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 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,
            () -> { java.util.stream.IntStream x = r.ints(-1L); },
            () -> { java.util.stream.IntStream x = r.ints(-1L, 2, 3); },
            () -> { java.util.stream.LongStream x = r.longs(-1L); },
            () -> { java.util.stream.LongStream x = r.longs(-1L, -1L, 1L); },
            () -> { java.util.stream.DoubleStream x = r.doubles(-1L); },
            () -> { java.util.stream.DoubleStream x = 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,
            () -> { java.util.stream.IntStream x = r.ints(2, 1); },
            () -> { java.util.stream.IntStream x = r.ints(10, 42, 42); },
            () -> { java.util.stream.LongStream x = r.longs(-1L, -1L); },
            () -> { java.util.stream.LongStream x = r.longs(10, 1L, -2L); },
            () -> { java.util.stream.DoubleStream x = r.doubles(0.0, 0.0); },
            () -> { java.util.stream.DoubleStream x = 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:	1.25
Committed:	Fri Feb 22 19:27:47 2019 UTC (5 years, 2 months ago) by jsr166
Branch:	MAIN
Changes since 1.24:	+24 -32 lines
Log Message:	improve assertThrows tests
#	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	dl	1.1
16	jsr166	1.16	import junit.framework.Test;
17			import junit.framework.TestSuite;
18
19	dl	1.1	public class SplittableRandomTest extends JSR166TestCase {
20
21			public static void main(String[] args) {
22	jsr166	1.18	main(suite(), args);
23	dl	1.1	}
24			public static Test suite() {
25			return new TestSuite(SplittableRandomTest.class);
26			}
27
28			/*
29			* Testing coverage notes:
30			*
31	jsr166	1.4	* 1. Many of the test methods are adapted from ThreadLocalRandomTest.
32	dl	1.1	*
33	jsr166	1.4	* 2. These tests do not check for random number generator quality.
34			* But we check for minimal API compliance by requiring that
35			* repeated calls to nextX methods, up to NCALLS tries, produce at
36			* least two distinct results. (In some possible universe, a
37			* "correct" implementation might fail, but the odds are vastly
38			* less than that of encountering a hardware failure while running
39			* the test.) For bounded nextX methods, we sample various
40			* intervals across multiples of primes. In other tests, we repeat
41			* under REPS different values.
42	dl	1.1	*/
43
44			// max numbers of calls to detect getting stuck on one value
45			static final int NCALLS = 10000;
46
47			// max sampled int bound
48	jsr166	1.11	static final int MAX_INT_BOUND = (1 << 26);
49	dl	1.1
50	jsr166	1.4	// max sampled long bound
51	jsr166	1.12	static final long MAX_LONG_BOUND = (1L << 40);
52	dl	1.1
53			// Number of replications for other checks
54	jsr166	1.7	static final int REPS =
55			Integer.getInteger("SplittableRandomTest.reps", 4);
56	dl	1.1
57			/**
58	jsr166	1.4	* Repeated calls to nextInt produce at least two distinct results
59	dl	1.1	*/
60			public void testNextInt() {
61			SplittableRandom sr = new SplittableRandom();
62			int f = sr.nextInt();
63			int i = 0;
64			while (i < NCALLS && sr.nextInt() == f)
65			++i;
66			assertTrue(i < NCALLS);
67			}
68
69			/**
70	jsr166	1.4	* Repeated calls to nextLong produce at least two distinct results
71	dl	1.1	*/
72			public void testNextLong() {
73			SplittableRandom sr = new SplittableRandom();
74			long f = sr.nextLong();
75			int i = 0;
76			while (i < NCALLS && sr.nextLong() == f)
77			++i;
78			assertTrue(i < NCALLS);
79			}
80
81			/**
82	jsr166	1.4	* Repeated calls to nextDouble produce at least two distinct results
83	dl	1.1	*/
84			public void testNextDouble() {
85			SplittableRandom sr = new SplittableRandom();
86			double f = sr.nextDouble();
87	jsr166	1.4	int i = 0;
88	dl	1.1	while (i < NCALLS && sr.nextDouble() == f)
89			++i;
90			assertTrue(i < NCALLS);
91			}
92
93			/**
94			* Two SplittableRandoms created with the same seed produce the
95			* same values for nextLong.
