Sunday, March 16, 2008
 

Functional and Concurrency

This week I was at the QCon London conference (where I talked about Xtext extensively, but that's not the point here). Once again, an important topic was functional programming. As wel all know, the main driver for the hype around functional programming is the "end of the free lunch", in other words, since we'll all work with many many CPUs or cores, we have to deal with concurrency more explicitly. Just using the Quake Algorithm (suggested by Ted Neward: return to your cubible, wait for 18 months until Moore's law increases computer speed and then come back and claim to have improved the software) will not be sufficient.

So, the common wisdom is that once we do everything in a pure functional manner, there's no problem with concurrency, because there is no shared, mutable state. Hence no need for locking, hence no problem. Great.

However, using purely functional programming is also not very useful, since, if we allow no side effects, our program will do nothing except heat up the CPU ((c) Simon Peyton Jones, who talked about Haskell (to the Conference, and to me in an SE Radio interview, during which I think I actually understood monads).

Also, Erlang's great support for concurrency does not come from its functional nature. Rather, it is a consequence of its efficient implementation of the actor model: no shared state, only message passing between concurrent entities (the actors). It does not matter much whether *inside* an actor you're functional or not.

So here are the questions that are really important, and that I would like to see answered in a future talk on the functional/concurrency topic:


So, functional and concurrency experts in the world, please unite! and write a bunch of (context,problem,solution,tradeoff)-tuples (also known as Patterns) and present them at a future JAOO or QCon conference. Or even better: if you are experienced here, contact me, so we can arrange for an SE Radio episode.
 
Comments: Post a Comment

<< Home

back to voelter.de

ABOUT ME
This is Markus Voelter's Blog. It is not intended as a replacement for my regular web site, but rather as a companion that contains ideas, thoughts and loose ends.

ARCHIVES
December 2005 / January 2006 / February 2006 / March 2006 / April 2006 / May 2006 / June 2006 / July 2006 / August 2006 / September 2006 / October 2006 / November 2006 / December 2006 / February 2007 / March 2007 / April 2007 / May 2007 / June 2007 / July 2007 / September 2007 / October 2007 / November 2007 / December 2007 / January 2008 / February 2008 / March 2008 / April 2008 / May 2008 / June 2008 / July 2008 / August 2008 / September 2008 / October 2008 / November 2008 / December 2008 / January 2009 / February 2009 / March 2009 / April 2009 / May 2009 / June 2009 / July 2009 / August 2009 / September 2009 / October 2009 / November 2009 / December 2009 / January 2010 / February 2010 / April 2010 / May 2010 / June 2010 / July 2010 / August 2010 / September 2010 / October 2010 / November 2010 / December 2010 / January 2011 / March 2011 / April 2011 / May 2011 / June 2011 / July 2011 / October 2011 / November 2011 / December 2011 / January 2012 / February 2012 / October 2012 / January 2013 /

FEED
You can get an atom feed for this blog.