On Thu, Dec 14, 2000 at 01:15:14PM +0100, David Olofson wrote:
> Thu, 14 Dec 2000 Eric Peterson wrote:
> > Hi,
> >
> > I'm trying to use RT-Linux (2.2) RT-FIFOs, and I have come up against
> > an apparent limitation with them: they only allow one writer (on the
> > Linux side) to open the FIFO. I would like multiple processes to be
> > able to open (and write to) a single RT task via a FIFO.
> >
> > Any suggestions?
David,
I previously replied to you, but neglected to cc: the rtl list.)
> There is an inherent implementation/semantics issue with multiple writer
> FIFOs; how do you guarantee that data from writers is not mixed up?
The same way that a non-RT FIFO does it (see fifo(4).) If any sender
sends a message smaller than the "atomic size", it is guaranteed to be
atomic.
> In short, you probably shouldn't use the RT-FIFO interface at all for
> multiple writers - sockets or QNX style messages would probably be more
> right for the job. Unfortunately, I'm not enough up to date with RTL to
> point you at available solutions, but I think there are some.
Agreed - anybody have a working multiple-writer message queue for RTL?
Regards,
Eric
--
An age is called Dark not because the light fails to shine, but because
people refuse to see it.
-- James Michener, "Space"
Eric Peterson WB6PYK (805)370-3046 [EMAIL PROTECTED] HOME: [EMAIL PROTECTED]
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