Python Parallel Paradigm

[Paul Boddie]

Sandy wrote:
>
>     A higher-level system of concurrency, not based on monitors and
> locks and great programmer discipline, will ultimately require making
> "Python 3000" a reality.

It would surprise me if Python 3000 introduced anything substantially
more than what Python 2.x provides in the area of concurrency.

>     In the meantime, is there anywhere, or any thing, that discusses the
> various concurrency options related to Python?  There's Stackless Python
> (which I can't make head or tail of; I have been unable to find any
> lucid overview, or genuine explanation of the purpose of the design.)

What about this introduction...?

http://members.verizon.net/olsongt/stackless/why_stackless.html

>  I know that there's a package for an Erlang system for Python, somewhere
> ("Parnassus" probably).  There's probably a Py-CSP somewhere too.  Lots
> of trees, but where's the Wood?

Here are some fairly similar projects in Python:

http://kamaelia.sourceforge.net/
 - a way of making general concurrency easy to work with, and fun

http://candygram.sourceforge.net/
 - a Python implementation of Erlang concurrency primitives

http://www.python.org/pypi/parallel
 - process forking and channel-based communication (using pickles)

>     Where are concurrency/distributed models compared and discussed?

In the following article and comments there are some opinions expressed
on Python concurrency (along with the usual dose of Ruby vapourware
promotion):

http://www.oreillynet.com/onlamp/blog/2005/10/does_python_have_a_concurrency.html

Meanwhile, the topic has been discussed on python-dev:

http://mail.python.org/pipermail/python-dev/2005-September/056801.html

That discussion led to a description of something which isn't so far
from parallel/pprocess, at least:

http://mail.python.org/pipermail/python-dev/2005-September/056829.html

Other searching yielded this interesting paper about PyPy and "hardware
transactional memory":

http://portal.acm.org/citation.cfm?id=1176617.1176758&coll=ACM&dl=ACM&type=series&idx=1176617&part=Proceedings&WantType=Proceedings&title=Conference%20on%20Object%20Oriented%20Programming%20Systems%20Languages%20and%20Applications&CFID=15151515&CFTOKEN=6184618

Paul