83 lines
3.3 KiB
Java
83 lines
3.3 KiB
Java
/*
|
|
* Copyright (c) 2013, 2022, 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 KeepAliveSoftReference
|
|
* @summary This test case uses a java.lang.ref.SoftReference referencing a class instance to keep a class alive.
|
|
* @requires vm.opt.final.ClassUnloading
|
|
* @modules java.base/jdk.internal.misc
|
|
* @library /test/lib
|
|
* @library classes
|
|
* @build jdk.test.whitebox.WhiteBox test.Empty
|
|
* @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
|
|
* @run main/othervm -Xbootclasspath/a:. -Xmn8m -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI KeepAliveSoftReference
|
|
*/
|
|
|
|
import java.lang.ref.SoftReference;
|
|
import jdk.test.whitebox.WhiteBox;
|
|
import jdk.test.lib.classloader.ClassUnloadCommon;
|
|
|
|
/**
|
|
* Test that verifies that classes are not unloaded when specific types of references are kept to them.
|
|
*/
|
|
public class KeepAliveSoftReference {
|
|
private static final String className = "test.Empty";
|
|
private static final WhiteBox wb = WhiteBox.getWhiteBox();
|
|
|
|
public static void main(String... args) throws Exception {
|
|
ClassLoader cl = ClassUnloadCommon.newClassLoader();
|
|
Class<?> c = cl.loadClass(className);
|
|
Object o = c.newInstance();
|
|
SoftReference<Object> sr = new SoftReference(o);
|
|
o = null; c = null; cl = null;
|
|
|
|
{
|
|
boolean isAlive = wb.isClassAlive(className);
|
|
System.out.println("testSoftReference (1) alive: " + isAlive);
|
|
boolean cleared = (sr.get() == null);
|
|
boolean shouldBeAlive = !cleared;
|
|
ClassUnloadCommon.failIf(isAlive != shouldBeAlive, "" + isAlive + " != " + shouldBeAlive);
|
|
}
|
|
|
|
ClassUnloadCommon.triggerUnloading();
|
|
|
|
{
|
|
boolean isAlive = wb.isClassAlive(className);
|
|
System.out.println("testSoftReference (2) alive: " + isAlive);
|
|
boolean cleared = (sr.get() == null);
|
|
boolean shouldBeAlive = !cleared;
|
|
ClassUnloadCommon.failIf(isAlive != shouldBeAlive, "" + isAlive + " != " + shouldBeAlive);
|
|
}
|
|
sr.clear();
|
|
ClassUnloadCommon.triggerUnloading();
|
|
|
|
{
|
|
boolean isAlive = wb.isClassAlive(className);
|
|
System.out.println("testSoftReference (3) alive: " + isAlive);
|
|
boolean cleared = (sr.get() == null);
|
|
boolean shouldBeAlive = !cleared;
|
|
ClassUnloadCommon.failIf(isAlive != shouldBeAlive, "" + isAlive + " != " + shouldBeAlive);
|
|
}
|
|
}
|
|
}
|