ALL_test_f_obj.F90

!Copyright 2018 Rene Halver, Forschungszentrum Juelich GmbH, Germany
!Copyright 2018 Godehard Sutmann, Forschungszentrum Juelich GmbH, Germany
!
!Redistribution and use in source and binary forms, with or without modification, are
!permitted provided that the following conditions are met:
!
!1. Redistributions of source code must retain the above copyright notice, this list
!   of conditions and the following disclaimer.
!
!2. Redistributions in binary form must reproduce the above copyright notice, this
!   list of conditions and the following disclaimer in the documentation and/or
!   other materials provided with the distribution.
!
!3. Neither the name of the copyright holder nor the names of its contributors
!   may be used to endorse or promote products derived from this software without
!   specific prior written permission.
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!THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
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!OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
!SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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!TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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! module for ALL access from Fortran
program ALL_test_f
    use ALL_module_obj
    use iso_c_binding
#ifndef ALL_USE_F08
    use mpi
#else
    use mpi_f08
#endif
    implicit none

#ifndef ALL_USE_F08
    integer                             ::  cart_comm
#else
    type(MPI_Comm)                      ::  cart_comm
#endif
    integer                             ::  dims(3)
    integer                             ::  coords(3)
    logical                             ::  period(3)
    real(8)                             ::  length(3)
    real(8)                             ::  vertices(3,2)
    integer                             ::  error
    integer                             ::  rank, n_ranks
    real(8),dimension(:,:),allocatable  ::  new_vertices
    integer                             ::  i,j

    type(ALL_t)     ::  lb

    call MPI_INIT(error)

    call MPI_COMM_RANK(MPI_COMM_WORLD, rank, error)
    call MPI_COMM_SIZE(MPI_COMM_WORLD, n_ranks, error)

    ! create cartesian communicator
    dims = 0
    period = .true.
    call MPI_DIMS_CREATE(n_ranks, 3, dims, error)
    call MPI_CART_CREATE(MPI_COMM_WORLD, 3, dims, period, .true., cart_comm, error)

    ! compute cell length
    length = 1.0d0 / real(dims,8)

    ! compute vertices of local domain
    call MPI_CART_COORDS(cart_comm, rank, 3, coords, error)
    vertices(:,1) = real(coords,8) * length
    vertices(:,2) = real(coords+1,8) * length

    do i = 0, n_ranks-1
        if (i == rank) then
            write(*,"(a,i7,2(a,3es14.7))") "rank: ", rank, " old vertices: ", vertices(:,1), ", ", vertices(:,2)
            call MPI_BARRIER(cart_comm, error)
        else
            call MPI_BARRIER(cart_comm, error)
        end if
    end do

    ! set up balancer
    call lb%init(ALL_STAGGERED, 3, 4.0d0)
    call lb%set_proc_tag(rank)
    call lb%set_vertices(vertices)
    ! if using a non cartesian communicator, this call would be required instead
    ! call lb%set_proc_grid_params(coords,dims)
    call lb%set_communicator(cart_comm)
    call lb%setup()

    do j = 1, 2
        call lb%set_work(real( product(coords,1)*64,8))
        call lb%balance()

        ! If not allocatable as target, must use
        ! lb%get_new_number_of_vertices and lb%get_vertices instead!
        call lb%get_vertices_alloc(new_vertices)

        do i = 0, n_ranks-1
            if (i == rank) then
                write(*,"(2(a,i7),2(a,3es14.7))") "rank: ", rank, " ", size(new_vertices,2), " new vertices: ", new_vertices(:,1), &
                    ", ", new_vertices(:,2)
                call MPI_BARRIER(cart_comm, error)
            else
                call MPI_BARRIER(cart_comm, error)
            end if
        end do
    end do
    deallocate(new_vertices)
    call MPI_FINALIZE(error);

END PROGRAM