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

Claes Redestad claes.redestad at oracle.com
Wed Aug 23 14:52:30 UTC 2017


On 08/21/2017 09:04 PM, Martin Buchholz wrote:
> OK, but ...
> I'd like to see further improvements here later, like switching to 
> upper case.
> I just realized we have
> java/nio/charset/StandardCharsets.java
> sun/nio/cs/StandardCharsets.java

I also realized my previous patch would allocate a new UTF_8 on every 
invocation of the
innermost lookup (oops!).

Avoiding the toLower means the non-standard Charset.forName("utf-8") 
will take a
slower path (it still works, of course), but removes a few bytecode from 
executing during
startup.  We still need to key on the lower-case name in the cache for now:


> and they both have a UTF_8 field !

Right, this is unfortunate. We could change the 
sun.nio.cs.StandardCharsets constants to
something else as they are encapsulated.



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