RFR 9: JDK-8146028 : Common Cleaner for finalization replacements in java.base

[Roger Riggs]

Hi Chris,

On 1/5/2016 2:33 PM, Chris Hegarty wrote:
> On 5 Jan 2016, at 18:24, Roger Riggs <Roger.Riggs at oracle.com> wrote:
>
>> The follow on work to adding the Cleaner is to replace uses of finalization with uses of the Cleaner.
>> For the 'easy' cases in the java.base module, it is useful to introduce a private Cleaner for the
>> java.base module.  It is proposed to be held weakly, to allow it to terminate on a lightly loaded
>> system.
>>
>> Webrev for Review:
>> http://cr.openjdk.java.net/~rriggs/webrev-cleaning-factory-8146028/
> Looks ok Roger.  Does it make sense to put CleanerFactory, and maybe
> CleanerImpl, into their own internal package, so that it can be used as a
> JDK platform Cleaner ( rather than a base module only cleaner, or having
> to qualify exports of jdk.internal.misc to other JDK modules ) ?
That could be useful; but it raises the question about the right/good 
granularity.
It might make sense that the desktop module might reasonably share the 
Cleaner.
Is there any comparable functionality/package already identified?

>
> Is it possible of the NIO Buffers to use this Cleaner?
I did prototype using the java.lang.ref.Cleaner instead of 
sun.misc.Cleaner and it didn't work so
well.  Some of the tests failed with out of memory exceptions.  I 
suspected that the fast path
through the reference processing for the Cleaner was managing to free 
memory more quickly than
was possible with the new Cleaner.

Roger


>
> -Chris.