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Re: a clarification on channel usage.

From: Kohei Honda <kohei@dcs.qmul.ac.uk>
Date: Wed, 20 Jul 2005 15:21:27 +0100
Message-ID: <42DE5DE7.3020607@dcs.qmul.ac.uk>
To: Monica J Martin <Monica.Martin@Sun.COM>
CC: public-ws-chor@w3.org, yoshida@doc.ic.ac.uk

Dear Monica,

My apologies that I was very late in my reply.

Monica J Martin wrote:

> Kohei, A brief question (or clarification for me): see inline.
>
>> (1) Two versions of the text.
>>
>> (1-1) version 1 (without must).
>>
>> Distinct instances of a (top-level or enclosed) choreography, if
>> they ever run in a temporarily overlapped fashion, are not assumed
>> to interfere with each other in their involved communication
>> actions.  In other words, given a choreography description,
>> interactions belonging to one of its instances are assumed to be
>> logically, hence executionally, distinguishable from those in
>> another.
>>
>> (1-2) version 2 (with must).
>>
>> Distinct instances of a (top-level or enclosed) choreography, if
>> they ever run in a temporarily overlapped fashion, must not
>> interfere with each other in their involved communication actions.
>> In other words, given a choreography description, interactions
>> belonging to one of its instances must be logically, hence
>> executionally, distinguishable from those in another.
>>
>> (2) Comments.
>>
>> Terminology: I used the term "instance". I am not sure this term
>> can be used for denoting a run of a top-level choreography (the
>> attribute name "choreographyInstanceId" seems to be used only for
>> enclosed choreographies). We can use the term "runs" instead of
>> "instances". I also used "temporarily ovelapped" instead of "in
>> parallel" or in "concurrent" to be concrete about what is meant.
>>
> mm1: Kohei, can you differentiate / explain why you don't use parallel 
> or concurrent, as opposed to temporarily overlapped. And, what is the 
> intent in what behavior we expect and wish to manage. Thanks.
>
There are many ways people define "concurrency" and "parallelism".
In this instance I would personally use the term "concurrent" (which
means, to me, there are logically several threads of activities going
on), but to be non-ambiguous I used "temporarily overlapped".

However I am glad it is changed into "concurrent". In fact "temporarily
overlapped" can also be misleading since it may connote they should
physically be runnig in parallel. This is not what I meant: they can be
run on the same single CPU machine as two or more logical units.

In this case "in a temporarily overlapped fasion" becomes "concurrently"
or "concurrently, for example in different threads or processes".

Best wishes,

kohei
Received on Wednesday, 20 July 2005 14:21:35 GMT

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