[Vm-dev] An idea about better finalization support

Igor Stasenko siguctua at gmail.com
Thu Apr 23 07:20:30 UTC 2009

2009/4/23 Igor Stasenko <siguctua at gmail.com>:
> 2009/4/23 John M McIntosh <johnmci at smalltalkconsulting.com>:
>> Well there was the Ephemerons stuff you can add too
>> http://map.squeak.org/package/fe2a35f5-3f97-431e-8596-58e810aa3c72
>> ian had a version he pushed out a couple of years, back which was retracted
>> because it
>> caused VM crashs, but later was proven to be an off by 1 C/slang coding
>> error.
>> But no-one I think had the courage to inflict back onto the community.
>> Er so how would compatibilty work with this new way given an image which may
>> or may not include image side companion code.
> I presume this is a question?
> If image don't have a class in special objects array, which should
> represent a class for such kind of weak references, then it will never
> get into that code, because
> (oop class isKindOf: nil "== WeakReferenceWithNotification ") will
> always be false.
> So, VM+image will behave exactly as in older versions of VM.

Things not so bright, if you run an image which expecting new
semantics on VMs which don't supports it.
Then it could use a fallback version of code (and handle things in a
way, how it currently done). It then will need to check if new
capability is available or not at image startup phase.

>> --
>> ===========================================================================
>> John M. McIntosh <johnmci at smalltalkconsulting.com>
>> Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com
>> ===========================================================================
> --
> Best regards,
> Igor Stasenko AKA sig.

Best regards,
Igor Stasenko AKA sig.

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