flow-based-pgmg-list — Discussion re Flow-Based Programming

Re: [Flow-based-pgmg-list] Book on eBay?

[Paul M. <pau...@ro...>]

Hi Wolfgang,

I guess I forgot to say that copies are still available via Amazon.com.  
Apologies!  A friend is acting as the middleperson as Amazon doesn't 
have a way to deal with suppliers in Canada - at least so far.   I 
checked with him and he says it will take about a month by surface 
mail.  Hope that's OK.   I am still thinking about your PDF 
suggestion... it would be great if some outfit could take PDFs and print 
them and bind them with a simple cover ;-)  Remember the book runs to 
300+ pages.

Regards,

Paul

Wolfgang Keller wrote:

>Hello,
>
>as  you  mentioned  that  you still have some copies left and it seems
>that  there  are  none available in the bookstores any more: How about
>selling your spares on ebay? I'd happily buy one if you accept payment
>by Paypal. ;-)
>
>Best regards
>
>Wolfgang Keller
>
>  
>


-- 
http://www.jpaulmorrison.com

[Flow-based-pgmg-list] Book on eBay?

[Wolfgang K. <wol...@gm...>]

Hello,

as  you  mentioned  that  you still have some copies left and it seems
that  there  are  none available in the bookstores any more: How about
selling your spares on ebay? I'd happily buy one if you accept payment
by Paypal. ;-)

Best regards

Wolfgang Keller

-- 
P.S.: My From-address is correct

[Flow-based-pgmg-list] Recent emails by Wolfgang Keller

[Paul M. <pau...@ro...>]

Hi Wolfgang,

I'd forgotten there was a mailing list!  Thanks for the feedback on Axon 
- do you have any more information on this approach?  There doesn't seem 
to be much on the Internet as yet - or too many different Axons (Axa?).

Re your suggestion about putting up a PDF - maybe I will do that once 
the last few paper copies of the book have been sold.  I still have a 
couple of dozen copies, and my wife is looking forward to getting the 
space in her closet back :-)  The book is still available via 
Amazon.com, although from time to time they forget to post the book as 
still available.  Besides, surely, as someone recently wrote me, a nice 
shiny, bound copy is more pleasant to hold than a computer print-out!  
And the diagrams would not be anything like as nice - at least not 
without a lot of work on my part!

Regards,

Paul M.

PS Have any of you contributed to the FBPWiki?  Please do!  There is a 
smple "captcha test" on the first page, but that is only to keep robotic 
vandals out!  It won't even stop the human kind!  The URL is

http://www.jpaulmorrison.com/cgi-bin/wiki.pl

[Flow-based-pgmg-list] Axon: an FBP framework (and it's in Python :-)

[Wolfgang K. <wol...@gm...>]

Hello,

recently the R&D department of BBC released their Axon framework - which
looks to me like a perfect "clone" of the concepts described in your FBP
book. Only that they have never heard or read of FBP before. :-) And, at
least for the current prototype stage, they are using Python for their
implementation, especially the "generator" feature.

Best regards

Wolfgang Keller

[Flow-based-pgmg-list] Book as PDF?

[Wolfgang K. <wol...@gm...>]

Hello,

BTW, as I'm laaazy and as your book does not seem to be available anywhere
any longer (sold out), how about putting the chapters on your WWW site also
as printer-friendly PDF files? Or am I really the only one who prefers
reading longer texts on paper? :-)

Best regards,

Wolfgang Keller

[Flow-based-pgmg-list] Re: FBP with (Stackless) Python?

[Wolfgang K. <wol...@gm...>]

Hello,

> This note is partly to check if this is really your e-mail address!   
> Classical allusions...!

It is - that's the trick. :-)

> I am curious about whether you are suggesting that Stackless Python 
> would be a better base for building an FBP environment, as compared 
> with, say, Java.

Stackless is excellent for every kind of application that needs to handle
asynchronous threads. Especially for I/O-bound applications, where each
thread usually wastes a lot of time waiting for something, you can
enormously speed up things by using _lots_ (tens or hundreds of thousands)
of threads in parallel and thus "interleaving" the waiting time, so that
there's always at least one thread which has everything it needs to
process.

