test/tck/SplittableRandomTest.java

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

import java.util.Arrays;
import java.util.List;
import java.util.SplittableRandom;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.LongAdder;
import java.lang.reflect.Method;
import java.util.function.Predicate;
import java.util.stream.Collectors;
import java.util.stream.DoubleStream;
import java.util.stream.IntStream;
import java.util.stream.LongStream;

import junit.framework.Test;
import junit.framework.TestSuite;

public class SplittableRandomTest extends JSR166TestCase {

    public static void main(String[] args) {
        main(suite(), args);
    }
    public static Test suite() {
        return new TestSuite(SplittableRandomTest.class);
    }

    /*
     * Testing coverage notes:
     *
     * 1. Many of the test methods are adapted from ThreadLocalRandomTest.
     *
     * 2. These tests do not check for random number generator quality.
     * But we check for minimal API compliance by requiring that
     * repeated calls to nextX methods, up to NCALLS tries, produce at
     * least two distinct results. (In some possible universe, a
     * "correct" implementation might fail, but the odds are vastly
     * less than that of encountering a hardware failure while running
     * the test.) For bounded nextX methods, we sample various
     * intervals across multiples of primes. In other tests, we repeat
     * under REPS different values.
     */

    // max numbers of calls to detect getting stuck on one value
    static final int NCALLS = 10000;

    // max sampled int bound
    static final int MAX_INT_BOUND = (1 << 26);

    // max sampled long bound
    static final long MAX_LONG_BOUND = (1L << 40);

    // Number of replications for other checks
    static final int REPS =
        Integer.getInteger("SplittableRandomTest.reps", 4);

    /**
     * Repeated calls to nextInt produce at least two distinct results
     */
    public void testNextInt() {
        SplittableRandom sr = new SplittableRandom();
        int f = sr.nextInt();
        int i = 0;
        while (i < NCALLS && sr.nextInt() == f)
            ++i;
        assertTrue(i < NCALLS);
    }

    /**
     * Repeated calls to nextLong produce at least two distinct results
     */
    public void testNextLong() {
        SplittableRandom sr = new SplittableRandom();
        long f = sr.nextLong();
        int i = 0;
        while (i < NCALLS && sr.nextLong() == f)
            ++i;
        assertTrue(i < NCALLS);
    }

    /**
     * Repeated calls to nextDouble produce at least two distinct results
     */
    public void testNextDouble() {
        SplittableRandom sr = new SplittableRandom();
        double f = sr.nextDouble();
        int i = 0;
        while (i < NCALLS && sr.nextDouble() == f)
            ++i;
        assertTrue(i < NCALLS);
    }

    /**
     * Two SplittableRandoms created with the same seed produce the
     * same values for nextLong.
     */
    public void testSeedConstructor() {
        for (long seed = 2; seed < MAX_LONG_BOUND; seed += 15485863) {
            SplittableRandom sr1 = new SplittableRandom(seed);
            SplittableRandom sr2 = new SplittableRandom(seed);
            for (int i = 0; i < REPS; ++i)
                assertEquals(sr1.nextLong(), sr2.nextLong());
        }
    }

    /**
     * A SplittableRandom produced by split() of a default-constructed
     * SplittableRandom generates a different sequence
     */
    public void testSplit1() {
        SplittableRandom sr = new SplittableRandom();
        for (int reps = 0; reps < REPS; ++reps) {
            SplittableRandom sc = sr.split();
            int i = 0;
            while (i < NCALLS && sr.nextLong() == sc.nextLong())
                ++i;
            assertTrue(i < NCALLS);
        }
    }

    /**
     * A SplittableRandom produced by split() of a seeded-constructed
     * SplittableRandom generates a different sequence
     */
    public void testSplit2() {
        SplittableRandom sr = new SplittableRandom(12345);
        for (int reps = 0; reps < REPS; ++reps) {
            SplittableRandom sc = sr.split();
            int i = 0;
            while (i < NCALLS && sr.nextLong() == sc.nextLong())
                ++i;
            assertTrue(i < NCALLS);
        }
    }

    /**
     * nextInt(non-positive) throws IllegalArgumentException
     */
    public void testNextIntBoundNonPositive() {
        SplittableRandom sr = new SplittableRandom();
        assertThrows(
            IllegalArgumentException.class,
            () -> sr.nextInt(-17),
            () -> sr.nextInt(0),
            () -> sr.nextInt(Integer.MIN_VALUE));
    }

    /**
     * nextInt(least >= bound) throws IllegalArgumentException
     */
    public void testNextIntBadBounds() {
        SplittableRandom sr = new SplittableRandom();
        assertThrows(
            IllegalArgumentException.class,
            () -> sr.nextInt(17, 2),
            () -> sr.nextInt(-42, -42),
            () -> sr.nextInt(Integer.MAX_VALUE, Integer.MIN_VALUE));
    }

    /**
     * nextInt(bound) returns 0 <= value < bound;
     * repeated calls produce at least two distinct results
     */
    public void testNextIntBounded() {
        SplittableRandom sr = new SplittableRandom();
        for (int i = 0; i < 2; i++) assertEquals(0, sr.nextInt(1));
        // sample bound space across prime number increments
        for (int bound = 2; bound < MAX_INT_BOUND; bound += 524959) {
            int f = sr.nextInt(bound);
            assertTrue(0 <= f && f < bound);
            int i = 0;
            int j;
            while (i < NCALLS &&
                   (j = sr.nextInt(bound)) == f) {
                assertTrue(0 <= j && j < bound);
                ++i;
            }
            assertTrue(i < NCALLS);
        }
    }