96			*/
97			public void testSeedConstructor() {
98	jsr166	1.14	for (long seed = 2; seed < MAX_LONG_BOUND; seed += 15485863) {
99	dl	1.1	SplittableRandom sr1 = new SplittableRandom(seed);
100			SplittableRandom sr2 = new SplittableRandom(seed);
101	jsr166	1.3	for (int i = 0; i < REPS; ++i)
102	dl	1.1	assertEquals(sr1.nextLong(), sr2.nextLong());
103			}
104			}
105
106			/**
107			* A SplittableRandom produced by split() of a default-constructed
108			* SplittableRandom generates a different sequence
109			*/
110			public void testSplit1() {
111			SplittableRandom sr = new SplittableRandom();
112			for (int reps = 0; reps < REPS; ++reps) {
113			SplittableRandom sc = sr.split();
114			int i = 0;
115			while (i < NCALLS && sr.nextLong() == sc.nextLong())
116			++i;
117			assertTrue(i < NCALLS);
118			}
119			}
120
121			/**
122			* A SplittableRandom produced by split() of a seeded-constructed
123			* SplittableRandom generates a different sequence
124			*/
125			public void testSplit2() {
126			SplittableRandom sr = new SplittableRandom(12345);
127			for (int reps = 0; reps < REPS; ++reps) {
128			SplittableRandom sc = sr.split();
129			int i = 0;
130			while (i < NCALLS && sr.nextLong() == sc.nextLong())
131			++i;
132			assertTrue(i < NCALLS);
133			}
134			}
135
136			/**
137	jsr166	1.9	* nextInt(non-positive) throws IllegalArgumentException
138	dl	1.1	*/
139	jsr166	1.13	public void testNextIntBoundNonPositive() {
140	dl	1.1	SplittableRandom sr = new SplittableRandom();
141	jsr166	1.25	assertThrows(
142			IllegalArgumentException.class,
143	jsr166	1.9	() -> sr.nextInt(-17),
144			() -> sr.nextInt(0),
145	jsr166	1.25	() -> sr.nextInt(Integer.MIN_VALUE));
146	dl	1.1	}
147
148			/**
149	jsr166	1.4	* nextInt(least >= bound) throws IllegalArgumentException
150	dl	1.1	*/
151			public void testNextIntBadBounds() {
152			SplittableRandom sr = new SplittableRandom();
153	jsr166	1.25	assertThrows(
154			IllegalArgumentException.class,
155	jsr166	1.10	() -> sr.nextInt(17, 2),
156			() -> sr.nextInt(-42, -42),
157	jsr166	1.25	() -> sr.nextInt(Integer.MAX_VALUE, Integer.MIN_VALUE));
158	dl	1.1	}
159
160			/**
161			* nextInt(bound) returns 0 <= value < bound;
162	jsr166	1.4	* repeated calls produce at least two distinct results
163	dl	1.1	*/
164			public void testNextIntBounded() {
165			SplittableRandom sr = new SplittableRandom();
166	jsr166	1.19	for (int i = 0; i < 2; i++) assertEquals(0, sr.nextInt(1));
167	dl	1.1	// sample bound space across prime number increments
168			for (int bound = 2; bound < MAX_INT_BOUND; bound += 524959) {
169			int f = sr.nextInt(bound);
170			assertTrue(0 <= f && f < bound);
171			int i = 0;
172			int j;
173			while (i < NCALLS &&
174			(j = sr.nextInt(bound)) == f) {
175			assertTrue(0 <= j && j < bound);
176			++i;
177			}
178			assertTrue(i < NCALLS);
179			}
180			}
181
182			/**
183			* nextInt(least, bound) returns least <= value < bound;
184	jsr166	1.4	* repeated calls produce at least two distinct results
185	dl	1.1	*/
186			public void testNextIntBounded2() {
187			SplittableRandom sr = new SplittableRandom();
188			for (int least = -15485863; least < MAX_INT_BOUND; least += 524959) {
189			for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 49979687) {
190			int f = sr.nextInt(least, bound);
191			assertTrue(least <= f && f < bound);
192			int i = 0;
193			int j;
194			while (i < NCALLS &&
195			(j = sr.nextInt(least, bound)) == f) {
