RE: TechEd 2006 -- "parallelism is the new OO"

[neil@xxxxxxxxxxxxxxxxx]

Kevin Chalmers wrote:
>The performance is fairly reasonable on a decent machine, considering the benefits of portability and  mobility that you get.  Its by no means up KRoC, C++CSP, or the Transterpreter speeds however.  

To be honest, comparing JCSP with C++CSP is unfair.  Mea culpa on that
one, as I did include a comparative benchmark in one of my papers. 
C++CSP is quick, but doesn't take advantage of multiple processors
seamlessly like JCSP can.  I believe the same may be true of KRoC?  So
it is a bit apples-and-oranges in that regard.  A better benchmark
would be against a POSIX-threads implementation of CSP (is there one
around?)

>Im estimating that a running thread in .NET needs about 1 Megabyte of memory, hardly lightweight.  This gives you around a maximum of around 2000 threads in a Windows XP 32-Bit machine.  I doubt an OO program with only 2000 objects is desirable in this respect.   

There is an MSDN blog post that I found while researching my CPA 2006
paper... 
http://blogs.msdn.com/oldnewthing/archive/2005/07/29/444912.aspx  I'm
told the author (Raymond Chen) is a well-respected Microsoft techie,
but as often when people from other schools of CS consider threading,
it is frustrating reading.  "Why are you creating so many threads that
this even becomes an issue?" he asks. 

It is clear that often the designers and users of threads believe that
one thread per CPU is all that is necessary, and anything else is
overkill.  As Kevin notes, how would they feel about one object per
CPU!  This is why I believe that many-to-many mapping of CSP/POP
processes onto threads is appropriate (multiple processes per thread,
and multiple threads).  More on this in my talk at CPA 2006, for those
who are attending :-)

Neil.