RFR: JDK-8202788: Explicitly reclaim cached thread-local direct buffers at thread exit

[Alan Bateman]

On 30/05/2018 22:16, Peter Levart wrote:
> I thought there would be some hint from Alan about which of the two 
> paths we should take for more refinement.
>
> The Tony's:
>
> http://cr.openjdk.java.net/~tonyp/8202788/webrev.1/
>
> Or the Alan's with my mods:
>
> http://cr.openjdk.java.net/~plevart/jdk-dev/DBBCache_Cleanup/webrev.02/
>
Finally getting back to this one.

I don't think the two approaches are all that different now. Tony's 
point on the number of hooks vs. number of locals was an important point 
but with Peter's update to use a thread local registry then I think we 
have easy to maintain solution in the DBBCache_Cleanup/webrev.02 patch. 
So I think I prefer that approach. We need to better name for 
"JdkThreadLocal", something to indicate that it holds resources or it 
notified when a thread terminates.

Also along the way, we touched on exposing getIfPresent and we should 
look at that again. If it is expose then it fits well with the second 
approach too.

-Alan