1 /*
   2  * Copyright (c) 2013, 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  * @library /runtime/testlibrary
  27  * @library classes
  28  * @build test.Empty ClassUnloadCommon
  29  * @run main/othervm/timeout=200 FragmentMetaspaceSimple
  30  */
  31 
  32 import java.util.ArrayList;
  33 
  34 /**
  35  * Test that tries to fragment the native memory used by class loaders.
  36  * Keeps every other class loader alive in order to fragment the memory space
  37  * used to store classes and meta data. Since the memory is probably allocated in
  38  * chunks per class loader this will cause a lot of fragmentation if not handled
  39  * properly since every other chunk will be unused.
  40  */
  41 public class FragmentMetaspaceSimple {
  42     public static void main(String... args) {
  43         runSimple(Long.valueOf(System.getProperty("time", "80000")));
  44         System.gc();
  45     }
  46 
  47     private static void runSimple(long time) {
  48         long startTime = System.currentTimeMillis();
  49         ArrayList<ClassLoader> cls = new ArrayList<>();
  50         for (int i = 0; System.currentTimeMillis() < startTime + time; ++i) {
  51             ClassLoader ldr = ClassUnloadCommon.newClassLoader();
  52             if (i % 1000 == 0) {
  53                 cls.clear();
  54             }
  55             // only keep every other class loader alive
  56             if (i % 2 == 1) {
  57                 cls.add(ldr);
  58             }
  59             Class<?> c = null;
  60             try {
  61                 c = ldr.loadClass("test.Empty");
  62             } catch (ClassNotFoundException ex) {
  63                 throw new RuntimeException(ex);
  64             }
  65             c = null;
  66         }
  67         cls = null;
  68     }
  69 }