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RE: concurrency research "hot" again?
Last week I attended a presentation by BillG where he also raised the topic of insufficient semantic richness in today's programming models - saying new developments are needed in programming languages to use the parallelism of multi-core CPU designs. In the same conference, the head of MS Research also talked about these challenges.
About 6 months ago I sat through a presentation about options for parallelism in .NET today, and it wasn't pretty - way too much locking litter and thread invocation for my liking. Having to understand the behaviour of the compiler so that your process control statements don't get optimised away, isn't goodness.
There is a proposed MS approach which seems to be a form of 'CPU transaction', where entire blocks of statements effectively compete for resources and the OS or hardware detects a livelock or deadlock or other problematic condition. At this point, blocks of process state are reversed by hardware. I need to find out more about this. These techniques will probably need to exist if you want to build a robust OS on top of multicore, where applications with different "parallel heritage" must run together. Nonetheless, the best approach for app construction is to start along CSP lines, not to rely on the system to reverse out of trouble...
From: owner-occam-com@xxxxxxxxxx [mailto:owner-occam-com@xxxxxxxxxx] On Behalf Of Allan McInnes
Sent: Wednesday, 14 February 2007 1:25 PM
To: occam list
Subject: concurrency research "hot" again?
It seems that concurrency is again getting "mainstream" attention. I've seen
several articles in the popular press over the last few days touting Intel's
new 80-core "teraflop-on-a-chip" demonstration chip. Most of the articles I've
seen have made a big deal out of how difficult programmers will find it to
program for 80 cores, and how lots of research needs to be done to develop new
techniques for programming parallel architectures (here's one sample of the
articles I've seen:
At the same time, I've seen several links to "The Landscape of Parallel
Computing Research: A View from Berkeley"
(http://www.eecs.berkeley.edu/Pubs/TechRpts/2006/EECS-2006-183.html) show up on
various websites that I check regularly. In that report, the folks from Berkeley
say, among other things:
"Since real world applications are naturally parallel and hardware is naturally
parallel, what we need is a programming model, system software, and a
supporting architecture that are naturally parallel. Researchers have the rare
opportunity to re-invent these cornerstones of computing, provided they
simplify the efficient programming of highly parallel systems."
So is research into concurrent programming becoming a hot topic again? And how
many of these research efforts are simply going to reinvent the occam wheel?
The Berkeley effort, in particular, sounds a lot like the occam/transputer
approach (at least at a high level). However, the tech report in question makes
no mention of CSP, occam, or transputers (OTOH, they also omit any mention of
Berkeley's Prof. Ed Lee, who has done a lot of work on concurrent programming
models via the Ptolemy project).
It'll be interesting to see where this goes. Hopefully it'll lead to an upswing
in funding for projects that can claim to be working towards support for
massive concurrency - like KRoC/nocc :-)
Allan McInnes <amcinnes@xxxxxxxxxx>
Dept. of Electrical and Computer Engineering
Utah State University