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

/*

 *  (C) 2007 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

/* Look for regressions in aggregator code.  A more simple access pattern than

 * aggregation1 */

#include <mpi.h>

#include <stdlib.h>

#include <stdio.h>

#include <time.h>

#include <sys/types.h>

#include <unistd.h>

#include <string.h>

#define BUFSIZE 512

static void handle_error(int errcode, const char *str)

{

    char msg[MPI_MAX_ERROR_STRING];

    int resultlen;

    MPI_Error_string(errcode, msg, &resultlen);

    fprintf(stderr, "%s: %s\n", str, msg);

    MPI_Abort(MPI_COMM_WORLD, 1);

}

int main(int argc, char **argv)

{

    MPI_Info info = MPI_INFO_NULL;

    MPI_File fh;

    MPI_Offset off = 0;

    MPI_Status status;

    int errcode;

    int i, rank, errs = 0, toterrs, buffer[BUFSIZE], buf2[BUFSIZE];

    MPI_Init(&argc, &argv);

    MPI_Comm_rank(MPI_COMM_WORLD, &rank;;

    MPI_Info_create(&info;;

    MPI_Info_set(info, "romio_cb_write", "enable");

    MPI_Info_set(info, "cb_nodes", "1");

    for (i = 0; i < BUFSIZE; i++) {

        buffer[i] = 10000 + rank;

    }

    off = rank * sizeof(buffer);

    errcode = MPI_File_open(MPI_COMM_WORLD, argv[1], MPI_MODE_WRONLY | MPI_MODE_CREATE, info, &fh;;

    if (errcode != MPI_SUCCESS)

        handle_error(errcode, "MPI_File_open");

    errcode = MPI_File_write_at_all(fh, off, buffer, BUFSIZE, MPI_INT, &status);

    if (errcode != MPI_SUCCESS)

        handle_error(errcode, "MPI_File_write_at_all");

    errcode = MPI_File_close(&fh;;

    if (errcode != MPI_SUCCESS)

        handle_error(errcode, "MPI_File_close");

    errcode = MPI_File_open(MPI_COMM_WORLD, argv[1], MPI_MODE_RDONLY, info, &fh;;

    if (errcode != MPI_SUCCESS)

        handle_error(errcode, "MPI_File_open");

    errcode = MPI_File_read_at_all(fh, off, buf2, BUFSIZE, MPI_INT, &status);

    if (errcode != MPI_SUCCESS)

        handle_error(errcode, "MPI_File_read_at_all");

    errcode = MPI_File_close(&fh;;

    if (errcode != MPI_SUCCESS)

        handle_error(errcode, "MPI_File_close");

    for (i = 0; i < BUFSIZE; i++) {

        if (buf2[i] != 10000 + rank)

            errs++;

    }

    MPI_Allreduce(&errs, &toterrs, 1, MPI_INT, MPI_SUM, MPI_COMM_WORLD);

    if (rank == 0) {

        if (toterrs > 0) {

            fprintf(stderr, "Found %d errors\n", toterrs);

        } else {

            fprintf(stdout, " No Errors\n");

        }

    }

    MPI_Info_free(&info;;

    MPI_Finalize();

    return 0;

}