1 /* 2 * Copyright (C) 2007 The Guava Authors 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 import java.lang.ref.ReferenceQueue; 21 22 /** 23 * Phantom reference with a {@code finalizeReferent()} method which a background thread invokes 24 * after the garbage collector reclaims the referent. This is a simpler alternative to using a 25 * {@link ReferenceQueue}. 26 * 27 * <p>Unlike a normal phantom reference, this reference will be cleared automatically. 28 * 29 * @author Bob Lee 30 * @since 2.0 (imported from Google Collections Library) 31 */ 32 public abstract class FinalizablePhantomReference<T> extends PhantomReference<T> 33 implements FinalizableReference { 34 /** 35 * Constructs a new finalizable phantom reference. 36 * 37 * @param referent to phantom reference 38 * @param queue that should finalize the referent 39 */ 40 protected FinalizablePhantomReference(T referent, FinalizableReferenceQueue queue) { 41 super(referent, queue.queue); 42 queue.cleanUp(); 43 } 44 } 45
