Re: C++0x and Threads - a poor relation to Ada's tasking model?

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Fri, 14 Aug 2009 13:50:11 +0100, John McCabe wrote:

> On Fri, 14 Aug 2009 14:23:49 +0200, "Dmitry A. Kazakov"
> <mailbox@dmitry-kazakov.de> wrote:
> 
>>On Fri, 14 Aug 2009 12:13:49 +0100, John McCabe wrote:
>>
>>> I'll have a look at that. As a matter of interest, a long time ago
>>> there were parallel C compilers for the Transputer. How did the
>>> thread/processors communicate/interact in those languages?
>>
>>That was an operating system called PARIX. The idea was that each processor
>>ran one process communicating with its neighbours over four serial 10Mbaud
>>links. Individual transputers didn't have much memory, normally 4MB. I
>>remember it was possible to have simple LIFO scheduling, so one could have
>>threads, but that was not the "intended" use. I played with an idea to make
>>an Ada (83) compiler for the beast. That never happened. It is close to 20
>>years ago... (:-()
> 
> I did a lot of work on Transputers, but in Occam which made it
> relatively easy for me to understand Ada's tasking when I got taught
> it. We had a C compiler for the T800 from Niche I think, but I don't
> remember anything specific about an OS.

To me it was the opposite, we didn't use Occam, only the C compiler, which
was a torture, because it was a native compiler! You first booted it into a
transputer closest to the host, then feed it with the code over the link,
make yourself a coffee and after a couple of minutes, you could read the
compiled image back...

As for the PARIX, it was rather a monitor than a true OS. It had some
rudimentary support for host communication with marshaling connections over
the transit nodes. I also remember that it had a TCP layer over the links.

----------
I wonder if transputers will make a come back. Arguably a multi-core memory
sharing architecture is a dead end. Transputers had local memory. If they
return as systems with 1000 and more loosely coupled nodes (cores), what
will be a programming of look like? Ada's rendezvous will probably shine
again...

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de