    /**
     * nextInt(least, bound) returns least <= value < bound;
     * repeated calls produce at least two distinct results
     */
    public void testNextIntBounded2() {
        SplittableRandom sr = new SplittableRandom();
        for (int least = -15485863; least < MAX_INT_BOUND; least += 524959) {
            for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 49979687) {
                int f = sr.nextInt(least, bound);
                assertTrue(least <= f && f < bound);
                int i = 0;
                int j;
                while (i < NCALLS &&
                       (j = sr.nextInt(least, bound)) == f) {
                    assertTrue(least <= j && j < bound);
                    ++i;
                }
                assertTrue(i < NCALLS);
            }
        }
    }

    /**
     * nextLong(non-positive) throws IllegalArgumentException
     */
    public void testNextLongBoundNonPositive() {
        SplittableRandom sr = new SplittableRandom();
        assertThrows(
            IllegalArgumentException.class,
            () -> sr.nextLong(-17L),
            () -> sr.nextLong(0L),
            () -> sr.nextLong(Long.MIN_VALUE));
    }

    /**
     * nextLong(least >= bound) throws IllegalArgumentException
     */
    public void testNextLongBadBounds() {
        SplittableRandom sr = new SplittableRandom();
        assertThrows(
            IllegalArgumentException.class,
            () -> sr.nextLong(17L, 2L),
            () -> sr.nextLong(-42L, -42L),
            () -> sr.nextLong(Long.MAX_VALUE, Long.MIN_VALUE));
    }

    /**
     * nextLong(bound) returns 0 <= value < bound;
     * repeated calls produce at least two distinct results
     */
    public void testNextLongBounded() {
        SplittableRandom sr = new SplittableRandom();
        for (int i = 0; i < 2; i++) assertEquals(0L, sr.nextLong(1L));
        for (long bound = 2; bound < MAX_LONG_BOUND; bound += 15485863) {
            long f = sr.nextLong(bound);
            assertTrue(0 <= f && f < bound);
            int i = 0;
            long j;
            while (i < NCALLS &&
                   (j = sr.nextLong(bound)) == f) {
                assertTrue(0 <= j && j < bound);
                ++i;
            }
            assertTrue(i < NCALLS);
        }
    }

    /**
     * nextLong(least, bound) returns least <= value < bound;
     * repeated calls produce at least two distinct results
     */
    public void testNextLongBounded2() {
        SplittableRandom sr = new SplittableRandom();
        for (long least = -86028121; least < MAX_LONG_BOUND; least += 982451653L) {
            for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) {
                long f = sr.nextLong(least, bound);
                assertTrue(least <= f && f < bound);
                int i = 0;
                long j;
                while (i < NCALLS &&
                       (j = sr.nextLong(least, bound)) == f) {
                    assertTrue(least <= j && j < bound);
                    ++i;
                }
                assertTrue(i < NCALLS);
            }
        }
    }

    /**
     * nextDouble(non-positive) throws IllegalArgumentException
     */
    public void testNextDoubleBoundNonPositive() {
        SplittableRandom sr = new SplittableRandom();
        assertThrows(
            IllegalArgumentException.class,
            () -> sr.nextDouble(-17.0d),
            () -> sr.nextDouble(0.0d),
            () -> sr.nextDouble(-Double.MIN_VALUE),
            () -> sr.nextDouble(Double.NEGATIVE_INFINITY),
            () -> sr.nextDouble(Double.NaN));
    }

    /**
     * nextDouble(! (least < bound)) throws IllegalArgumentException
     */
    public void testNextDoubleBadBounds() {
        SplittableRandom sr = new SplittableRandom();
        assertThrows(
            IllegalArgumentException.class,
            () -> sr.nextDouble(17.0d, 2.0d),
            () -> sr.nextDouble(-42.0d, -42.0d),
            () -> sr.nextDouble(Double.MAX_VALUE, Double.MIN_VALUE),
            () -> sr.nextDouble(Double.NaN, 0.0d),
            () -> sr.nextDouble(0.0d, Double.NaN));
    }

    // TODO: Test infinite bounds!
    //() -> sr.nextDouble(Double.NEGATIVE_INFINITY, 0.0d),
    //() -> sr.nextDouble(0.0d, Double.POSITIVE_INFINITY),

    /**
     * nextDouble(least, bound) returns least <= value < bound;
     * repeated calls produce at least two distinct results
     */
    public void testNextDoubleBounded2() {
        SplittableRandom sr = new SplittableRandom();
        for (double least = 0.0001; least < 1.0e20; least *= 8) {
            for (double bound = least * 1.001; bound < 1.0e20; bound *= 16) {
                double f = sr.nextDouble(least, bound);
                assertTrue(least <= f && f < bound);
                int i = 0;
                double j;
                while (i < NCALLS &&
                       (j = sr.nextDouble(least, bound)) == f) {
                    assertTrue(least <= j && j < bound);
                    ++i;
                }
                assertTrue(i < NCALLS);
            }
        }
    }

