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
