2 * Copyright (C) 2014, United States Government, as represented by the
3 * Administrator of the National Aeronautics and Space Administration.
6 * The Java Pathfinder core (jpf-core) platform is licensed under the
7 * Apache License, Version 2.0 (the "License"); you may not use this file except
8 * in compliance with the License. You may obtain a copy of the License at
10 * http://www.apache.org/licenses/LICENSE-2.0.
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
18 package java.lang.ref;
21 * MJI model class for java.lang.ref.Reference library abstraction
22 * we model this so that we can rely on our WeakRefence implementation
24 public abstract class Reference<T> {
27 * the object we reference
28 * NOTE: this has to be the *first* field, or we break WeakReference handling in
29 * the garbage collection!!
33 /** the optional queue for us */
34 ReferenceQueue<? super T> queue;
36 /** link to enqueue w/o additional memory requirements */
43 Reference (T r, ReferenceQueue<? super T> q) {
48 /** is the referenced object enqueued */
49 public boolean isEnqueued () {
54 /** clear, but do not enqueue the referenced object */
55 public void clear () {
59 /** add the referenced object to its queue */
60 public void enqueue () {
63 /** return the referenced object */