/*
 * $RCSfile: pi_mpi.idl,v $ $Revision: 1.4 $ $Date: 2005/02/16 06:01:33 $
 * $AIST_Release: 4.2.4 $
 * $AIST_Copyright:
 *  Copyright 2003, 2004, 2005, 2006 Grid Technology Research Center,
 *  National Institute of Advanced Industrial Science and Technology
 *  Copyright 2003, 2004, 2005, 2006 National Institute of Informatics
 *  
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *  $
 */
Module pi_mpi;

Compiler "/path/to/mpicc";
Linker "/path/to/mpicc";

Define pi_trial(IN long counter, OUT long *answer)
Required "pi_trial.o"
Backend "MPI"
{
    /* Prototype declaration */
    extern long pi_trial(int, long);

    int my_rank;
    int tag = 0;
    long times;
    long result;

    MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);
    if (my_rank != 0) {
        int dest = 0;

        MPI_Bcast(&times, 1, MPI_LONG, 0, MPI_COMM_WORLD);
        result = pi_trial(my_rank, times);
        MPI_Send(&result, 1, MPI_LONG, dest, tag, MPI_COMM_WORLD);
    } else {
        int process_num;
        int source;
        long total;
        MPI_Status recv_status;

        MPI_Comm_size(MPI_COMM_WORLD, &process_num);
        times = counter / process_num;
        MPI_Bcast(&times, 1, MPI_LONG, 0, MPI_COMM_WORLD);

        times += counter % process_num;

        total = pi_trial(my_rank, times);
        for (source = 1; source < process_num; source++) {
            MPI_Recv(&result, 1, MPI_LONG, source, tag, MPI_COMM_WORLD,
                &recv_status);
            total += result;
        }
        *answer = total;
    }
}