RFR [9] 8151384: Examine sun.misc.ASCIICaseInsensitiveComparator

Claes Redestad claes.redestad at oracle.com
Wed Mar 9 13:03:19 UTC 2016

On 2016-03-09 13:17, Peter Levart wrote:
>> When digging through old history to try to find out why 
>> java.util.jar.Attributes
>> was ever using ASCIICaseInsensitiveComparator, it was not clear that
>> performance was the motivation.
> I guess looking-up a manifest attribute is not a performance critical 
> operation, you are right. 

Could this be an old startup optimization, since first call to 
String.toLowerCase/toUpperCase will initialize and pull in 
java.util.Locale and friends? If so it's probably not effective any more.

Coincidentally - due to a recent regression - we're currently spending 
quite a bit of time parsing manifests of all jar files on the classpath, 
making ASCIICaseInsensitiveComparator show up prominently in some 
startup profiles.


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