LAM/MPI General User's Mailing List Archives

From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2005-09-30 16:26:10

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• In reply to: burri_at_[hidden]: "LAM: Constructing a Derived datatype"

On Sep 29, 2005, at 4:56 PM, burri_at_[hidden] wrote:

> MPI_Datatype *mpiDummy = NULL;
> [snip]
> DerivedTypeMPIDummyStruct(dummy, mpiDummy);

This is your problem -- mpiDummy is a pointer to NULL. You need:

MPI_Datatype mpiDummy;
DerivedTypeMPIDummyStruct(dummy, &mpiDummy);

That is, MPI does not allocate an MPI_Datatype handle for you -- you
need to pass a handle to MPI and MPI will fill it up for you.

Hope this helps.

-- 
{+} Jeff Squyres
{+} The Open MPI Project
{+} http://www.open-mpi.org/

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• In reply to: burri_at_[hidden]: "LAM: Constructing a Derived datatype"