196			assertTrue(least <= j && j < bound);
197			++i;
198			}
199			assertTrue(i < NCALLS);
200			}
201			}
202			}
203
204			/**
205	jsr166	1.9	* nextLong(non-positive) throws IllegalArgumentException
206	dl	1.1	*/
207	jsr166	1.13	public void testNextLongBoundNonPositive() {
208	dl	1.1	SplittableRandom sr = new SplittableRandom();
209	jsr166	1.25	assertThrows(
210			IllegalArgumentException.class,
211	jsr166	1.9	() -> sr.nextLong(-17L),
212			() -> sr.nextLong(0L),
213	jsr166	1.25	() -> sr.nextLong(Long.MIN_VALUE));
214	dl	1.1	}
215
216			/**
217	jsr166	1.4	* nextLong(least >= bound) throws IllegalArgumentException
218	dl	1.1	*/
219			public void testNextLongBadBounds() {
220			SplittableRandom sr = new SplittableRandom();
221	jsr166	1.25	assertThrows(
222			IllegalArgumentException.class,
223	jsr166	1.10	() -> sr.nextLong(17L, 2L),
224			() -> sr.nextLong(-42L, -42L),
225	jsr166	1.25	() -> sr.nextLong(Long.MAX_VALUE, Long.MIN_VALUE));
226	dl	1.1	}
227
228			/**
229			* nextLong(bound) returns 0 <= value < bound;
230	jsr166	1.4	* repeated calls produce at least two distinct results
231	dl	1.1	*/
232			public void testNextLongBounded() {
233			SplittableRandom sr = new SplittableRandom();
234	jsr166	1.19	for (int i = 0; i < 2; i++) assertEquals(0L, sr.nextLong(1L));
235	dl	1.1	for (long bound = 2; bound < MAX_LONG_BOUND; bound += 15485863) {
236			long f = sr.nextLong(bound);
237			assertTrue(0 <= f && f < bound);
238			int i = 0;
239			long j;
240			while (i < NCALLS &&
241			(j = sr.nextLong(bound)) == f) {
242			assertTrue(0 <= j && j < bound);
243			++i;
244			}
245			assertTrue(i < NCALLS);
246			}
247			}
248
249			/**
250			* nextLong(least, bound) returns least <= value < bound;
251	jsr166	1.4	* repeated calls produce at least two distinct results
252	dl	1.1	*/
253			public void testNextLongBounded2() {
254			SplittableRandom sr = new SplittableRandom();
255			for (long least = -86028121; least < MAX_LONG_BOUND; least += 982451653L) {
256			for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) {
257			long f = sr.nextLong(least, bound);
258			assertTrue(least <= f && f < bound);
259			int i = 0;
260			long j;
261			while (i < NCALLS &&
262			(j = sr.nextLong(least, bound)) == f) {
263			assertTrue(least <= j && j < bound);
264			++i;
265			}
266			assertTrue(i < NCALLS);
267			}
268			}
269			}
270
271			/**
272	jsr166	1.9	* nextDouble(non-positive) throws IllegalArgumentException
273			*/
274	jsr166	1.13	public void testNextDoubleBoundNonPositive() {
275	jsr166	1.9	SplittableRandom sr = new SplittableRandom();
276	jsr166	1.25	assertThrows(
277			IllegalArgumentException.class,
278	jsr166	1.9	() -> sr.nextDouble(-17.0d),
279			() -> sr.nextDouble(0.0d),
280			() -> sr.nextDouble(-Double.MIN_VALUE),
281			() -> sr.nextDouble(Double.NEGATIVE_INFINITY),
282	jsr166	1.25	() -> sr.nextDouble(Double.NaN));
283	jsr166	1.9	}
284
285			/**
286	jsr166	1.10	* nextDouble(! (least < bound)) throws IllegalArgumentException
287			*/
288			public void testNextDoubleBadBounds() {
289			SplittableRandom sr = new SplittableRandom();
290	jsr166	1.25	assertThrows(
291			IllegalArgumentException.class,
292	jsr166	1.10	() -> sr.nextDouble(17.0d, 2.0d),
293			() -> sr.nextDouble(-42.0d, -42.0d),
294			() -> sr.nextDouble(Double.MAX_VALUE, Double.MIN_VALUE),
295			() -> sr.nextDouble(Double.NaN, 0.0d),
296	jsr166	1.25	() -> sr.nextDouble(0.0d, Double.NaN));
297	jsr166	1.10	}
298
299			// TODO: Test infinite bounds!
