1 /* 2 * Copyright (c) 2003, 2015, 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 4530538 27 * @summary Basic unit test of ClassLoadingMXBean.getLoadedClassCount() 28 * ClassLoadingMXBean.getTotalLoadedClassCount() 29 * ClassLoadingMXBean.getUnloadedClassCount() 30 * @author Alexei Guibadoulline 31 * 32 * @run main/othervm LoadCounts 33 */ 34 35 import java.lang.management.*; 36 37 public class LoadCounts { 38 private static ClassLoadingMXBean mbean 39 = ManagementFactory.getClassLoadingMXBean(); 40 41 public static void main(String argv[]) throws Exception { 42 // Get current count 43 int classesNowPrev = mbean.getLoadedClassCount(); 44 long classesTotalPrev = mbean.getTotalLoadedClassCount(); 45 46 System.out.println("Loading 4 classes with the system class loader"); 47 48 new SimpleOne(); 49 new SimpleTwo(); 50 new Chain(); 51 52 int classesNow = mbean.getLoadedClassCount(); 53 long classesTotal = mbean.getTotalLoadedClassCount(); 54 55 if (classesNow > classesTotal) 56 throw new RuntimeException("getLoadedClassCount() > " 57 + "getTotalLoadedClassCount()"); 58 59 if (classesNowPrev + 4 > classesNow) 60 throw new RuntimeException("Number of loaded classes is " 61 + "expected to be at least " 62 + (classesNowPrev + 4) + ", but " 63 + "MBean.getLoadedClassCount() returned " 64 + classesNow); 65 if (classesTotalPrev + 4 > classesTotal) 66 throw new RuntimeException("Total number of loaded classes is " 67 + "expected to be at least " 68 + (classesTotalPrev + 4) + ", but " 69 + "MBean.getTotalLoadedClassCount() " 70 + "returned " + classesTotal); 71 72 System.out.println("Creating new class loader instances"); 73 74 LeftHand leftHand = new LeftHand(); 75 RightHand rightHand = new RightHand(); 76 LoaderForTwoInstances ins1 = new LoaderForTwoInstances(); 77 LoaderForTwoInstances ins2 = new LoaderForTwoInstances(); 78 79 // Load different type of classes with different 80 // initiating classloaders but the same defining class loader. 81 System.out.println("Loading 2 class instances; each by " + 82 "2 initiating class loaders."); 83 84 classesNowPrev = mbean.getLoadedClassCount(); 85 classesTotalPrev = mbean.getTotalLoadedClassCount(); 86 try { 87 Class.forName("Body", true, leftHand); 88 Class.forName("Body", true, rightHand); 89 Class.forName("TheSameClass", true, ins1); 90 Class.forName("TheSameClass", true, ins2); 91 } catch (ClassNotFoundException e) { 92 System.out.println("Unexpected excetion " + e); 93 e.printStackTrace(System.out); 94 throw new RuntimeException(); 95 } 96 classesNow = mbean.getLoadedClassCount(); 97 classesTotal = mbean.getTotalLoadedClassCount(); 98 99 // Expected 2 classes got loaded since they are loaded by 100 // same defining class loader 101 if (classesNowPrev + 2 > classesNow) 102 throw new RuntimeException("Number of loaded classes is " 103 + "expected to be at least " 104 + (classesNowPrev + 4) + ", but " 105 + "MBean.getLoadedClassCount() returned " 106 + classesNow); 107 if (classesTotalPrev + 2 > classesTotal) 108 throw new RuntimeException("Total number of loaded classes is " 109 + "expected to be at least " 110 + (classesTotalPrev + 4) + ", but " 111 + "MBean.getTotalLoadedClassCount() " 112 + "returned " + classesTotal); 113 114 System.out.println("Test passed."); 115 } 116 } 117 118 class SimpleOne {} 119 class SimpleTwo {} 120 121 class Chain { 122 Slave slave = new Slave(); 123 } 124 class Slave {} 125 126 class LeftHand extends ClassLoader { 127 public LeftHand() { 128 super(LeftHand.class.getClassLoader()); 129 } 130 } 131 class RightHand extends ClassLoader { 132 public RightHand() { 133 super(RightHand.class.getClassLoader()); 134 } 135 } 136 class Body {} 137 138 class LoaderForTwoInstances extends ClassLoader { 139 public LoaderForTwoInstances() { 140 super(LoaderForTwoInstances.class.getClassLoader()); 141 } 142 } 143 class TheSameClass {}