[MOAB-dev] exchanging sets of entities between processors in parallel

[Tim Tautges]

On 04/18/2012 11:24 AM, Iulian Grindeanu wrote:
ter a ticket for this
>
>     2) I attach a simple example when moab hangs inside exchange_ghost_cells
>     attachments are:
>     a. an initial mesh nmesh-0.vtk
>     b. mesh out.mhdf prepared by mbpart with command ./mbpart -p partgeomkway 6 nmesh-0.vtk out.mhdf
>     c. simple code bug.cpp that can be compiled by
>     mpicxx bug.cpp -lMOAB -lnetcdf
>     and run by
>     mpiexec -np 6 ./a.out out.mhdf
>
>     it fails to pass exchange_ghost_cells
>
>
>
> ...
> result = pcomm.exchange_ghost_cells(3,2,1,0,1);
> CHKERR("cannot exchange ghost\n");
> ...
>
> for this one, it seems that you are passing the bridge dimension as "2". If you pass 0 for bridge dimension, it works.
> I think the problem is that there are no faces created by default (internally). It should work if you generate all the
> internal faces, then partition the mesh.
>

I haven't looked at the code, but if it's requesting resolve_shared_ents, then there should be faces on the skin.

Still, it shouldn't die with zero faces.

- tim

> As a reminder, faces between tets are not generated automatically, to keep the database small. You can request that,
> with a method like
>
> mb->get_adjacencies(Range tets,
> const int to_dimension /*2 for faces*/,
> const bool create_if_missing /* true*/,
> Range & out,
> const int operation_type /* Interface::UNION*/);
>
> you may need to pass in all tets, and set "create_if_missing=true"
>
>
>     I'll try to replace code for message passing inside this function
>     If I'll have a success I'll share it with you
>
>
>
>         I will look at your code more, but I don't think I can be of much help, sorry about that.
>
>         Iulian
>
>
>
>
>

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              Tim Tautges            Argonne National Laboratory
          (tautges at mcs.anl.gov)      (telecommuting from UW-Madison)
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