| 1 |
/* |
| 2 |
* Written by members of JCP JSR-166 Expert Group and released to the |
| 3 |
* public domain. Use, modify, and redistribute this code in any way |
| 4 |
* without acknowledgement. Other contributors include Andrew Wright, |
| 5 |
* Jeffrey Hayes, Pat Fischer, Mike Judd. |
| 6 |
*/ |
| 7 |
|
| 8 |
import junit.framework.*; |
| 9 |
import java.util.concurrent.atomic.*; |
| 10 |
import java.io.*; |
| 11 |
|
| 12 |
public class AtomicIntegerArrayTest extends JSR166TestCase { |
| 13 |
|
| 14 |
public static void main (String[] args) { |
| 15 |
junit.textui.TestRunner.run (suite()); |
| 16 |
} |
| 17 |
public static Test suite() { |
| 18 |
return new TestSuite(AtomicIntegerArrayTest.class); |
| 19 |
} |
| 20 |
|
| 21 |
|
| 22 |
/** |
| 23 |
* constructor creates array of given size with all elements zero |
| 24 |
*/ |
| 25 |
public void testConstructor() { |
| 26 |
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); |
| 27 |
for (int i = 0; i < SIZE; ++i) |
| 28 |
assertEquals(0,ai.get(i)); |
| 29 |
} |
| 30 |
|
| 31 |
/** |
| 32 |
* get and set for out of bound indices throw IndexOutOfBoundsException |
| 33 |
*/ |
| 34 |
public void testIndexing(){ |
| 35 |
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); |
| 36 |
try { |
| 37 |
ai.get(SIZE); |
| 38 |
} catch(IndexOutOfBoundsException success){ |
| 39 |
} |
| 40 |
try { |
| 41 |
ai.get(-1); |
| 42 |
} catch(IndexOutOfBoundsException success){ |
| 43 |
} |
| 44 |
try { |
| 45 |
ai.set(SIZE, 0); |
| 46 |
} catch(IndexOutOfBoundsException success){ |
| 47 |
} |
| 48 |
try { |
| 49 |
ai.set(-1, 0); |
| 50 |
} catch(IndexOutOfBoundsException success){ |
| 51 |
} |
| 52 |
} |
| 53 |
|
| 54 |
/** |
| 55 |
* get returns the last value set at index |
| 56 |
*/ |
| 57 |
public void testGetSet() { |
| 58 |
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); |
| 59 |
for (int i = 0; i < SIZE; ++i) { |
| 60 |
ai.set(i, 1); |
| 61 |
assertEquals(1,ai.get(i)); |
| 62 |
ai.set(i, 2); |
| 63 |
assertEquals(2,ai.get(i)); |
| 64 |
ai.set(i, -3); |
| 65 |
assertEquals(-3,ai.get(i)); |
| 66 |
} |
| 67 |
} |
| 68 |
|
| 69 |
/** |
| 70 |
* compareAndSet succeeds in changing value if equal to expected else fails |
| 71 |
*/ |
| 72 |
public void testCompareAndSet() { |
| 73 |
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); |
| 74 |
for (int i = 0; i < SIZE; ++i) { |
| 75 |
ai.set(i, 1); |
| 76 |
assertTrue(ai.compareAndSet(i, 1,2)); |
| 77 |
assertTrue(ai.compareAndSet(i, 2,-4)); |
| 78 |
assertEquals(-4,ai.get(i)); |
| 79 |
assertFalse(ai.compareAndSet(i, -5,7)); |
| 80 |
assertFalse((7 == ai.get(i))); |
| 81 |
assertTrue(ai.compareAndSet(i, -4,7)); |
| 82 |
assertEquals(7,ai.get(i)); |
| 83 |
} |
| 84 |
} |
| 85 |
|
| 86 |
/** |
| 87 |
* compareAndSet in one thread enables another waiting for value |
| 88 |
* to succeed |
| 89 |
*/ |
| 90 |
public void testCompareAndSetInMultipleThreads() { |
| 91 |
final AtomicIntegerArray a = new AtomicIntegerArray(1); |
| 92 |
a.set(0, 1); |
| 93 |
Thread t = new Thread(new Runnable() { |
| 94 |
public void run() { |
| 95 |
while(!a.compareAndSet(0, 2, 3)) Thread.yield(); |
| 96 |
}}); |
| 97 |
try { |
| 98 |
t.start(); |
| 99 |
assertTrue(a.compareAndSet(0, 1, 2)); |
| 100 |
t.join(LONG_DELAY_MS); |
| 101 |
assertFalse(t.isAlive()); |
| 102 |
assertEquals(a.get(0), 3); |
