Name: dk106046 Date: 02/26/2004

Operating System: Windows

Full JDK version: java version "1.4.2"
                         Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2-b28)
                         Java HotSpot(TM) Client VM (build 1.4.2-b28, mixed mode)

Testcase:

/* This test shows that keys registered with a selector are still valid after
the selector has been closed. The API doc for close states that:

    Any uncancelled keys still associated with this selector are
    invalidated, their channels are deregistered, and any other
    resources associated with this selector are released.
*/

import java.util.*;
import java.nio.*;
import java.nio.channels.*;
        
    
public class SelectorCloseTest
{
    public static void main( String[] args )
    {
        new SelectorCloseTest() . runTest();
    }
    
    public void runTest()
    {
        try {
            // Open a selector and register four channels.
            Selector selector = Selector.open();
            Pipe pipe1 = Pipe.open();
            Pipe pipe2 = Pipe.open();

            pipe1.source().configureBlocking( false );
            pipe1.sink(). configureBlocking( false );
            pipe2.source().configureBlocking( false );
            pipe2.sink(). configureBlocking( false );

            SelectionKey[] k = new SelectionKey[4];
            k[0] = pipe1.source().register( selector, SelectionKey.OP_READ );
            k[1] = pipe1.sink(). register( selector, SelectionKey.OP_WRITE );
            k[2] = pipe2.source().register( selector, SelectionKey.OP_READ );
            k[3] = pipe2.sink(). register( selector, SelectionKey.OP_WRITE );

            // This select will return immediately as sinks are ready for writing.
            selector.select();
            
            // Close the selector and check it is closed.
            selector.close();
            System.out.println( "selector.isOpen()=" + selector.isOpen() );
            
            // All keys should have been invalidated and de-registered by the
            // close. This doesn't work, they are still valid and registered.
            
            System.out.println( "Number of registered keys=" + selector.keys().size() );
            
            // Find how many keys are still valid.
            int numValidKeys = 0;
            for ( int i=0; i<4; i++ ) {
                if ( k[i].isValid() ) {
                    ++numValidKeys;
                }
            }
            System.out.println( "Number of valid keys=" + numValidKeys );

        } catch ( Exception e ) {
            System.out.println( "runTest: " + e );
        }
    }
}

Prposed fix: the implmentation should cancel keys before closing the selector.

[This bug is being submitted as a courtesy, in order to maintain uniformity between Sun & IBM JDKs. It has been fixed in IBM JDKs.
Please contact ###@###.### if you have questions.]

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