1 /*
2  * Written by Doug Lea with assistance from members of JCP JSR-166
3  * Expert Group and released to the public domain, as explained at
4  * http://creativecommons.org/publicdomain/zero/1.0/
5  */
6 
7 package jsr166;
8 
9 import java.util.concurrent.ThreadLocalRandom;
10 import java.util.concurrent.atomic.AtomicInteger;
11 import java.util.concurrent.atomic.LongAdder;
12 
13 import junit.framework.Test;
14 import junit.framework.TestSuite;
15 
16 public class ThreadLocalRandom8Test extends JSR166TestCase {
17 
18     // android-note: Removed because the CTS runner does a bad job of
19     // retrying tests that have suite() declarations.
20     //
21     // public static void main(String[] args) {
22     //     main(suite(), args);
23     // }
24     // public static Test suite() {
25     //     return new TestSuite(ThreadLocalRandom8Test.class);
26     // }
27 
28     // max sampled int bound
29     static final int MAX_INT_BOUND = (1 << 26);
30 
31     // max sampled long bound
32     static final long MAX_LONG_BOUND = (1L << 42);
33 
34     // Number of replications for other checks
35     static final int REPS =
36         Integer.getInteger("ThreadLocalRandom8Test.reps", 4);
37 
38     /**
39      * Invoking sized ints, long, doubles, with negative sizes throws
40      * IllegalArgumentException
41      */
testBadStreamSize()42     public void testBadStreamSize() {
43         ThreadLocalRandom r = ThreadLocalRandom.current();
44         Runnable[] throwingActions = {
45             () -> r.ints(-1L),
46             () -> r.ints(-1L, 2, 3),
47             () -> r.longs(-1L),
48             () -> r.longs(-1L, -1L, 1L),
49             () -> r.doubles(-1L),
50             () -> r.doubles(-1L, .5, .6),
51         };
52         assertThrows(IllegalArgumentException.class, throwingActions);
53     }
54 
55     /**
56      * Invoking bounded ints, long, doubles, with illegal bounds throws
57      * IllegalArgumentException
58      */
testBadStreamBounds()59     public void testBadStreamBounds() {
60         ThreadLocalRandom r = ThreadLocalRandom.current();
61         Runnable[] throwingActions = {
62             () -> r.ints(2, 1),
63             () -> r.ints(10, 42, 42),
64             () -> r.longs(-1L, -1L),
65             () -> r.longs(10, 1L, -2L),
66             () -> r.doubles(0.0, 0.0),
67             () -> r.doubles(10, .5, .4),
68         };
69         assertThrows(IllegalArgumentException.class, throwingActions);
70     }
71 
72     /**
73      * A parallel sized stream of ints generates the given number of values
74      */
testIntsCount()75     public void testIntsCount() {
76         LongAdder counter = new LongAdder();
77         ThreadLocalRandom r = ThreadLocalRandom.current();
78         long size = 0;
79         for (int reps = 0; reps < REPS; ++reps) {
80             counter.reset();
81             r.ints(size).parallel().forEach(x -> counter.increment());
82             assertEquals(size, counter.sum());
83             size += 524959;
84         }
85     }
86 
87     /**
88      * A parallel sized stream of longs generates the given number of values
89      */
testLongsCount()90     public void testLongsCount() {
91         LongAdder counter = new LongAdder();
92         ThreadLocalRandom r = ThreadLocalRandom.current();
93         long size = 0;
94         for (int reps = 0; reps < REPS; ++reps) {
95             counter.reset();
96             r.longs(size).parallel().forEach(x -> counter.increment());
97             assertEquals(size, counter.sum());
98             size += 524959;
99         }
100     }
101 
102     /**
103      * A parallel sized stream of doubles generates the given number of values
104      */
testDoublesCount()105     public void testDoublesCount() {
106         LongAdder counter = new LongAdder();
107         ThreadLocalRandom r = ThreadLocalRandom.current();
108         long size = 0;
109         for (int reps = 0; reps < REPS; ++reps) {
110             counter.reset();
111             r.doubles(size).parallel().forEach(x -> counter.increment());
112             assertEquals(size, counter.sum());
113             size += 524959;
114         }
115     }
116 
117     /**
118      * Each of a parallel sized stream of bounded ints is within bounds
119      */
testBoundedInts()120     public void testBoundedInts() {
121         AtomicInteger fails = new AtomicInteger(0);
122         ThreadLocalRandom r = ThreadLocalRandom.current();
123         long size = 12345L;
124         for (int least = -15485867; least < MAX_INT_BOUND; least += 524959) {
125             for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 67867967) {
