Same Code Different Behaviour

[Abu Nene]

Hi guys, any idea why I'm getting different result on different machine with the same piece of code?

import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;

public class X
{
  /**
   * @param args
   */
  public static void main(String[] args)
  {
      ...

      socket.setSoTimeout(5000);
      while ((byteRead = _inFromServer.read(response, remains, BUFFER_SIZE - remains)) >= 0)
      {
        ByteBuffer buf = ByteBuffer.wrap(response);
        buf.order(ByteOrder.LITTLE_ENDIAN);

        int messageSize = 0;
        while (nextMessage < (byteRead + remains))
        {
          offset = nextMessage;
          messageSize = (int) buf.getChar(offset);
          messageSize &= 0xff;

          if (messageSize <= 0 || messageSize > 255)
          {
            return;
          }

          nextMessage += messageSize;

          System.out.println("messageSize: " + messageSize);
          System.out.println("nextMessage: " + nextMessage);
          System.out.println("byteRead: " + byteRead);
          System.out.println("remains: " + remains);

          if (nextMessage > (byteRead + remains))
          {
            break;
          }
        }

        if ((byteRead + remains) >= BUFFER_SIZE)
        {
          remains = BUFFER_SIZE - offset;
          for (int i = 0; i < remains; i++)
          {
            response[i] = response[i + offset];
          }
          offset = 0;
          nextMessage = 0;
        }
        else
        {
          break;
        }
      }
    }
    catch (Exception e)
    {
      e.printStackTrace();
    }
    finally
    {
      try
      {
        if (socket != null)
        {
          socket.close();
        }
      }
      catch (Exception e)
      {
        e.printStackTrace();
      }
    }   
  }
}

One is running using Eclipse java-6-sun-1.6.0.22 on a Ubuntu and the other is running on a Gentoo Java SE Runtime Environment (build 1.6.0_1103).
'
Please advise.

[Mohamed Sanaulla]

What are the different outputs?

[Abu Nene]

Output that is correct running on Ubuntu.

messageSize: 76
nextMessage: 76
byteRead: 1024
remains: 0
messageSize: 172
nextMessage: 248
byteRead: 1024
remains: 0
messageSize: 156
nextMessage: 404
byteRead: 1024
remains: 0
messageSize: 172
nextMessage: 576
byteRead: 1024
remains: 0
messageSize: 142
nextMessage: 718
byteRead: 1024
remains: 0
messageSize: 172
nextMessage: 890
byteRead: 1024
remains: 0
messageSize: 156
nextMessage: 1046
byteRead: 1024
remains: 0
messageSize: 156
nextMessage: 156
byteRead: 890
remains: 134
messageSize: 108
nextMessage: 264
byteRead: 890
remains: 134
messageSize: 172
nextMessage: 436
byteRead: 890
remains: 134
messageSize: 14
nextMessage: 450
byteRead: 890
remains: 134
messageSize: 178
nextMessage: 628
byteRead: 890
remains: 134
messageSize: 14
nextMessage: 642
byteRead: 890
remains: 134
messageSize: 124
nextMessage: 766
byteRead: 890
remains: 134
messageSize: 172
nextMessage: 938
byteRead: 890
remains: 134
messageSize: 142
nextMessage: 1080
byteRead: 890
remains: 134
messageSize: 142
nextMessage: 142
byteRead: 938
remains: 86
messageSize: 178
nextMessage: 320
byteRead: 938
remains: 86
messageSize: 174
nextMessage: 494
byteRead: 938
remains: 86
messageSize: 92
nextMessage: 586
byteRead: 938
remains: 86
messageSize: 44
nextMessage: 630
byteRead: 938
remains: 86
messageSize: 28
nextMessage: 658
byteRead: 938
remains: 86
messageSize: 126
nextMessage: 784
byteRead: 938
remains: 86
messageSize: 172
nextMessage: 956
byteRead: 938
remains: 86
messageSize: 124
nextMessage: 1080
byteRead: 938
remains: 86
messageSize: 124
nextMessage: 124
byteRead: 956
remains: 68
messageSize: 13
nextMessage: 137
byteRead: 956
remains: 68
messageSize: 174
nextMessage: 311
byteRead: 956
remains: 68
messageSize: 172
nextMessage: 483
byteRead: 956
remains: 68
messageSize: 172
nextMessage: 655
byteRead: 956
remains: 68
messageSize: 108
nextMessage: 763
byteRead: 956
remains: 68
messageSize: 14
nextMessage: 777
byteRead: 956
remains: 68
messageSize: 172
nextMessage: 949
byteRead: 956
remains: 68
messageSize: 172
nextMessage: 1121
byteRead: 956
remains: 68
messageSize: 172
nextMessage: 172
byteRead: 949
remains: 75
messageSize: 172
nextMessage: 344
byteRead: 949
remains: 75
messageSize: 172
nextMessage: 516
byteRead: 949
remains: 75
messageSize: 15
nextMessage: 531
byteRead: 949
remains: 75
messageSize: 178
nextMessage: 709
byteRead: 949
remains: 75
messageSize: 172
nextMessage: 881
byteRead: 949
remains: 75
messageSize: 172
nextMessage: 1053
byteRead: 949
remains: 75
messageSize: 172
nextMessage: 172
byteRead: 635
remains: 143
messageSize: 172
nextMessage: 344
byteRead: 635
remains: 143
messageSize: 174
nextMessage: 518
byteRead: 635
remains: 143
messageSize: 44
nextMessage: 562
byteRead: 635
remains: 143
messageSize: 44
nextMessage: 606
byteRead: 635
remains: 143
messageSize: 172
nextMessage: 778
byteRead: 635
remains: 143

