| /* |
| * Copyright (c) 2002, 2006, 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. |
| * |
| * 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 sun.jvm.hotspot.utilities; |
| |
| import java.util.*; |
| import sun.jvm.hotspot.oops.*; |
| |
| /** ReversePtrs hashtable. */ |
| |
| public class ReversePtrs { |
| private HashMap rp; |
| |
| public ReversePtrs() { |
| rp = new HashMap(); |
| } |
| |
| public void put(LivenessPathElement from, Oop to) { |
| if (to == null) return; |
| ArrayList al = (ArrayList) rp.get((Object) to); |
| if (al == null) al = new ArrayList(); |
| // Inserting at the beginning is a hack to change the reported |
| // paths from LivenessAnalysis to look more like they used to; |
| // otherwise paths through the Finalizer queue to popular objects |
| // seem to be preferred |
| al.add(0, (Object) from); |
| rp.put((Object) to, (Object) al); |
| } |
| |
| /** Returns an ArrayList of the incoming references to this Oop if |
| it is alive, and null if it is dead according to the |
| ReversePtrsAnalysis. Currently not all roots are scanned so this |
| result is frequently inaccurate for JVM-internal objects, but is |
| usually correct for Java-level objects. */ |
| public ArrayList/*<LivenessPathElement>*/ get(Oop obj) { |
| return (ArrayList) rp.get((Object)obj); |
| } |
| } |