1 |
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/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
3 |
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* Expert Group and released to the public domain, as explained at |
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* http://creativecommons.org/licenses/publicdomain |
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* http://creativecommons.org/publicdomain/zero/1.0/ |
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*/ |
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import junit.framework.*; |
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import java.util.concurrent.*; |
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import java.util.*; |
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< |
|
8 |
> |
import java.util.concurrent.ThreadLocalRandom; |
9 |
> |
import java.util.concurrent.atomic.AtomicLong; |
10 |
> |
import java.util.concurrent.atomic.AtomicInteger; |
11 |
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import java.util.concurrent.atomic.AtomicReference; |
12 |
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import java.util.concurrent.atomic.LongAdder; |
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|
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public class ThreadLocalRandomTest extends JSR166TestCase { |
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|
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public static void main(String[] args) { |
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junit.textui.TestRunner.run (suite()); |
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junit.textui.TestRunner.run(suite()); |
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} |
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public static Test suite() { |
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return new TestSuite(ThreadLocalRandomTest.class); |
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} |
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|
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/** |
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/* |
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* Testing coverage notes: |
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* |
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* We don't test randomness properties, but only that repeated |
29 |
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* across multiples of primes. |
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*/ |
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|
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// |
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// max numbers of calls to detect getting stuck on one value |
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static final int NCALLS = 10000; |
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|
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// max sampled int bound |
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static final int MAX_INT_BOUND = (1 << 28); |
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|
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// Max sampled long bound |
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> |
// max sampled long bound |
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static final long MAX_LONG_BOUND = (1L << 42); |
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|
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// Number of replications for other checks |
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static final int REPS = 20; |
43 |
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|
44 |
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/** |
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* setSeed throws UnsupportedOperationException |
46 |
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*/ |
52 |
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} |
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|
54 |
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/** |
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* Repeated calls to nextInt produce at least one different result |
55 |
> |
* Repeated calls to nextInt produce at least two distinct results |
56 |
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*/ |
57 |
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public void testNextInt() { |
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int f = ThreadLocalRandom.current().nextInt(); |
63 |
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} |
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|
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/** |
66 |
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* Repeated calls to nextLong produce at least one different result |
66 |
> |
* Repeated calls to nextLong produce at least two distinct results |
67 |
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*/ |
68 |
