Re: concurrent process vs. parallel process
From: Nick Maclaren (nmm1_at_cus.cam.ac.uk)
Date: 14 Mar 2004 11:17:01 GMT
In article <firstname.lastname@example.org>,
Jack Klein <email@example.com> wrote:
>On 13 Mar 2004 17:17:37 -0800, firstname.lastname@example.org (Ben) wrote in
>> I'm having confusion understanding the differences between concurrent
>> and parallel processes (or programs). As far as I understand, parallel
>> processing is simultaneous use of more than one CPU to execute a
>> program, thus "dividing" a program to be executed by disparate CPUs.
>> Now what exactly is concurrent process? Is it similar as
>> multithreading? Are these terms used interchangeably?
>Why did you cross-post this to comp.lang.c, where it is completely
Well, I am not going to justify his excessive cross-posting of a
non-trivial but basic question, but the issue is most definitely NOT
off-topic for comp.lang.c!
There are some VERY serious problems with incompatibilities between
the architectural models used by C, POSIX threads and OpenMP - and,
to a slightly lesser extent, Fortran and MPI - and I spent some time
trying to get ANY of the relevant standardisation groups to take the
issues on. All of them admitted that the issues were real and serious,
but were Someone Else's Problem.
The only significant progress in this area since the beginning of
those projects has been in Fortran 200x, and it is a pretty trivial
one. I am uncertain in my own mind whether it is even POSSIBLE to
get very far with integrating the C, POSIX threads and OpenMP models
(or even just any two of them!)
Howewer, I doubt VERY much that the original poster was asking for
a description of the issues at the level I am describing :-)