[aosd-discuss] discuss Digest, Vol 43, Issue 5

Thu Apr 19 02:52:48 EDT 2007

I do also agree on the point of locality's great influence over 
applications. During the software developing process, we try to map the 
real world into the computing model, as you know, the problem we confronted 
are becoming increasing complicated, OO's one vertical demension takes most 
abstractions of fundermental concerns. Masters always say "seperation of 
concerns". Yeah, that's the way of divide and conquer, it seems like some 
kinds of principle. And the locality for the complex and heterogeneous 
computing evironments seems more concrete behaves more exact in the 
programming design way. as we know, the middleware that widely adopted by 
the art of produce line, what makes it so efficient to solve the wide 
spectrums of applications, I think just like the de facto standard CORBA's 
goal ---transparency of location that plays the great role.

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>Subject: discuss Digest, Vol 43, Issue 5
>Date: Wed, 18 Apr 2007 12:00:03 -0400
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>Today's Topics:
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>    1. Re: Inheritance hierarchies (Ashley at Metamaxim)
>    2. Re: Inheritance hierarchies (Dean Wampler)
>    3. Re: Inheritance hierarchies (Ashley at Metamaxim)
>
>
>----------------------------------------------------------------------
>
>Message: 1
>Date: Tue, 17 Apr 2007 17:35:25 +0100
>From: "Ashley at Metamaxim" <ashley.mcneile at metamaxim.com>
>Subject: Re: [aosd-discuss] Inheritance hierarchies
>To: "Raffi Khatchadourian" <khatchad at cse.ohio-state.edu>
>Cc: discuss at aosd.net
>Message-ID: <007001c7810e$66a31ec0$4001a8c0 at Ashley>
>Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>	reply-type=response
>
>Raffi
>
> > But how are aspects compositional? The problem with reasoning about AO
> > programs is that doing so generally requires whole-program analysis.
>
>At least in the approach we have been using, a well defined form of local
>reasoning is possible, so whole-program analysis is not required. 
Primarily
>this is because we are using the parallel composition operator (P||Q) of
>Hoare's CSP to combine aspects with their base. The form of local 
reasoning
>this enables is fully described in the paper I referenced.
>
>I find it hard to understand how it is possible to use aspects to any
>significant degree unless at least some degree of local reasoning is
>possible.
>
>Rgds
>Ashley
>
>
>
>
>------------------------------
>
>Message: 2
>Date: Tue, 17 Apr 2007 11:58:55 -0500
>From: Dean Wampler <dean at aspectprogramming.com>
>Subject: Re: [aosd-discuss] Inheritance hierarchies
>To: "Ashley at Metamaxim" <ashley.mcneile at metamaxim.com>
>Cc: discuss at aosd.net
>Message-ID:
>	<A49346F2-A20D-4A5F-B158-F2FDAC1CE7BD at aspectprogramming.com>
>Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
>
>
>On Apr 17, 2007, at 11:35 AM, Ashley at Metamaxim wrote:
>
> > Raffi
> >
> >> But how are aspects compositional? The problem with reasoning
> >> about AO
> >> programs is that doing so generally requires whole-program analysis.
> >
> > At least in the approach we have been using, a well defined form of
> > local
> > reasoning is possible, so whole-program analysis is not required.
> > Primarily
> > this is because we are using the parallel composition operator (P||
> > Q) of
> > Hoare's CSP to combine aspects with their base. The form of local
> > reasoning
> > this enables is fully described in the paper I referenced.
> >
> > I find it hard to understand how it is possible to use aspects to any
> > significant degree unless at least some degree of local reasoning is
> > possible.
>
>+1. That's why I think most aspects should only add orthogonal state
>and behavior to the modules they advise. Otherwise, you have a non-
>trivial problem of reasoning about the behavior. (Even then, such
>aspects can impact performance and other systemic properties.) Non-
>orthogonal aspects should be used deliberately and with caution, at
>least given the current state of our art.
>
>Coming from industry, the vast majority of developers simply won't
>use aspects if they have to do some sort of global analysis to ensure
>correct behavior. Very few organizations do anything like that today.
>It would be too big a barrier. Fortunately, the problem is diminished
>by using mostly orthogonal aspects. Also, rigorous automated testing,
>which is already a best practice that emerged in the last decade,
>will help detect many problems.
>
>dean
>
> >
> > Rgds
> > Ashley
> >
> >
> > _______________________________________________
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>Dean Wampler, Ph.D.
>dean at objectmentor.com
>http://www.objectmentor.com
>http://www.aspectprogramming.com
>http://www.contract4j.org
>
>I want my tombstone to say:
>    Unknown Application Error in Dean Wampler.exe.
>    Application Terminated.
>        [Okay]        [Cancel]
>
>
>
>
>
>
>------------------------------
>
>Message: 3
>Date: Tue, 17 Apr 2007 18:26:22 +0100
>From: "Ashley at Metamaxim" <ashley.mcneile at metamaxim.com>
>Subject: Re: [aosd-discuss] Inheritance hierarchies
>To: "Dean Wampler" <dean at aspectprogramming.com>
>Cc: discuss at aosd.net
>Message-ID: <000b01c78115$85292130$4001a8c0 at Ashley>
>Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>	reply-type=response
>
>Dean
>
> > +1. That's why I think most aspects should only add orthogonal state
> > and behavior to the modules they advise. Otherwise, you have a non-
> > trivial problem of reasoning about the behavior.
>
>Bingo! I absolutely agree.
>
> > Coming from industry, the vast majority of developers simply won't
> > use aspects if they have to do some sort of global analysis to ensure
> > correct behavior. Very few organizations do anything like that today.
> > It would be too big a barrier. Fortunately, the problem is diminished
> > by using mostly orthogonal aspects. Also, rigorous automated testing,
> > which is already a best practice that emerged in the last decade,
> > will help detect many problems.
>
>I agree absolutely with that, too!
>
>Rgds
>Ashley
>
>
>
>------------------------------
>
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>End of discuss Digest, Vol 43, Issue 5
>**************************************

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