PETSc version 3.16.4
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 NULL if you do not need a tag)
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
level MPI_Comm that may be performing communication for the user or other library and so IS NOT used by PETSc.
See Also
PetscObjectGetNewTag(), PetscCommGetNewTag(), PetscCommDestroy()
Level
developer
Location
src/sys/objects/tagm.c
Examples
src/ksp/ksp/tutorials/ex73.c.html
Index of all Sys routines
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Index of all manual pages