1 /* 2 * Copyright (c) 2000, 2020, 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.oops; 26 27 import java.util.*; 28 import sun.jvm.hotspot.debugger.*; 29 import sun.jvm.hotspot.memory.*; 30 import sun.jvm.hotspot.runtime.*; 31 import sun.jvm.hotspot.types.*; 32 import sun.jvm.hotspot.utilities.Observable; 33 import sun.jvm.hotspot.utilities.Observer; 34 35 // Array is an abstract superclass for TypeArray and ObjArray 36 37 public class Array extends Oop { 38 static { 39 VM.registerVMInitializedObserver(new Observer() { 40 public void update(Observable o, Object data) { 41 initialize(VM.getVM().getTypeDataBase()); 42 } 43 }); 44 } 45 46 Array(OopHandle handle, ObjectHeap heap) { 47 super(handle, heap); 48 } 49 50 private static void initialize(TypeDataBase db) throws WrongTypeException { 51 Type type = db.lookupType("arrayOopDesc"); 52 typeSize = (int)type.getSize(); 53 } 54 55 // Size of the arrayOopDesc 56 private static long headerSize=0; 57 private static long lengthOffsetInBytes=0; 58 private static long typeSize; 59 60 private static long headerSizeInBytes() { 61 if (headerSize != 0) { 62 return headerSize; 63 } 64 if (VM.getVM().isCompactObjectHeadersEnabled()) { 65 headerSize = lengthOffsetInBytes() + VM.getVM().getIntSize(); 66 } else { 67 if (VM.getVM().isCompressedKlassPointersEnabled()) { 68 headerSize = typeSize; 69 } else { 70 headerSize = VM.getVM().alignUp(typeSize + VM.getVM().getIntSize(), 71 VM.getVM().getHeapWordSize()); 72 } 73 } 74 return headerSize; 75 } 76 77 private static long headerSize(BasicType type) { 78 if (Universe.elementTypeShouldBeAligned(type)) { 79 return alignObjectSize(headerSizeInBytes())/VM.getVM().getHeapWordSize(); 80 } else { 81 return headerSizeInBytes()/VM.getVM().getHeapWordSize(); 82 } 83 } 84 85 private static long lengthOffsetInBytes() { 86 if (lengthOffsetInBytes != 0) { 87 return lengthOffsetInBytes; 88 } 89 if (VM.getVM().isCompactObjectHeadersEnabled()) { 90 lengthOffsetInBytes = Oop.getHeaderSize(); 91 } else { 92 if (VM.getVM().isCompressedKlassPointersEnabled()) { 93 lengthOffsetInBytes = typeSize - VM.getVM().getIntSize(); 94 } else { 95 lengthOffsetInBytes = typeSize; 96 } 97 } 98 return lengthOffsetInBytes; 99 } 100 101 // Accessors for declared fields 102 public long getLength() { 103 boolean isUnsigned = true; 104 return this.getHandle().getCIntegerAt(lengthOffsetInBytes(), VM.getVM().getIntSize(), isUnsigned); 105 } 106 107 public long getObjectSize() { 108 ArrayKlass klass = (ArrayKlass) getKlass(); 109 // We have to fetch the length of the array, shift (multiply) it 110 // appropriately, up to wordSize, add the header, and align to 111 // object size. 112 long s = getLength() << klass.getLog2ElementSize(); 113 s += klass.getArrayHeaderInBytes(); 114 s = Oop.alignObjectSize(s); 115 return s; 116 } 117 118 public static long baseOffsetInBytes(BasicType type) { 119 if (VM.getVM().isCompactObjectHeadersEnabled()) { 120 long typeSizeInBytes = headerSizeInBytes(); 121 if (Universe.elementTypeShouldBeAligned(type)) { 122 VM vm = VM.getVM(); 123 return vm.alignUp(typeSizeInBytes, vm.getVM().getHeapWordSize()); 124 } else { 125 return typeSizeInBytes; 126 } 127 } else { 128 return headerSize(type) * VM.getVM().getHeapWordSize(); 129 } 130 } 131 132 public boolean isArray() { return true; } 133 134 public void iterateFields(OopVisitor visitor, boolean doVMFields) { 135 super.iterateFields(visitor, doVMFields); 136 } 137 }