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/*
* Copyright (c) 2003, 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 4530538
* @summary Basic unit test of ClassLoadingMXBean.getLoadedClassCount()
* ClassLoadingMXBean.getTotalLoadedClassCount()
* ClassLoadingMXBean.getUnloadedClassCount()
* @author Alexei Guibadoulline
*
* @run main/othervm LoadCounts
*/
import java.lang.management.*;
public class LoadCounts {
private static ClassLoadingMXBean mbean
= ManagementFactory.getClassLoadingMXBean();
public static void main(String argv[]) throws Exception {
// Get current count
int classesNowPrev = mbean.getLoadedClassCount();
long classesTotalPrev = mbean.getTotalLoadedClassCount();
System.out.println("Loading 4 classes with the system class loader");
new SimpleOne();
new SimpleTwo();
new Chain();
int classesNow = mbean.getLoadedClassCount();
long classesTotal = mbean.getTotalLoadedClassCount();
if (classesNow > classesTotal)
throw new RuntimeException("getLoadedClassCount() > "
+ "getTotalLoadedClassCount()");
if (classesNowPrev + 4 > classesNow)
throw new RuntimeException("Number of loaded classes is "
+ "expected to be at least "
+ (classesNowPrev + 4) + ", but "
+ "MBean.getLoadedClassCount() returned "
+ classesNow);
if (classesTotalPrev + 4 > classesTotal)
throw new RuntimeException("Total number of loaded classes is "
+ "expected to be at least "
+ (classesTotalPrev + 4) + ", but "
+ "MBean.getTotalLoadedClassCount() "
+ "returned " + classesTotal);
System.out.println("Creating new class loader instances");
LeftHand leftHand = new LeftHand();
RightHand rightHand = new RightHand();
LoaderForTwoInstances ins1 = new LoaderForTwoInstances();
LoaderForTwoInstances ins2 = new LoaderForTwoInstances();
// Load different type of classes with different
// initiating classloaders but the same defining class loader.
System.out.println("Loading 2 class instances; each by " +
"2 initiating class loaders.");
classesNowPrev = mbean.getLoadedClassCount();
classesTotalPrev = mbean.getTotalLoadedClassCount();
try {
Class.forName("Body", true, leftHand);
Class.forName("Body", true, rightHand);
Class.forName("TheSameClass", true, ins1);
Class.forName("TheSameClass", true, ins2);
} catch (ClassNotFoundException e) {
System.out.println("Unexpected excetion " + e);
e.printStackTrace(System.out);
throw new RuntimeException();
}
classesNow = mbean.getLoadedClassCount();
classesTotal = mbean.getTotalLoadedClassCount();
// Expected 2 classes got loaded since they are loaded by
// same defining class loader
if (classesNowPrev + 2 > classesNow)
throw new RuntimeException("Number of loaded classes is "
+ "expected to be at least "
+ (classesNowPrev + 4) + ", but "
+ "MBean.getLoadedClassCount() returned "
+ classesNow);
if (classesTotalPrev + 2 > classesTotal)
throw new RuntimeException("Total number of loaded classes is "
+ "expected to be at least "
+ (classesTotalPrev + 4) + ", but "
+ "MBean.getTotalLoadedClassCount() "
+ "returned " + classesTotal);
System.out.println("Test passed.");
}
}
class SimpleOne {}
class SimpleTwo {}
class Chain {
Slave slave = new Slave();
}
class Slave {}
class LeftHand extends ClassLoader {
public LeftHand() {
super(LeftHand.class.getClassLoader());
}
}
class RightHand extends ClassLoader {
public RightHand() {
super(RightHand.class.getClassLoader());
}
}
class Body {}
class LoaderForTwoInstances extends ClassLoader {
public LoaderForTwoInstances() {
super(LoaderForTwoInstances.class.getClassLoader());
}
}
class TheSameClass {}
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