Dear all,
I will make a better implementation at image side, and cover
everything with comments, as Eliot suggested.

On 20 May 2010 22:23, Stéphane Ducasse <stephane.ducasse at inria.fr> wrote:
> igor
>
> I have a question about your new finalization. Can we add it to Pharo?

yes, you can. But without VM modifications it won't work. That's why i
postponed image-side integration
for a better time(s).
Old images, how Chris already mentioned, don't need to be aware of
changes on VM side and will continue
to function as if nothing happen.

> Should we replace something else (I mean it is something to replace an existing solution).

Well, it works best if you having a lot of weak refs, while only few
of them dying time to time.
You are free to implement a post-mortem action however you like (but
this is also true for current implementation,
except that new scheme is much more effective).

> How does it interact with existing code?

I will replace an existing WeakRegistry, which will work exactly as an old one.
Also, if you want, i can add a fallback mechanism, if you will run
your image using older VM.

Any other uses of new finalization is up to you :)

As you may guess, a Magma exploits new finalization enhancement for own needs.
For this, I implemented a specialized weak dictionaries, which clean
themselves automatically
(Magma don't needs to deal with finalization of objects, it just needs
to keep buffers free of garbage).
This was a real-world use of new features, which shown us its benefits.
Thanks to Cris for taking care integrating and testing it.

> You see I will learn a lot again :)
>
> Stef
>
>
>> From: "David T. Lewis" <lewis at mail.msen.com>
>> Date: May 20, 2010 5:59:07 PM GMT+02:00
>> To: ma.chris.m at gmail.com, The general-purpose Squeak developers list <squeak-dev at lists.squeakfoundation.org>
>> Cc: vm-dev at lists.squeakfoundation.org
>> Subject: Re: [squeak-dev] Finalization enhancement for 4.2
>> Reply-To: The general-purpose Squeak developers list <squeak-dev at lists.squeakfoundation.org>
>>
>> CC to vm-dev list, follow up on technical issues should go to vm-dev.
>>
>> Chris, Igor, this sounds very encouraging. Yes, I'll help on the
>> VM side, with guidance from Andreas and others (I am not technically
>> competent on this issue). I'll probably be off list for a few days,
>> but will catch up on this next week.
>>
>> Andreas, Eliot, others - any advice or guidance?
>>
>> Dave
>>
>> On Thu, May 20, 2010 at 10:14:00AM -0500, Chris Muller wrote:
>>> I have packaged up Igor's change-sets for the finalization fix:
>>>
>>>  http://bugs.squeak.org/view.php?id=7525
>>>  http://bugs.squeak.org/view.php?id=7473
>>>
>>> into their respective MC packages and uploaded them to the Inbox.
>>>
>>> Recall the original discussion:
>>>
>>>  http://lists.squeakfoundation.org/pipermail/vm-dev/2010-March/003958.html
>>>
>>> I have been running with Igor's enhanced VM and image-side
>>> finalization patches for a few weeks now.  The results are striking.
>>> Squeak applications using large Weak-collections deteriorate to a
>>> point of unusability without this fix because Squeak spends 95% of its
>>> time in the finalization process, leaving no time for application
>>> processing. With this fix installed, CPU utilization is 0% when the
>>> application is idle, providing excellent responsiveness.
>>>
>>> This is a big, big, win for any application that uses Weak
>>> collections, and a win for Squeak overall because it's own use of
>>> weak-collections is enhanced.
>>>
>>> While it seems to be backward compatible, e.g. I am able to run the
>>> enhanced VM on older images (including 3.9), and I am able to run with
>>> these image changes on an older VM, both are required to take
>>> advantage of the enhanced finalization.
>>>
>>> I would like to push this into the trunk, but will need help from the
>>> VMMaker developers for that piece.  David?
>>>
>>> For Magma, this wil be the most exciting and important fix since
>>> #becomeForward:copyHash: introduced back in 2004.
>>>
>>> - Chris
>>
>
>
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-- 
Best regards,
Igor Stasenko AKA sig.