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

/*

 *  (C) 2001 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpi.h"

#include <stdio.h>

#include "mpitest.h"

void addem(int *, int *, int *, MPI_Datatype *);

void assoc(int *, int *, int *, MPI_Datatype *);

void addem(int *invec, int *inoutvec, int *len, MPI_Datatype * dtype)

{

    int i;

    for (i = 0; i < *len; i++)

        inoutvec[i] += invec[i];

}

#define BAD_ANSWER 100000

/*

    The operation is inoutvec[i] = invec[i] op inoutvec[i]

    (see 4.9.4).  The order is important.

    Note that the computation is in process rank (in the communicator)

    order, independant of the root.

 */

void assoc(int *invec, int *inoutvec, int *len, MPI_Datatype * dtype)

{

    int i;

    for (i = 0; i < *len; i++) {

        if (inoutvec[i] <= invec[i]) {

            int rank;

            MPI_Comm_rank(MPI_COMM_WORLD, &rank;;

            fprintf(stderr, "[%d] inout[0] = %d, in[0] = %d\n", rank, inoutvec[0], invec[0]);

            inoutvec[i] = BAD_ANSWER;

        }

        else

            inoutvec[i] = invec[i];

    }

}

int main(int argc, char **argv)

{

    int rank, size, i;

    int data;

    int errors = 0;

    int result = -100;

    int correct_result;

    MPI_Op op_assoc, op_addem;

    MPI_Comm comm = MPI_COMM_WORLD;

    MPI_Init(&argc, &argv);

    MPI_Op_create((MPI_User_function *) assoc, 0, &op_assoc);

    MPI_Op_create((MPI_User_function *) addem, 1, &op_addem);

    /* Run this for a variety of communicator sizes */

    MPI_Comm_rank(comm, &rank;;

    MPI_Comm_size(comm, &size);

    data = rank;

    correct_result = 0;

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

        correct_result += i;

    MPI_Scan(&data, &result, 1, MPI_INT, MPI_SUM, comm);

    if (result != correct_result) {

        fprintf(stderr, "[%d] Error suming ints with scan\n", rank);

        errors++;

    }

    MPI_Scan(&data, &result, 1, MPI_INT, MPI_SUM, comm);

    if (result != correct_result) {

        fprintf(stderr, "[%d] Error summing ints with scan (2)\n", rank);

        errors++;

    }

    data = rank;

    result = -100;

    MPI_Scan(&data, &result, 1, MPI_INT, op_addem, comm);

    if (result != correct_result) {

        fprintf(stderr, "[%d] Error summing ints with scan (userop)\n", rank);

        errors++;

    }

    MPI_Scan(&data, &result, 1, MPI_INT, op_addem, comm);

    if (result != correct_result) {

        fprintf(stderr, "[%d] Error summing ints with scan (userop2)\n", rank);

        errors++;

    }

    result = -100;

    data = rank;

    MPI_Scan(&data, &result, 1, MPI_INT, op_assoc, comm);

    if (result == BAD_ANSWER) {

        fprintf(stderr, "[%d] Error scanning with non-commutative op\n", rank);

        errors++;

    }

    MPI_Op_free(&op_assoc);

    MPI_Op_free(&op_addem);

    MPI_Finalize();

    if (errors)

        printf("[%d] done with ERRORS(%d)!\n", rank, errors);

    else {

        if (rank == 0)

            printf(" No Errors\n");

    }

    return errors;

}