1 /*
   2  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /**
  25  * @test
  26  * @bug 8040076
  27  * @summary AwtList not garbage collected
  28  * @run main/othervm -Xmx100m AwtListGarbageCollectionTest
  29  */
  30 
  31 import java.awt.*;
  32 import java.awt.event.WindowAdapter;
  33 import java.awt.event.WindowEvent;
  34 import java.lang.ref.WeakReference;
  35 
  36 public class AwtListGarbageCollectionTest {
  37     public static void main(String[] args) {
  38         Frame frame = new Frame("List leak test");
  39         try {
  40             test(frame);
  41         } finally {
  42             frame.dispose();
  43         }
  44     }
  45 
  46     private static void test(Frame frame) {
  47         WeakReference<List> weakListRef = null;
  48         try {
  49             frame.setSize(300, 200);
  50             frame.setVisible(true);
  51 
  52             List strongListRef = new List();
  53             frame.add(strongListRef);
  54             strongListRef.setMultipleMode(true);
  55             frame.remove(strongListRef);
  56             weakListRef = new WeakReference<List>(strongListRef);
  57             strongListRef = null;
  58 
  59             //make out of memory to force gc
  60             String veryLongString = new String(new char[100]);
  61             while (true) {
  62                 veryLongString += veryLongString;
  63             }
  64         } catch (OutOfMemoryError e) {
  65             if (weakListRef == null) {
  66                 throw new RuntimeException("Weak list ref wasn't created");
  67             } else if (weakListRef.get() != null) {
  68                 throw new RuntimeException("List wasn't garbage collected");
  69             }
  70         }
  71     }
  72 }