RFR: JDK-8057632 - Remove auxiliary code used to handle the generations array

Kim Barrett kim.barrett at oracle.com
Tue Mar 3 23:01:18 UTC 2015


On Mar 3, 2015, at 5:47 PM, Jesper Wilhelmsson <jesper.wilhelmsson at oracle.com> wrote:
> 
>> ------------------------------------------------------------------------------
>> src/share/vm/memory/defNewGeneration.cpp
>> 
>> Maybe this will be part of the planned future cleanups, but I'll
>> mention it now, just in case.
>> 
>> There are various places where _old_gen is assigned or tested for
>> NULL.  This all seems rather odd; shouldn't there just be an
>> associated old generation that is recorded in _old_gen at construction
>> time or thereabouts, and be done with it?
> 
> Yes, there is room for more improvements here :)
> I have added this to my list of future cleanups which is now up to nine separate cleanup changes after the generation array removal.

OK.

>> ------------------------------------------------------------------------------
>> src/share/vm/runtime/vmStructs.cpp
>> Removed:
>>  533   nonstatic_field(DefNewGeneration,            _next_gen,                                     Generation*)                           \
>> 
>> Was it intentional to remove rather than rename to _old_gen here?
>> 
> 
> It was intentional. The field is not used in the SA code so it really doesn't matter if it is present in VM_STRUCTS or not. After consulting the SA expertise I was advised to rename the field instead to keep the VM_STRUCTS in sync with the code as much as possible.

OK.

> A new webrev is available. The _old_gen field in vmStructs.cpp is the only change from the last webrev:
> 
> http://cr.openjdk.java.net/~jwilhelm/8057632/webrev.03/
> 
> For some reason though the webrev script thought that the files parNewGeneration.cpp/hpp are new in this webrev, so they don't have any old version here. I see nothing wrong in the hg diff or status of the repository...
> Anyway, there are no new changes in those files.

Your’s is the second review I’ve seen in the last couple of days that had this sort of problem.  New webrev script with a bug?

Looks good.




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