Another issue (which you address in
http://www.jpaulmorrison.com/fbp/method.htm if I understood it right):

Python is not only an excellent "middleware" language (as it interfaces
with practically everything easily, including Java and .net), it's also an
excellent prototyping language, with development times which are typically
a fraction of those for the same application in Java. And once the Python
prototype is finished, all you have to do to turn it into a productive
application is to profile it and re-implement those modules which are
considered too slow for example with Pyrex, which gives your "prototype"
native C(++) speed.

>  I would assume that ports and the network definition 
> would have to be added.  I didn't get much out of  Christian Tismer's 
> web site..

Unfortunately he's too busy earning his live and trying to keep the
Stackless implementation in sync with the "mainstream" Python versions. :-(

> What on earth is Pickling? :-)

A very simple Python persistence/serialisation module.

> Also, as I posted on SourceForge and the wiki, what is so great about 
> getting rid of stacks - or am I reading too much into "stackless"? :-)

The name of "Stackless" is somewhat misleading (or at least bad PR ;-).
Getting rid of the C stack in Stackless is just a means for the aim of
handling a lot of concurrent tasklets (=microthreads) with reasonable
ressource requirements. IMHO Stackless should be renamed into something
like "Microthreaded Python" "Parallel Python" or something like that... Or
even better, the main Python implementation should be "Stackless"ed. :-)

Best regards,

Wolfgang Keller

[Flow-based-pgmg-list] Stackless

[Paul M. <pau...@ro...>]

Hi Wolfgang,

I guess our notes crossed in mid-air!   Maybe the wiki will be a better 
place to exchange information...?  When I get your comments, I will post 
them there.

> Can it handle more than a very limited quantity of concurrent threads?

> Stackless can easily handle hundreds of thousands of concurrent tasklets on
  common desktop hardware.


You're probably right - I had to guess at the size of each stack, and 
picked an arbitrary 4K bytes.   So that would limit one to 2 ^ 20 
tasklets, with nothing else in the machine...   Is my arithmetic 
right?   However,  I also get a flavour that the tasklets typically run 
for a much shorter time than FBP processes - more similar to the FBP 
"non-looping" mode.   While FBP supports both "looping" and 
"non-looping" modes, over the years, I have found the looping mode 
somehow brings out more clearly the architecture of FBP, and in fact 
business apps built with FBP rarely seem to exceed 50 or 60 threads.

I would assume that in Stackless, all storage must be allocated 
explicitly, or does each tasklet get a chunk of local storage?  One 
point of convergence is that I have been thinking for a while that FBP 
would be cleaner if you only allowed a thread's main-line (not 
subroutines under it)  to do sends and receives, so the amount of stack 
that has to be saved across context switches would be considerably smaller.

Hope this makes sense,

Regards,

Paul

-- 
http://www.jpaulmorrison.com/

[Flow-based-pgmg-list] Stackless Python

[Paul M. <pau...@ro...>]

A recently joined subscriber has pointed out the similarities between 
FBP and Stackless Python.  Looking at 
http://www.c2.com/cgi/wiki?StacklessPython, there seems to be some 
confusion as to whether it has continuations any more.  Can anyone shed 
light on this?    Also, I guess I don't quite see what is so bad about 
multiple stacks - my C implementation (THREADS) has no problem switching 
stacks... :-)   What am I missing?!

Also this is a good opportunity to ask people to contribute to the 
FBPWiki at  http://www.jpaulmorrison.com/cgi-bin/wiki.pl.  Look forward 
to hearing from you!

Regards,

Paul M.

-- 
http://www.jpaulmorrison.com/

[Flow-based-pgmg-list] 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
_______________________________________________________________________

[Flow-based-pgmg-list] Flow-Based Programming Wiki

[Paul M. <pau...@ro...>]

This is to let you know about the recent creation of a wiki (FBPWiki) 
which is intended to provide a shared space for collaboration on 
Flow-Based Programming and related concepts.

Its URL is http://www.jpaulmorrison.com/cgi-bin/wiki.pl

Look forward to hearing from you!

Regards,

Paul Morrison

-- 
http://www.jpaulmorrison.com/