vm/tests/smoke/gc/RefRemove.java

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
/**
 * @author Salikh Zakirov
 */
package gc;

import java.lang.ref.PhantomReference;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;

/**
 * @keyword
 */
public class RefRemove {

    public static void main(String[] args) throws Exception {
        ReferenceQueue queue = new ReferenceQueue();
        Object o = new RefRemove();
        Reference ref = new PhantomReference(o, queue);
        o = null;
        System.gc();
        System.err.println("waiting for a reference..");
        Reference enqueued = queue.remove();
        if (enqueued == ref) {
            System.out.println("PASSED, " + ref);
        } else {
            System.out.println("FAILED, wrong reference enqueued " + ref);
        }
    }
}