RFR(xs): 8199431: Split up class Metaspace into a static and a non-static part

[coleen.phillimore at oracle.com]

On 3/14/18 12:24 PM, Thomas Stüfe wrote:
> Hi Andrew,
>
> On Wed, Mar 14, 2018 at 5:03 PM, Andrew Dinn <adinn at redhat.com 
> <mailto:adinn at redhat.com>> wrote:
>
>     On 14/03/18 13:42, Thomas Stüfe wrote:
>     > Thank you all for the feedback!
>     >
>     > New webrev to address Coleens points:
>     >
>     > complete:
>     http://cr.openjdk.java.net/~stuefe/webrevs/8199431-split-class-metaspace-into-two-parts/webrev.00/webrev/
>     <http://cr.openjdk.java.net/%7Estuefe/webrevs/8199431-split-class-metaspace-into-two-parts/webrev.00/webrev/>
>
>     I think that is meant to be webrev.01 :-)
>
>
> Yes. Juggling more than one incremental webrev confuses me too much :)
>
> Correct link: 
> http://cr.openjdk.java.net/~stuefe/webrevs/8199431-split-class-metaspace-into-two-parts/webrev.01/webrev/ 
> <http://cr.openjdk.java.net/%7Estuefe/webrevs/8199431-split-class-metaspace-into-two-parts/webrev.01/webrev/>
>
>     The white space is gone but I am not clear that you have correctly
>     addresseed Coleen's second point.
>
>     In this new version Metaspace is no longer a friend of
>     SpaceManager but
>     ClassLoaderMetaspace has been made a friend in its place. If the last
>     version worked without the friend declaration for
>     ClassLoaderMetaspace,
>     then why does this new version need to make ClassLoaderMetaspace a
>     friend?
>
>
> Thats ok. ClassLoaderMetaspace - like the instance part of Metaspace 
> before - needs access to SpaceManager private functions to access the 
> expand_lock and some other stuff.
>
> In the first version of my webrev I added ClassLoaderMetaspaceas 
> friend but forgot to remove friend Metaspace, I think this is what 
> Coleen meant.

That was what I meant but thanks for checking that ClassLoaderMetaspace 
is still needed, which is unfortunate.

I filed a bug to make MetaspaceExpand_lock a global lock in 
mutexLocker.hpp.  https://bugs.openjdk.java.net/browse/JDK-8198760
It's assigned to me but you're welcome to fix it and then maybe the 
friend declaration won't be needed anymore.

Thanks,
Coleen

>
>     regards,
>
>
>     Andrew Dinn
>     -----------
>     Senior Principal Software Engineer
>     Red Hat UK Ltd
>     Registered in England and Wales under Company Registration No.
>     03798903
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>
>
>
> Best Regards, Thomas
>