| 103 |
} |
| 104 |
catch(Exception e) { |
| 105 |
unexpectedException(); |
| 106 |
} |
| 107 |
} |
| 108 |
|
| 109 |
/** |
| 110 |
* repeated weakCompareAndSet succeeds in changing value when equal |
| 111 |
* to expected |
| 112 |
*/ |
| 113 |
public void testWeakCompareAndSet() { |
| 114 |
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); |
| 115 |
for (int i = 0; i < SIZE; ++i) { |
| 116 |
ai.set(i, 1); |
| 117 |
while(!ai.weakCompareAndSet(i, 1,2)); |
| 118 |
while(!ai.weakCompareAndSet(i, 2,-4)); |
| 119 |
assertEquals(-4,ai.get(i)); |
| 120 |
while(!ai.weakCompareAndSet(i, -4,7)); |
| 121 |
assertEquals(7,ai.get(i)); |
| 122 |
} |
| 123 |
} |
| 124 |
|
| 125 |
/** |
| 126 |
* getAndSet returns previous value and sets to given value at given index |
| 127 |
*/ |
| 128 |
public void testGetAndSet() { |
| 129 |
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); |
| 130 |
for (int i = 0; i < SIZE; ++i) { |
| 131 |
ai.set(i, 1); |
| 132 |
assertEquals(1,ai.getAndSet(i,0)); |
| 133 |
assertEquals(0,ai.getAndSet(i,-10)); |
| 134 |
assertEquals(-10,ai.getAndSet(i,1)); |
| 135 |
} |
| 136 |
} |
| 137 |
|
| 138 |
/** |
| 139 |
* getAndAdd returns previous value and adds given value |
| 140 |
*/ |
| 141 |
public void testGetAndAdd() { |
| 142 |
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); |
| 143 |
for (int i = 0; i < SIZE; ++i) { |
| 144 |
ai.set(i, 1); |
| 145 |
assertEquals(1,ai.getAndAdd(i,2)); |
| 146 |
assertEquals(3,ai.get(i)); |
| 147 |
assertEquals(3,ai.getAndAdd(i,-4)); |
| 148 |
assertEquals(-1,ai.get(i)); |
| 149 |
} |
| 150 |
} |
| 151 |
|
| 152 |
/** |
| 153 |
* getAndDecrement returns previous value and decrements |
| 154 |
*/ |
| 155 |
public void testGetAndDecrement() { |
| 156 |
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); |
| 157 |
for (int i = 0; i < SIZE; ++i) { |
| 158 |
ai.set(i, 1); |
| 159 |
assertEquals(1,ai.getAndDecrement(i)); |
| 160 |
assertEquals(0,ai.getAndDecrement(i)); |
| 161 |
assertEquals(-1,ai.getAndDecrement(i)); |
| 162 |
} |
| 163 |
} |
| 164 |
|
| 165 |
/** |
| 166 |
* getAndIncrement returns previous value and increments |
| 167 |
*/ |
| 168 |
public void testGetAndIncrement() { |
| 169 |
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); |
| 170 |
for (int i = 0; i < SIZE; ++i) { |
| 171 |
ai.set(i, 1); |
| 172 |
assertEquals(1,ai.getAndIncrement(i)); |
| 173 |
assertEquals(2,ai.get(i)); |
| 174 |
ai.set(i,-2); |
| 175 |
assertEquals(-2,ai.getAndIncrement(i)); |
| 176 |
assertEquals(-1,ai.getAndIncrement(i)); |
| 177 |
assertEquals(0,ai.getAndIncrement(i)); |
| 178 |
assertEquals(1,ai.get(i)); |
| 179 |
} |
| 180 |
} |
| 181 |
|
| 182 |
/** |
| 183 |
* addAndGet adds given value to current, and returns current value |
| 184 |
*/ |
| 185 |
public void testAddAndGet() { |
| 186 |
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); |
| 187 |
for (int i = 0; i < SIZE; ++i) { |
| 188 |
ai.set(i, 1); |
| 189 |
assertEquals(3,ai.addAndGet(i,2)); |
| 190 |
assertEquals(3,ai.get(i)); |
| 191 |
assertEquals(-1,ai.addAndGet(i,-4)); |
| 192 |
assertEquals(-1,ai.get(i)); |
| 193 |
} |
| 194 |
} |
| 195 |
|
| 196 |
/** |
| 197 |
* decrementAndGet decrements and returns current value |
| 198 |
*/ |
| 199 |
public void testDecrementAndGet() { |
| 200 |
