group_union.java

MPI for java for Distributed Programming

package mpi.group;

import mpjdev.*;
import mpjbuf.*;
import mpi.*;
import java.util.Arrays;

public class Group_union {

  public static void main(String args[]) throws Exception{
  }

  public Group_union() {
  }

  public Group_union(String[] args) throws Exception {
    MPI.Init(args);		
    int me = MPI.COMM_WORLD.Rank();
    int size = MPI.COMM_WORLD.Size();

    if(size < 8) {
      if(me == 0) {
        System.out.println("group->Group_union: MUST HAVE 8 TASKS");	      
      }
      MPI.COMM_WORLD.Barrier();
      MPI.Finalize();
      return;
    }

    mpi.Group grp = MPI.COMM_WORLD.Group();		
    me = grp.Rank();
    int[] incl1 = {4,0,5};
    int[] incl2 = {6,7,4};
    mpi.Group grp1 = grp.Incl(incl1);		
    mpi.Group grp2 = grp.Incl(incl2);
    mpi.Group grp3 = null;
    grp3 = mpi.Group.Union(grp1,grp2);	

    if(grp3.Size() != 5) {
      System.out.println("Error(1): the new group should've five processes "+
		         "in it ... " );	    
    }
    
    MPI.COMM_WORLD.Barrier();

    if(me == 0) 
      System.out.println("Group_union TEST COMPLETED"); 	    

    MPI.Finalize();
  }
}