1 /* 2 * Copyright (c) 2011, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package gc.gctests.PhantomReference; 24 25 import java.lang.ref.PhantomReference; 26 import java.lang.ref.ReferenceQueue; 27 28 /** 29 * Helper class that extends PhantomReference, that we can use 30 * to match the hash code for the referent object. 31 */ 32 public final class PRHelper extends PhantomReference { 33 34 private int referentHashCode; 35 36 /** 37 * Constructor for extended PhantomReference class. 38 * 39 * @param o Referred object 40 * @param referenceQueue Reference queue to attach the PR to 41 */ 42 public PRHelper(Object o, ReferenceQueue referenceQueue) { 43 super(o, referenceQueue); 44 referentHashCode = -1; 45 } 46 47 /** 48 * Get the referred objects hash code. 49 * 50 * @return Hash code for referred object 51 */ 52 public int getReferentHashCode() { 53 return referentHashCode; 54 } 55 56 /** 57 * Set the original referred objects hash code for tracking. 58 * 59 * @param referentHashCode New hash code 60 */ 61 public void setReferentHashCode(int referentHashCode) { 62 this.referentHashCode = referentHashCode; 63 } 64 }