/* -*- 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;
}