[MPIWG Fortran] Questions about MPI_Comm_spawn

[Rolf Rabenseifner]

Dear Junchao,

The values of len(command) and len(argv(1)) may be different.
All len(argv(i)) are identical.
All details are described in MPI-3.0 p378:20 - p379:20.

There is nothing new since MPI-2.0.

Rolf

----- Original Message -----
> From: "Junchao Zhang" <jczhang at mcs.anl.gov>
> To: "MPI-WG Fortran working group" <mpiwg-fortran at lists.mpi-forum.org>
> Sent: Tuesday, March 25, 2014 3:51:37 PM
> Subject: [MPIWG Fortran] Questions about MPI_Comm_spawn
> 
> 
> 
> 
> Hello, Fortran experts,
>   
>   p.377 of MPI3 defines prototype of MPI_Comm_spawn.
> 
> 
>   MPI_Comm_spawn(command, argv, maxprocs, info, root, comm,
> intercomm, array_of_errcodes, ierror) 
>      CHARACTER(LEN=*), INTENT(IN) ::  command, argv(*)
>      ...
> 
> 
> I can understand that command is a variable-length character. I fetch
> its length by len(command). The Fortran compiler needs to pass in
> data of command, as well as length of command.
> But I can't understand argv(*). I interpret it as an assumed-size
> array of variable-length characters. Does that imply each argv(i)
> could have different lengths, e.g., len(argv(1)) may be different
> from len(argv(2))?
> I think it is unreasonable, since if that, the compiler has to pass
> in length of every element of argv(*).
> 
> 
> Thank you
> 
> --Junchao Zhang
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> mpiwg-fortran mailing list
> mpiwg-fortran at lists.mpi-forum.org
> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran

-- 
Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner at hlrs.de
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)