1/* 2 * Copyright 2016 Google, Inc. 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 * @test 26 * @bug 8148174 27 * @summary brittle white box test of internal array management 28 * @run testng ArrayManagement 29 */ 30 31import java.lang.reflect.Field; 32import java.util.AbstractList; 33import java.util.Vector; 34import java.util.Collections; 35import java.util.List; 36import java.util.SplittableRandom; 37 38import org.testng.annotations.Test; 39import static org.testng.Assert.*; 40 41public class ArrayManagement { 42 43 /** 44 * A Vector that exposes all protected elements, and checks class 45 * invariants. 46 */ 47 static class PublicVector<E> extends Vector<E> { 48 public PublicVector() { super(); } 49 public PublicVector(int capacity) { super(capacity); } 50 public PublicVector(int capacity, int capacityIncrement) { 51 super(capacity, capacityIncrement); 52 } 53 public Object[] elementData() { return elementData; } 54 public int modCount() { return modCount; } 55 public int capacityIncrement() { return capacityIncrement; } 56 public int capacity() { return elementData.length; } 57 58 public void ensureCapacity(int minCapacity) { 59 int oldCapacity = capacity(); 60 int oldModCount = modCount(); 61 super.ensureCapacity(minCapacity); 62 assertTrue(capacity() >= minCapacity); 63 if (minCapacity <= oldCapacity) 64 assertEquals(capacity(), oldCapacity); 65 if (minCapacity > 0) 66 assertEquals(modCount(), oldModCount + 1); 67 } 68 } 69 70 static final int DEFAULT_CAPACITY = 10; 71 static final SplittableRandom rnd = new SplittableRandom(); 72 73 static int newCapacity(int oldCapacity) { 74 return 2 * oldCapacity; 75 } 76 77 static List<Object> singletonList() { 78 return Collections.singletonList(Boolean.TRUE); 79 } 80 81 /** Opportunistically randomly test various add operations. */ 82 static void addOneElement(PublicVector<Object> list) { 83 int size = list.size(); 84 int modCount = list.modCount(); 85 switch (rnd.nextInt(4)) { 86 case 0: assertTrue(list.add(Boolean.TRUE)); break; 87 case 1: list.add(size, Boolean.TRUE); break; 88 case 2: assertTrue(list.addAll(singletonList())); break; 89 case 3: assertTrue(list.addAll(size, singletonList())); break; 90 default: throw new AssertionError(); 91 } 92 assertEquals(list.modCount(), modCount + 1); 93 assertEquals(list.size(), size + 1); 94 } 95 96 @Test public void defaultCapacity() { 97 PublicVector<Object> list = new PublicVector<>(); 98 assertEquals(new PublicVector<Object>().capacity(), DEFAULT_CAPACITY); 99 for (int i = 0; i < DEFAULT_CAPACITY; i++) { 100 addOneElement(list); 101 assertEquals(list.capacity(), DEFAULT_CAPACITY); 102 } 103 addOneElement(list); 104 assertEquals(list.capacity(), newCapacity(DEFAULT_CAPACITY)); 105 } 106 107 @Test public void defaultCapacityEnsureCapacity() { 108 PublicVector<Object> list = new PublicVector<>(); 109 for (int i = 0; i <= DEFAULT_CAPACITY; i++) { 110 list.ensureCapacity(i); // no-op! 111 assertEquals(list.capacity(), DEFAULT_CAPACITY); 112 } 113 for (int i = 0; i < DEFAULT_CAPACITY; i++) { 114 addOneElement(list); 115 assertEquals(list.capacity(), DEFAULT_CAPACITY); 116 } 117 addOneElement(list); 118 assertEquals(list.capacity(), newCapacity(DEFAULT_CAPACITY)); 119 { 120 int capacity = list.capacity(); 121 list.ensureCapacity(capacity + 1); 122 assertEquals(list.capacity(), newCapacity(capacity)); 123 } 124 { 125 int capacity = list.capacity(); 126 list.ensureCapacity(3 * capacity); 127 assertEquals(list.capacity(), 3 * capacity); 128 } 129 } 130 131 @Test public void ensureCapacityBeyondDefaultCapacity() { 132 PublicVector<Object> list = new PublicVector<>(); 133 list.ensureCapacity(DEFAULT_CAPACITY + 1); 134 assertEquals(list.capacity(), newCapacity(DEFAULT_CAPACITY)); 135 } 136 137 @Test public void explicitZeroCapacity() { 138 PublicVector<Object> list = new PublicVector<>(0); 139 assertEquals(list.capacity(), 0); 140 addOneElement(list); 141 assertEquals(list.capacity(), 1); 142 addOneElement(list); 143 assertEquals(list.capacity(), 2); 144 addOneElement(list); 145 assertEquals(list.capacity(), 4); 146 addOneElement(list); 147 assertEquals(list.capacity(), 4); 148 addOneElement(list); 149 assertEquals(list.capacity(), 8); 150 addOneElement(list); 151 assertEquals(list.capacity(), 8); 152 addOneElement(list); 153 assertEquals(list.capacity(), 8); 154 list.clear(); 155 assertEquals(list.capacity(), 8); 156 } 157 158 @Test public void explicitZeroCapacityWithCapacityIncrement() { 159 PublicVector<Object> list = new PublicVector<>(0, 2); 160 assertEquals(list.capacity(), 0); 161 addOneElement(list); 162 assertEquals(list.capacity(), 2); 163 addOneElement(list); 164 assertEquals(list.capacity(), 2); 165 addOneElement(list); 166 assertEquals(list.capacity(), 4); 167 addOneElement(list); 168 assertEquals(list.capacity(), 4); 169 addOneElement(list); 170 assertEquals(list.capacity(), 6); 171 addOneElement(list); 172 assertEquals(list.capacity(), 6); 173 addOneElement(list); 174 assertEquals(list.capacity(), 8); 175 list.clear(); 176 assertEquals(list.capacity(), 8); 177 } 178 179 @Test public void explicitLargeCapacity() { 180 int n = DEFAULT_CAPACITY * 3; 181 PublicVector<Object> list = new PublicVector<>(n); 182 assertEquals(list.capacity(), n); 183 list.ensureCapacity(0); 184 list.ensureCapacity(n); 185 for (int i = 0; i < n; i++) addOneElement(list); 186 assertEquals(list.capacity(), n); 187 188 addOneElement(list); 189 assertEquals(list.capacity(), newCapacity(n)); 190 } 191 192 @Test public void explicitLargeCapacityWithCapacityIncrement() { 193 int n = DEFAULT_CAPACITY * 3; 194 PublicVector<Object> list = new PublicVector<>(n, 2); 195 assertEquals(list.capacity(), n); 196 list.ensureCapacity(0); 197 list.ensureCapacity(n); 198 for (int i = 0; i < n; i++) addOneElement(list); 199 assertEquals(list.capacity(), n); 200 201 addOneElement(list); 202 assertEquals(list.capacity(), n + 2); 203 } 204 205 @Test public void emptyArraysAreNotShared() { 206 assertNotSame(new PublicVector<Object>(0).elementData(), 207 new PublicVector<Object>(0).elementData()); 208 } 209 210 @Test public void negativeCapacity() { 211 for (int capacity : new int[] { -1, Integer.MIN_VALUE }) { 212 try { 213 new Vector<Object>(capacity); 214 fail("should throw"); 215 } catch (IllegalArgumentException success) {} 216 } 217 } 218} 219