RFR: 8214712: Archive Attributes$Name.KNOWN_NAMES
Claes Redestad
claes.redestad at oracle.com
Mon Dec 3 16:02:53 UTC 2018
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
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