RFR: 8229839: Break circular dependency between oop.inline.hpp and markWord.inline.hpp

Per Liden per.liden at oracle.com
Tue Aug 20 10:07:24 UTC 2019

Still looks good.


On 2019-08-20 10:56, Stefan Karlsson wrote:
> Thanks Per.
> As you might have seen in my reply to Tony, I've updated the patch 
> slightly:
>   http://cr.openjdk.java.net/~stefank/8229839/webrev.02.delta/
>   http://cr.openjdk.java.net/~stefank/8229839/webrev.02/
> Thanks,
> StefanK
> On 2019-08-20 10:43, Per Liden wrote:
>> Looks good!
>> /Per
>> On 2019-08-19 16:11, Stefan Karlsson wrote:
>>> Hi all,
>>> Please review this patch to break the circular dependency between 
>>> oop.inline.hpp and markWord.inline.hpp.
>>> http://cr.openjdk.java.net/~stefank/8229839/webrev.01/
>>> https://bugs.openjdk.java.net/browse/JDK-8229839
>>> The patch removes the call to oopDesc::klass() from 
>>> markWord.inline.hpp. This is done by passing in the klass from 
>>> callers to the different markWord::must_be_preserved functions.
>>> Some of the paths inside markWord::must_be:preserved don't need the 
>>> klass, and calling oopDesc::klass() in those cases would be wasteful. 
>>> To prevent this, I changed the code to allow the callers to provide a 
>>> KlassProxy that can resolve to a const Klass* when and if a Klass is 
>>> needed. I'm not sure if this is needed or not, but I didn't want to 
>>> pessimise the code by introducing new calls to oopDesc::klass().
>>> I also took the opportunity to consolidate and remove some code 
>>> duplication in must_be_preserved functions. This could of course be 
>>> split into a separate patch if that's requested.
>>> Testing done locally. Will run tier123.
>>> Thanks,
>>> StefanK

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