JEP 132: More-prompt finalization (Re: Another take on Finalization)

Kim Barrett kim.barrett at oracle.com
Mon Jun 8 19:47:33 UTC 2015


On Jun 6, 2015, at 11:02 AM, Peter Levart <peter.levart at gmail.com> wrote:
> 
> I understand that it would be desirable for a finalizable object to be made "untracked" as soon as it is manually cleaned-up. This would most certainly give a relief to GC as it could reclaim such untracked objects immediately like normal objects without pushing them through all the finalization steps.
> 
> Such feature would need new API. Here's my take on such API incorporated in my prototype. This feature is mostly independent of other changes in the prototype and could be provided stand-alone. I choose to incorporate it into the prototype to compare it's overhead with classical finalization in unchanged and changed JDKs:
> 
>     http://cr.openjdk.java.net/~plevart/misc/JEP132/ReferenceHandling/webrev.03/

While changes are needed to do this sort of thing, it seems to me a better change would be to not use finalize() at all, but instead use PhantomReference-based cleanup. It provides exactly that kind of behavior, and has other benefits besides.

There is some discussion about doing exactly that for File{Input,Output}Stream (see https://bugs.openjdk.java.net/browse/JDK-8080225).



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