>>>>> On Tue, 28 Nov 2006 13:52:30 -0500 (EST), >>>>> Alexander Shirokov <[EMAIL PROTECTED]> said:
> I would like to embed guile interpreter into my application - a > parallel program using MPI (message passing interface) and operating > massive data and computations. I would like that program to be able to > process standard input in order to be able to have a live interactive > session with my application. Below I describe the problem i > encountered. ... > With guile however, I am limited to using > scm_shell(argc, argv); > which is supposed to do the stdin processing itself, - I hoped it would > even in the parallel environment. I inserted > MPI_Init(&argc,&argv); > MPI_Finalize() > into the tortoise.c program of the guile tutorial (the complete copy of > the program is attached) and compiled it with 'mpicc', but I do not get > the expected behavior, for example when i run on 4 processes: > mpirun -np 4 ./tortoise2 guile> (tortoise-move 100) > the next guile prompt does not appear after the entered command has > completed. > I looked into the guile archieves using search "MPI" and found > that another person was having the same problem one year ago. > That user has recieved a very informative message : > http://lists.gnu.org/archive/html/guile-user/2005-02/msg00018.html > but unfortunately, the thread stops there. > I did some followup and found nice documentation on setting custom > ports on stdin at > http://www.gnu.org/software/guile/docs/docs-1.8/guile-ref/Port-Types.html#Port-Types > but the resources of my expertise in scheme and setting custom > ports have exhausted there. > There are many people using MPI, I think a solution very be greatly > appreciated by a sizable community of MPI users. One issue in wrapping MPI for Guile is calling the `MPI_Init()' before entering Guile. This is done in the code you sent. With that code you can use MPI in background (I guess). For instance try to write a small script and then run it in background with MPI. $ mpirun -np xx tortoise -s myscript.scm That should work. (I use `scm_boot_guile' instead of `gh_enter.' I think that the `gh_..' stuff is deprecated, but I don't know if this is relevant in the discussion. ) Note that with a small effort you have something that is not completely useless: you can use it * interactively in sequential mode, and * in parallel (but not interactively) I have made some experiments in this line, wrapping the most simple MPI functions (mpi-send, mpi-recv, mpi-bcast...) and some basic stuff from PETSc. Now, if you want to use it in parallel and in an interactive environment, then I think the solution is to replace the REPL evaluator, so that each time he founds a `sexp' or whatever to be evaluated, it sends the expression to the nodes with `MPI_Bcast'. I know of something being done with Python and I think it's much the same. http://www.cimec.org.ar/python/ http://sourceforge.net/projects/mpi4py/ I think that this broadcasting of the input from the master to the nodes is something that you can't avoid whenever you want to wrap MPI for any scripting language. Mario _______________________________________________ Guile-user mailing list Guile-user@gnu.org http://lists.gnu.org/mailman/listinfo/guile-user
