mappedbuffer.java

MPI for java for Distributed Programming

package mpjdev.buffertest;

import mpjdev.*;
import mpjbuf.*;
import java.util.Arrays;
import java.nio.*;
import java.nio.channels.FileChannel.*;
import java.nio.channels.*;
import java.io.*;

public class MappedBuffer {
    public MappedBuffer() {
    }

    public MappedBuffer(String[] args) throws Exception {

    int DATA_SIZE = 100;
    File f = new File("mappedfile1");
    RandomAccessFile raf = new RandomAccessFile(f, "rw");
    FileChannel fileChannel = raf.getChannel();
    MappedByteBuffer mappedByteBuffer =
	    fileChannel.map(MapMode.READ_WRITE, 0, 400);//f.length());
 
    MPJDev.init(args);   
    int intArray[] = new int[DATA_SIZE];    

    for(int k=1 ; k<2; k++) {
	    
        for (int i = 0; i < DATA_SIZE; i++) {
            intArray[i] = 8;
	}
	
	if (MPJDev.WORLD.id() == 0) {      	    
	    for(int i=0 ; i< DATA_SIZE ; i++) {
 	        mappedByteBuffer.putInt(intArray[i]);
	    }	
            //mappedByteBuffer.flip();
    	} else if ( MPJDev.WORLD.id() == 1 ) {
	    /* Just make sure that this reads when the data is in there */	
	    try { Thread.currentThread().sleep(1000); }catch(Exception e){}
     	    int intReadArray[] = new int[DATA_SIZE];      
            for (int i = 0; i < DATA_SIZE; i++) {
  	        intReadArray[i] = 9;
	    }
            for(int i=0 ; i< DATA_SIZE ; i++) {
 	        intReadArray[i] = mappedByteBuffer.getInt();
	    }
            if (Arrays.equals(intArray, intReadArray)) {
 	         System.out.println("\n#################" +
				 "\n <<<<PASSED>>>> " +
				 "\n################");
	    } else {
		 System.out.println("\n#################" +
				 "\n <<<<FAILED>>>> " +
				 "\n################");
	    }
	}
    }

    try {
      Thread.currentThread().sleep(10000);
    }
    catch (Exception e) {e.printStackTrace(); }
    
    raf.close();
    //f.close();
    fileChannel.close();
    MPJDev.finish();
  }
}