jassda-discuss — List to discuss and post new features or changes

[Jassda-discuss] FASD project: Online survey launched

[<ben...@id...>]

Dear Open Source developer

I am doing a research project on "Fun and Software Development" in which I kindly invite you to participate.
You will find the online survey under http://fasd.ethz.ch/qsf/. The questionnaire consists of 53 questions and you will need about 15 minutes to complete it.

With the FASD project (Fun and Software Development) we want to define the motivational significance of fun when software developers decide to engage in Open Source projects. What is special about our research project is that a similar survey is planned with software developers in commercial firms. This procedure allows the immediate comparison between the involved individuals and the conditions of production of these two development models. Thus we hope to obtain substantial new insights to the phenomenon of Open Source Development.


With many thanks for your participation,
Benno Luthiger


PS:
The results of the survey will be published under http://www.isu.unizh.ch/fuehrung/blprojects/FASD/.
We have set up the mailing list fa...@we... for this study. Please see http://fasd.ethz.ch/qsf/mailinglist_en.html for registration to this mailing list.

_______________________________________________________________________

Benno Luthiger
Swiss Federal Institute of Technology Zurich
8092 Zurich

Mail: benno.luthiger(at)id.ethz.ch
_______________________________________________________________________

[Jassda-discuss] Re: CSPJassda parallel operator

[Michael M. <Michael.Moeller@Informatik.Uni-Oldenburg.DE>]

Dear Missi,

(This could be interesting for all, so I Cc to the list)

On Wednesday 17 March 2004 11:47, you wrote:
> > Dear Missi,
> >
> > On Wednesday 17 March 2004 10:36, you wrote:
> > > Hi.
> > >
> > > Is there only one parallel operator in CSPJassda ?
> > > Does it correspond to the parallel operator || in CSP
> > > (synchronization on all actions) or the other parallel=20
> > > operator ||| in CSP (strict interleaving) ?
> >
> > Yes, only one parallel operator with synchronisation on all common
> > events (intersection of the alphabets).
>
> Do you plan to implement the parallel operator that corresponds to the
> strict interleaving ? Or can we use the parallel operator || to
> describe that ?

Short answer: no and no   ;-)

We could implement an interleaving operator, but I'm not sure if this would=
 be=20
a good idea. I would not like the semantics for this very much:

1.)
 P --e--> P' , \notexists Q' : Q --e--> Q'
___________________________________________
       P ||| Q   --e-->   P' ||| Q =20

2.)
 Q --e--> Q' , \notexists P' : P --e--> P'
___________________________________________
       P ||| Q   --e-->   P ||| Q' =20

3.)
     P --e--> P' , Q' : Q --e--> Q'
___________________________________________
  P ||| Q   --e-->   P' ||| Q [] P ||| Q'=20


This "expansion" of the state space (or better: the "state size") in the th=
ird=20
rule of the operational semantics could be somewhat dangerous (especially f=
or=20
runtime checking). But we already have a similar construction for the=20
skipping so perhaps this is not a real problem.

> [...]
> write something like that:
> eventset a1{...}
> eventset a2{...} // a1 and a2 correspond to the same eventset in fact
> eventset b{...}
> eventset c{...}
> R =3D a1.begin -> a1.end -> b.begin -> b.end -> R [] SKIP
> S =3D a2.begin -> a2.end -> c.begin -> c.end -> S [] SKIP
> M =3D R || S ; STOP
>
No, this would not work. The names of the event sets are not relevant for=20
alphabet calculation.

But are you sure, that a1 and a2 should be the same event sets? Or should i=
t=20
read as:

R(c) =3D c.a.begin -> c.a.end -> SKIP
P(b) =3D b.begin -> b.end -> SKIP
M =3D ||c:[instance] @ R(c) ; ( P(b) || P(c) ) ; STOP

In any case this seems to be a complicated process. Can you give me an idea=
 of=20
what kind of software should behave accordingly to this specification?


> >The alphabet is calculated such that it
> > includes the minimum number of required events.
> >
> > (using simplified syntax:)
> >
> > P =3D a -> P [] SKIP
> > Q =3D b -> Q [] SKIP
> >
> > In case of:
> > 1.) M =3D a -> (P || Q ) ; b -> STOP
> >   alphabet(P) =3D a
> >   alphabet(Q) =3D b
> > 2.) M =3D a -> (P || Q ) ; Q
> >   alphabet(P) =3D a
> >   alphabet(Q) =3D a+b
> > (with + meaning event set union)
>
> I am a bit lost here. Why do the alphabets of P and Q depend on the
> way other processes (in that case, M) refer to them ?
>
This is because process references must have the same static alphabet in an=
y=20
context (only parameters may have different bindings and thus could result =
in=20
different dynamic alphabets). Since we "guess" the alphabet of a process fr=
om=20
its context we choose the minimum set of events.
 We could require explicit alphabets. This would sometimes be more easy to=
=20
understand, but I think it is also inconvenient.

So the rules are:
  a -> P  requires  alphabet(a -> P) =3D alphabet(P) and a \subset alphabet=
(P)
  P [] Q  requires  alphabet(P [] Q) =3D alphabet(P) =3D alphabet(Q)=20
  P || Q  requires  alphabet(P || Q) =3D alphabet(P) \union alphabet(Q)=20
  P ; Q   requires  alphabet(P ; Q)  =3D alphabet(P) =3D alphabet(Q)=20

In the first case it is not required that alphabet(Q) includes b whereas in=
=20
the second case the last rule requires it.

BTW: I'm unsure about the second rule. This is the way it is implemented, b=
ut=20
perhaps the second "=3D" should be replaced by a \union. Only in case of=20
process references this would make a difference. Has anyone an opinion on=20
that?


> > So with the new version of Jassda I provided a patch-script. Have
> > you tried to get your example running with Jassda, again? Have you=20
> > been successful?
>
> Yes, I have used the patch and my example works now :)

That is good news! :o)

> Well, my example is just a very simple java class, I have not used
> jassda on more interesting examples yet.
>
If you have more interesting examples sometime and you would like to share=
=20
them we would be happy if we could include them in a Jassda release.

Best regards,
  Michael

=2D-=20
Michael M=F6ller      University of Oldenburg, Faculty II,
	         Dept. of Computing Science, D-26111 Oldenburg, Germany
                     phone:+49 441 798-3483    fax:+49 441 798-2965
        mailto:Mic...@in...

[Jassda-discuss] Jassda 0.6.0 Release

[Michael M. <Michael.Moeller@Informatik.Uni-Oldenburg.DE>]

Hi all,

We did it... Jassda 0.6.0 release is out!


Changes (between 0.6 RC1 and 0.6.0):
=2D bin/jassda.bat=20
	fixed (changes to the directory of the config file)
=2D bin/jassda-patch.sh bin/jassda-patch.bat
	shell scripts utilising de.jassda.core.bytecode.ClassPatcher
=2D bin
	removed unused shell scripts
=2D examples
	source code of the examples


Thanks for the good work!


Best regards,
  Michael


BTW: This also means that feature freeze is over, now. New features (see RF=
E)=20
are welcome in CVS (for 0.7.0 release). But we should also back-port report=
ed=20
bugs (for a 0.6.1 release). =20
=2D-=20
Michael M=F6ller      University of Oldenburg, Faculty II,
	         Dept. of Computing Science, D-26111 Oldenburg, Germany
                     phone:+49 441 798-3483    fax:+49 441 798-2965
        mailto:Mic...@in...