RFR: 8209120: Archive the Integer.IntegerCache

[Peter Levart]

Hi Claes,

When is this archived cache created? Is it possible to create archived 
cache with java.lang.Integer.IntegerCache.high system property set to > 
127 ? Wouldn't then at runtime, when cache is initialized from such 
oversized archive and no java.lang.Integer.IntegerCache.high system 
property is specified, the resulting cache array be to big?

Perhaps you could allocate a copy of the prefix of the de-archived array 
in that case to release the unused Integer instances.

Regards, Peter

On 08/09/2018 01:33 PM, Claes Redestad wrote:
> Hi,
>
> using the new ability to archive immutable heap graphs into the CDS 
> archive, even archiving small things like the Integer.IntegerCache can 
> be profitable.
>
> Webrev: http://cr.openjdk.java.net/~redestad/8209120/open.00/
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8209120
>
> For a default cache (256 elements), this change saves us ~1 million 
> instructions. Applications that use -XX:AutoBoxCacheMax can profit 
> further (and we can use this to stress test the archiving feature..)
>
> The patch is built on top of and tested with Jiangli's patch for 
> https://bugs.openjdk.java.net/browse/JDK-8207263 and I don't intent to 
> push this before that is in.
>
> Thanks!
>
> /Claes
>