    /**
     * Invoking sized ints, long, doubles, with negative sizes throws
     * IllegalArgumentException
     */
    public void testBadStreamSize() {
        SplittableRandom r = new SplittableRandom();
        assertThrows(
            IllegalArgumentException.class,
            () -> { IntStream unused = r.ints(-1L); },
            () -> { IntStream unused = r.ints(-1L, 2, 3); },
            () -> { LongStream unused = r.longs(-1L); },
            () -> { LongStream unused = r.longs(-1L, -1L, 1L); },
            () -> { DoubleStream unused = r.doubles(-1L); },
            () -> { DoubleStream unused = r.doubles(-1L, .5, .6); });
    }

    /**
     * Invoking bounded ints, long, doubles, with illegal bounds throws
     * IllegalArgumentException
     */
    public void testBadStreamBounds() {
        SplittableRandom r = new SplittableRandom();
        assertThrows(
            IllegalArgumentException.class,
            () -> { IntStream unused = r.ints(2, 1); },
            () -> { IntStream unused = r.ints(10, 42, 42); },
            () -> { LongStream unused = r.longs(-1L, -1L); },
            () -> { LongStream unused = r.longs(10, 1L, -2L); },
            () -> { DoubleStream unused = r.doubles(0.0, 0.0); },
            () -> { DoubleStream unused = r.doubles(10, .5, .4); });
    }

    /**
     * A parallel sized stream of ints generates the given number of values
     */
    public void testIntsCount() {
        LongAdder counter = new LongAdder();
        SplittableRandom r = new SplittableRandom();
        long size = 0;
        for (int reps = 0; reps < REPS; ++reps) {
            counter.reset();
            r.ints(size).parallel().forEach(x -> counter.increment());
            assertEquals(size, counter.sum());
            size += 524959;
        }
    }

    /**
     * A parallel sized stream of longs generates the given number of values
     */
    public void testLongsCount() {
        LongAdder counter = new LongAdder();
        SplittableRandom r = new SplittableRandom();
        long size = 0;
        for (int reps = 0; reps < REPS; ++reps) {
            counter.reset();
            r.longs(size).parallel().forEach(x -> counter.increment());
            assertEquals(size, counter.sum());
            size += 524959;
        }
    }

    /**
     * A parallel sized stream of doubles generates the given number of values
     */
    public void testDoublesCount() {
        LongAdder counter = new LongAdder();
        SplittableRandom r = new SplittableRandom();
        long size = 0;
        for (int reps = 0; reps < REPS; ++reps) {
            counter.reset();
            r.doubles(size).parallel().forEach(x -> counter.increment());
            assertEquals(size, counter.sum());
            size += 524959;
        }
    }

    /**
     * Each of a parallel sized stream of bounded ints is within bounds
     */
    public void testBoundedInts() {
        AtomicInteger fails = new AtomicInteger(0);
        SplittableRandom r = new SplittableRandom();
        long size = 12345L;
        for (int least = -15485867; least < MAX_INT_BOUND; least += 524959) {
            for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 67867967) {
                final int lo = least, hi = bound;
                r.ints(size, lo, hi).parallel().forEach(
                    x -> {
                        if (x < lo || x >= hi)
                            fails.getAndIncrement(); });
            }
        }
        assertEquals(0, fails.get());
    }

    /**
     * Each of a parallel sized stream of bounded longs is within bounds
     */
    public void testBoundedLongs() {
        AtomicInteger fails = new AtomicInteger(0);
        SplittableRandom r = new SplittableRandom();
        long size = 123L;
        for (long least = -86028121; least < MAX_LONG_BOUND; least += 1982451653L) {
            for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) {
                final long lo = least, hi = bound;
                r.longs(size, lo, hi).parallel().forEach(
                    x -> {
                        if (x < lo || x >= hi)
                            fails.getAndIncrement(); });
            }
        }
        assertEquals(0, fails.get());
    }

    /**
     * Each of a parallel sized stream of bounded doubles is within bounds
     */
    public void testBoundedDoubles() {
        AtomicInteger fails = new AtomicInteger(0);
        SplittableRandom r = new SplittableRandom();
        long size = 456;
        for (double least = 0.00011; least < 1.0e20; least *= 9) {
            for (double bound = least * 1.0011; bound < 1.0e20; bound *= 17) {
                final double lo = least, hi = bound;
                r.doubles(size, lo, hi).parallel().forEach(
                    x -> {
                        if (x < lo || x >= hi)
                            fails.getAndIncrement(); });
            }
        }
        assertEquals(0, fails.get());
    }

    /**
     * A parallel unsized stream of ints generates at least 100 values
     */
    public void testUnsizedIntsCount() {
        LongAdder counter = new LongAdder();
        SplittableRandom r = new SplittableRandom();
        long size = 100;
        r.ints().limit(size).parallel().forEach(x -> counter.increment());
        assertEquals(size, counter.sum());
    }

    /**
     * A parallel unsized stream of longs generates at least 100 values
     */
    public void testUnsizedLongsCount() {
        LongAdder counter = new LongAdder();
        SplittableRandom r = new SplittableRandom();
        long size = 100;
        r.longs().limit(size).parallel().forEach(x -> counter.increment());
        assertEquals(size, counter.sum());
    }

