On Tue, Jul 29, 2008 at 12:12:05PM -0700, Bakul Shah wrote:
>
> It is slightly depressing to think that the situation has not really
> changed since EWD wrote this in 1975. It will take some young
> whippersnapper of a Dijkstra or Hoare or Strachey or Iverson or Backus
> to find the critical insight that will make reasoning about parallel
> algorithm no more difficult than sequential ones.
Is the human thought process parallel? For _my capacities_, I have the
impression that I'm more multitask than parallel. And context switch is
expensive because there is not only explicit data, but also implicit and
I'm not able, if I'm really doing something involved, to restore the
previous state without much ado.
CSP is (for me) the best answer to problem involving blocking/waiting on
input. But this is not parallelism.
And for processing, finally threads are also called in some
implementations: LWP, that is simply something that could have been
solved with Processes, if it was not so costly.
I have the impression that LWP is just a solution to poor process
creation and to poor IPC tools (threads are the solution not for
parallelism by itself, but because there is need to share resources
between processes and that it is simplest to put them in the same
address space).
The most efficient is to have tools that match the way our brains work
(or not...). I'm not convinced our brains are "parallel" (at least mines
are not).
--
Thierry Laronde (Alceste) <tlaronde +AT+ polynum +dot+ com>
http://www.kergis.com/
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