[Pympi-users] Converting Communicators to and from fortran modules

[Mike S. <st...@gm...>]

Hi All,

I think this is a question that Pat will have to answer, but perhaps
some of you have seen it or have the same question:

I have a fortran module wrapped using f2py.  The module in this case
is MPH, the Multi Program Handshaking utility.  It is mostly used to
help setup the MPI environment for multiple mpi executables.  I need
to call some of these library routines, some of which are supposed to
return communicators.

However, the values that are supposed to be communicators show up as
python integers.  While these may be completely usable for passing to
extension codes they are worthless for actually doing anything in
python.

I've noticed that pyMPI is capable of handling the opposite though, if
I pass a pyMPI communicator object to wrapped code expecting a fortran
communicator the wrapped code still works.

Is there any way for me to take a communicator from fortran and
"promote" it to a python communicator so that I can get information
like the size of the communicator?

If there is no pyMPI way to do it at the moment, how else could I get
this information?
Write wrappers around a few MPI functions like MPI_Comm_rank and
MPI_Comm_size in fortran or c?  Then just call those with the fortran
communicator to get the info i need?

Thanks in advance,

~Mike