/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */

/*

 *

 *  (C) 2014 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

/*

 * This program tests MPI_Aint_add/diff in MPI-3.1.

 * The two functions are often used in RMA code.

 * See https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/349

 */

#include <stdio.h>

#include <mpi.h>

#include "mpitest.h"

int main(int argc, char **argv)

{

    int rank, nproc;

    int errs = 0;

    int array[1024];

    int val = 0;

    int target_rank;

    MPI_Aint bases[2];

    MPI_Aint disp, offset;

    MPI_Win win;

    MTest_Init(&argc, &argv);

    MPI_Comm_rank(MPI_COMM_WORLD, &rank;;

    MPI_Comm_size(MPI_COMM_WORLD, &nproc);

    if (rank == 0 && nproc != 2) {

        MTestError("Must run with 2 ranks\n");

    }

    /* Get the base address in the middle of the array */

    if (rank == 0) {

        target_rank = 1;

        array[0] = 1234;

        MPI_Get_address(&array[512], &bases[0]);

    }

    else if (rank == 1) {

        target_rank = 0;

        array[1023] = 1234;

        MPI_Get_address(&array[512], &bases[1]);

    }

    /* Exchange bases */

    MPI_Allgather(MPI_IN_PLACE, 0, MPI_DATATYPE_NULL, bases, 1, MPI_AINT, MPI_COMM_WORLD);

    MPI_Win_create_dynamic(MPI_INFO_NULL, MPI_COMM_WORLD, &win);

    MPI_Win_attach(win, array, sizeof(int) * 1024);

    /* Do MPI_Aint addressing arithmetic */

    if (rank == 0) {

        disp = sizeof(int) * 511;

        offset = MPI_Aint_add(bases[1], disp);  /* offset points to array[1023] */

    }

    else if (rank == 1) {

        disp = sizeof(int) * 512;

        offset = MPI_Aint_diff(bases[0], disp); /* offset points to array[0] */

    }

    /* Get val and verify it */

    MPI_Win_fence(MPI_MODE_NOPRECEDE, win);

    MPI_Get(&val, 1, MPI_INT, target_rank, offset, 1, MPI_INT, win);

    MPI_Win_fence(MPI_MODE_NOSUCCEED, win);

    if (val != 1234) {

        errs++;

        printf("%d -- Got %d, expected 1234\n", rank, val);

    }

    MPI_Win_detach(win, array);

    MPI_Win_free(&win);

    MTest_Finalize(errs);

    MPI_Finalize();

    return 0;

}