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().isCompressedKlassPointersEnabled()) {
65 headerSize = typeSize;
66 } else {
67 headerSize = VM.getVM().alignUp(typeSize + VM.getVM().getIntSize(),
68 VM.getVM().getHeapWordSize());
69 }
70 return headerSize;
71 }
72
73 private static long headerSize(BasicType type) {
74 if (Universe.elementTypeShouldBeAligned(type)) {
75 return alignObjectSize(headerSizeInBytes())/VM.getVM().getHeapWordSize();
76 } else {
77 return headerSizeInBytes()/VM.getVM().getHeapWordSize();
78 }
79 }
80
81 private long lengthOffsetInBytes() {
82 if (lengthOffsetInBytes != 0) {
83 return lengthOffsetInBytes;
84 }
85 if (VM.getVM().isCompressedKlassPointersEnabled()) {
86 lengthOffsetInBytes = typeSize - VM.getVM().getIntSize();
87 } else {
88 lengthOffsetInBytes = typeSize;
89 }
90 return lengthOffsetInBytes;
91 }
92
93 // Accessors for declared fields
94 public long getLength() {
95 boolean isUnsigned = true;
96 return this.getHandle().getCIntegerAt(lengthOffsetInBytes(), VM.getVM().getIntSize(), isUnsigned);
97 }
98
99 public long getObjectSize() {
100 ArrayKlass klass = (ArrayKlass) getKlass();
101 // We have to fetch the length of the array, shift (multiply) it
102 // appropriately, up to wordSize, add the header, and align to
103 // object size.
104 long s = getLength() << klass.getLog2ElementSize();
105 s += klass.getArrayHeaderInBytes();
106 s = Oop.alignObjectSize(s);
107 return s;
108 }
109
110 public static long baseOffsetInBytes(BasicType type) {
111 return headerSize(type) * VM.getVM().getHeapWordSize();
112 }
113
114 public boolean isArray() { return true; }
115
116 public void iterateFields(OopVisitor visitor, boolean doVMFields) {
117 super.iterateFields(visitor, doVMFields);
118 }
119 }