[Python-Dev] [ANN] VPython 0.1

A.M. Kuchling amk at amk.ca
Thu Oct 23 14:25:56 CEST 2008


On Thu, Oct 23, 2008 at 01:31:48AM -0600, Adam Olsen wrote:
> To clarify: This is *NOT* actually a form of threading, is it?  It
> "merely" breaks the giant dispatch table into a series of small ones,
> while also grouping instructions into larger superinstructions?  OS
> threads are not touched at any point?

I haven't looked at Vmgen or VPython at all, but that's probably correct.
From: http://foldoc.org/foldoc.cgi?query=threaded+code

    threaded code: A technique for implementing virtual machine
    interpreters, introduced by J.R. Bell in 1973, where each op-code in
    the virtual machine instruction set is the address of some (lower
    level) code to perform the required operation. This kind of virtual
    machine can be implemented efficiently in machine code on most
    processors by simply performing an indirect jump to the address which
    is the next instruction.

    Many Forth implementations use threaded code and nowadays some use
    the term "threading" for almost any technique used to implement
    Forth's virtual machine.

--amk


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