2: static char help[] = "Tests using PetscViewerGetSubViewer() recursively\n\n";

  4: /*T
  5:    Concepts: viewers
  6:    Processors: n
  7: T*/
  8:  #include <petscsys.h>
  9:  #include <petscviewer.h>


 12: int main(int argc,char **argv)
 13: {
 14:   PetscErrorCode    ierr;
 15:   PetscViewer       viewer,subviewer,subsubviewer;
 16:   PetscViewerFormat format;
 17:   PetscBool         flg;
 18:   PetscSubcomm      psubcomm,psubsubcomm;
 19:   MPI_Comm          comm,subcomm,subsubcomm;
 20:   PetscMPIInt       size;

 22:   /*
 23:     Every PETSc routine should begin with the PetscInitialize() routine.
 24:     argc, argv - These command line arguments are taken to extract the options
 25:                  supplied to PETSc and options supplied to MPI.
 26:     help       - When PETSc executable is invoked with the option -help,
 27:                  it prints the various options that can be applied at
 28:                  runtime.  The user can use the "help" variable place
 29:                  additional help messages in this printout.
 30:   */
 31:   PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
 32:   comm = PETSC_COMM_WORLD;
 33:   MPI_Comm_size(comm,&size);
 34:   if (size < 4) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"Must run with at least 4 MPI processes");
 35:   PetscOptionsGetViewer(comm,NULL,"-viewer",&viewer,&format,&flg);
 36:   if (!viewer) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"Must use -viewer option");

 38:   PetscViewerASCIIPrintf(viewer,"Print called on original full viewer %d\n",PetscGlobalRank);

 40:   PetscSubcommCreate(comm,&psubcomm);
 41:   PetscSubcommSetNumber(psubcomm,2);
 42:   PetscSubcommSetType(psubcomm,PETSC_SUBCOMM_CONTIGUOUS);
 43:   /* enable runtime switch of psubcomm type, e.g., '-psubcomm_type interlaced */
 44:   PetscSubcommSetFromOptions(psubcomm);
 45:   subcomm = PetscSubcommChild(psubcomm);

 47:   PetscViewerGetSubViewer(viewer,subcomm,&subviewer);

 49:   PetscViewerASCIIPrintf(subviewer,"  Print called on sub viewers %d\n",PetscGlobalRank);

 51:   PetscSubcommCreate(subcomm,&psubsubcomm);
 52:   PetscSubcommSetNumber(psubsubcomm,2);
 53:   PetscSubcommSetType(psubsubcomm,PETSC_SUBCOMM_CONTIGUOUS);
 54:   /* enable runtime switch of psubcomm type, e.g., '-psubcomm_type interlaced */
 55:   PetscSubcommSetFromOptions(psubsubcomm);
 56:   subsubcomm = PetscSubcommChild(psubsubcomm);

 58:   PetscViewerGetSubViewer(subviewer,subsubcomm,&subsubviewer);

 60:   PetscViewerASCIIPrintf(subsubviewer,"  Print called on sub sub viewers %d\n",PetscGlobalRank);

 62:   PetscViewerRestoreSubViewer(subviewer,subsubcomm,&subsubviewer);
 63:   PetscViewerRestoreSubViewer(viewer,subcomm,&subviewer);

 65:   PetscSubcommDestroy(&psubsubcomm);
 66:   PetscSubcommDestroy(&psubcomm);
 67:   PetscViewerDestroy(&viewer);
 68:   PetscFinalize();
 69:   return ierr;
 70: }


 73: /*TEST

 75:    test:
 76:       nsize: 4
 77:       args: -viewer

 79: TEST*/