Name: yyC67448 Date: 08/28/98




read() call on InputStream associated with Socket infinitly blocks
ever if the SO_TIMEOUT value is set to positive ( > 0 ) value via
Socket.setSoTimeout(int tout) call.


Here is the javadoc comment for Socket.setSoTimeout() method:

    /**
     * Enable/disable SO_TIMEOUT with the specified timeout, in
     * milliseconds. With this option set to a non-zero timeout,
     * a read() call on the InputStream associated with this Socket
     * will block for only this amount of time. If the timeout expires,
     * a <B>java.io.InterruptedIOException</B> is raised, though the
     * Socket is still valid. The option <B>must</B> be enabled
     * prior to entering the blocking operation to have effect. The
     * timeout must be > 0.
     * A timeout of zero is interpreted as an infinite timeout.
     *
     * @since JDK 1.1
     */


Here is the test demonstrating the bug:

---------------------------- test.java --------------------------------
import java.net.*;
import java.io.*;


class test
{

  public static void main(String args[])
  {
    InetAddress sin = null;
    Socket soc = null,soc1 = null;
    InputStream is = null;
    OutputStream os = null;
    ServerSocket srv = null;
    int port = 0;
    int tout = 1000;


    /*
     * Try to get localhost address
     */
    try {
      sin = InetAddress.getLocalHost();
    } catch(Exception e)
    {
      System.out.println("Can not get localhost Address:" + e);
      System.exit(-1);
    }


    try {
      srv = new ServerSocket(port);
      port = srv.getLocalPort();
    } catch(Exception e)
    {
      System.out.println("Unexpected Exception thrown " + e );
      System.exit(-1);
    }

    try {
      soc = new Socket(sin, port, true);
      soc1 = srv.accept();
    } catch(Exception e)
    {
      System.out.println("Can not create socket:" + e);
      System.exit(-1);
    }

    System.out.println("Connection accepted!");


    /*
     * Try to set SO_TIMEOUT value
     */
    try {
      soc.setSoTimeout(tout);
      System.out.println("value = " + soc.getSoTimeout());
    }
    catch(Exception e)
    {
      try {
soc.close();
soc1.close();
srv.close();
      } catch(Exception e1)
      {
System.out.println("Can not close socket :" + e1);
System.exit(-1);
      }
      System.out.println("Unexpected exception:" + e);
    }

    try {
      is = soc.getInputStream();
      os = soc1.getOutputStream();
      System.out.println("Got Input/Ouput Streams");
      is.read();
    } catch(InterruptedIOException e)
    {
System.out.println("OKAY");
        System.exit(0);
    }
    catch(Exception e)
    {
System.out.println("Unexpected exception:" + e);
System.exit(0);
    }
    
    System.out.println("No exceptions !");

    try {
      soc.close();
      soc1.close();
      srv.close();
    } catch(Exception e)
    {
      System.out.println("Can not close socket:" + e);
      System.exit(-1);
    }
    
  }
}

---------------------- Output from the test on JDK-1.2beta4-K -------------
Connection accepted!
value = 1000
Got Input/Ouput Streams
OKAY
------------------------------------------------------------------------------


---------------------- Output from the test on JDK-1.2fcs-C ----------------
Connection accepted!
value = 1000
Got Input/Ouput Streams
OKAY
------------------------------------------------------------------------------

---------------------- Output from the test on JDK-1.2fcs-G ----------------
Connection accepted!
value = 1000
Got Input/Ouput Streams
------------------------------------------------------------------------------



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