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80 lines
3.2 KiB
80 lines
3.2 KiB
/* |
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* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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/* |
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* @test KeepAliveSoftReference |
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* @summary This test case uses a java.lang.ref.SoftReference referencing a class instance to keep a class alive. |
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* @library /testlibrary /testlibrary/whitebox /runtime/testlibrary |
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* @library classes |
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* @build KeepAliveSoftReference test.Empty |
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* @build ClassUnloadCommon |
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* @run main ClassFileInstaller sun.hotspot.WhiteBox |
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* @run main/othervm -Xbootclasspath/a:. -Xmn8m -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI KeepAliveSoftReference |
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*/ |
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import java.lang.ref.SoftReference; |
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import sun.hotspot.WhiteBox; |
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/** |
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* Test that verifies that classes are not unloaded when specific types of references are kept to them. |
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*/ |
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public class KeepAliveSoftReference { |
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private static final String className = "test.Empty"; |
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private static final WhiteBox wb = WhiteBox.getWhiteBox(); |
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public static void main(String... args) throws Exception { |
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ClassLoader cl = ClassUnloadCommon.newClassLoader(); |
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Class<?> c = cl.loadClass(className); |
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Object o = c.newInstance(); |
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SoftReference<Object> sr = new SoftReference(o); |
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o = null; c = null; cl = null; |
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{ |
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boolean isAlive = wb.isClassAlive(className); |
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System.out.println("testSoftReference (1) alive: " + isAlive); |
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boolean cleared = (sr.get() == null); |
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boolean shouldBeAlive = !cleared; |
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ClassUnloadCommon.failIf(isAlive != shouldBeAlive, "" + isAlive + " != " + shouldBeAlive); |
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} |
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ClassUnloadCommon.triggerUnloading(); |
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{ |
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boolean isAlive = wb.isClassAlive(className); |
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System.out.println("testSoftReference (2) alive: " + isAlive); |
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boolean cleared = (sr.get() == null); |
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boolean shouldBeAlive = !cleared; |
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ClassUnloadCommon.failIf(isAlive != shouldBeAlive, "" + isAlive + " != " + shouldBeAlive); |
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} |
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sr.clear(); |
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ClassUnloadCommon.triggerUnloading(); |
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{ |
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boolean isAlive = wb.isClassAlive(className); |
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System.out.println("testSoftReference (3) alive: " + isAlive); |
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boolean cleared = (sr.get() == null); |
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boolean shouldBeAlive = !cleared; |
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ClassUnloadCommon.failIf(isAlive != shouldBeAlive, "" + isAlive + " != " + shouldBeAlive); |
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} |
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} |
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}
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