Should PetscObjectName be collective?

[Lisandro Dalcin]

On Mon, Nov 16, 2009 at 10:49 AM, Jed Brown <jed at 59a2.org> wrote:
> Since it is not collective, the names can get out of sync, even with
> "reasonable" usage.  Consider a case where rank 0 views a serial Vec
> (say with the Matlab viewer), and then a parallel Vec (e.g. to
> HDF5). The result would either be deadlock (with collective IO) or a
> file where Vec_0 contains all but rank 0's part, and Vec_1 contains only
> rank 0's part (and an HDF5 error once another vector is viewed because
> the Vec_1 dataspace cannot be created if it already exists).
>
> Is it reasonable to make PetscObjectName (and necessary dependents)
> collective where it performs this?
>
>  MPI_Allreduce(MPI_IN_PLACE,&counter,1,MPI_INT,MPI_MAX,obj->comm);
>

And what about VecView() of serial objects on two different processes?
What about parallel Vec's on subcommunicators of COMM_WORLD?


-- 
Lisandro Dalcín
---------------
Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
PTLC - Güemes 3450, (3000) Santa Fe, Argentina
Tel/Fax: +54-(0)342-451.1594