! -*- Mode: Fortran; -*-

!

!  (C) 2011 by Argonne National Laboratory.

!      See COPYRIGHT in top-level directory.

!

! Test just the MPI-IO FILE object

      program main

      use mpi_f08

      integer errs, toterrs, ierr

      integer wrank

      type(MPI_Group) wgroup

      integer fsize, frank

      type(MPI_Comm) comm

      type(MPI_File) file

      type(MPI_Group) group

      integer result

      integer c2ffile

      errs = 0

      call mpi_init( ierr )

      call mpi_comm_rank( MPI_COMM_WORLD, wrank, ierr )

      call  mpi_comm_group( MPI_COMM_WORLD, wgroup, ierr )

      call mpi_file_open( MPI_COMM_WORLD, "temp", MPI_MODE_RDWR + &

      &     MPI_MODE_DELETE_ON_CLOSE + MPI_MODE_CREATE, MPI_INFO_NULL, &

      &     file, ierr )

      if (ierr .ne. 0) then

         errs = errs + 1

      else

         errs = errs + c2ffile( file )

         call mpi_file_close( file, ierr )

      endif

      call f2cfile( file )

!     name is temp, in comm world, no info provided

      call mpi_file_get_group( file, group, ierr )

      call mpi_group_compare( group, wgroup, result, ierr )

      if (result .ne. MPI_IDENT) then

          errs = errs + 1

          print *, "Group of file not the group of comm_world"

      endif

      call mpi_group_free( group, ierr )

      call mpi_group_free( wgroup, ierr )

      call mpi_file_close( file, ierr )

!

! Summarize the errors

!

      call mpi_allreduce( errs, toterrs, 1, MPI_INTEGER, MPI_SUM, &

      &     MPI_COMM_WORLD, ierr )

      if (wrank .eq. 0) then

         if (toterrs .eq. 0) then

            print *, ' No Errors'

         else

            print *, ' Found ', toterrs, ' errors'

         endif

      endif

      end