    /**
     * A parallel unsized stream of doubles generates at least 100 values
     */
    public void testUnsizedDoublesCount() {
        LongAdder counter = new LongAdder();
        SplittableRandom r = new SplittableRandom();
        long size = 100;
        r.doubles().limit(size).parallel().forEach(x -> counter.increment());
        assertEquals(size, counter.sum());
    }

    /**
     * A sequential unsized stream of ints generates at least 100 values
     */
    public void testUnsizedIntsCountSeq() {
        LongAdder counter = new LongAdder();
        SplittableRandom r = new SplittableRandom();
        long size = 100;
        r.ints().limit(size).forEach(x -> counter.increment());
        assertEquals(size, counter.sum());
    }

    /**
     * A sequential unsized stream of longs generates at least 100 values
     */
    public void testUnsizedLongsCountSeq() {
        LongAdder counter = new LongAdder();
        SplittableRandom r = new SplittableRandom();
        long size = 100;
        r.longs().limit(size).forEach(x -> counter.increment());
        assertEquals(size, counter.sum());
    }

    /**
     * A sequential unsized stream of doubles generates at least 100 values
     */
    public void testUnsizedDoublesCountSeq() {
        LongAdder counter = new LongAdder();
        SplittableRandom r = new SplittableRandom();
        long size = 100;
        r.doubles().limit(size).forEach(x -> counter.increment());
        assertEquals(size, counter.sum());
    }

    /**
     * SplittableRandom should implement most of Random's public methods
     */
    public void testShouldImplementMostRandomMethods() throws Throwable {
        Predicate<Method> wasForgotten = method -> {
            String name = method.getName();
            // some methods deliberately not implemented
            if (name.equals("setSeed")) return false;
            if (name.equals("nextFloat")) return false;
            if (name.equals("nextGaussian")) return false;
            try {
                SplittableRandom.class.getMethod(
                    method.getName(), method.getParameterTypes());
            } catch (ReflectiveOperationException ex) {
                return true;
            }
            return false;
        };
        List<Method> forgotten =
            Arrays.stream(java.util.Random.class.getMethods())
            .filter(wasForgotten)
            .collect(Collectors.toList());
        if (!forgotten.isEmpty())
            throw new AssertionError("Please implement: " + forgotten);
    }

    /**
     * Repeated calls to nextBytes produce at least values of different signs for every byte
     */
    public void testNextBytes() {
        SplittableRandom sr = new SplittableRandom();
        int n = sr.nextInt(1, 20);
        byte[] bytes = new byte[n];
        outer:
        for (int i = 0; i < n; i++) {
            for (int tries = NCALLS; tries-->0; ) {
                byte before = bytes[i];
                sr.nextBytes(bytes);
                byte after = bytes[i];
                if (after * before < 0)
                    continue outer;
            }
            fail("not enough variation in random bytes");
        }
    }

    /**
     * Filling an empty array with random bytes succeeds without effect.
     */
    public void testNextBytes_emptyArray() {
        new SplittableRandom().nextBytes(new byte[0]);
    }

    public void testNextBytes_nullArray() {
        try {
            new SplittableRandom().nextBytes(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