126                 final int lo = least, hi = bound;
127                 r.ints(size, lo, hi).parallel().forEach(
128                     x -> {
129                         if (x < lo || x >= hi)
130                             fails.getAndIncrement(); });
131             }
132         }
133         assertEquals(0, fails.get());
134     }
135 
136     /**
137      * Each of a parallel sized stream of bounded longs is within bounds
138      */
testBoundedLongs()139     public void testBoundedLongs() {
140         AtomicInteger fails = new AtomicInteger(0);
141         ThreadLocalRandom r = ThreadLocalRandom.current();
142         long size = 123L;
143         for (long least = -86028121; least < MAX_LONG_BOUND; least += 1982451653L) {
144             for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) {
145                 final long lo = least, hi = bound;
146                 r.longs(size, lo, hi).parallel().forEach(
147                     x -> {
148                         if (x < lo || x >= hi)
149                             fails.getAndIncrement(); });
150             }
151         }
152         assertEquals(0, fails.get());
153     }
154 
155     /**
156      * Each of a parallel sized stream of bounded doubles is within bounds
157      */
testBoundedDoubles()158     public void testBoundedDoubles() {
159         AtomicInteger fails = new AtomicInteger(0);
160         ThreadLocalRandom r = ThreadLocalRandom.current();
161         long size = 456;
162         for (double least = 0.00011; least < 1.0e20; least *= 9) {
163             for (double bound = least * 1.0011; bound < 1.0e20; bound *= 17) {
164                 final double lo = least, hi = bound;
165                 r.doubles(size, lo, hi).parallel().forEach(
166                     x -> {
167                         if (x < lo || x >= hi)
168                             fails.getAndIncrement(); });
169             }
170         }
171         assertEquals(0, fails.get());
172     }
173 
174     /**
175      * A parallel unsized stream of ints generates at least 100 values
176      */
testUnsizedIntsCount()177     public void testUnsizedIntsCount() {
178         LongAdder counter = new LongAdder();
179         ThreadLocalRandom r = ThreadLocalRandom.current();
180         long size = 100;
181         r.ints().limit(size).parallel().forEach(x -> counter.increment());
182         assertEquals(size, counter.sum());
183     }
184 
185     /**
186      * A parallel unsized stream of longs generates at least 100 values
187      */
testUnsizedLongsCount()188     public void testUnsizedLongsCount() {
189         LongAdder counter = new LongAdder();
190         ThreadLocalRandom r = ThreadLocalRandom.current();
191         long size = 100;
192         r.longs().limit(size).parallel().forEach(x -> counter.increment());
193         assertEquals(size, counter.sum());
194     }
195 
196     /**
197      * A parallel unsized stream of doubles generates at least 100 values
198      */
testUnsizedDoublesCount()199     public void testUnsizedDoublesCount() {
200         LongAdder counter = new LongAdder();
201         ThreadLocalRandom r = ThreadLocalRandom.current();
202         long size = 100;
203         r.doubles().limit(size).parallel().forEach(x -> counter.increment());
204         assertEquals(size, counter.sum());
205     }
206 
207     /**
208      * A sequential unsized stream of ints generates at least 100 values
209      */
testUnsizedIntsCountSeq()210     public void testUnsizedIntsCountSeq() {
211         LongAdder counter = new LongAdder();
212         ThreadLocalRandom r = ThreadLocalRandom.current();
213         long size = 100;
214         r.ints().limit(size).forEach(x -> counter.increment());
215         assertEquals(size, counter.sum());
216     }
217 
218     /**
219      * A sequential unsized stream of longs generates at least 100 values
220      */
testUnsizedLongsCountSeq()221     public void testUnsizedLongsCountSeq() {
222         LongAdder counter = new LongAdder();
223         ThreadLocalRandom r = ThreadLocalRandom.current();
224         long size = 100;
225         r.longs().limit(size).forEach(x -> counter.increment());
226         assertEquals(size, counter.sum());
227     }
228 
229     /**
230      * A sequential unsized stream of doubles generates at least 100 values
231      */
testUnsizedDoublesCountSeq()232     public void testUnsizedDoublesCountSeq() {
233         LongAdder counter = new LongAdder();
234         ThreadLocalRandom r = ThreadLocalRandom.current();
235         long size = 100;
236         r.doubles().limit(size).forEach(x -> counter.increment());
237         assertEquals(size, counter.sum());
238     }
239 
240 }
241