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); |
| 201 |
for (int i = 0; i < SIZE; ++i) { |
| 202 |
ai.set(i, 1); |
| 203 |
assertEquals(0,ai.decrementAndGet(i)); |
| 204 |
assertEquals(-1,ai.decrementAndGet(i)); |
| 205 |
assertEquals(-2,ai.decrementAndGet(i)); |
| 206 |
assertEquals(-2,ai.get(i)); |
| 207 |
} |
| 208 |
} |
| 209 |
|
| 210 |
/** |
| 211 |
* incrementAndGet increments and returns current value |
| 212 |
*/ |
| 213 |
public void testIncrementAndGet() { |
| 214 |
AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); |
| 215 |
for (int i = 0; i < SIZE; ++i) { |
| 216 |
ai.set(i, 1); |
| 217 |
assertEquals(2,ai.incrementAndGet(i)); |
| 218 |
assertEquals(2,ai.get(i)); |
| 219 |
ai.set(i, -2); |
| 220 |
assertEquals(-1,ai.incrementAndGet(i)); |
| 221 |
assertEquals(0,ai.incrementAndGet(i)); |
| 222 |
assertEquals(1,ai.incrementAndGet(i)); |
| 223 |
assertEquals(1,ai.get(i)); |
| 224 |
} |
| 225 |
} |
| 226 |
|
| 227 |
static final int COUNTDOWN = 100000; |
| 228 |
|
| 229 |
class Counter implements Runnable { |
| 230 |
final AtomicIntegerArray ai; |
| 231 |
volatile int counts; |
| 232 |
Counter(AtomicIntegerArray a) { ai = a; } |
| 233 |
public void run() { |
| 234 |
for (;;) { |
| 235 |
boolean done = true; |
| 236 |
for (int i = 0; i < ai.length(); ++i) { |
| 237 |
int v = ai.get(i); |
| 238 |
threadAssertTrue(v >= 0); |
| 239 |
if (v != 0) { |
| 240 |
done = false; |
| 241 |
if (ai.compareAndSet(i, v, v-1)) |
| 242 |
++counts; |
| 243 |
} |
| 244 |
} |
| 245 |
if (done) |
| 246 |
break; |
| 247 |
} |
| 248 |
} |
| 249 |
} |
| 250 |
|
| 251 |
/** |
| 252 |
* Multiple threads using same array of counters successfully |
| 253 |
* update a number of times equal to total count |
| 254 |
*/ |
| 255 |
public void testCountingInMultipleThreads() { |
| 256 |
try { |
| 257 |
final AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); |
| 258 |
for (int i = 0; i < SIZE; ++i) |
| 259 |
ai.set(i, COUNTDOWN); |
| 260 |
Counter c1 = new Counter(ai); |
| 261 |
Counter c2 = new Counter(ai); |
| 262 |
Thread t1 = new Thread(c1); |
| 263 |
Thread t2 = new Thread(c2); |
| 264 |
t1.start(); |
| 265 |
t2.start(); |
| 266 |
t1.join(); |
| 267 |
t2.join(); |
| 268 |
assertEquals(c1.counts+c2.counts, SIZE * COUNTDOWN); |
| 269 |
} |
| 270 |
catch(InterruptedException ie) { |
| 271 |
unexpectedException(); |
| 272 |
} |
| 273 |
} |
| 274 |
|
| 275 |
|
| 276 |
/** |
| 277 |
* a deserialized serialized array holds same values |
| 278 |
*/ |
| 279 |
public void testSerialization() { |
| 280 |
AtomicIntegerArray l = new AtomicIntegerArray(SIZE); |
| 281 |
for (int i = 0; i < SIZE; ++i) |
| 282 |
l.set(i, -i); |
| 283 |
|
| 284 |
try { |
| 285 |
ByteArrayOutputStream bout = new ByteArrayOutputStream(10000); |
| 286 |
ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout)); |
| 287 |
out.writeObject(l); |
| 288 |
out.close(); |
| 289 |
|
| 290 |
ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray()); |
| 291 |
ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin)); |
| 292 |
AtomicIntegerArray r = (AtomicIntegerArray) in.readObject(); |
| 293 |
for (int i = 0; i < SIZE; ++i) { |
| 294 |
assertEquals(l.get(i), r.get(i)); |
| 295 |
} |
| 296 |
} catch(Exception e){ |
| 297 |
e.printStackTrace(); |
| 298 |
unexpectedException(); |
| 299 |
} |
| 300 |
} |
| 301 |
|
| 302 |
} |
