RFR [10]: 8186517: sun.nio.cs.StandardCharsets$Aliases and ClassMap can be lazily loaded

Xueming Shen xueming.shen at oracle.com
Fri Aug 25 17:59:36 UTC 2017

On 08/24/2017 01:00 PM, Claes Redestad wrote:
> On 2017-08-24 20:06, Claes Redestad wrote:
> http://cr.openjdk.java.net/~redestad/8186517/jdk.03/
> Manually verified that generated charsets look correct and ran all charset tests without issue.
>> Should be a nice reduction in retained objects on minimal apps.
> 425 fewer objects allocated, -16.5Kb.
> /Claes


It might be worth adding the "instance" field  for the utf-16/be/le as well?  otherwise it
appears a reference to any of the java.nio.charset.StandardCharsets.UTF_8/ISO_8859_1/
US_ASCII will still trigger the mapping loadup in sun.nio.cs.StandardCharsets.

I doubt the "identity" still works here, does it? can CDS play the magic here?

Take a step back, it might be reasonable to consider to insert the "aliases_xyz"
into individual class directly instead of keeping them in provider ... not sure whether
or not it is worth though, I think we can leave it for next visit :-)

btw, there are some tests at closed test repo for sun/nio/cs need to be run as well. I should
bring them into openjdk when have time.


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