Name: nt126004 Date: 10/24/2001


java version "1.4.0-beta2"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta2-b77)
Java HotSpot(TM) Client VM (build 1.4.0-beta2-b77, mixed mode)

The following Memory.java ends up with an OutOfMemory error. This is very unpleasant concerning that javax.swing.SwingUtilities.invokeLater() executes run() method of a thread which means that recommended use of it leads to memory leaks. By making MemorySpace not a subclass of Thread, there is no OutOfMemoryError.

import java.util.*;
import java.lang.ref.*;

public class Memory {
    public static void main(String argv[]) {
        GarbageListener gl = new GarbageListener();

        while (true) {
            gl.register(new MemorySpace());
        }
    }
}

class MemorySpace extends Thread {
    int [] some = new int[10000];
    public void run() {
    }
}

class GarbageListener {
    Map types = new HashMap();
    ReferenceQueue queue = new ReferenceQueue();
    Thread printer = null;

    public void register(Object o) {
        if (null == printer) {
            printer = new Thread() {
                public void run() {
                    while (true) {
                        try {
                            Reference r = queue.remove();
                            System.err.println(types.get(r));
                        }
                        catch(InterruptedException ie) {
                        }
                    }
                }
            };
            printer.start();
        }
        types.put(new WeakReference(o, queue), o.getClass().getName());
    }
}
(Review ID: 134378)
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