}
Revision:	1.26
Committed:	Mon Dec 16 22:55:54 2019 UTC (4 years, 5 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.25:	+15 -12 lines
Log Message:	fix a few [UnusedVariable] warnings
#	User	Rev	Content
1	dl	1.1	/*
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	jsr166	1.16
7	jsr166	1.22	import java.util.Arrays;
8			import java.util.List;
9	dl	1.1	import java.util.SplittableRandom;
10			import java.util.concurrent.atomic.AtomicInteger;
11			import java.util.concurrent.atomic.LongAdder;
12	jsr166	1.22	import java.lang.reflect.Method;
13			import java.util.function.Predicate;
14			import java.util.stream.Collectors;
15	jsr166	1.26	import java.util.stream.DoubleStream;
16			import java.util.stream.IntStream;
17			import java.util.stream.LongStream;
18	dl	1.1
19	jsr166	1.16	import junit.framework.Test;
20			import junit.framework.TestSuite;
21
22	dl	1.1	public class SplittableRandomTest extends JSR166TestCase {
23
24			public static void main(String[] args) {
25	jsr166	1.18	main(suite(), args);
26	dl	1.1	}
27			public static Test suite() {
28			return new TestSuite(SplittableRandomTest.class);
29			}
30
31			/*
32			* Testing coverage notes:
33			*
34	jsr166	1.4	* 1. Many of the test methods are adapted from ThreadLocalRandomTest.
35	dl	1.1	*
36	jsr166	1.4	* 2. These tests do not check for random number generator quality.
37			* But we check for minimal API compliance by requiring that
38			* repeated calls to nextX methods, up to NCALLS tries, produce at
39			* least two distinct results. (In some possible universe, a
40			* "correct" implementation might fail, but the odds are vastly
41			* less than that of encountering a hardware failure while running
42			* the test.) For bounded nextX methods, we sample various
43			* intervals across multiples of primes. In other tests, we repeat
44			* under REPS different values.
45	dl	1.1	*/
46
47			// max numbers of calls to detect getting stuck on one value
48			static final int NCALLS = 10000;
49
50			// max sampled int bound
51	jsr166	1.11	static final int MAX_INT_BOUND = (1 << 26);
52	dl	1.1
53	jsr166	1.4	// max sampled long bound
54	jsr166	1.12	static final long MAX_LONG_BOUND = (1L << 40);
55	dl	1.1
56			// Number of replications for other checks
57	jsr166	1.7	static final int REPS =
58			Integer.getInteger("SplittableRandomTest.reps", 4);
59	dl	1.1
60			/**
61	jsr166	1.4	* Repeated calls to nextInt produce at least two distinct results
62	dl	1.1	*/
63			public void testNextInt() {
64			SplittableRandom sr = new SplittableRandom();
65			int f = sr.nextInt();
66			int i = 0;
67			while (i < NCALLS && sr.nextInt() == f)
68			++i;
69			assertTrue(i < NCALLS);
70			}
71
72			/**
73	jsr166	1.4	* Repeated calls to nextLong produce at least two distinct results
74	dl	1.1	*/
75			public void testNextLong() {
76			SplittableRandom sr = new SplittableRandom();
77			long f = sr.nextLong();
78			int i = 0;
79			while (i < NCALLS && sr.nextLong() == f)
80			++i;
81			assertTrue(i < NCALLS);
82			}
83
84			/**
85	jsr166	1.4	* Repeated calls to nextDouble produce at least two distinct results
86	dl	1.1	*/
87			public void testNextDouble() {
88			SplittableRandom sr = new SplittableRandom();
89			double f = sr.nextDouble();
90	jsr166	1.4	int i = 0;
91	dl	1.1	while (i < NCALLS && sr.nextDouble() == f)
92			++i;
93			assertTrue(i < NCALLS);
94			}
95
96			/**
97			* Two SplittableRandoms created with the same seed produce the
98			* same values for nextLong.
99			*/
100			public void testSeedConstructor() {
101	jsr166	1.14	for (long seed = 2; seed < MAX_LONG_BOUND; seed += 15485863) {
102	dl	1.1	SplittableRandom sr1 = new SplittableRandom(seed);
103			SplittableRandom sr2 = new SplittableRandom(seed);
104	jsr166	1.3	for (int i = 0; i < REPS; ++i)
105	dl	1.1	assertEquals(sr1.nextLong(), sr2.nextLong());
106			}
107			}
108
109			/**
110			* A SplittableRandom produced by split() of a default-constructed
111			* SplittableRandom generates a different sequence
112			*/
113			public void testSplit1() {
114			SplittableRandom sr = new SplittableRandom();
115			for (int reps = 0; reps < REPS; ++reps) {
116			SplittableRandom sc = sr.split();
117			int i = 0;
118			while (i < NCALLS && sr.nextLong() == sc.nextLong())
119			++i;
120			assertTrue(i < NCALLS);
121			}
122			}
123
124			/**
125			* A SplittableRandom produced by split() of a seeded-constructed
126			* SplittableRandom generates a different sequence
127			*/
128			public void testSplit2() {
129			SplittableRandom sr = new SplittableRandom(12345);
130			for (int reps = 0; reps < REPS; ++reps) {
131			SplittableRandom sc = sr.split();
132			int i = 0;
133			while (i < NCALLS && sr.nextLong() == sc.nextLong())
134			++i;
135			assertTrue(i < NCALLS);
136			}
137			}
138
139			/**
140	jsr166	1.9	* nextInt(non-positive) throws IllegalArgumentException
141	dl	1.1	*/
142	jsr166	1.13	public void testNextIntBoundNonPositive() {
