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/*
* Copyright (c) 2013, 2018, 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 7042126
* @summary Verify that we do not leak contents when we clone a HashMap
* @author david.buck@oracle.com
* @run main/othervm HashMapCloneLeak
* @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:+EliminateAutoBox -XX:AutoBoxCacheMax=20000 HashMapCloneLeak
*/
import java.util.HashMap;
import java.lang.ref.WeakReference;
public class HashMapCloneLeak {
static WeakReference<Object> wr = null;
// helper method to keep testObject and map out of main method's scope
private static HashMap<Integer, Object> makeMap() {
HashMap<Integer, Object> map = new HashMap<Integer, Object>();
Object testObject = new Object();
wr = new WeakReference<Object>(testObject);
map.put(42, testObject);
return map;
}
public static void main(String[] args) throws Exception {
HashMap<Integer, Object> hm = makeMap();
hm = (HashMap<Integer, Object>)hm.clone();
hm.clear();
// There should no longer be a strong reference to testObject
// the WeakReference should be nulled out by GC. If not,
// we will hang here until timed out by the test harness.
Object[] chain = null;
while (wr.get() != null) {
try {
Object[] allocate = new Object[1000000];
allocate[0] = chain;
chain = allocate;
} catch (OutOfMemoryError oome) {
chain = null;
}
System.gc();
Thread.sleep(100);
}
}
}
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