Output that is not correct running on Gentoo.

messageSize: 76
nextMessage: 76
byteRead: 1024
remains: 0
messageSize: 172
nextMessage: 248
byteRead: 1024
remains: 0
messageSize: 156
nextMessage: 404
byteRead: 1024
remains: 0
messageSize: 172
nextMessage: 576
byteRead: 1024
remains: 0
messageSize: 142
nextMessage: 718
byteRead: 1024
remains: 0
messageSize: 172
nextMessage: 890
byteRead: 1024
remains: 0
messageSize: 156
nextMessage: 1046
byteRead: 1024
remains: 0
messageSize: 156
nextMessage: 156
byteRead: 424
remains: 134
messageSize: 108
nextMessage: 264
byteRead: 424
remains: 134
messageSize: 172
nextMessage: 436
byteRead: 424
remains: 134
messageSize: 14
nextMessage: 450
byteRead: 424
remains: 134
messageSize: 178
nextMessage: 628
byteRead: 424
remains: 134

[Mohamed Sanaulla]

Did you try to run the code twice on same machine?

[Abu Nene]

Mohamed Sanaulla wrote:Did you try to run the code twice on same machine?

Yes. The one that is correct running on Ubuntu always return the same result. The one that is not correct running on Gentoo sometimes return me this.