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public void testNextLong() { |
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long f = ThreadLocalRandom.current().nextLong(); |
73 |
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assertTrue(i < NCALLS); |
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} |
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|
70 |
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|
76 |
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/** |
77 |
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* Repeated calls to nextBoolean produce at least one different result |
77 |
> |
* Repeated calls to nextBoolean produce at least two distinct results |
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*/ |
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public void testNextBoolean() { |
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boolean f = ThreadLocalRandom.current().nextBoolean(); |
85 |
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} |
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|
87 |
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/** |
88 |
< |
* Repeated calls to nextFloat produce at least one different result |
88 |
> |
* Repeated calls to nextFloat produce at least two distinct results |
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*/ |
90 |
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public void testNextFloat() { |
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float f = ThreadLocalRandom.current().nextFloat(); |
96 |
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} |
97 |
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|
98 |
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/** |
99 |
< |
* Repeated calls to nextDouble produce at least one different result |
99 |
> |
* Repeated calls to nextDouble produce at least two distinct results |
100 |
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*/ |
101 |
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public void testNextDouble() { |
102 |
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double f = ThreadLocalRandom.current().nextDouble(); |
103 |
< |
double i = 0; |
103 |
> |
int i = 0; |
104 |
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while (i < NCALLS && ThreadLocalRandom.current().nextDouble() == f) |
105 |
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++i; |
106 |
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assertTrue(i < NCALLS); |
107 |
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} |
108 |
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|
109 |
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/** |
110 |
< |
* Repeated calls to nextGaussian produce at least one different result |
110 |
> |
* Repeated calls to nextGaussian produce at least two distinct results |
111 |
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*/ |
112 |
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public void testNextGaussian() { |
113 |
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double f = ThreadLocalRandom.current().nextGaussian(); |
117 |
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assertTrue(i < NCALLS); |
118 |
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} |
119 |
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|
115 |
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|
120 |
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/** |
121 |
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* nextInt(negative) throws IllegalArgumentException; |
121 |
> |
* nextInt(negative) throws IllegalArgumentException |
122 |
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*/ |
123 |
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public void testNextIntBoundedNeg() { |
124 |
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try { |
125 |
< |
int f = ThreadLocalRandom.current().nextInt(-17); |
125 |
> |
int f = ThreadLocalRandom.current().nextInt(-17); |
126 |
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shouldThrow(); |
127 |
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} catch (IllegalArgumentException success) {} |
128 |
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} |
129 |
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|
130 |
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/** |
131 |
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* nextInt(least >= bound) throws IllegalArgumentException; |
131 |
> |
* nextInt(least >= bound) throws IllegalArgumentException |
132 |
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*/ |
133 |
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public void testNextIntBadBounds() { |
134 |
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try { |
135 |
< |
int f = ThreadLocalRandom.current().nextInt(17, 2); |
135 |
> |
int f = ThreadLocalRandom.current().nextInt(17, 2); |
136 |
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shouldThrow(); |
137 |
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} catch (IllegalArgumentException success) {} |
138 |
