#include <stdio.h>
#include <mpi.h>

int main(int argc, char *argv[])
{
    MPI_Win win;
    void *base;
    MPI_Aint size = 1024, size_obtained;
    int flag, ret = 0;

    MPI_Init(&argc, &argv);

    MPI_Win_allocate(size, 1 /* disp_unit */, MPI_INFO_NULL,
        MPI_COMM_WORLD, &base, &win);

    MPI_Win_get_attr(win, MPI_WIN_SIZE, &size_obtained, &flag);
    if (!flag) {
        fprintf(stderr, "Failed to obtain MPI_WIN_SIZE\n");
        ret = 1;
    } else if (size_obtained != size) {
        fprintf(stderr, "Got size=%zu, while expecting %zu\n",
            size_obtained, size);
        ret = 1;
    }

    MPI_Win_free(&win);

    MPI_Finalize();

    return ret;
}