1 /*
  2  * Copyright (c) 2026, 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 import java.util.Arrays;
 26 import jdk.internal.value.ValueClass;
 27 
 28 public class ArchivedArrayLayoutsApp {
 29 
 30     public static class ArchivedData {
 31         Point[] pointArray;
 32         Point[] nullRestrictedArray;
 33         Point[] nullableAtomicArray;
 34     }
 35 
 36     public static value class Point implements Comparable<Point> {
 37         int x, y;
 38 
 39         public int compareTo(Point p) {
 40             return (x - p.x) - (y - p.y);
 41         }
 42 
 43         public String toString() {
 44             return "(" + x + ", " + y + ")";
 45         }
 46 
 47         public Point(int x, int y) {
 48             this.x = x;
 49             this.y = y;
 50         }
 51     }
 52 
 53     static ArchivedData archivedObjects;
 54     static boolean restored;
 55     static {
 56         if (archivedObjects == null) {
 57             restored = false;
 58             System.out.println("Not archived");
 59             archivedObjects = new ArchivedData();
 60 
 61             // Point cannot be flattened and so will create a RefArrayKlass
 62             archivedObjects.pointArray = new Point[3];
 63             archivedObjects.pointArray[0] = new Point(0, 1);
 64             archivedObjects.pointArray[1] = new Point(1, 0);
 65             archivedObjects.pointArray[2] = new Point(1, 1);
 66 
 67 
 68             // An array of null-restricted Point can be flattened
 69             archivedObjects.nullRestrictedArray = (Point[])ValueClass.newNullRestrictedAtomicArray(Point.class, 3, new Point(0, 0));
 70             archivedObjects.nullRestrictedArray[0] = new Point(0, 1);
 71             archivedObjects.nullRestrictedArray[1] = new Point(1, 0);
 72             archivedObjects.nullRestrictedArray[2] = new Point(1, 1);
 73 
 74             // A nullable array of Point cannot be flattened so it will a RefArrayKlass with a different layout
 75             archivedObjects.nullableAtomicArray = (Point[])ValueClass.newNullableAtomicArray(Point.class, 3);
 76             archivedObjects.nullableAtomicArray[0] = new Point(0, 1);
 77             archivedObjects.nullableAtomicArray[1] = new Point(1, 0);
 78             archivedObjects.nullableAtomicArray[2] = new Point(1, 1);
 79         } else {
 80             restored = true;
 81             System.out.println("Initialized from CDS");
 82         }
 83     }
 84 
 85 
 86     public static void checkFlat(Point[] p, boolean shouldBe) throws Exception {
 87         boolean isFlat = ValueClass.isFlatArray(p);
 88         if (isFlat && !shouldBe) {
 89             throw new RuntimeException("Should not be flat");
 90         }
 91         if (!isFlat && shouldBe) {
 92             throw new RuntimeException("Should be flat");
 93         }
 94     }
 95 
 96     public static void checkArray(Point[] p0, Point[] p1) {
 97         if (Arrays.compare(p0, p1) != 0) {
 98             for (Point i : p0) {
 99                 System.out.println(i);
100             }
101             System.out.println("vs");
102             for (Point i : p1) {
103                 System.out.println(i);
104             }
105             System.out.println();
106             throw new RuntimeException("Array not restored correctly");
107         }
108     }
109 
110     public static void main(String[] args) throws Exception {
111 
112         checkFlat(archivedObjects.pointArray, false);
113         checkFlat(archivedObjects.nullRestrictedArray, true);
114         checkFlat(archivedObjects.nullableAtomicArray, false);
115 
116         if (restored) {
117             Point[] runtimeArray = new Point[3];
118             runtimeArray[0] = new Point(0, 1);
119             runtimeArray[1] = new Point(1, 0);
120             runtimeArray[2] = new Point(1, 2);
121 
122             checkArray(archivedObjects.pointArray, runtimeArray);
123             checkArray(archivedObjects.nullRestrictedArray, runtimeArray);
124             checkArray(archivedObjects.nullableAtomicArray, runtimeArray);
125         }
126 
127         System.out.println("PASSED");
128     }
129 }