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

/*

 *

 *  (C) 2003 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpi.h"

#include <stdio.h>

#include <stdlib.h>

#include "mpitest.h"

#include "mpitestconf.h"

#ifdef HAVE_STRING_H

#include <string.h>

#endif

#ifdef HAVE_MEMORY_H

#include <memory.h>

#endif

/*

static char MTEST_Descrip[] = "Test reading and writing zero bytes (set status correctly)";

*/

int main(int argc, char *argv[])

{

    int errs = 0;

    int size, rank, i, *buf, count, rc;

    MPI_File fh;

    MPI_Comm comm;

    MPI_Status status;

    MTest_Init(&argc, &argv);

    comm = MPI_COMM_WORLD;

    rc = MPI_File_open(comm, (char *) "test.ord",

                       MPI_MODE_RDWR | MPI_MODE_CREATE |

                       MPI_MODE_DELETE_ON_CLOSE, MPI_INFO_NULL, &fh;;

    if (rc) {

        MTestPrintErrorMsg("File_open", rc);

        errs++;

        /* If the open fails, there isn't anything else that we can do */

        goto fn_fail;

    }

    MPI_Comm_size(comm, &size);

    MPI_Comm_rank(comm, &rank;;

    buf = (int *) malloc(size * sizeof(int));

    buf[0] = rank;

    /* Write to file */

    rc = MPI_File_write_ordered(fh, buf, 1, MPI_INT, &status);

    if (rc) {

        MTestPrintErrorMsg("File_write_ordered", rc);

        errs++;

    }

    else {

        MPI_Get_count(&status, MPI_INT, &count);

        if (count != 1) {

            errs++;

            fprintf(stderr, "Wrong count (%d) on write-ordered\n", count);

        }

    }

    /* Set the individual pointer to 0, since we want to use a read_all */

    MPI_File_seek(fh, 0, MPI_SEEK_SET);

    /* Read nothing (check status) */

    memset(&status, 0xff, sizeof(MPI_Status));

    MPI_File_read(fh, buf, 0, MPI_INT, &status);

    MPI_Get_count(&status, MPI_INT, &count);

    if (count != 0) {

        errs++;

        fprintf(stderr, "Count not zero (%d) on read\n", count);

    }

    /* Write nothing (check status) */

    memset(&status, 0xff, sizeof(MPI_Status));

    MPI_File_write(fh, buf, 0, MPI_INT, &status);

    if (count != 0) {

        errs++;

        fprintf(stderr, "Count not zero (%d) on write\n", count);

    }

    /* Read shared nothing (check status) */

    MPI_File_seek_shared(fh, 0, MPI_SEEK_SET);

    /* Read nothing (check status) */

    memset(&status, 0xff, sizeof(MPI_Status));

    MPI_File_read_shared(fh, buf, 0, MPI_INT, &status);

    MPI_Get_count(&status, MPI_INT, &count);

    if (count != 0) {

        errs++;

        fprintf(stderr, "Count not zero (%d) on read shared\n", count);

    }

    /* Write nothing (check status) */

    memset(&status, 0xff, sizeof(MPI_Status));

    MPI_File_write_shared(fh, buf, 0, MPI_INT, &status);

    if (count != 0) {

        errs++;

        fprintf(stderr, "Count not zero (%d) on write\n", count);

    }

    MPI_Barrier(comm);

    MPI_File_seek_shared(fh, 0, MPI_SEEK_SET);

    for (i = 0; i < size; i++)

        buf[i] = -1;

    MPI_File_read_ordered(fh, buf, 1, MPI_INT, &status);

    if (buf[0] != rank) {

        errs++;

        fprintf(stderr, "%d: buf = %d\n", rank, buf[0]);

    }

    free(buf);

    MPI_File_close(&fh;;

  fn_fail:

    MTest_Finalize(errs);

    MPI_Finalize();

    return 0;

}