!
!  Program to test PetscSubcomm.
!
program main

#include <petsc/finclude/petscsys.h>
  use petscsys
  implicit none

  PetscErrorCode ierr
  PetscSubcomm r
  PetscMPIInt rank, size
  MPI_Comm scomm

  PetscCallA(PetscInitialize(ierr))
  PetscCallMPIA(MPI_Comm_size(PETSC_COMM_WORLD, size, ierr))
  PetscCallMPIA(MPI_Comm_rank(PETSC_COMM_WORLD, rank, ierr))
  PetscCallA(PetscSubcommCreate(PETSC_COMM_WORLD, r, ierr))
  PetscCallA(PetscSubcommSetFromOptions(r, ierr))
  PetscCallA(PetscSubcommSetTypeGeneral(r, rank, rank, ierr))

  PetscCallA(PetscSubcommGetChild(r, scomm, ierr))
  PetscCallA(PetscSubcommView(r, PETSC_VIEWER_STDOUT_WORLD, ierr))
  PetscCallA(PetscSubcommDestroy(r, ierr))
  PetscCallA(PetscFinalize(ierr))
end

!
!/*TEST
!
!   test:
!     nsize: 2
!
!TEST*/