RFR: 8252103: Parallel heap inspection for ParallelScavengeHeap [v9]

Lin Zang lzang at openjdk.java.net
Wed Nov 4 10:53:58 UTC 2020


On Wed, 4 Nov 2020 09:56:31 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

>> Dear @tschatzl , 
>>     Thanks for your proposed fix, I also prefer it because it could avoid the conversion between signed and unsigned. I will make a new commit to incorporate it. 
>> 
>> Thanks!
>> Lin
>
> I recommend changing the `(size_t)-1` assignment to `SIZE_MAX`.
> 
> While there is (to my knowledge) no compiler (that supports the JVM) that does not use two's complement for integer representation, officially only with C++20 (or later) the result of this operation is exactly defined. We know that other code just does the cast as this does ;), but if you use `SIZE_MAX`, the comment above the definition of `InvalidIndex` can also be removed then.
> 
> I would also move `InvalidIndex` as the first in the list of constants because it's not really related to numbers assigned because of the spaces (while `NumNonOldGenClaims` is).
> 
> Lgtm otherwise. Thanks for bearing with us.

Dear @tschatzl @kstefanj  and @albertnetymk, 
So appericated for your suggestion and guidance. I have upload a new commit. 
would you like to help review it again. 

BRs,
Lin

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PR: https://git.openjdk.java.net/jdk/pull/25


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