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

/*

 *  (C) 2007 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpi.h"

#include <stdio.h>

#include <string.h>

#include "mpitest.h"

/* Check that Comm_create detects the case where the group is not a subset of

   the group of the input communicator */

void abortMsg(const char *, int);

void abortMsg(const char *str, int code)

{

    char msg[MPI_MAX_ERROR_STRING];

    int class, resultLen;

    MPI_Error_class(code, &class);

    MPI_Error_string(code, msg, &resultLen);

    fprintf(stderr, "%s: errcode = %d, class = %d, msg = %s\n", str, code, class, msg);

    MPI_Abort(MPI_COMM_WORLD, code);

}

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

{

    MPI_Comm evencomm, lowcomm, newcomm;

    int wrank, wsize, gsize, err, errs = 0;

    int ranges[1][3], mygrank;

    MPI_Group wGroup, godd, ghigh, geven;

    MTest_Init(&argc, &argv);

    MPI_Comm_set_errhandler(MPI_COMM_WORLD, MPI_ERRORS_RETURN);

    MPI_Comm_size(MPI_COMM_WORLD, &wsize);

    MPI_Comm_rank(MPI_COMM_WORLD, &wrank);

    /* Create some communicators */

    MPI_Comm_split(MPI_COMM_WORLD, wrank % 2, wrank, &evencomm);

    MPI_Comm_split(MPI_COMM_WORLD, wrank < wsize / 2, wsize - wrank, &lowcomm);

    MPI_Comm_set_errhandler(evencomm, MPI_ERRORS_RETURN);

    MPI_Comm_set_errhandler(lowcomm, MPI_ERRORS_RETURN);

    /* Create some groups */

    MPI_Comm_group(MPI_COMM_WORLD, &wGroup);

    ranges[0][0] = 2 * (wsize / 2) - 1;

    ranges[0][1] = 1;

    ranges[0][2] = -2;

    err = MPI_Group_range_incl(wGroup, 1, ranges, &godd);

    if (err)

        abortMsg("Failed to create odd group: ", err);

    err = MPI_Group_size(godd, &gsize);

    if (err)

        abortMsg("Failed to get size of odd group: ", err);

    if (gsize != wsize / 2) {

        fprintf(stderr, "Group godd size is %d should be %d\n", gsize, wsize / 2);

        errs++;

    }

    ranges[0][0] = wsize / 4;

    ranges[0][1] = wsize - 1;

    ranges[0][2] = 1;

    err = MPI_Group_range_incl(wGroup, 1, ranges, &ghigh);

    if (err)

        abortMsg("Failed to create high group\n", err);

    ranges[0][0] = 0;

    ranges[0][1] = wsize - 1;

    ranges[0][2] = 2;

    err = MPI_Group_range_incl(wGroup, 1, ranges, &geven);

    if (err)

        abortMsg("Failed to create even group:", err);

    /* Check that a correct case returns success */

    if ((wrank % 2) == 0) {

        err = MPI_Group_rank(geven, &mygrank);

        if (err) {

            errs++;

            fprintf(stderr, "Could not get rank from geven group\n");

        }

        else if (mygrank == MPI_UNDEFINED) {

            errs++;

            fprintf(stderr, "mygrank should be %d but is undefined\n", wrank / 2);

        }

        err = MPI_Comm_create(evencomm, geven, &newcomm);

        /* printf("Created new even comm\n"); */

        if (err != MPI_SUCCESS) {

            errs++;

            fprintf(stderr, "Failed to allow creation from even group\n");

        }

        else {

            MPI_Comm_free(&newcomm);

        }

    }

    /* Now, test that these return errors when we try to use them to create

     * groups */

    if ((wrank % 2) == 0) {

        /* printf("Even comm...\n"); */

        /* evencomm is the comm of even-ranked processed in comm world */

        err = MPI_Comm_create(evencomm, godd, &newcomm);

        MPI_Group_rank(godd, &mygrank);

        if (err == MPI_SUCCESS) {

            if (mygrank != MPI_UNDEFINED) {

                errs++;

                fprintf(stderr, "Did not detect group of odd ranks in even comm\n");

            }

            MPI_Comm_free(&newcomm);

        }

    }

    if (wrank < wsize / 2) {

        /* printf("low comm...\n"); */

        err = MPI_Comm_create(lowcomm, ghigh, &newcomm);

        MPI_Group_rank(ghigh, &mygrank);

        if (err == MPI_SUCCESS) {

            if (mygrank != MPI_UNDEFINED) {

                errs++;

                fprintf(stderr, "Did not detect group of high ranks in low comm\n");

            }

            MPI_Comm_free(&newcomm);

        }

    }

    MPI_Comm_free(&lowcomm);

    MPI_Comm_free(&evencomm);

    MPI_Group_free(&ghigh);

    MPI_Group_free(&godd);

    MPI_Group_free(&geven);

    MPI_Group_free(&wGroup);

    MTest_Finalize(errs);

    MPI_Finalize();

    return 0;

}