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} |
139 |
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|
136 |
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|
140 |
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/** |
141 |
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* nextInt(bound) returns 0 <= value < bound; |
142 |
< |
* repeated calls produce at least one different result |
142 |
> |
* repeated calls produce at least two distinct results |
143 |
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*/ |
144 |
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public void testNextIntBounded() { |
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// sample bound space across prime number increments |
157 |
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} |
158 |
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} |
159 |
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|
157 |
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|
160 |
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/** |
161 |
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* nextInt(least, bound) returns least <= value < bound; |
162 |
< |
* repeated calls produce at least one different result |
162 |
> |
* repeated calls produce at least two distinct results |
163 |
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*/ |
164 |
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public void testNextIntBounded2() { |
165 |
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for (int least = -15485863; least < MAX_INT_BOUND; least += 524959) { |
179 |
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} |
180 |
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|
181 |
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/** |
182 |
< |
* nextLong(negative) throws IllegalArgumentException; |
182 |
> |
* nextLong(negative) throws IllegalArgumentException |
183 |
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*/ |
184 |
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public void testNextLongBoundedNeg() { |
185 |
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try { |
186 |
< |
long f = ThreadLocalRandom.current().nextLong(-17); |
186 |
> |
long f = ThreadLocalRandom.current().nextLong(-17); |
187 |
|
shouldThrow(); |
188 |
|
} catch (IllegalArgumentException success) {} |
189 |
|
} |
190 |
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|
191 |
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/** |
192 |
< |
* nextLong(least >= bound) throws IllegalArgumentException; |
192 |
> |
* nextLong(least >= bound) throws IllegalArgumentException |
193 |
|
*/ |
194 |
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public void testNextLongBadBounds() { |
195 |
|
try { |
196 |
< |
long f = ThreadLocalRandom.current().nextLong(17, 2); |
196 |
> |
long f = ThreadLocalRandom.current().nextLong(17, 2); |
197 |
|
shouldThrow(); |
198 |
|
} catch (IllegalArgumentException success) {} |
199 |
|
} |
200 |
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|
201 |
|
/** |
202 |
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* nextLong(bound) returns 0 <= value < bound; |
203 |
< |
* repeated calls produce at least one different result |
203 |
> |
* repeated calls produce at least two distinct results |
204 |
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*/ |
205 |
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public void testNextLongBounded() { |
206 |
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for (long bound = 2; bound < MAX_LONG_BOUND; bound += 15485863) { |
219 |
|
|
220 |
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/** |
221 |
|
* nextLong(least, bound) returns least <= value < bound; |
222 |
< |
* repeated calls produce at least one different result |
222 |
> |
* repeated calls produce at least two distinct results |
223 |
|
*/ |
224 |
|
public void testNextLongBounded2() { |
225 |
|
for (long least = -86028121; least < MAX_LONG_BOUND; least += 982451653L) { |
238 |
|
} |
239 |
|
} |
240 |
|
|
239 |
– |
|
241 |
|
/** |
242 |
|
* nextDouble(least, bound) returns least <= value < bound; |
243 |
< |
* repeated calls produce at least one different result |
243 |
> |
* repeated calls produce at least two distinct results |
244 |
|
*/ |
245 |
|
public void testNextDoubleBounded2() { |
246 |
|
for (double least = 0.0001; least < 1.0e20; least *= 8) { |
259 |
|
} |
260 |
|
} |
261 |
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|
262 |
+ |
/** |
263 |
+ |
* Different threads produce different pseudo-random sequences |
264 |
+ |
*/ |
265 |
+ |
public void testDifferentSequences() { |
266 |
+ |
// Don't use main thread's ThreadLocalRandom - it is likely to |
267 |
+ |
// be polluted by previous tests. |
268 |
+ |
final AtomicReference<ThreadLocalRandom> threadLocalRandom = |
269 |
+ |
new AtomicReference<ThreadLocalRandom>(); |
270 |
+ |
final AtomicLong rand = new AtomicLong(); |
271 |
+ |
|
272 |
+ |
long firstRand = 0; |
273 |
+ |
ThreadLocalRandom firstThreadLocalRandom = null; |
274 |
+ |
|
275 |
+ |
