ------------------------------------------------------- The SF.Net email is sponsored by: Beat the post-holiday blues Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek. It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt _______________________________________________ JBoss-Development mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/jboss-development
