package microbenchmarkmpiJava.pingpong.Bsend; //// mpiJava version : Taboada//                   July 2002// DES//import java.io.*;import java.text.NumberFormat;import java.lang.Math;import mpi.*;import java.nio.ByteBuffer ;//no detach thing.public class PingPong {	static private byte A[];	//static final private byte B[] = new byte [10000000];	//static final private mpi.Buffer B = new mpi.Buffer(10000000+100);  	static final private ByteBuffer B = 		ByteBuffer.allocate( 10000000+100);    public static void main(String[] args) throws MPIException {  }  public PingPong() {  }  public PingPong(String[] args) throws Exception {	      double      startwtime, endwtime;     int         i, iterations, size, ns, my_pe, npes, pot2size;    Status      status;	int 		MPI_BSEND_OVERHEAD = 10000000;	long 		time;	    MPI.Init(args);    my_pe = MPI.COMM_WORLD.Rank();    npes  = MPI.COMM_WORLD.Size();		  iterations = Integer.parseInt(System.getProperty("ITERATIONS"));		  size = Integer.parseInt(System.getProperty("SIZE"));	       A = new byte [size];    // byte B[] = new byte [MPI_BSEND_OVERHEAD];	                  		MPI.Buffer_attach(B);		pot2size = (int)(Math.log((double) size)/1.386294361);		if (pot2size < 0) pot2size = 0;		for (i = 0; i < size; i++) {	    	A[i] = (byte)'0'; //(double) 1. / (i + 1);      	}					MPI.COMM_WORLD.Barrier();			  	if (my_pe == 0) {		for (ns = 0; ns < iterations; ns++) {							startwtime = MPI.Wtime();				MPI.COMM_WORLD.Bsend(A, 0, size, MPI.BYTE, 1, 10);			status = MPI.COMM_WORLD.Recv(A, 0, size, MPI.BYTE, 1, 20);			  				endwtime = MPI.Wtime();			//Format the Number to Display			NumberFormat nf = NumberFormat.getInstance();			nf.setMaximumFractionDigits(6);			nf.setMinimumFractionDigits(6);			  						time = (long) (500000.*(endwtime - startwtime));				System.out.println(nf.format((double) time/1000000)+" \t "+time+" \t "+nf.format((double) size/time)+" \t "+size+" \t "+pot2size);		}	}	if (my_pe == 1) {		for (ns = 0; ns < iterations; ns++) {						status = MPI.COMM_WORLD.Recv(A, 0 , size, MPI.BYTE, 0, 10);			MPI.COMM_WORLD.Bsend(A, 0, size, MPI.BYTE, 0, 20);		}	  			}    MPI.Finalize();        if(my_pe == 0) {       System.out.println(" Bsend PingPong TEST COMPLETE");	        }  }}