%IMPI_VAL was a typo. %MPI_VAL is correct, see MPI-4.0 page 18, line 20. ----- Original Message -----
From: "Pritchard" <[email protected]> To: "Rolf Rabenseifner" <[email protected]>, "Main MPI Forum mailing list" <[email protected]> Sent: Tuesday, August 24, 2021 10:55:51 PM Subject: Re: [EXTERNAL] Re: [Mpi-forum] An f2c question
Hi Ralph,
Okay, not quite right, looks like both mpich and open mpi use %MPI_VAL, so I'll go with that.
Thanks,
Howard
On 8/24/21, 2:28 PM, "Rolf Rabenseifner" <[email protected]> wrote:
Dear Howard,
SUBROUTINE MPI_TYPE_COMMIT(DATATYPE, IERR) INTEGER :: IERR ! some module USE to include the definition of TYPE(MPI_Datatype) TYPE(MPI_Datatype) :: DATATYPE CALL MPI_X_TYPE_COMMIT(DATATYPE%IMPI_VAL, IERR) RETURN END
I do not know how to handle the optional ierr, but here is the way you should handle the datatype handle.
Best regards Rolf
----- Original Message ----- > From: "Main MPI Forum mailing list" <[email protected]> > To: "Main MPI Forum mailing list" <[email protected]> > Cc: "Pritchard" <[email protected]> > Sent: Tuesday, August 24, 2021 10:19:27 PM > Subject: [Mpi-forum] An f2c question
> Hi All, > > > > In porting an MPI application written mainly in Fortran and a little c to using > mpi_f08 rather than mpi, I’ve hit an issue. > > > > Namely, how would I write example 19.11 in the MPI 4 standard if the app uses > type(MPI_Type) rather than integer? > > Note I’m working with an application, so the MPI_Type structure is opaque, or at > least I thought we’re supposed to treat it as opaque. > > > > Here’s the example: > > > > Example 19.11 The example below illustrates how the Fortran MPI function > > MPI_TYPE_COMMIT can be implemented by wrapping the C MPI function > > MPI_Type_commit with a C wrapper to do handle conversions. In this example a > Fortran-C > > interface is assumed where a Fortran function is all upper case when referred to > from C and > > arguments are passed by addresses. > > ! FORTRAN PROCEDURE > > SUBROUTINE MPI_TYPE_COMMIT(DATATYPE, IERR) > > INTEGER :: DATATYPE, IERR > > CALL MPI_X_TYPE_COMMIT(DATATYPE, IERR) > > RETURN > > END > > /* C wrapper */ > > void MPI_X_TYPE_COMMIT(MPI_Fint *f_handle, MPI_Fint *ierr) > > { > > MPI_Datatype datatype; > > datatype = MPI_Type_f2c(*f_handle); > > *ierr = (MPI_Fint)MPI_Type_commit(&datatype); > > *f_handle = MPI_Type_c2f(datatype); > > return; > > } > > > > Now I suspect that most of the time if one has some old ‘c’ code assuming a > pointer to a 4 byte fortran integer argument for the datatype is just going to > work, but I’d rather not just try to be lucky. > > Anyway, there are fortran gurus on this project and they’d be sure to want a > better solution. > > > > Thanks for any help/ideas, > > > > Howard > > > > > > — > > > > > > > Howard Pritchard > > Research Scientist > > HPC-ENV > > > > Los Alamos National Laboratory > > [email protected] > > > > [ https://www.instagram.com/losalamosnatlab/ ] [ > https://twitter.com/LosAlamosNatLab ] [ > https://www.linkedin.com/company/los-alamos-national-laboratory/ ] [ > https://www.facebook.com/LosAlamosNationalLab/ ] > > > > > > > _______________________________________________ > mpi-forum mailing list > [email protected] > https://lists.mpi-forum.org/mailman/listinfo/mpi-forum
-- Dr. Rolf Rabenseifner . . . . . . . . . .. email [email protected] . High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 . University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 . Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner . Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) .
-- Dr. Rolf Rabenseifner . . . . . . . . . .. email [email protected] . High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 . University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 . Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner . Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) .