Re: object serialization

[Mario Storti]

 --- Mikael Djurfeldt <address@hidden> escribió: 
> On Sat, 5 Feb 2005 11:40:36 -0600 (CST), Mario Storti
> <address@hidden> wrote:
> > I´m writing a parallel Finite Element
> > (http://www.cimec.org.ar/petscfem) program and I´m making some
> > experiments with extending it with Guile.
> 
> That's very exciting!  I've written a neuron simulator which is
> parallelized with MPI and extended with Guile.  (It's not publicly
> available right now.  It's GPL:ed alright, but not in a releasable
> state and doesn't have enough docs.)

Sounds nice...

> > The program runs in parallel using Message Passing with the MPI
Library
> > (http://www-unix.mcs.anl.gov/mpi/). I have wrapped some basic MPI
> > functions (MPI_Comm_rank,MPI_Comm_size,MPI_Recv and MPI_Wend), and
> it
> > seems to work fine, but I ask you people if someone knows of a port
> of
> > MPI to Guile.
> 
> I've never seen one.  I don't think it exists.  However, I would
> welcome one!
> 
> > When running in parallel I had to compile myself the Guile
> interpreter
> > since I need that all processes read and interpret the script. This
> > prevents me to using the interpreter in interactive form (when
> running
> > in parallel) because MPI does not broadcast the standard input to
> the
> > other processes. I think that this can be fixed by modifiying the
> REPL,
> > i.e. when running in interactive mode, in parallel, the REPL in the
> > master node should be in charge of broadcasting the standard input
> to
> > the nodes. Any ideas?
> 
> Maybe you should have a look at how to implement custom port objects.
> 
> There should be some documentation in the reference manual and
> guile-readline is one example. The idea would then be that you
> interact with a master process with a custom standard input port. At
> every newline, it sends data to another kind of custom standard input
> port on the slaves.
> 
> Once you have figured out how to make the ports, you can simply
> redirect input with:
> 
> (set-current-input-port MY-PORT)

I will investigate this.

> > Also, i´m not very happy with the way I do the MPI initialization.
> I
> > had to write my own guile interpreter because MPI needs to have
> accesss
> > to the argc, argv arguments of main(), so that MPI initialization
> is
> > done _always_. I would like rather to have a Scheme `mpi-init'
> function
> > called by the user.
> 
> My view on this situation is that since the installed Guile
> interpreter currently can't run any custom code before parsing its
> arguments and since MPI *has to* parse the arguments before that,
> there's no other choice but to write your own interpreter like you've
> done.
> 
> > But, on the other hand I can´t do the finalization
> > in the `inner_main()´ because I receive a lot of `net_recv' errors
> > _before_ reaching the MPI_Finalize().
> 
> But this should be due to some synchronization problem in your
> program.  Maybe everybody hasn't received all data before senders
> begin to finalize?  Have you tried to but a call to MPI_Barrier right
> before MPI_Finalize?

Hmmmmm... I will check... That's possible. 

If I write something about MPI wrapping I will keep you informed. 

Regards, Mario

=====
-------------------------
Mario Alberto Storti
Centro Internacional de Metodos Computacionales
  en Ingenieria - CIMEC (INTEC/CONICET-UNL)
INTEC, Guemes 3450 - 3000 Santa Fe, Argentina
Tel/Fax: +54-342-4511594, cel: +54-342-156144983
e-mail: address@hidden
http://www.cimec.org.ar/mstorti, http://www.cimec.org.ar
-------------------------

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