1 /* 2 * Copyright 2003-2008 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 * 23 */ 24 25 package sun.jvm.hotspot.memory; 26 27 import java.util.*; 28 import sun.jvm.hotspot.debugger.*; 29 import sun.jvm.hotspot.types.*; 30 import sun.jvm.hotspot.runtime.*; 31 import sun.jvm.hotspot.oops.*; 32 33 public class FreeChunk extends VMObject { 34 static { 35 VM.registerVMInitializedObserver(new Observer() { 36 public void update(Observable o, Object data) { 37 initialize(VM.getVM().getTypeDataBase()); 38 } 39 }); 40 } 41 42 private static synchronized void initialize(TypeDataBase db) { 43 Type type = db.lookupType("FreeChunk"); 44 nextField = type.getAddressField("_next"); 45 prevField = type.getAddressField("_prev"); 46 sizeField = type.getAddressField("_size"); 47 } 48 49 // Fields 50 private static AddressField nextField; 51 private static AddressField prevField; 52 private static AddressField sizeField; 53 54 // Accessors 55 public FreeChunk next() { 56 return (FreeChunk) VMObjectFactory.newObject(FreeChunk.class, nextField.getValue(addr)); 57 } 58 59 public FreeChunk prev() { 60 Address prev = prevField.getValue(addr).andWithMask(~0x3); 61 return (FreeChunk) VMObjectFactory.newObject(FreeChunk.class, prev); 62 } 63 64 public long size() { 65 if (VM.getVM().isCompressedOopsEnabled()) { 66 Mark mark = new Mark(sizeField.getValue(addr)); 67 return mark.getSize(); 68 } else { 69 Address size = sizeField.getValue(addr); 70 Debugger dbg = VM.getVM().getDebugger(); 71 return dbg.getAddressValue(size); 72 } 73 } 74 75 public FreeChunk(Address addr) { 76 super(addr); 77 } 78 79 public static boolean indicatesFreeChunk(Address cur) { 80 FreeChunk f = new FreeChunk(cur); 81 return f.isFree(); 82 } 83 84 public boolean isFree() { 85 if (VM.getVM().isCompressedOopsEnabled()) { 86 Mark mark = new Mark(sizeField.getValue(addr)); 87 return mark.isCmsFreeChunk(); 88 } else { 89 Address prev = prevField.getValue(addr); 90 Debugger dbg = VM.getVM().getDebugger(); 91 long word = dbg.getAddressValue(prev); 92 return (word & 0x1L) == 0x1L; 93 } 94 } 95 }