final CheckedRunnable getRandomState = new CheckedRunnable() { |
276 |
+ |
public void realRun() { |
277 |
+ |
ThreadLocalRandom current = ThreadLocalRandom.current(); |
278 |
+ |
assertSame(current, ThreadLocalRandom.current()); |
279 |
+ |
// test bug: the following is not guaranteed and not true in JDK8 |
280 |
+ |
// assertNotSame(current, threadLocalRandom.get()); |
281 |
+ |
rand.set(current.nextLong()); |
282 |
+ |
threadLocalRandom.set(current); |
283 |
+ |
}}; |
284 |
+ |
|
285 |
+ |
Thread first = newStartedThread(getRandomState); |
286 |
+ |
awaitTermination(first); |
287 |
+ |
firstRand = rand.get(); |
288 |
+ |
firstThreadLocalRandom = threadLocalRandom.get(); |
289 |
+ |
|
290 |
+ |
for (int i = 0; i < NCALLS; i++) { |
291 |
+ |
Thread t = newStartedThread(getRandomState); |
292 |
+ |
awaitTermination(t); |
293 |
+ |
if (firstRand != rand.get()) |
294 |
+ |
return; |
295 |
+ |
} |
296 |
+ |
fail("all threads generate the same pseudo-random sequence"); |
297 |
+ |
} |
298 |
+ |
|
299 |
+ |
/** |
300 |
+ |
* Invoking sized ints, long, doubles, with negative sizes throws |
301 |
+ |
* IllegalArgumentException |
302 |
+ |
*/ |
303 |
+ |
public void testBadStreamSize() { |
304 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
305 |
+ |
try { |
306 |
+ |
java.util.stream.IntStream x = r.ints(-1L); |
307 |
+ |
shouldThrow(); |
308 |
+ |
} catch (IllegalArgumentException success) {} |
309 |
+ |
try { |
310 |
+ |
java.util.stream.IntStream x = r.ints(-1L, 2, 3); |
311 |
+ |
shouldThrow(); |
312 |
+ |
} catch (IllegalArgumentException success) {} |
313 |
+ |
try { |
314 |
+ |
java.util.stream.LongStream x = r.longs(-1L); |
315 |
+ |
shouldThrow(); |
316 |
+ |
} catch (IllegalArgumentException success) {} |
317 |
+ |
try { |
318 |
+ |
java.util.stream.LongStream x = r.longs(-1L, -1L, 1L); |
319 |
+ |
shouldThrow(); |
320 |
+ |
} catch (IllegalArgumentException success) {} |
321 |
+ |
try { |
322 |
+ |
java.util.stream.DoubleStream x = r.doubles(-1L); |
323 |
+ |
shouldThrow(); |
324 |
+ |
} catch (IllegalArgumentException success) {} |
325 |
+ |
try { |
326 |
+ |
java.util.stream.DoubleStream x = r.doubles(-1L, .5, .6); |
327 |
+ |
shouldThrow(); |
328 |
+ |
} catch (IllegalArgumentException success) {} |
329 |
+ |
} |
330 |
+ |
|
331 |
+ |
/** |
332 |
+ |
* Invoking bounded ints, long, doubles, with illegal bounds throws |
333 |
+ |
* IllegalArgumentException |
334 |
+ |
*/ |
335 |
+ |
public void testBadStreamBounds() { |
336 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
337 |
+ |
try { |
338 |
+ |
java.util.stream.IntStream x = r.ints(2, 1); |
339 |
+ |
shouldThrow(); |
340 |
+ |
} catch (IllegalArgumentException success) {} |
341 |
+ |
try { |
342 |
+ |
java.util.stream.IntStream x = r.ints(10, 42, 42); |
343 |
+ |
shouldThrow(); |
344 |
+ |
} catch (IllegalArgumentException success) {} |
345 |
+ |
try { |
346 |
+ |
java.util.stream.LongStream x = r.longs(-1L, -1L); |
347 |
+ |
shouldThrow(); |
348 |
+ |
} catch (IllegalArgumentException success) {} |
349 |
+ |
try { |
350 |
+ |
java.util.stream.LongStream x = r.longs(10, 1L, -2L); |
351 |
+ |
shouldThrow(); |
352 |
+ |
} catch (IllegalArgumentException success) {} |
353 |
+ |
try { |
354 |
+ |
java.util.stream.DoubleStream x = r.doubles(0.0, 0.0); |
355 |
+ |
shouldThrow(); |
356 |
+ |
} catch (IllegalArgumentException success) {} |
357 |
+ |
try { |
358 |
+ |
java.util.stream.DoubleStream x = r.doubles(10, .5, .4); |
359 |
+ |
shouldThrow(); |
360 |
+ |
} catch (IllegalArgumentException success) {} |
361 |
+ |
} |
362 |
+ |
|
363 |
+ |
/** |
364 |
+ |
* A parallel sized stream of ints generates the given number of values |
365 |
+ |
*/ |
366 |
+ |
public void testIntsCount() { |
367 |
+ |
LongAdder counter = new LongAdder(); |
368 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
369 |
+ |
long size = 0; |
370 |
+ |
for (int reps = 0; reps < REPS; ++reps) { |
371 |
+ |
counter.reset(); |
372 |
+ |
r.ints(size).parallel().forEach(x -> {counter.increment();}); |
373 |
+ |
assertEquals(size, counter.sum()); |
374 |
+ |
size += 524959; |
375 |
+ |
} |
376 |
+ |
} |
377 |
+ |
|
378 |
+ |
/** |
379 |
+ |
* A parallel sized stream of longs generates the given number of values |
380 |
+ |
*/ |
381 |
+ |
public void testLongsCount() { |
382 |
+ |
LongAdder counter = new LongAdder(); |
383 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
384 |
+ |
long size = 0; |
385 |
+ |
for (int reps = 0; reps < REPS; ++reps) { |
386 |
+ |
counter.reset(); |
387 |
+ |
r.longs(size).parallel().forEach(x -> {counter.increment();}); |
388 |
+ |
assertEquals(size, counter.sum()); |
389 |
+ |
size += 524959; |
390 |
+ |
} |
391 |
+ |
} |
392 |
+ |
|
393 |
+ |
/** |
394 |
+ |
* A parallel sized stream of doubles generates the given number of values |
395 |
+ |
*/ |
396 |
+ |
public void testDoublesCount() { |
397 |
+ |
LongAdder counter = new LongAdder(); |
398 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
399 |
+ |
long size = 0; |
400 |
+ |
for (int reps = 0; reps < REPS; ++reps) { |
401 |
+ |
counter.reset(); |
402 |
+ |
