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

Stefan Karlsson stefan.karlsson at oracle.com
Tue Aug 20 08:56:03 UTC 2019

Thanks Per.

As you might have seen in my reply to Tony, I've updated the patch slightly:


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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