Compile the follwoing program:

    import java.util.LinkedList;

    public class InternStringALot {
        // The point of this class is to intern a lot of Strings,
        // to fill up the permanent generation and fail an assertion 
        // during shutdown.
        // This is *not* a bug with interning Strings, just that
        // this was the easiest way I could think of to fill up
        // the permanent generation.
        //
        // Run with:
        //    java -XX:MaxPermSize=4M -XX:+PrintGCDetails -XX:+PrintHeapAtGC InternStringALot

        public static void main(String arg[]) {
            long count = 20000;
            String base = "ABCEDFEGHIJKLMNOPQRSTUVWXYZ1234567890abcdefghijklmnopqrstuvwxyz";
            if (arg.length > 0) {
                try {
                    count = Long.parseLong(arg[0]);
                } catch (NumberFormatException nfe) {
                    // Just ignore it.
                }
            }
            if (arg.length > 1) {
                base = arg[1];
            }
            System.out.println("Running with ");
            System.out.println("    base:  " + base);
            System.out.println("    count: " + Long.toString(count));
            long i = 0;
            try {
                for (i = 0; i < count; i += 1) {
                    list.add(base.concat(Long.toString(i)).intern());
                }
            } catch (OutOfMemoryError oome) {
                System.out.println("Caught OutOfMemoryError at iteration: " +
                                   Long.toString(i));
            }
        }

        private static LinkedList list = new LinkedList();
    }

and run it with the command line:

    % java -XX:MaxPermSize=4M InternStringALot

and you should produce the result:

    Running with 
	base:  ABCEDFEGHIJKLMNOPQRSTUVWXYZ1234567890abcdefghijklmnopqrstuvwxyz
	count: 20000
    Caught OutOfMemoryError at iteration: 18345
    #
    # HotSpot Virtual Machine Error, Internal Error
    # Please report this error at
    # http://java.sun.com/cgi-bin/bugreport.cgi
    #
    # Java VM: Java HotSpot(TM) Client VM (1.4.2-beta-b08 mixed mode)
    #
    # Error ID: 455843455054494F4E530E4350500104 01
    #
    # Problematic Thread: prio=5 tid=0x0002e158 nid=0x1 runnable 
    #

    Heap at VM Abort:
    Heap
     def new generation   total 2112K, used 0K [0xf5000000, 0xf5220000, 0xf5710000)
      eden space 2048K,   0% used [0xf5000000, 0xf5000000, 0xf5200000)
      from space 64K,   0% used [0xf5200000, 0xf5200000, 0xf5210000)
      to   space 64K,   0% used [0xf5210000, 0xf5210000, 0xf5220000)
     tenured generation   total 1408K, used 514K [0xf5710000, 0xf5870000, 0xf9000000)
       the space 1408K,  36% used [0xf5710000, 0xf5790870, 0xf5790a00, 0xf5870000)
     compacting perm gen  total 4096K, used 4095K [0xf9000000, 0xf9400000, 0xf9400000)
       the space 4096K,  99% used [0xf9000000, 0xf93fffd0, 0xf9400000, 0xf9400000)
    Abort (core dumped)

The problem is that permanent generation is full when the JVM goes 
to run the shutdown hooks by loading java.lang.Shutdown.