RFR: 8209120: Archive the Integer.IntegerCache

Peter Levart peter.levart at gmail.com
Thu Aug 9 16:38:56 UTC 2018

On 08/09/2018 06:28 PM, Claes Redestad wrote:
> On 2018-08-09 17:41, Peter Levart wrote:
>> There's danger when you overwrite a non-null @Stable field with 
>> another value that this new value will not be seen. Or is <clinit> 
>> code an exception where @Stable is not honored yet...
> Typically IntegerCache::<clinit> runs before JIT has even started, so 
> I think we're OK even though the double-assignment is undefined. But 
> it's a good question what happens in cases we're running AOTd code, so 
> perhaps this pattern might be problematic in some future..

What if you run it with -Xcomp ? Would still be run by interpreter at 

Regards, Peter

>> To mitigate this possibility, you could have two fields:
>> static Integer cache[];
>> static final Integer finalCache[];
>> The 'cache' field is archived and de-archived. The final result is 
>> set to 'cache' by overwriting and to 'finalCache'. The later is then 
>> also used in Integer.valueOf().
> Right, this would be a cheap way to dispel any concerns here.
> /Claes

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