RFR: 8166276: Refactor gen_process_roots to allow simpler fix for 8165949

[Stefan Johansson]

Thanks for reviewing Mikael,

On 2016-09-20 14:11, Mikael Gerdin wrote:
> Hi Stefan,
>
>
> On 2016-09-20 11:08, Stefan Johansson wrote:
>> Hi all,
>>
>> While working on JDK-8165949 [0] I realized that gen_process_roots
>> needed to be cleaned/split up to allow it to be fixed. This work had in
>> big parts already been done as part of an enhancement [1] that never got
>> pushed. That enhancement included another cleanup as well but I have
>> split it out to only include the necessary part in this fix. It splits
>> gen_process_roots into two different versions, one used for young
>> collections and one for old. This make the two methods much easier to
>> follow and removes some special cases. I will post a second review for
>> the actual bug-fix.
>>
>> Webrev:
>> http://cr.openjdk.java.net/~sjohanss/8166276/hotspot.00/
>
> Overall I think this looks good but it might be a good idea to have a 
> look at the comment just above the definition of enum ScanningOption, 
> it describes concepts which you are removing (such as not_older_gens)
>
Good catch, removed parts of it and move the other part down to 
old_process_roots:
Full: http://wikifiles.se.oracle.com/dev/sjohanss/8166276/hotspot.01
Inc: http://wikifiles.se.oracle.com/dev/sjohanss/8166276/hotspot.00-01/

Thanks,
Stefan

> /Mikael
>
>>
>> Subtask:
>> https://bugs.openjdk.java.net/browse/JDK-8166276
>>
>> Testing:
>> * JTREG tests locally
>> * RBT on HS-gc tier 2-4
>>
>> Thanks,
>> Stefan
>>
>> [0] https://bugs.openjdk.java.net/browse/JDK-8165949
>> [1] https://bugs.openjdk.java.net/browse/JDK-8072809