1 /*
2  * Copyright (C) 2007 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 import java.util.Arrays;
18 
19 /**
20  * System.arraycopy cases
21  */
22 public class Main {
main(String args[])23     public static void main(String args[]) {
24         testObjectCopy();
25         testOverlappingMoves();
26         testFloatAndDouble();
27     }
28 
testObjectCopy()29     public static void testObjectCopy() {
30         String[] stringArray = new String[8];
31         Object[] objectArray = new Object[8];
32 
33         for (int i = 0; i < stringArray.length; i++)
34             stringArray[i] = new String(Integer.toString(i));
35 
36         System.out.println("string -> object");
37         System.arraycopy(stringArray, 0, objectArray, 0, stringArray.length);
38         System.out.println("object -> string");
39         System.arraycopy(objectArray, 0, stringArray, 0, stringArray.length);
40         System.out.println("object -> string (modified)");
41         objectArray[4] = new ImplA();
42         try {
43             System.arraycopy(objectArray, 0, stringArray, 0,stringArray.length);
44         }
45         catch (ArrayStoreException ase) {
46             System.out.println("caught ArrayStoreException (expected)");
47         }
48     }
49 
50     static final int ARRAY_SIZE = 8;
51 
initByteArray(byte[] array)52     static void initByteArray(byte[] array) {
53         for (int i = 0; i < ARRAY_SIZE; i++) {
54             array[i] = (byte) i;
55         }
56     }
initShortArray(short[] array)57     static void initShortArray(short[] array) {
58         for (int i = 0; i < ARRAY_SIZE; i++) {
59             array[i] = (short) i;
60         }
61     }
initIntArray(int[] array)62     static void initIntArray(int[] array) {
63         for (int i = 0; i < ARRAY_SIZE; i++) {
64             array[i] = (int) i;
65         }
66     }
initLongArray(long[] array)67     static void initLongArray(long[] array) {
68         for (int i = 0; i < ARRAY_SIZE; i++) {
69             array[i] = (long) i;
70         }
71     }
initCharArray(char[] array)72     static void initCharArray(char[] array) {
73         for (int i = 0; i < ARRAY_SIZE; i++) {
74             array[i] = (char) i;
75         }
76     }
77 
78     /*
79      * Perform an array copy operation on primitive arrays with different
80      * element widths.
81      */
makeCopies(int srcPos, int dstPos, int length)82     static void makeCopies(int srcPos, int dstPos, int length) {
83         byte[] byteArray = new byte[ARRAY_SIZE];
84         short[] shortArray = new short[ARRAY_SIZE];
85         int[] intArray = new int[ARRAY_SIZE];
86         long[] longArray = new long[ARRAY_SIZE];
87         char[] charArray = new char[ARRAY_SIZE];
88 
89         initByteArray(byteArray);
90         initShortArray(shortArray);
91         initIntArray(intArray);
92         initLongArray(longArray);
93         initCharArray(charArray);
94 
95         System.arraycopy(byteArray, srcPos, byteArray, dstPos, length);
96         System.arraycopy(shortArray, srcPos, shortArray, dstPos, length);
97         System.arraycopy(intArray, srcPos, intArray, dstPos, length);
98         System.arraycopy(longArray, srcPos, longArray, dstPos, length);
99         System.arraycopy(charArray, srcPos, charArray, dstPos, length);
100 
101         for (int i = 0; i < ARRAY_SIZE; i++) {
102             if (intArray[i] != byteArray[i]) {
103                 System.out.println("mismatch int vs byte at " + i + " : " +
104                     Arrays.toString(byteArray));
105                 break;
106             } else if (intArray[i] != shortArray[i]) {
107                 System.out.println("mismatch int vs short at " + i + " : " +
108                     Arrays.toString(shortArray));
109                 break;
110             } else if (intArray[i] != longArray[i]) {
111                 System.out.println("mismatch int vs long at " + i + " : " +
112                     Arrays.toString(longArray));
113                 break;
114             } else if (intArray[i] != charArray[i]) {
115                 System.out.println("mismatch int vs char at " + i + " : " +
116                     Arrays.toString(charArray));
117                 break;
118             }
119         }
120 
121         System.out.println("copy: " + srcPos + "," + dstPos + "," + length +
122             ": " + Arrays.toString(intArray));
123     }
124 
testOverlappingMoves()125     public static void testOverlappingMoves() {
126         /* do nothing */
127         makeCopies(0, 0, 0);
128 
129         /* do more nothing */
130         makeCopies(0, 0, ARRAY_SIZE);
131 
132         /* copy forward, even alignment */
133         makeCopies(0, 2, 4);
134 
135         /* copy backward, even alignment */
136         makeCopies(2, 0, 4);
137 
138         /* copy forward, odd alignment */
139         makeCopies(1, 3, 4);
140 
141         /* copy backward, odd alignment */
142         makeCopies(3, 1, 4);
143 
144         /* copy backward, odd length */
145         makeCopies(3, 1, 5);
146 
147         /* copy forward, odd length */
148         makeCopies(1, 3, 5);
149 
150         /* copy forward, mixed alignment */
151         makeCopies(0, 3, 5);
152 
153         /* copy backward, mixed alignment */
154         makeCopies(3, 0, 5);
155 
156         /* copy forward, mixed alignment, trivial length */
157         makeCopies(0, 5, 1);
158     }
159 
testFloatAndDouble()160     private static void testFloatAndDouble() {
161         // Float & double copies have the same implementation as int & long. However, there are
162         // protective DCHECKs in the code (there is nothing unifying like ByteSizedArray or
163         // ShortSizedArray). Just test that we don't fail those checks.
164         final int len = 10;
165         System.arraycopy(new float[len], 0, new float[len], 0, len);
166         System.arraycopy(new double[len], 0, new double[len], 0, len);
167     }
168 }
169