/* -*- 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 allgather test";

int main(int argc, char *argv[])
{
    int errs = 0;
    int *rbuf = 0, *sbuf = 0;
    int leftGroup, i, count, rank, rsize;
    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) {
            /* Get an intercommunicator */
            /* The left group will send rank to the right group;
             * The right group will send -rank to the left group */
            rank = comm.Get_rank();
            rsize = comm.Get_remote_size();
            rbuf = new int[count * rsize];
            sbuf = new int[count];
            for (i = 0; i < count * rsize; i++)
                rbuf[i] = -1;
            if (leftGroup) {
                for (i = 0; i < count; i++)
                    sbuf[i] = i + rank * count;
            } else {
                for (i = 0; i < count; i++)
                    sbuf[i] = -(i + rank * count);
            }
            try {
                comm.Allgather(sbuf, count, datatype, rbuf, count, datatype);
            }
            catch(MPI::Exception e) {
                errs++;
                MTestPrintError(e.Get_error_code());
            }
            if (leftGroup) {
                for (i = 0; i < count * rsize; i++) {
                    if (rbuf[i] != -i) {
                        errs++;
                    }
                }
            } else {
                for (i = 0; i < count * rsize; i++) {
                    if (rbuf[i] != i) {
                        errs++;
                    }
                }
            }

            /* Use Allgather in a unidirectional way */
            for (i = 0; i < count * rsize; i++)
                rbuf[i] = -1;
            if (leftGroup) {
                try {
                    comm.Allgather(sbuf, 0, datatype, rbuf, count, datatype);
                }
                catch(MPI::Exception e) {
                    errs++;
                    MTestPrintError(e.Get_error_code());
                }
                for (i = 0; i < count * rsize; i++) {
                    if (rbuf[i] != -i) {
                        errs++;
                    }
                }
            } else {
                try {
                    comm.Allgather(sbuf, count, datatype, rbuf, 0, datatype);
                }
                catch(MPI::Exception e) {
                    errs++;
                    MTestPrintError(e.Get_error_code());
                }
                for (i = 0; i < count * rsize; i++) {
                    if (rbuf[i] != -1) {
                        errs++;
                    }
                }
            }
            delete[]rbuf;
            delete[]sbuf;
        }
        MTestFreeComm(comm);
    }

    MTest_Finalize(errs);
    return 0;
}