1 /* 2 * Copyright (c) 2013, 2015, 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 */ 24 25 package sun.jvm.hotspot.gc.g1; 26 27 import java.util.Iterator; 28 import java.util.Observable; 29 import java.util.Observer; 30 31 import sun.jvm.hotspot.debugger.Address; 32 import sun.jvm.hotspot.runtime.VM; 33 import sun.jvm.hotspot.runtime.VMObject; 34 import sun.jvm.hotspot.runtime.VMObjectFactory; 35 import sun.jvm.hotspot.types.AddressField; 36 import sun.jvm.hotspot.types.CIntegerField; 37 import sun.jvm.hotspot.types.Type; 38 import sun.jvm.hotspot.types.TypeDataBase; 39 40 // Mirror class for G1HeapRegionTable. It's essentially an index -> HeapRegion map. 41 42 public class G1HeapRegionTable extends VMObject { 43 // HeapRegion** _base; 44 static private AddressField baseField; 45 // uint _length; 46 static private CIntegerField lengthField; 47 // HeapRegion** _biased_base 48 static private AddressField biasedBaseField; 49 // size_t _bias 50 static private CIntegerField biasField; 51 // uint _shift_by 52 static private CIntegerField shiftByField; 53 54 static { 55 VM.registerVMInitializedObserver(new Observer() { 56 public void update(Observable o, Object data) { 57 initialize(VM.getVM().getTypeDataBase()); 58 } 59 }); 60 } 61 62 static private synchronized void initialize(TypeDataBase db) { 63 Type type = db.lookupType("G1HeapRegionTable"); 64 65 baseField = type.getAddressField("_base"); 66 lengthField = type.getCIntegerField("_length"); 67 biasedBaseField = type.getAddressField("_biased_base"); 68 biasField = type.getCIntegerField("_bias"); 69 shiftByField = type.getCIntegerField("_shift_by"); 70 } 71 72 private HeapRegion at(long index) { 73 Address arrayAddr = baseField.getValue(addr); 74 // Offset of &_base[index] 75 long offset = index * VM.getVM().getAddressSize(); 76 Address regionAddr = arrayAddr.getAddressAt(offset); 77 return (HeapRegion) VMObjectFactory.newObject(HeapRegion.class, 78 regionAddr); 79 } 80 81 public long length() { 82 return lengthField.getValue(addr); 83 } 84 85 public long bias() { 86 return biasField.getValue(addr); 87 } 88 89 public long shiftBy() { 90 return shiftByField.getValue(addr); 91 } 92 93 private class HeapRegionIterator implements Iterator<HeapRegion> { 94 private long index; 95 private long length; 96 private HeapRegion next; 97 98 public HeapRegion positionToNext() { 99 HeapRegion result = next; 100 while (index < length && at(index) == null) { 101 index++; 102 } 103 if (index < length) { 104 next = at(index); 105 index++; // restart search at next element 106 } else { 107 next = null; 108 } 109 return result; 110 } 111 112 @Override 113 public boolean hasNext() { return next != null; } 114 115 @Override 116 public HeapRegion next() { return positionToNext(); } 117 118 @Override 119 public void remove() { /* not supported */ } 120 121 HeapRegionIterator(long totalLength) { 122 index = 0; 123 length = totalLength; 124 positionToNext(); 125 } 126 } 127 128 public Iterator<HeapRegion> heapRegionIterator(long committedLength) { 129 return new HeapRegionIterator(committedLength); 130 } 131 132 public G1HeapRegionTable(Address addr) { 133 super(addr); 134 } 135 }