[cap-talk] gauntlet - one way IPC considered practically useless

[Norman Hardy]

I just noticed this 6 months old thread. I was not following the list  
closely at that time.
I have not entirely digested the content of the thread.
A similar question arose in another context this April.
At that time I wrote a note on simplex communications channels into a  
confined compartment.
See <http://cap-lore.com/CapTheory/KK/Simplex/>.
The solutions are in the Keykos context. It wasn't hard but neither  
was it trivial.
The solution relies on the non-standard Keykos subroutine mechanism  
which is a style of 'continuations'.
(See <http://en.wikipedia.org/wiki/Continuation_passing_style>.)

On Jan 19, 2006, at 11:27 AM, Jed at Webstart wrote:

> At 08:14 PM 1/13/2006, John C. McCabe-Dansted wrote:
>> On Saturday 14 January 2006 04:23, Ian G wrote:
>> > John C. McCabe-Dansted wrote:
>> > > David Wagner suggested that it is impossible to write reliable  
>> software
>> > > without bidirectional communication. I am not yet convinced  
>> this is the
>> > > case.
>> >
>> > As a generalism I think it is quite true, and I'd
>> > be fascinated if you could find a case where you
>> > could challenge it.  As a comp sci problem it is
>> > called "the coordination problem" I gather although
>> > there isn't an easy / good reference for it.
>> >
>> > One of the common things that happens is that designs
>> > ignore this and use uni-directional comms.  Then,
>> > the software becomes "unreliable" and as a consequence
>> > users implement a reliability protocol over the top,
>> > often in meatspace not digitalspace.
>>
>> I understand that "the coordination problem" cannot be solved by
>> bi-directional communication.
>
> Did you mean one way communication above?  Or perhaps you meant
> can be solved over one way communication?  The coordination problem
> certainly can be solved over bi-directional communication as that is
> the common case I think.
.......



Norm Hardy: <http://cap-lore.com>

Nothing has an uglier look to us than reason, when it is not on our  
side.
Lord Halifax