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From: Brian Barrett (brbarret_at_[hidden])
Date: 2006-06-07 19:07:06


On Jun 7, 2006, at 2:21 PM, Jonathan Day wrote:

> Sorry if this sounds idiotic, but I'm having problems
> with the MPI get operation in OpenMPI. I have test
> program that calls OpenMPI's get operation, which
> performs a send operation. This fails with a null
> pointer exception in the opal library, after preparing
> the source.
>
> With the shared memory driver, when performing a get,
> the shared memory code seems to be being passed a null
> pointer. Using the TCP driver also crashes with
> dereferencing a null pointer.
>
> Anyone have any suggestions on what might be causing
> the problem? I assume others are using get, so
> presumably someone else will have encountered this
> problem (assuming it's a quirk that's in a common
> component and not in the test program).

Are you referring to MPI_GET, part of the one-sided chapter or the get
() call that is part of the btl interface? Based on your
description, I'm guessing the second. Currently, we do not require
BTLs to implement the put or get call. You have to check the btl
flags for MCA_BTL_FLAGS_PUT and MCA_BTL_FLAGS_GET -- if they are not
set, those functions are not implemented.

If you were talking about the MPI_GET function, a stack trace and
sample application would be most useful.

Brian

-- 
   Brian Barrett
   Open MPI developer
   http://www.open-mpi.org/