RFR: 8245024: Simplify and eagerly initialize StringConcatFactory

[Jim Laskey]

Will this have an effect on JDK-8218173 <https://bugs.openjdk.java.net/browse/JDK-8218173> ?

> On May 14, 2020, at 11:39 AM, Claes Redestad <claes.redestad at oracle.com> wrote:
> 
> Hi,
> 
> JDK-8155090 added some measures to StringConcatFactory to prevent
> certain bootstrapping issues. I think we should consider eagerly
> initializing the StringConcatFactory base class during bootstrap
> instead.
> 
> Doing so will add a tiny bit of class loading overhead to bootstrap
> (which of course will be amortized on first use of SCF) but still this
> would also be a good opportunity to clean up a little.
> 
> One straightforward means to do so is to move the CACHE, DUMPER and
> CACHE_ENABLE fields to BytecodeStringBuilderStrategy, since it's the
> only place where they are used (the MethodHandle based strategies don't
> manually spin classes and rely on LF sharing to de-duplicate shared
> components).
> 
> Webrev: http://cr.openjdk.java.net/~redestad/8245024/open.00/
> Bug:    https://bugs.openjdk.java.net/browse/JDK-8245024
> 
> This reduces initialization overhead and simplifices bootstraps for the
> default case, while still passing relevant test cases such as test/jdk
> /java/lang/String/concat/WithSecurityManager.java for all strategies.
> 
> Testing: tier1-2
> 
> Thanks!
> 
> /Claes