300			//() -> sr.nextDouble(Double.NEGATIVE_INFINITY, 0.0d),
301			//() -> sr.nextDouble(0.0d, Double.POSITIVE_INFINITY),
302
303			/**
304	dl	1.1	* nextDouble(least, bound) returns least <= value < bound;
305	jsr166	1.4	* repeated calls produce at least two distinct results
306	dl	1.1	*/
307			public void testNextDoubleBounded2() {
308			SplittableRandom sr = new SplittableRandom();
309			for (double least = 0.0001; least < 1.0e20; least *= 8) {
310			for (double bound = least * 1.001; bound < 1.0e20; bound *= 16) {
311			double f = sr.nextDouble(least, bound);
312			assertTrue(least <= f && f < bound);
313			int i = 0;
314			double j;
315			while (i < NCALLS &&
316			(j = sr.nextDouble(least, bound)) == f) {
317			assertTrue(least <= j && j < bound);
318			++i;
319			}
320			assertTrue(i < NCALLS);
321			}
322			}
323			}
324
325			/**
326			* Invoking sized ints, long, doubles, with negative sizes throws
327			* IllegalArgumentException
328			*/
329			public void testBadStreamSize() {
330			SplittableRandom r = new SplittableRandom();
331	jsr166	1.25	assertThrows(
332			IllegalArgumentException.class,
333	jsr166	1.8	() -> { java.util.stream.IntStream x = r.ints(-1L); },
334			() -> { java.util.stream.IntStream x = r.ints(-1L, 2, 3); },
335			() -> { java.util.stream.LongStream x = r.longs(-1L); },
336			() -> { java.util.stream.LongStream x = r.longs(-1L, -1L, 1L); },
337			() -> { java.util.stream.DoubleStream x = r.doubles(-1L); },
338	jsr166	1.25	() -> { java.util.stream.DoubleStream x = r.doubles(-1L, .5, .6); });
339	dl	1.1	}
340
341			/**
342			* Invoking bounded ints, long, doubles, with illegal bounds throws
343			* IllegalArgumentException
344			*/
345			public void testBadStreamBounds() {
346			SplittableRandom r = new SplittableRandom();
347	jsr166	1.25	assertThrows(
348			IllegalArgumentException.class,
349	jsr166	1.8	() -> { java.util.stream.IntStream x = r.ints(2, 1); },
350			() -> { java.util.stream.IntStream x = r.ints(10, 42, 42); },
351			() -> { java.util.stream.LongStream x = r.longs(-1L, -1L); },
352			() -> { java.util.stream.LongStream x = r.longs(10, 1L, -2L); },
353			() -> { java.util.stream.DoubleStream x = r.doubles(0.0, 0.0); },
354	jsr166	1.25	() -> { java.util.stream.DoubleStream x = r.doubles(10, .5, .4); });
355	dl	1.1	}
356
357			/**
358			* A parallel sized stream of ints generates the given number of values
359			*/
360			public void testIntsCount() {
361			LongAdder counter = new LongAdder();
362			SplittableRandom r = new SplittableRandom();
363			long size = 0;
364			for (int reps = 0; reps < REPS; ++reps) {
365			counter.reset();
366	jsr166	1.6	r.ints(size).parallel().forEach(x -> counter.increment());
367	jsr166	1.4	assertEquals(size, counter.sum());
368	dl	1.1	size += 524959;
369			}
370			}
371
372			/**
373			* A parallel sized stream of longs generates the given number of values
374			*/
375			public void testLongsCount() {
376			LongAdder counter = new LongAdder();
377			SplittableRandom r = new SplittableRandom();
378			long size = 0;
379			for (int reps = 0; reps < REPS; ++reps) {
380			counter.reset();
381	jsr166	1.6	r.longs(size).parallel().forEach(x -> counter.increment());
382	jsr166	1.4	assertEquals(size, counter.sum());
383	dl	1.1	size += 524959;
384			}
385			}
386
387			/**
388			* A parallel sized stream of doubles generates the given number of values
389			*/
390			public void testDoublesCount() {
391			LongAdder counter = new LongAdder();
392			SplittableRandom r = new SplittableRandom();
393			long size = 0;
394			for (int reps = 0; reps < REPS; ++reps) {
395			counter.reset();
396	jsr166	1.6	r.doubles(size).parallel().forEach(x -> counter.increment());
