/*

 * Copyright (c) 1997, 2020, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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.

 */

package java.lang.ref;

/**

 * Final references, used to implement finalization

 */

class FinalReference<T> extends Reference<T> {

    public FinalReference(T referent, ReferenceQueue<? super T> q) {

        super(referent, q);

    }

    /* May only be called when the reference is inactive, so no longer weak. */

    @Override

    public T get() {

        // Cannot call super.get() when active, as the GC could

        // deactivate immediately after the test.

        return getFromInactiveFinalReference();

    }

    /* May only be called when the reference is inactive, so no longer weak.

     * Clearing while active would discard the finalization request.

     */

    @Override

    public void clear() {

        clearInactiveFinalReference();

    }

    @Override

    public boolean enqueue() {

        throw new InternalError("should never reach here");

    }

}