/* This is sample server-side program for Ninf-G, calculate PI on MPI */

Module pi_mpi;

Compiler "/usr/local/mpich/bin/mpicc";
Linker "/usr/local/mpich/bin/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;
    }
}