/*
 * Copyright (C) by Argonne National Laboratory
 *     See COPYRIGHT in top-level directory
 */

#include "mpi.h"
#include "mpitestconf.h"
#ifdef HAVE_IOSTREAM
// Not all C++ compilers have iostream instead of iostream.h
#include <iostream>
#ifdef HAVE_NAMESPACE_STD
// Those that do need the std namespace; otherwise, a bare "cout"
// is likely to fail to compile
using namespace std;
#endif
#else
#include <iostream.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include "mpitestcxx.h"

int main(int argc, char **argv)
{
    MPI::Intracomm comm;
    MPI::File fh;
    int r, s, i;
    int fileintsize;
    int errs = 0;
    char filename[1024];
    MPI::Offset offset;

    MTest_Init();

    strcpy(filename, "iotest.txt");
    comm = MPI::COMM_WORLD;
    s = comm.Get_size();
    r = comm.Get_rank();
    // Try writing the file, then check it
    fh = MPI::File::Open(comm, filename, MPI::MODE_RDWR | MPI::MODE_CREATE, MPI::INFO_NULL);

    // Get the size of an INT in the file
    fileintsize = fh.Get_type_extent(MPI::INT);

    // We let each process write in turn, getting the position after each
    // write
    for (i = 0; i < s; i++) {
        if (i == r) {
            fh.Write_shared(&i, 1, MPI::INT);
        }
        comm.Barrier();
        offset = fh.Get_position_shared();
        if (offset != fileintsize * (i + 1)) {
            errs++;
            cout << r << " Shared position is " << offset <<
                " should be " << fileintsize * (i + 1) << "\n";
        }
        comm.Barrier();
    }

    fh.Close();
    comm.Barrier();
    if (r == 0) {
        MPI::File::Delete(filename, MPI::INFO_NULL);
    }

    MTest_Finalize(errs);
}
