PETSc version 3.17.5
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PetscCommGetComm

get an MPI communicator from a PETSc communicator that can be passed off to another package

Synopsis

#include "petscsys.h"   
PetscErrorCode  PetscCommGetComm(MPI_Comm comm_in,MPI_Comm *comm_out)
Collective

Input Parameter

comm_in - Input communicator

Output Parameters

comm_out - Output communicator

Notes

Use PetscCommRestoreComm() to return the communicator when the external package no longer needs it

Certain MPI implementations have MPI_Comm_free() that do not work, thus one can run out of available MPI communicators causing mysterious crashes in the code after running a long time. This routine allows reusing previously obtained MPI communicators that are no longer needed.

See Also

PetscObjectGetNewTag(), PetscCommGetNewTag(), PetscCommDestroy(), PetscCommRestoreComm()

Level

developer

Location

src/sys/objects/tagm.c
Index of all Sys routines
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