Hi Claes, Meta-comment: are these Names candidates for the forthcoming compile-time evaluation of constants? Just wondering if these optimizations (and even the archiving itself) will be moot in the future? Thanks, David On 4/12/2018 2:02 am, Claes Redestad wrote:
Hi,
initializing java.util.jar.Attributes.Name.<clinit> executes ~20k bytecodes setting up and eagerly calculating case-insensitive hash codes for a slew of Name objects.
By archiving the resulting set of Names and initializing public constants from the archived map, we reduce time spent starting up (Name.<clinit> drops to 368 executed bytecodes) and improve the footprint sharing effect of using CDS:
http://cr.openjdk.java.net/~redestad/8214712/jdk.00/
Testing: tier1-2 running
Verified a 1-2.5ms startup improvement on java -jar Hello.jar - significant and stable reduction in instruction count, branches and branch misses - only adds ~1.1Kb to the dumped CDS archive
Thanks!
/Claes