r.doubles(size).parallel().forEach(x -> {counter.increment();}); |
403 |
+ |
assertEquals(size, counter.sum()); |
404 |
+ |
size += 524959; |
405 |
+ |
} |
406 |
+ |
} |
407 |
+ |
|
408 |
+ |
/** |
409 |
+ |
* Each of a parallel sized stream of bounded ints is within bounds |
410 |
+ |
*/ |
411 |
+ |
public void testBoundedInts() { |
412 |
+ |
AtomicInteger fails = new AtomicInteger(0); |
413 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
414 |
+ |
long size = 12345L; |
415 |
+ |
for (int least = -15485867; least < MAX_INT_BOUND; least += 524959) { |
416 |
+ |
for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 67867967) { |
417 |
+ |
final int lo = least, hi = bound; |
418 |
+ |
r.ints(size, lo, hi).parallel(). |
419 |
+ |
forEach(x -> {if (x < lo || x >= hi) |
420 |
+ |
fails.getAndIncrement(); }); |
421 |
+ |
} |
422 |
+ |
} |
423 |
+ |
assertEquals(0, fails.get()); |
424 |
+ |
} |
425 |
+ |
|
426 |
+ |
/** |
427 |
+ |
* Each of a parallel sized stream of bounded longs is within bounds |
428 |
+ |
*/ |
429 |
+ |
public void testBoundedLongs() { |
430 |
+ |
AtomicInteger fails = new AtomicInteger(0); |
431 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
432 |
+ |
long size = 123L; |
433 |
+ |
for (long least = -86028121; least < MAX_LONG_BOUND; least += 1982451653L) { |
434 |
+ |
for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) { |
435 |
+ |
final long lo = least, hi = bound; |
436 |
+ |
r.longs(size, lo, hi).parallel(). |
437 |
+ |
forEach(x -> {if (x < lo || x >= hi) |
438 |
+ |
fails.getAndIncrement(); }); |
439 |
+ |
} |
440 |
+ |
} |
441 |
+ |
assertEquals(0, fails.get()); |
442 |
+ |
} |
443 |
+ |
|
444 |
+ |
/** |
445 |
+ |
* Each of a parallel sized stream of bounded doubles is within bounds |
446 |
+ |
*/ |
447 |
+ |
public void testBoundedDoubles() { |
448 |
+ |
AtomicInteger fails = new AtomicInteger(0); |
449 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
450 |
+ |
long size = 456; |
451 |
+ |
for (double least = 0.00011; least < 1.0e20; least *= 9) { |
452 |
+ |
for (double bound = least * 1.0011; bound < 1.0e20; bound *= 17) { |
453 |
+ |
final double lo = least, hi = bound; |
454 |
+ |
r.doubles(size, lo, hi).parallel(). |
455 |
+ |
forEach(x -> {if (x < lo || x >= hi) |
456 |
+ |
fails.getAndIncrement(); }); |
457 |
+ |
} |
458 |
+ |
} |
459 |
+ |
assertEquals(0, fails.get()); |
460 |
+ |
} |
461 |
+ |
|
462 |
+ |
/** |
463 |
+ |
* A parallel unsized stream of ints generates at least 100 values |
464 |
+ |
*/ |
465 |
+ |
public void testUnsizedIntsCount() { |
466 |
+ |
LongAdder counter = new LongAdder(); |
467 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
468 |
+ |
long size = 100; |
469 |
+ |
r.ints().limit(size).parallel().forEach(x -> {counter.increment();}); |
470 |
+ |
assertEquals(size, counter.sum()); |
471 |
+ |
} |
472 |
+ |
|
473 |
+ |
/** |
474 |
+ |
* A parallel unsized stream of longs generates at least 100 values |
475 |
+ |
*/ |
476 |
+ |
public void testUnsizedLongsCount() { |
477 |
+ |
LongAdder counter = new LongAdder(); |
478 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
479 |
+ |
long size = 100; |
480 |
+ |
r.longs().limit(size).parallel().forEach(x -> {counter.increment();}); |
481 |
+ |
assertEquals(size, counter.sum()); |
482 |
+ |
} |
483 |
+ |
|
484 |
+ |
/** |
485 |
+ |
* A parallel unsized stream of doubles generates at least 100 values |
486 |
+ |
*/ |
487 |
+ |
public void testUnsizedDoublesCount() { |
488 |
+ |
LongAdder counter = new LongAdder(); |
489 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
490 |
+ |
long size = 100; |
491 |
+ |
r.doubles().limit(size).parallel().forEach(x -> {counter.increment();}); |
492 |
+ |
assertEquals(size, counter.sum()); |
493 |
+ |
} |
494 |
+ |
|
495 |
+ |
/** |
496 |
+ |
* A sequential unsized stream of ints generates at least 100 values |
497 |
+ |
*/ |
498 |
+ |
public void testUnsizedIntsCountSeq() { |
499 |
+ |
LongAdder counter = new LongAdder(); |
500 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
501 |
+ |
long size = 100; |
502 |
+ |
r.ints().limit(size).forEach(x -> {counter.increment();}); |
503 |
+ |
assertEquals(size, counter.sum()); |
504 |
+ |
} |
505 |
+ |
|
506 |
+ |
/** |
507 |
+ |
* A sequential unsized stream of longs generates at least 100 values |
508 |
+ |
*/ |
509 |
+ |
public void testUnsizedLongsCountSeq() { |
510 |
+ |
LongAdder counter = new LongAdder(); |
511 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
512 |
+ |
long size = 100; |
513 |
+ |
r.longs().limit(size).forEach(x -> {counter.increment();}); |
514 |
+ |
assertEquals(size, counter.sum()); |
515 |
+ |
} |
516 |
+ |
|
517 |
+ |
/** |
518 |
+ |
* A sequential unsized stream of doubles generates at least 100 values |
519 |
+ |
*/ |
520 |
+ |
public void testUnsizedDoublesCountSeq() { |
521 |
+ |
LongAdder counter = new LongAdder(); |
522 |
+ |
ThreadLocalRandom r = ThreadLocalRandom.current(); |
523 |
+ |
long size = 100; |
524 |
+ |
r.doubles().limit(size).forEach(x -> {counter.increment();}); |
525 |
+ |
assertEquals(size, counter.sum()); |
526 |
+ |
} |
527 |
|
|
528 |
|
} |