Request for Review 8024483 - assertion failure: (!mirror_alive || loader_alive) failed AND 8024954: CMS: CMSClassUnloadingMaxInterval is not implemented correctly

Jon Masamitsu jon.masamitsu at oracle.com
Tue Nov 5 18:22:33 UTC 2013


I've updated the webrev for 8024954 for review
comments (thanks, Bengt)

http://cr.openjdk.java.net/~jmasa/8024954/webrev.02/

On 11/1/2013 5:02 PM, Jon Masamitsu wrote:
> 8024483 - assertion failure: (!mirror_alive || loader_alive) failed
>
> The default value of _should_unload_classes in CMSCollector is false.
> The default value of CMSClassUnloadingEnabled is true (changed in jdk8)
> and is used to set the root scanning options.  This inconsistency leads to
> dead class loaders without unloading classes.
>
> The fix for 8024954 fixes (or works around) this inconsistency by 
> resetting
> the root scanning options based on _should_unload_classes.
>
> Additionally there is a missing call to update_should_unload_classes() in
> the CMS foreground collector.  Adding the call allows the test for
> CMSClassUnloadingEnabled  to pass but may not be a complete fix.
>
> http://cr.openjdk.java.net/~jmasa/8024483/webrev.00/
>
>
> 8024954: CMS: CMSClassUnloadingMaxInterval is not implemented correctly
>
> For 8024954 the classes used as roots was being set at initialization 
> based on
> the value of CMSClassUnloadingEnabled. For a value of 
> CMSClassUnloadingMaxInterval
> greater than 1, the roots need to be set dynamically
> (done in CMSCollector::setup_cms_unloading_and_verification_state with 
> this fix).
>
> http://cr.openjdk.java.net/~jmasa/8024954/webrev.01/ 

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