Design Ideals Goals Python 3 - Forest for the trees

[Alice Bevan–McGregor]

> So do the new changes(to the GIL) nullify concerns raised by David 
> Beazely here http://dabeaz.com/python/UnderstandingGIL.pdf

Ah, good catch.  I had watched the recorded presentation some time ago. 
 Yes, the rewritten GIL should alleviate those problems.  Instead of 
simply releasing and re-acquiring the GIL, it releases, then determines 
thread scheduling using the brainfuck algorithm instead of leaving it 
up to the kernel in the brief instant the GIL is unassigned (which 
often doesn't context switch to another thread, thus the performance 
penalty).

(I beleive that algorithm, whose name -is- accurate, was the winner of 
the long, long discussion on the Python ticket.)

> Some projects have been using and requiring psyco to gain speed 
> improvements in python http://psyco.sourceforge.net/introduction.html 
> however it seems that the developer is not active on this project 
> anymore and is more active on PyPy 
> http://codespeak.net/pypy/dist/pypy/doc/

I've never really attempted to use JIT optimizers due to the fact that 
all of my development and production environments are 64-bit, and I 
haven't found one yet that supports 64-bit properly.  Relying on dead 
projects, however, is an issue of larger scope than mere portability.  
;)

> A program such as AVSP http://avisynth.org/qwerpoi/ which relies on 
> psyco what would be a good proposition to use when taking the project 
> to python 3.0 if psyco will remain unavailable?

I'd take the same approach Python 3 itself did; rewrite it for Python 3 
and take the opportunity to remove excessive backwards compatibility 
cruft, streamline algorithms, etc.  With a suite of existing 
unit/functional tests, that possibility is the ultimate in test-driven 
development.  ;)  It would also follow the write clean code, then 
profile and optimize where actually needed philosophy.

Obviously that recommendation won't be the "best" solution for every project.

With all of the FOSS projects I really, really care about I'm writing 
from near-scratch (the code, if not the algorithms) with 2.6+ and 3.1+ 
polygot (no conversion tools like 2to3, and no split packaging) 
compatibility as a primary design goal.  So far it's working out quite 
well.

	- Alice