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

[Alan Bateman]

On 17/06/2018 22:20, Peter Levart wrote:
> Update: the discussion on concurrent-interest about possible future 
> addition of public ThreadLocal.getIfPresent() or 
> ThreadLocal.isPresent() has died out, but it nevertheless reached a 
> point where ThreadLocal.isPresent() was found the least problematic. 
> So I would like to get further with this proposal using the last 
> webrev.04 version of the patch that uses ThreadLocal.isPresent() 
> internally - still package-private at the moment.
>
> Here's the webrev (unchanged from the day it was published):
>
> http://cr.openjdk.java.net/~plevart/jdk-dev/DBBCache_Cleanup/webrev.04/
>
> Would this version be OK?
I think looks quite good.

One small nit is that the update to ThreadLocal.setInitialValue makes it 
look like all locals are registered when setting the initial value. What 
would you think about moving the instanceof check from 
TerminatingThreadLocal.register so that it's a bit more obvious.

-Alan