dcevm/dcevm/src/test/java7/com/github/dcevm/test/methods/ClassObjectSynchronizationTest.java

/*
 * Copyright (c) 2011, 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
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package com.github.dcevm.test.methods;

import org.junit.Before;
import org.junit.Test;

import static com.github.dcevm.test.util.HotSwapTestHelper.__toVersion__;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

/**
 * Redefines a class and tests that the lock on the java.lang.Class object
 * is retained. Also tests that the object identity of the java.lang.Class
 * object is not changed.
 *
 * @author Thomas Wuerthinger
 */
public class ClassObjectSynchronizationTest {

    @Before
    public void setUp() throws Exception {
        __toVersion__(0);
    }

    // Version 0
    public static class A {

        public int value() {
            return 1;
        }
    }

    // Version 1
    public static class A___1 {

        public int value() {
            return 2;
        }
    }

    @Test
    public void testClassObjectSynchronization() {
        A a = new A();
        Class clazz = a.getClass();
        synchronized (clazz) {
            assertEquals(1, a.value());
            __toVersion__(1);
            assertEquals(2, a.value());
            assertTrue(a.getClass() == clazz);
            assertTrue(a.getClass() == ClassObjectSynchronizationTest.A.class);
        }
        assertEquals(2, a.value());
        assertTrue(a.getClass() == clazz);
        __toVersion__(0);
        assertTrue(a.getClass() == clazz);
    }
}