1 /* 2 * Copyright (C) 2007 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.common.base; 18 19 import java.lang.ref.PhantomReference; 20 21 /** 22 * Phantom reference with a {@code finalizeReferent()} method which a 23 * background thread invokes after the garbage collector reclaims the 24 * referent. This is a simpler alternative to using a {@link 25 * java.lang.ref.ReferenceQueue}. 26 * 27 * <p>Unlike a normal phantom reference, this reference will be cleared 28 * automatically. 29 * 30 * @author Bob Lee 31 * @since 2010.01.04 <b>stable</b> (imported from Google Collections Library) 32 */ 33 public abstract class FinalizablePhantomReference<T> 34 extends PhantomReference<T> implements FinalizableReference { 35 36 /** 37 * Constructs a new finalizable phantom reference. 38 * 39 * @param referent to phantom reference 40 * @param queue that should finalize the referent 41 */ 42 protected FinalizablePhantomReference(T referent, 43 FinalizableReferenceQueue queue) { 44 super(referent, queue.queue); 45 queue.cleanUp(); 46 } 47 } 48
