Vassili Bykov wrote:
> 
> Eliot's OOPSLA paper describes that improvement, as well as gives a good
> intro to closure implementation in VW in general:
> 
> http://www.squeak.org/oopsla99_vmworkshop/oopsla99-contexts.pdf

I have to put some water into the wine here... ;-(

The paper is interesting and stands in the tradition of and is related to
earlier VW implementations, which have extended the ST80 specification.
It addresses the realization of very fast block closures, so far so good.

But to reach this goal, native stack layout is used and different kind of
mappings of ST contexts to native stack frames. I think this fits good into
JIT-Compiler work, but

*** this isn't a platform independent approach ***.

Moreover I don't see a realization just by changing the interpreter and ST
contexts, methods and related things.

To reach platform independence, we should use a slower, but compatible
realization of block closures. More sophisticated techniques should be
applied after a working common variant.

BTW: Are there any papers describing BlockClosures without referring to
native stack layout?


Greetings,

Stephan

 
> --
> Vassili Bykov
> VisualWorks development
> vassili at parcplace.com
> 
> > -----Original Message-----
> > From: Tim Rowledge [mailto:tim at sumeru.stanford.edu]
> > Sent: Thursday, July 27, 2000 2:29 PM
> > To: squeak at cs.uiuc.edu
> > Subject: Re: Block closures
> >
> >
> > Mats, if you're serious about this, do yourself a big favour
> > and talk to
> > Eliot Miranda about his recent (as in a year or so ago)
> > improvements to
> > block handling in VW; he's explained it to me but I couldn't for the
> > life of me explain it to you and get it right. Basically I
> > think it ...
> > oh hell, get him to explain it.
> >
> > And don't forget to talk with Ian Piumarta to make sure he isn't
> > duplicating the work (he said at ECOOP he'd tackle it soon)
> > and that you
> > don't do anything that will break the jitter. Craig Latta did some
> > pretty serious planning with Ian some time ago on this subject so he
> > might some useful input for you as well. And don't forget the
> > VM changes
> > you'll need.
> >
> > And don't forget to work out howto get there from here; the
> > bit that has
> > always put me off trying anything. I'd suggest using the
> > SystemTracer to
> > clone a new image with BlockClosures rather than trying to manage with
> > both styles. At least with Squeak you can simulate the new system and
> > have a decent debugger.
> >
> > tim
> >
> > --
> > Tim Rowledge, tim at sumeru.stanford.edu, http://sumeru.stanford.edu/tim
> > To err is human; to forgive, beyond the scope of the Operating System.
> >

-- 
Stephan Rudlof (sr at evolgo.de)
   "Genius doesn't work on an assembly line basis.
    You can't simply say, 'Today I will be brilliant.'"
    -- Kirk, "The Ultimate Computer", stardate 4731.3