Report on POSIX.4, .4a, .4b, .13: POSIX Realtime Extensions

[Peter da Silva]

Submitted-by: peter at ficc.ferranti.com (Peter da Silva)

There are two points in this report I'd like to comment on, one of which is
a request for further information.

In article <1991Jun24.004051.13025 at uunet.uu.net> pc at hillside.co.uk (Peter Collinson) writes:
> The large group also agreed to work closely with the
> POSIX.12 sockets group on their interface to ensure that a ``Real-Time
> Protocol,'' could be implemented on top of sockets to meet real-time
> message passing requirements.

ARGH!

Yes, yes. I understand the reasoning. The IPC doesn't look very UNIXish. It
does, however, look very real-time-ish. Sockets don't.

IMHO, in any case, sockets don't look very UNIX-ish either.

> The timeouts group received some conflicting advice.  Many people do
> not want this interface at all.  Of those who did, there was strong
> consensus for new function calls for each blocking call, i.e., we'd
> have timeout_read(), which could time out after a certain interval of
> time, since read() is a blocking call.

What's wrong with using a conventional event-flag/signal and multi-way-wait
interface, with timers being one of the events to wait on? That would solve
the problem, and file descriptors could be used as the flag identifiers.
-- 
Peter da Silva; Ferranti International Controls Corporation; +1 713 274 5180;
Sugar Land, TX  77487-5012;         `-_-' "Have you hugged your wolf, today?"


Volume-Number: Volume 24, Number 19