From: "B. Lee" Newsgroups: comp.parallel.mpi Subject: Re: C and FORTRAN Date: Sat, 10 Oct 1998 09:53:18 +0900 Organization: ETRI/Super Computer Center Message-Id: <361EAFFE.DEE@pvmcube4.snu.ac.kr> References: <361E42C2.4DB1EE55@ifd.mavt.ethz.ch> Reply-To: bslee@pvmcube4.snu.ac.kr Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Michele Milano wrote: > > Hi all, > > I'm using MPI to parallelize a code that is written part in C and part > in FORTRAN. > > The main program is in C, then from the C program a FORTRAN subroutine > is called; this FORTRAN subroutine itself calls a C function. > > Anyway, there is no "cross communication" between parts of code written > in different languages, i.e. FORTRAN written routines communicate only > with FORTRAN written routines, and the same for the C part of the code. > I know that "cross communication" between codes written in different > languages is a problem, because of typing differences, so I avoided to > do that. > > Now, my concern is the following: where should I initialize the MPI > environment? There are 3 possibilities: > > 1) call MPI_Init from the C part only > 2) call MPI_INIT from the FORTRAN part only > 3) initialize MPI from both the parts of the code > > I would like to have an opinion/advice... > Another option is using PVM. In PVM, cross communication is possible. If your parallelization is now beginning, I advice you to use PVM as cross communication. Especially master program is developed with C, and sub-programs are already developed with Fortran. Or another choice is using MPI and PVM both. If cross communication is needed, use PVM elsewhere use MPI. This has no problem. ++++++++++++++++++++++++++++++++++++++++++++++++ Lee, Bo-sung ETRI/Super Computer Center, S. Korea mailto:bslee@pvmcube4.snu.ac.kr mailto:bslee@linuxsvr.seri.re.kr ++++++++++++++++++++++++++++++++++++++++++++++++