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test/runtime/ClassUnload/KeepAliveSoftReference.java@fb9d124d9192 (annotated)

test/runtime/ClassUnload/KeepAliveSoftReference.java

Wed, 21 May 2014 10:56:41 -0700

author

katleman

date

Wed, 21 May 2014 10:56:41 -0700

changeset 6672

fb9d124d9192

parent 0

f90c822e73f8

permissions

-rw-r--r--

Added tag jdk8u20-b15 for changeset 8c785f9bde6f

aoqi@0	1	/*
aoqi@0	2	* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0	4	*
aoqi@0	5	* This code is free software; you can redistribute it and/or modify it
aoqi@0	6	* under the terms of the GNU General Public License version 2 only, as
aoqi@0	7	* published by the Free Software Foundation.
aoqi@0	8	*
aoqi@0	9	* This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
aoqi@0	12	* version 2 for more details (a copy is included in the LICENSE file that
aoqi@0	13	* accompanied this code).
aoqi@0	14	*
aoqi@0	15	* You should have received a copy of the GNU General Public License version
aoqi@0	16	* 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0	18	*
aoqi@0	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0	20	* or visit www.oracle.com if you need additional information or have any
aoqi@0	21	* questions.
aoqi@0	22	*/
aoqi@0	23
aoqi@0	24	/*
aoqi@0	25	* @test KeepAliveSoftReference
aoqi@0	26	* @summary This test case uses a java.lang.ref.SoftReference referencing a class instance to keep a class alive.
aoqi@0	27	* @library /testlibrary /testlibrary/whitebox /runtime/testlibrary
aoqi@0	28	* @library classes
aoqi@0	29	* @build KeepAliveSoftReference test.Empty
aoqi@0	30	* @build ClassUnloadCommon
aoqi@0	31	* @run main ClassFileInstaller sun.hotspot.WhiteBox
aoqi@0	32	* @run main/othervm -Xbootclasspath/a:. -Xmn8m -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI KeepAliveSoftReference
aoqi@0	33	*/
aoqi@0	34
aoqi@0	35	import java.lang.ref.SoftReference;
aoqi@0	36	import sun.hotspot.WhiteBox;
aoqi@0	37
aoqi@0	38	/**
aoqi@0	39	* Test that verifies that classes are not unloaded when specific types of references are kept to them.
aoqi@0	40	*/
aoqi@0	41	public class KeepAliveSoftReference {
aoqi@0	42	private static final String className = "test.Empty";
aoqi@0	43	private static final WhiteBox wb = WhiteBox.getWhiteBox();
aoqi@0	44
aoqi@0	45	public static void main(String... args) throws Exception {
aoqi@0	46	ClassLoader cl = ClassUnloadCommon.newClassLoader();
aoqi@0	47	Class<?> c = cl.loadClass(className);
aoqi@0	48	Object o = c.newInstance();
aoqi@0	49	SoftReference<Object> sr = new SoftReference(o);
aoqi@0	50	o = null; c = null; cl = null;
aoqi@0	51
aoqi@0	52	{
aoqi@0	53	boolean isAlive = wb.isClassAlive(className);
aoqi@0	54	System.out.println("testSoftReference (1) alive: " + isAlive);
aoqi@0	55	boolean cleared = (sr.get() == null);
aoqi@0	56	boolean shouldBeAlive = !cleared;
aoqi@0	57	ClassUnloadCommon.failIf(isAlive != shouldBeAlive, "" + isAlive + " != " + shouldBeAlive);
aoqi@0	58	}
aoqi@0	59
aoqi@0	60	ClassUnloadCommon.triggerUnloading();
aoqi@0	61
aoqi@0	62	{
aoqi@0	63	boolean isAlive = wb.isClassAlive(className);
aoqi@0	64	System.out.println("testSoftReference (2) alive: " + isAlive);
aoqi@0	65	boolean cleared = (sr.get() == null);
aoqi@0	66	boolean shouldBeAlive = !cleared;
aoqi@0	67	ClassUnloadCommon.failIf(isAlive != shouldBeAlive, "" + isAlive + " != " + shouldBeAlive);
aoqi@0	68	}
aoqi@0	69	sr.clear();
aoqi@0	70	ClassUnloadCommon.triggerUnloading();
aoqi@0	71
aoqi@0	72	{
aoqi@0	73	boolean isAlive = wb.isClassAlive(className);
aoqi@0	74	System.out.println("testSoftReference (3) alive: " + isAlive);
aoqi@0	75	boolean cleared = (sr.get() == null);
aoqi@0	76	boolean shouldBeAlive = !cleared;
aoqi@0	77	ClassUnloadCommon.failIf(isAlive != shouldBeAlive, "" + isAlive + " != " + shouldBeAlive);
aoqi@0	78	}
aoqi@0	79	}
aoqi@0	80	}