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 com.oracle.java.testlibrary.* 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 }