Hi,
as a follow-up to JDK-8086045, further analysis has found a number of
small, simple improvements that can be made to further improve startup
characteristics of typical usage of java.lang.invoke:
- CallSite::<clinit> looks up two MethodHandles that aren't used in many
typical applications and should be lazily constructed
- CallSite.CONTEXT_OFFSET is calculated but never used
- The ConcurrentHashMap in MethodType$ConcurrentWeakInternSet is resized
multiple times even for relatively trivial tests, and initializing it to
a larger size is footprint neutral but beneficial to startup to many
applications
Bug: https://bugs.openjdk.java.net/browse/JDK-8172905
Webrev: http://cr.openjdk.java.net/~redestad/8172905/webrev.01/
This small set of relatively non-intrusive changes has a measurable
impact to startup - generates fewer classes on some tests, does less
work on all - which partially help with a number of startup regressions
tracked in 9 due to heavier and earlier use of j.l.invoke.
Thanks!
/Claes