143	dl	1.1	SplittableRandom sr = new SplittableRandom();
144	jsr166	1.25	assertThrows(
145			IllegalArgumentException.class,
146	jsr166	1.9	() -> sr.nextInt(-17),
147			() -> sr.nextInt(0),
148	jsr166	1.25	() -> sr.nextInt(Integer.MIN_VALUE));
149	dl	1.1	}
150
151			/**
152	jsr166	1.4	* nextInt(least >= bound) throws IllegalArgumentException
153	dl	1.1	*/
154			public void testNextIntBadBounds() {
155			SplittableRandom sr = new SplittableRandom();
156	jsr166	1.25	assertThrows(
157			IllegalArgumentException.class,
158	jsr166	1.10	() -> sr.nextInt(17, 2),
159			() -> sr.nextInt(-42, -42),
160	jsr166	1.25	() -> sr.nextInt(Integer.MAX_VALUE, Integer.MIN_VALUE));
161	dl	1.1	}
162
163			/**
164			* nextInt(bound) returns 0 <= value < bound;
165	jsr166	1.4	* repeated calls produce at least two distinct results
166	dl	1.1	*/
167			public void testNextIntBounded() {
168			SplittableRandom sr = new SplittableRandom();
169	jsr166	1.19	for (int i = 0; i < 2; i++) assertEquals(0, sr.nextInt(1));
170	dl	1.1	// sample bound space across prime number increments
171			for (int bound = 2; bound < MAX_INT_BOUND; bound += 524959) {
172			int f = sr.nextInt(bound);
173			assertTrue(0 <= f && f < bound);
174			int i = 0;
175			int j;
176			while (i < NCALLS &&
177			(j = sr.nextInt(bound)) == f) {
178			assertTrue(0 <= j && j < bound);
179			++i;
180			}
181			assertTrue(i < NCALLS);
182			}
183			}
184
185			/**
186			* nextInt(least, bound) returns least <= value < bound;
187	jsr166	1.4	* repeated calls produce at least two distinct results
188	dl	1.1	*/
189			public void testNextIntBounded2() {
190			SplittableRandom sr = new SplittableRandom();
191			for (int least = -15485863; least < MAX_INT_BOUND; least += 524959) {
192			for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 49979687) {
193			int f = sr.nextInt(least, bound);
194			assertTrue(least <= f && f < bound);
195			int i = 0;
196			int j;
197			while (i < NCALLS &&
198			(j = sr.nextInt(least, bound)) == f) {
199			assertTrue(least <= j && j < bound);
200			++i;
201			}
202			assertTrue(i < NCALLS);
203			}
204			}
205			}
206
207			/**
208	jsr166	1.9	* nextLong(non-positive) throws IllegalArgumentException
209	dl	1.1	*/
210	jsr166	1.13	public void testNextLongBoundNonPositive() {
211	dl	1.1	SplittableRandom sr = new SplittableRandom();
212	jsr166	1.25	assertThrows(
213			IllegalArgumentException.class,
214	jsr166	1.9	() -> sr.nextLong(-17L),
215			() -> sr.nextLong(0L),
216	jsr166	1.25	() -> sr.nextLong(Long.MIN_VALUE));
217	dl	1.1	}
218
219			/**
220	jsr166	1.4	* nextLong(least >= bound) throws IllegalArgumentException
221	dl	1.1	*/
222			public void testNextLongBadBounds() {
223			SplittableRandom sr = new SplittableRandom();
224	jsr166	1.25	assertThrows(
225			IllegalArgumentException.class,
226	jsr166	1.10	() -> sr.nextLong(17L, 2L),
227			() -> sr.nextLong(-42L, -42L),
228	jsr166	1.25	() -> sr.nextLong(Long.MAX_VALUE, Long.MIN_VALUE));
229	dl	1.1	}
230
231			/**
232			* nextLong(bound) returns 0 <= value < bound;
233	jsr166	1.4	* repeated calls produce at least two distinct results
234	dl	1.1	*/
235			public void testNextLongBounded() {
236			SplittableRandom sr = new SplittableRandom();
237	jsr166	1.19	for (int i = 0; i < 2; i++) assertEquals(0L, sr.nextLong(1L));
238	dl	1.1	for (long bound = 2; bound < MAX_LONG_BOUND; bound += 15485863) {
239			long f = sr.nextLong(bound);
240			assertTrue(0 <= f && f < bound);
241			int i = 0;
242			long j;
243			while (i < NCALLS &&
244			(j = sr.nextLong(bound)) == f) {
245			assertTrue(0 <= j && j < bound);
246			++i;
247			}
248			assertTrue(i < NCALLS);
249			}
250			}
251
252			/**
253			* nextLong(least, bound) returns least <= value < bound;
254	jsr166	1.4	* repeated calls produce at least two distinct results
255	dl	1.1	*/
256			public void testNextLongBounded2() {
257			SplittableRandom sr = new SplittableRandom();
258			for (long least = -86028121; least < MAX_LONG_BOUND; least += 982451653L) {
259			for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) {
260			long f = sr.nextLong(least, bound);
261			assertTrue(least <= f && f < bound);
262			int i = 0;
263			long j;
264			while (i < NCALLS &&
265			(j = sr.nextLong(least, bound)) == f) {
266			assertTrue(least <= j && j < bound);
267			++i;
268			}
269			assertTrue(i < NCALLS);
270			}
271			}
272			}
273
274			/**
275	jsr166	1.9	* nextDouble(non-positive) throws IllegalArgumentException
276			*/
277	jsr166	1.13	public void testNextDoubleBoundNonPositive() {
278	jsr166	1.9	SplittableRandom sr = new SplittableRandom();
279	jsr166	1.25	assertThrows(
280			IllegalArgumentException.class,
281	jsr166	1.9	() -> sr.nextDouble(-17.0d),
282			() -> sr.nextDouble(0.0d),
283			() -> sr.nextDouble(-Double.MIN_VALUE),
284			() -> sr.nextDouble(Double.NEGATIVE_INFINITY),
285	jsr166	1.25	() -> sr.nextDouble(Double.NaN));
286	jsr166	1.9	}
287
288			/**
