/* -*- Mode: C++; c-basic-offset:4 ; -*- */

/*

 *

 *  (C) 2003 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpi.h"

#include <iostream>

#include "mpitestconf.h"

#include "mpitestcxx.h"

static char MTEST_Descrip[] = "Simple intercomm reduce test";

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

{

    int errs = 0;

    int *sendbuf = 0, *recvbuf = 0;

    int leftGroup, i, count, rank;

    MPI::Intercomm comm;

    MPI::Datatype datatype;

    MTest_Init();

    datatype = MPI::INT;

    while (MTestGetIntercomm(comm, leftGroup, 4)) {

        if (comm == MPI::COMM_NULL)

            continue;

        for (count = 1; count < 65000; count = 2 * count) {

            sendbuf = new int[count];

            recvbuf = new int[count];

            /* Get an intercommunicator */

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

                sendbuf[i] = -1;

                recvbuf[i] = -1;

            }

            if (leftGroup) {

                rank = comm.Get_rank();

                try {

                    comm.Reduce(sendbuf, recvbuf, count, datatype, MPI::SUM,

                                (rank == 0) ? MPI::ROOT : MPI::PROC_NULL);

                }

                catch(MPI::Exception e) {

                    errs++;

                    MTestPrintError(e.Get_error_code());

                }

                /* Test that no other process in this group received the

                 * broadcast, and that we got the right answers */

                if (rank == 0) {

                    int rsize;

                    rsize = comm.Get_remote_size();

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

                        if (recvbuf[i] != i * rsize) {

                            errs++;

                        }

                    }

                } else {

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

                        if (recvbuf[i] != -1) {

                            errs++;

                        }

                    }

                }

            } else {

                /* In the right group */

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

                    sendbuf[i] = i;

                try {

                    comm.Reduce(sendbuf, recvbuf, count, datatype, MPI::SUM, 0);

                }

                catch(MPI::Exception e) {

                    errs++;

                    MTestPrintError(e.Get_error_code());

                }

                /* Check that we have received no data */

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

                    if (recvbuf[i] != -1) {

                        errs++;

                    }

                }

            }

            delete[]sendbuf;

            delete[]recvbuf;

        }

        MTestFreeComm(comm);

    }

    MTest_Finalize(errs);

    return 0;

}