[Dune] MPI Handling in dgfparser

[Markus Blatt]

Hi,

as some of you might habe noticed I changed some of the defines in the
dgfparser to make it work work with lam-mpi. As I already feared this
broke quite some tests in the grid check. (see:
<http://www.dune-project.org/checklog?display=log&revision=2006-07-14T00%3A00%2B0200&mode=build&module=test-alu3dgrid&path=%2Fdune-grid%2Fgrid%2Ftest&tag=Head%20Build&host=hal%20%28Linux%20i686%2C%20gcc%203.4%29> ) 

The error seems now that there is no mpi.h included in the dgfparser's
header files and therefore MPI_Comm and MPI_COMM_WORLD are not
defined.

As it is quite easy to include them conditionally if MPI is installed
,by:
#ifdef HAVE_MPI
#include"mpi.h"
#endif

I am wondering whether there is a reason for not doing this in the
dgfparser header files.

It would be really nice if somebody could explain me what the rational
behind the defines of MPI_Comm, MPI_COMM_WORLD, MPI_Init,
MPI_Finalize, ... was.

Was it intended to be able to compile a programm in sequential mode even
if Dune is configured with mpi-support. If so, how was this supposed
to work?

Looking forward to some enlightenment.

Cheers,

Markus
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DUNE -- The Distributed And Unified Numerics Environment 
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