289	jsr166	1.10	* nextDouble(! (least < bound)) throws IllegalArgumentException
290			*/
291			public void testNextDoubleBadBounds() {
292			SplittableRandom sr = new SplittableRandom();
293	jsr166	1.25	assertThrows(
294			IllegalArgumentException.class,
295	jsr166	1.10	() -> sr.nextDouble(17.0d, 2.0d),
296			() -> sr.nextDouble(-42.0d, -42.0d),
297			() -> sr.nextDouble(Double.MAX_VALUE, Double.MIN_VALUE),
298			() -> sr.nextDouble(Double.NaN, 0.0d),
299	jsr166	1.25	() -> sr.nextDouble(0.0d, Double.NaN));
300	jsr166	1.10	}
301
302			// TODO: Test infinite bounds!
303			//() -> sr.nextDouble(Double.NEGATIVE_INFINITY, 0.0d),
304			//() -> sr.nextDouble(0.0d, Double.POSITIVE_INFINITY),
305
306			/**
307	dl	1.1	* nextDouble(least, bound) returns least <= value < bound;
308	jsr166	1.4	* repeated calls produce at least two distinct results
309	dl	1.1	*/
310			public void testNextDoubleBounded2() {
311			SplittableRandom sr = new SplittableRandom();
312			for (double least = 0.0001; least < 1.0e20; least *= 8) {
313			for (double bound = least * 1.001; bound < 1.0e20; bound *= 16) {
314			double f = sr.nextDouble(least, bound);
315			assertTrue(least <= f && f < bound);
316			int i = 0;
317			double j;
318			while (i < NCALLS &&
319			(j = sr.nextDouble(least, bound)) == f) {
320			assertTrue(least <= j && j < bound);
321			++i;
322			}
323			assertTrue(i < NCALLS);
324			}
325			}
326			}
327
328			/**
329			* Invoking sized ints, long, doubles, with negative sizes throws
330			* IllegalArgumentException
331			*/
332			public void testBadStreamSize() {
333			SplittableRandom r = new SplittableRandom();
334	jsr166	1.25	assertThrows(
335			IllegalArgumentException.class,
336	jsr166	1.26	() -> { IntStream unused = r.ints(-1L); },
337			() -> { IntStream unused = r.ints(-1L, 2, 3); },
338			() -> { LongStream unused = r.longs(-1L); },
339			() -> { LongStream unused = r.longs(-1L, -1L, 1L); },
340			() -> { DoubleStream unused = r.doubles(-1L); },
341			() -> { DoubleStream unused = r.doubles(-1L, .5, .6); });
342	dl	1.1	}
343
344			/**
345			* Invoking bounded ints, long, doubles, with illegal bounds throws
346			* IllegalArgumentException
347			*/
348			public void testBadStreamBounds() {
349			SplittableRandom r = new SplittableRandom();
350	jsr166	1.25	assertThrows(
351			IllegalArgumentException.class,
352	jsr166	1.26	() -> { IntStream unused = r.ints(2, 1); },
353			() -> { IntStream unused = r.ints(10, 42, 42); },
354			() -> { LongStream unused = r.longs(-1L, -1L); },
355			() -> { LongStream unused = r.longs(10, 1L, -2L); },
356			() -> { DoubleStream unused = r.doubles(0.0, 0.0); },
357			() -> { DoubleStream unused = r.doubles(10, .5, .4); });
358	dl	1.1	}
359
360			/**
361			* A parallel sized stream of ints generates the given number of values
362			*/
363			public void testIntsCount() {
364			LongAdder counter = new LongAdder();
365			SplittableRandom r = new SplittableRandom();
366			long size = 0;
367			for (int reps = 0; reps < REPS; ++reps) {
368			counter.reset();
369	jsr166	1.6	r.ints(size).parallel().forEach(x -> counter.increment());
370	jsr166	1.4	assertEquals(size, counter.sum());
371	dl	1.1	size += 524959;
372			}
373			}
374
375			/**
376			* A parallel sized stream of longs generates the given number of values
377			*/
378			public void testLongsCount() {
379			LongAdder counter = new LongAdder();
380			SplittableRandom r = new SplittableRandom();
381			long size = 0;
382			for (int reps = 0; reps < REPS; ++reps) {
383			counter.reset();
384	jsr166	1.6	r.longs(size).parallel().forEach(x -> counter.increment());
385	jsr166	1.4	assertEquals(size, counter.sum());
386	dl	1.1	size += 524959;
387			}
388			}
389
390			/**
391			* A parallel sized stream of doubles generates the given number of values
392			*/
393			public void testDoublesCount() {
394			LongAdder counter = new LongAdder();
395			SplittableRandom r = new SplittableRandom();
396			long size = 0;
397			for (int reps = 0; reps < REPS; ++reps) {
398			counter.reset();
399	jsr166	1.6	r.doubles(size).parallel().forEach(x -> counter.increment());
400	jsr166	1.4	assertEquals(size, counter.sum());
401	dl	1.1	size += 524959;
402			}
403			}
404
405			/**
406			* Each of a parallel sized stream of bounded ints is within bounds
407			*/
408			public void testBoundedInts() {
409			AtomicInteger fails = new AtomicInteger(0);
410			SplittableRandom r = new SplittableRandom();
411			long size = 12345L;
412			for (int least = -15485867; least < MAX_INT_BOUND; least += 524959) {
413			for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 67867967) {
414			final int lo = least, hi = bound;
415	jsr166	1.17	r.ints(size, lo, hi).parallel().forEach(
416			x -> {
417			if (x < lo \|\| x >= hi)
418			fails.getAndIncrement(); });
419	dl	1.1	}
420			}
421	jsr166	1.4	assertEquals(0, fails.get());
422	dl	1.1	}
423
424			/**
425			* Each of a parallel sized stream of bounded longs is within bounds
426			*/
