PetscCommDuplicate#
Duplicates the communicator only if it is not already a PETSc communicator.
Synopsis#
#include "petscsys.h"   
PetscErrorCode PetscCommDuplicate(MPI_Comm comm_in, MPI_Comm *comm_out, PetscMPIInt *first_tag)
Collective
Input Parameter#
- comm_in - Input communicator 
Output Parameters#
- comm_out - Output communicator. May be - comm_in.
- first_tag - Tag available that has not already been used with this communicator (you may pass in - NULLif you do not need a tag)
Note#
PETSc communicators are just regular MPI communicators that keep track of which
tags have been used to prevent tag conflict. If you pass a non-PETSc communicator into
a PETSc creation routine it will attach a private communicator for use in the objects communications.
The internal MPI_Comm is used to perform all the MPI calls for PETSc, the outer MPI_Comm is a user
and is not used by PETSc.
See Also#
PetscObjectGetNewTag(), PetscCommGetNewTag(), PetscCommDestroy()
Level#
developer
Location#
Examples#
Index of all Sys routines
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Index of all manual pages