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/*
* Copyright (c) 2013, 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 KeepAliveClassLoader
* @summary This test case uses a java.lang.ClassLoader instance to keep a class alive.
* @library /testlibrary /testlibrary/whitebox /runtime/testlibrary
* @library classes
* @build KeepAliveClassLoader test.Empty
* @build ClassUnloadCommon
* @run main ClassFileInstaller sun.hotspot.WhiteBox
* @run main/othervm -Xbootclasspath/a:. -Xmn8m -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI KeepAliveClassLoader
*/
import sun.hotspot.WhiteBox;
/**
* Test that verifies that classes are not unloaded when specific types of references are kept to them.
*/
public class KeepAliveClassLoader {
private static final String className = "test.Empty";
private static final WhiteBox wb = WhiteBox.getWhiteBox();
public static Object escape = null;
public static void main(String... args) throws Exception {
ClassLoader cl = ClassUnloadCommon.newClassLoader();
Class<?> c = cl.loadClass(className);
Object o = c.newInstance();
o = null; c = null;
escape = cl;
{
boolean isAlive = wb.isClassAlive(className);
System.out.println("testClassLoader (1) alive: " + isAlive);
ClassUnloadCommon.failIf(!isAlive, "should be alive");
}
ClassUnloadCommon.triggerUnloading();
{
boolean isAlive = wb.isClassAlive(className);
System.out.println("testClassLoader (2) alive: " + isAlive);
ClassUnloadCommon.failIf(!isAlive, "should be alive");
}
cl = null;
escape = null;
ClassUnloadCommon.triggerUnloading();
{
boolean isAlive = wb.isClassAlive(className);
System.out.println("testClassLoader (3) alive: " + isAlive);
ClassUnloadCommon.failIf(isAlive, "should be unloaded");
}
}
}
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