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Subject: Re: [OMPI devel] About Marshalling and Umarshalling
From: Ralph Castain (rhc_at_[hidden])
Date: 2012-11-05 10:13:20


We adhere to the MPI standard, so we expect the user in such an instance to define a datatype that reflects the structure they are trying to send. We will then do the voodoo to correctly send that data in a heterogeneous environment, and pass the data back (in the defined datatype) to the user on the remote end. They can then put the various items back into their structure.

I'm not sure what you mean by an "ideal style language". See the MPI standard or our doc page, for example

http://www.open-mpi.org/doc/v1.6/man3/MPI_Type_create_struct.3.php

for an explanation of how one defines a datatype.

On Nov 4, 2012, at 8:14 PM, Santhosh Kokala <Santhosh.Kokala_at_[hidden]> wrote:

> Now I get it.
>
> Marshalling – the process of taking a collection of data items
> and assembling them into a form suitable for transmission in
> a message
> Unmarshalling – is the process of disassembling them on
> arrival into an equivalent representation at the destination
>
> Santhosh
>
> From: devel-bounces_at_[hidden] [mailto:devel-bounces_at_[hidden]] On Behalf Of Paul Hargrove
> Sent: Sunday, November 04, 2012 8:10 PM
> To: Open MPI Developers
> Subject: Re: [OMPI devel] About Marshalling and Umarshalling
>
> Santhosh,
>
> I think Ralph wants you to give your definitions for "Marshlling" and "Unmashalling".
> Otherwise, it is not clear to him or others exactly what you are asking, because there are multiple possible meanings for those terms.
>
> -Paul
>
> On Sun, Nov 4, 2012 at 7:56 PM, Santhosh Kokala <Santhosh.Kokala_at_[hidden]> wrote:
> I wanted to know how does OpenMPI achieve marshaling and unmarshalling? If not how does it communicate with various hosts with various architectures?
>
> From: devel-bounces_at_[hidden] [mailto:devel-bounces_at_[hidden]] On Behalf Of Ralph Castain
> Sent: Sunday, November 04, 2012 7:46 PM
> To: Open MPI Developers
> Subject: Re: [OMPI devel] About Marshalling and Umarshalling
>
> Could you provide a little more definition of your terms? Just want to ensure we are talking the same language as I don't immediately see the relationship between these three questions.
>
>
> On Nov 4, 2012, at 6:19 PM, Santhosh Kokala <Santhosh.Kokala_at_[hidden]> wrote:
>
>
> Hi All,
> Does OpenMPI support Marshalling/Unmarshalling? If so does it use ideal style language? If not how does it support heterogenous hosts?
> Santhosh
>
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>
> --
> Paul H. Hargrove PHHargrove_at_[hidden]
> Future Technologies Group
> Computer and Data Sciences Department Tel: +1-510-495-2352
> Lawrence Berkeley National Laboratory Fax: +1-510-486-6900
>
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