427			public void testBoundedLongs() {
428			AtomicInteger fails = new AtomicInteger(0);
429			SplittableRandom r = new SplittableRandom();
430			long size = 123L;
431			for (long least = -86028121; least < MAX_LONG_BOUND; least += 1982451653L) {
432			for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) {
433			final long lo = least, hi = bound;
434	jsr166	1.17	r.longs(size, lo, hi).parallel().forEach(
435			x -> {
436			if (x < lo \|\| x >= hi)
437			fails.getAndIncrement(); });
438	dl	1.1	}
439			}
440	jsr166	1.4	assertEquals(0, fails.get());
441	dl	1.1	}
442
443			/**
444			* Each of a parallel sized stream of bounded doubles is within bounds
445			*/
446			public void testBoundedDoubles() {
447			AtomicInteger fails = new AtomicInteger(0);
448			SplittableRandom r = new SplittableRandom();
449			long size = 456;
450			for (double least = 0.00011; least < 1.0e20; least *= 9) {
451			for (double bound = least * 1.0011; bound < 1.0e20; bound *= 17) {
452			final double lo = least, hi = bound;
453	jsr166	1.17	r.doubles(size, lo, hi).parallel().forEach(
454			x -> {
455			if (x < lo \|\| x >= hi)
456			fails.getAndIncrement(); });
457	dl	1.1	}
458			}
459	jsr166	1.4	assertEquals(0, fails.get());
460	dl	1.1	}
461
462	dl	1.2	/**
463			* A parallel unsized stream of ints generates at least 100 values
464			*/
465			public void testUnsizedIntsCount() {
466			LongAdder counter = new LongAdder();
467			SplittableRandom r = new SplittableRandom();
468			long size = 100;
469	jsr166	1.6	r.ints().limit(size).parallel().forEach(x -> counter.increment());
470	jsr166	1.4	assertEquals(size, counter.sum());
471	dl	1.2	}
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			SplittableRandom r = new SplittableRandom();
479			long size = 100;
480	jsr166	1.6	r.longs().limit(size).parallel().forEach(x -> counter.increment());
481	jsr166	1.4	assertEquals(size, counter.sum());
482	dl	1.2	}
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			SplittableRandom r = new SplittableRandom();
490			long size = 100;
491	jsr166	1.6	r.doubles().limit(size).parallel().forEach(x -> counter.increment());
492	jsr166	1.4	assertEquals(size, counter.sum());
493	dl	1.2	}
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			SplittableRandom r = new SplittableRandom();
501			long size = 100;
502	jsr166	1.6	r.ints().limit(size).forEach(x -> counter.increment());
503	jsr166	1.4	assertEquals(size, counter.sum());
504	dl	1.2	}
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			SplittableRandom r = new SplittableRandom();
512			long size = 100;
513	jsr166	1.6	r.longs().limit(size).forEach(x -> counter.increment());
514	jsr166	1.4	assertEquals(size, counter.sum());
515	dl	1.2	}
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			SplittableRandom r = new SplittableRandom();
523			long size = 100;
524	jsr166	1.6	r.doubles().limit(size).forEach(x -> counter.increment());
525	jsr166	1.4	assertEquals(size, counter.sum());
526	dl	1.2	}
527
528	jsr166	1.22	/**
529			* SplittableRandom should implement most of Random's public methods
530			*/
531			public void testShouldImplementMostRandomMethods() throws Throwable {
532			Predicate<Method> wasForgotten = method -> {
533			String name = method.getName();
534			// some methods deliberately not implemented
535			if (name.equals("setSeed")) return false;
536			if (name.equals("nextFloat")) return false;
537			if (name.equals("nextGaussian")) return false;
538			try {
539			SplittableRandom.class.getMethod(
540			method.getName(), method.getParameterTypes());
541			} catch (ReflectiveOperationException ex) {
542			return true;
543			}
544			return false;
545			};
546			List<Method> forgotten =
547			Arrays.stream(java.util.Random.class.getMethods())
548			.filter(wasForgotten)
549			.collect(Collectors.toList());
550			if (!forgotten.isEmpty())
551			throw new AssertionError("Please implement: " + forgotten);
552			}
553
554			/**
555			* Repeated calls to nextBytes produce at least values of different signs for every byte
556			*/
557			public void testNextBytes() {
558			SplittableRandom sr = new SplittableRandom();
559	jsr166	1.23	int n = sr.nextInt(1, 20);
560	jsr166	1.22	byte[] bytes = new byte[n];
561			outer:
562			for (int i = 0; i < n; i++) {
563			for (int tries = NCALLS; tries-->0; ) {
564			byte before = bytes[i];
565			sr.nextBytes(bytes);
566			byte after = bytes[i];
567			if (after * before < 0)
568			continue outer;
569			}
570			fail("not enough variation in random bytes");
571			}
572			}
573
574	jsr166	1.23	/**
575			* Filling an empty array with random bytes succeeds without effect.
576			*/
577			public void testNextBytes_emptyArray() {
578			new SplittableRandom().nextBytes(new byte[0]);
579			}
580
581			public void testNextBytes_nullArray() {
582			try {
583			new SplittableRandom().nextBytes(null);
584			shouldThrow();
585			} catch (NullPointerException success) {}
586			}
587
588	dl	1.1	}