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 }