messageSize: 76
nextMessage: 76
byteRead: 1024
remains: 0
messageSize: 172
nextMessage: 248
byteRead: 1024
remains: 0
messageSize: 156
nextMessage: 404
byteRead: 1024
remains: 0
messageSize: 172
nextMessage: 576
byteRead: 1024
remains: 0
messageSize: 142
nextMessage: 718
byteRead: 1024
remains: 0
messageSize: 172
nextMessage: 890
byteRead: 1024
remains: 0
messageSize: 156
nextMessage: 1046
byteRead: 1024
remains: 0
messageSize: 156
nextMessage: 156
byteRead: 890
remains: 134
messageSize: 108
nextMessage: 264
byteRead: 890
remains: 134
messageSize: 172
nextMessage: 436
byteRead: 890
remains: 134
messageSize: 14
nextMessage: 450
byteRead: 890
remains: 134
messageSize: 178
nextMessage: 628
byteRead: 890
remains: 134
messageSize: 14
nextMessage: 642
byteRead: 890
remains: 134
messageSize: 124
nextMessage: 766
byteRead: 890
remains: 134
messageSize: 172
nextMessage: 938
byteRead: 890
remains: 134
messageSize: 142
nextMessage: 1080
byteRead: 890
remains: 134
messageSize: 142
nextMessage: 142
byteRead: 938
remains: 86
messageSize: 178
nextMessage: 320
byteRead: 938
remains: 86
messageSize: 174
nextMessage: 494
byteRead: 938
remains: 86
messageSize: 92
nextMessage: 586
byteRead: 938
remains: 86
messageSize: 44
nextMessage: 630
byteRead: 938
remains: 86
messageSize: 28
nextMessage: 658
byteRead: 938
remains: 86
messageSize: 126
nextMessage: 784
byteRead: 938
remains: 86
messageSize: 172
nextMessage: 956
byteRead: 938
remains: 86
messageSize: 124
nextMessage: 1080
byteRead: 938
remains: 86
messageSize: 124
nextMessage: 124
byteRead: 956
remains: 68
messageSize: 13
nextMessage: 137
byteRead: 956
remains: 68
messageSize: 174
nextMessage: 311
byteRead: 956
remains: 68
messageSize: 172
nextMessage: 483
byteRead: 956
remains: 68
messageSize: 172
nextMessage: 655
byteRead: 956
remains: 68
messageSize: 108
nextMessage: 763
byteRead: 956
remains: 68
messageSize: 14
nextMessage: 777
byteRead: 956
remains: 68
messageSize: 172
nextMessage: 949
byteRead: 956
remains: 68
messageSize: 172
nextMessage: 1121
byteRead: 956
remains: 68
messageSize: 172
nextMessage: 172
byteRead: 536
remains: 75
messageSize: 172
nextMessage: 344
byteRead: 536
remains: 75
messageSize: 172
nextMessage: 516
byteRead: 536
remains: 75
messageSize: 15
nextMessage: 531
byteRead: 536
remains: 75
messageSize: 178
nextMessage: 709
byteRead: 536
remains: 75

[Campbell Ritchie]

And what were the errors? Are you sure the input was the same in both cases?

I think this question is too difficult for "beginning", so I shall move it.

[Abu Nene]

Campbell Ritchie wrote:And what were the errors? Are you sure the input was the same in both cases?

I think this question is too difficult for "beginning", so I shall move it.

There is no error or exception. Initially I thought it's caused by different JDK version. Could it be the machine distance from the server but then again it's unicast using TCP.

[Mohamed Sanaulla]

As this program reads the input from the Socket stream, I think the network latency might be the reason for this different output.

[Abu Nene]

Mohamed Sanaulla wrote:As this program reads the input from the Socket stream, I think the network latency might be the reason for this different output.

Any idea how can I resolve this caused by network latency?

[Mohamed Sanaulla]

Abu Nene wrote:
Any idea how can I resolve this caused by network latency?

Is this behavior causing other issues? I dont know if there's some way to resolve it or if there's any way to resolve it.

[Abu Nene]

Mohamed Sanaulla wrote:

Abu Nene wrote:
Any idea how can I resolve this caused by network latency?

Is this behavior causing other issues? I dont know if there's some way to resolve it or if there's any way to resolve it.

This is what I did which fix the problem.

      ByteArrayOutputStream baos = new ByteArrayOutputStream();
      BufferedInputStream bis = new BufferedInputStream(_inFromServer);
      
      int available = 0;
      
      do
      {
        byteRead = bis.read(); // block and read
        baos.write(byteRead); //store
        
        available = bis.available(); //check
        
        if(available == 0)
        {
          Thread.sleep(50); //safety pause in case there's network latency
          available = bis.available(); //check again
        }
      }
      while(available > 0);

      //close ByteArrayOutputStream and BufferedInputStream