Re: DatagramSocket receive performance

On Mar 15, 7:36 pm, Esmond Pitt <esmond.p...@nospam.bigpond.com>
wrote:


I certainly can!

I retried the test with a version that does not use swing and does not
create any additional threads. The source is below. I get the exact
same result.

The messsage source (DSP board) is sending UDP packets of 125 bytes to
a PC that is running a C and Java program that do nothing but count
these arrivals and print out message counts every 1000 messages. I
can control the send rate at the source. At 50/messages per second,
the C and Java program are both printing out 1000, 2000, 3000, etc at
the same time, and in addition this also matches the count of sent
messages at the source. I increase to 75/messages per second. The C
program message count continues to match the send count on the DSP
board, but the Java program starts to lag behind (the C program prints
out 1000...the java program prints out 1000 several seconds later).

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketException;
import java.net.SocketTimeoutException;

public class test
{
   public static final int SERVER_PORT = 4242;

   public static final String SERVER_IP = "192.168.1.10";

   public static final int RECV_BUFFER_SIZE = 1024;

   public static void main(String args[])
   {
      int messageCount = 0;
      byte[] recvBytes = new byte[ RECV_BUFFER_SIZE ];
      InetSocketAddress address = new
InetSocketAddress(test.SERVER_IP, test.SERVER_PORT );
      DatagramPacket packet = new DatagramPacket( recvBytes,
RECV_BUFFER_SIZE);
      DatagramSocket socket;

      try
      {
         socket = new DatagramSocket();
         socket.connect( address );
         // Send registration message
         byte[] sendBuf = new byte[1];
         sendBuf[0] = 1;
         DatagramPacket sendPacket = new DatagramPacket( sendBuf,
            sendBuf.length,
            address );
         socket.send( sendPacket );

         // Wait for registration response
         socket.setSoTimeout(30000);
         socket.receive( packet );
         socket.setSoTimeout(0);

         while( true )
         {
            socket.receive( packet );

            messageCount++;

            if( (messageCount % 1000) == 0 )
            {
               System.out.println( "Messages = " + messageCount );
            }
         }
      }
      catch (IOException ex)
      {
         ex.printStackTrace();
         System.exit(1);
      }
   }
}