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/*
* Copyright (c) 2021, 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.
*/
import java.lang.ref.WeakReference;
import java.lang.reflect.Constructor;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.ObjectStreamClass;
import java.io.ObjectStreamField;
import java.io.Serializable;
import java.util.Arrays;
import org.testng.annotations.Test;
import static org.testng.Assert.assertTrue;
import static org.testng.Assert.assertFalse;
import jdk.test.lib.util.ForceGC;
/* @test
* @bug 8277072
* @library /test/lib/
* @build jdk.test.lib.util.ForceGC
* @summary ObjectStreamClass caches keep ClassLoaders alive
* @run testng TestOSCClassLoaderLeak
*/
public class TestOSCClassLoaderLeak {
@Test
public void testClassLoaderLeak() throws Exception {
TestClassLoader myOwnClassLoader = new TestClassLoader();
Class<?> loadClass = myOwnClassLoader.loadClass("ObjectStreamClass_MemoryLeakExample");
Constructor con = loadClass.getConstructor();
con.setAccessible(true);
Object objectStreamClass_MemoryLeakExample = con.newInstance();
objectStreamClass_MemoryLeakExample.toString();
WeakReference<Object> myOwnClassLoaderWeakReference = new WeakReference<>(myOwnClassLoader);
assertFalse(myOwnClassLoaderWeakReference.refersTo(null));
objectStreamClass_MemoryLeakExample = null;
myOwnClassLoader = null;
loadClass = null;
con = null;
assertFalse(myOwnClassLoaderWeakReference.refersTo(null));
assertTrue(ForceGC.wait(() -> myOwnClassLoaderWeakReference.refersTo(null)));
}
}
class ObjectStreamClass_MemoryLeakExample {
private static final ObjectStreamField[] fields = ObjectStreamClass.lookup(TestClass.class).getFields();
public ObjectStreamClass_MemoryLeakExample() {
}
@Override
public String toString() {
return Arrays.toString(fields);
}
}
class TestClassLoader extends ClassLoader {
@Override
public Class<?> loadClass(String name) throws ClassNotFoundException {
if (name.equals("TestClass") || name.equals("ObjectStreamClass_MemoryLeakExample")) {
byte[] bt = loadClassData(name);
return defineClass(name, bt, 0, bt.length);
} else {
return super.loadClass(name);
}
}
private static byte[] loadClassData(String className) {
ByteArrayOutputStream byteSt = new ByteArrayOutputStream();
try (InputStream is = TestClassLoader.class.getClassLoader().getResourceAsStream(className.replace(".", "/") + ".class")) {
int len = 0;
while ((len = is.read()) != -1) {
byteSt.write(len);
}
} catch (java.io.IOException e) {
e.printStackTrace();
}
return byteSt.toByteArray();
}
}
class TestClass implements Serializable {
public String x;
}
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