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
35import java.lang.management.*;
36
37public 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
118class SimpleOne {}
119class SimpleTwo {}
120
121class Chain {
122    Slave slave = new Slave();
123}
124class Slave {}
125
126class LeftHand extends ClassLoader {
127    public LeftHand() {
128        super(LeftHand.class.getClassLoader());
129    }
130}
131class RightHand extends ClassLoader {
132    public RightHand() {
133        super(RightHand.class.getClassLoader());
134    }
135}
136class Body {}
137
138class LoaderForTwoInstances extends ClassLoader {
139    public LoaderForTwoInstances() {
140        super(LoaderForTwoInstances.class.getClassLoader());
141    }
142}
143class TheSameClass {}
144