[Fwd: Re: Model of Concurrency in DAML-S -Reposted]

On Friday, September 19, 2003, at 06:59  AM, Monika Solanki wrote:
[snip description and option 1, as I disscuss it elsewhere]

> Option 2:
> Since communication will actually happen within the atomic services of 
> these composite services and since atomic services can execute 
> sequentially or independently in parallel with each other, the 
>  representation of this problem in DAML-S is possible in terms of 
> atomic services and control constructs.
>
> I am certain abut option 1, however option 2 may solve this problem. I 
> want a second opinion about option 2. Will the actual solution need 
> new constructs or is option 2 the solution
[snip]

I'm not sure I understand option 2. I don't see how communication 
happens *within* the atomic services. If you mean that we can notice 
the dataflow dependancy and rewrite the parallel construct as a 
sequential one, that seems right to me.

I'd go further and point out that if we have glass box views of the 
communicating process, we might discover that B needs info for A in 
step 47 of (rather than step 1). So, sequencing all of A before all of 
B would be unfortunate. (It still could be handled. I'm not sure, but I 
think SHOP2 would be able to build this compositoin (well, with 
concurrancy awareness added in.) You should get something like a split 
all of A, steps 1-46 of B, join on 47, etc..

I'll note that this seems to be the kind of composition (coordinating 
message exchanges) folks like Richard Hull are talking about.

Cheers,
Bijan.



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Monika Solanki
Software Technology Research Laboratory(STRL)
De Montfort University
Hawthorn building, H00.18
The Gateway
Leicester LE1 9BH, UK

phone: +44 (0)116 250 6170 intern: 6170
email: monika@dmu.ac.uk
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Received on Monday, 22 September 2003 02:44:15 UTC