[concurrency] Common Concurrent Problems

[Paul Boddie]

Hello,

I noticed recently that there's an effort to show solutions to common 
concurrent problems on the python.org Wiki, and I've been using this effort 
as an excuse to look over my own work and to improve it in various ways. I 
even made a remark on the "99 Concurrent Bottles of Beer" page which appears 
to have been wide of the mark - that one would surely try and use operating 
system features in the given example in order to provide a more optimal 
implementation - and I note that Glyph appears to regard the stated problem 
as not really being concurrent.

http://wiki.python.org/moin/Concurrency/99Bottles

In the next few days, I intend to release a new version of my pprocess library 
in order to more conveniently support problems like the one on the Wiki, but 
previous experience has shown that more compelling problems are required. 
Some time ago, the "Wide Finder" project attempted to document concurrency 
solutions for a log parsing problem which was regarded by some as being 
I/O-dominated, and for others led to optimised serial solutions that could 
outperform parallel solutions due to the scope for optimisation in most 
people's naive code. With pprocess, I bundle the PyGmy raytracer in order to 
demonstrate that multiple processes really do get used and can benefit 
programs on multiple cores, but I imagine that many people don't regard this 
as being "real world"-enough.

How should we extend the problem on the Wiki to be something that doesn't have 
a workable serial solution? Does anyone have any suggestions of more 
realistic problems, or are we back at the level of Wide Finder?

Paul