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