397	jsr166	1.4	assertEquals(size, counter.sum());
398	dl	1.1	size += 524959;
399			}
400			}
401
402			/**
403			* Each of a parallel sized stream of bounded ints is within bounds
404			*/
405			public void testBoundedInts() {
406			AtomicInteger fails = new AtomicInteger(0);
407			SplittableRandom r = new SplittableRandom();
408			long size = 12345L;
409			for (int least = -15485867; least < MAX_INT_BOUND; least += 524959) {
410			for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 67867967) {
411			final int lo = least, hi = bound;
412	jsr166	1.17	r.ints(size, lo, hi).parallel().forEach(
413			x -> {
414			if (x < lo \|\| x >= hi)
415			fails.getAndIncrement(); });
416	dl	1.1	}
417			}
418	jsr166	1.4	assertEquals(0, fails.get());
419	dl	1.1	}
420
421			/**
422			* Each of a parallel sized stream of bounded longs is within bounds
423			*/
424			public void testBoundedLongs() {
425			AtomicInteger fails = new AtomicInteger(0);
426			SplittableRandom r = new SplittableRandom();
427			long size = 123L;
428			for (long least = -86028121; least < MAX_LONG_BOUND; least += 1982451653L) {
429			for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) {
430			final long lo = least, hi = bound;
431	jsr166	1.17	r.longs(size, lo, hi).parallel().forEach(
432			x -> {
433			if (x < lo \|\| x >= hi)
434			fails.getAndIncrement(); });
435	dl	1.1	}
436			}
437	jsr166	1.4	assertEquals(0, fails.get());
438	dl	1.1	}
439
440			/**
441			* Each of a parallel sized stream of bounded doubles is within bounds
442			*/
443			public void testBoundedDoubles() {
444			AtomicInteger fails = new AtomicInteger(0);
445			SplittableRandom r = new SplittableRandom();
446			long size = 456;
447			for (double least = 0.00011; least < 1.0e20; least *= 9) {
448			for (double bound = least * 1.0011; bound < 1.0e20; bound *= 17) {
449			final double lo = least, hi = bound;
450	jsr166	1.17	r.doubles(size, lo, hi).parallel().forEach(
451			x -> {
452			if (x < lo \|\| x >= hi)
453			fails.getAndIncrement(); });
454	dl	1.1	}
455			}
456	jsr166	1.4	assertEquals(0, fails.get());
457	dl	1.1	}
458
459	dl	1.2	/**
460			* A parallel unsized stream of ints generates at least 100 values
461			*/
462			public void testUnsizedIntsCount() {
463			LongAdder counter = new LongAdder();
464			SplittableRandom r = new SplittableRandom();
465			long size = 100;
466	jsr166	1.6	r.ints().limit(size).parallel().forEach(x -> counter.increment());
467	jsr166	1.4	assertEquals(size, counter.sum());
468	dl	1.2	}
469
470			/**
471			* A parallel unsized stream of longs generates at least 100 values
472			*/
473			public void testUnsizedLongsCount() {
474			LongAdder counter = new LongAdder();
475			SplittableRandom r = new SplittableRandom();
476			long size = 100;
477	jsr166	1.6	r.longs().limit(size).parallel().forEach(x -> counter.increment());
478	jsr166	1.4	assertEquals(size, counter.sum());
479	dl	1.2	}
480
481			/**
482			* A parallel unsized stream of doubles generates at least 100 values
483			*/
484			public void testUnsizedDoublesCount() {
485			LongAdder counter = new LongAdder();
486			SplittableRandom r = new SplittableRandom();
487			long size = 100;
488	jsr166	1.6	r.doubles().limit(size).parallel().forEach(x -> counter.increment());
489	jsr166	1.4	assertEquals(size, counter.sum());
490	dl	1.2	}
491
492			/**
493			* A sequential unsized stream of ints generates at least 100 values
494			*/
495			public void testUnsizedIntsCountSeq() {
496			LongAdder counter = new LongAdder();
497			SplittableRandom r = new SplittableRandom();
498			long size = 100;
499	jsr166	1.6	r.ints().limit(size).forEach(x -> counter.increment());
500	jsr166	1.4	assertEquals(size, counter.sum());
501	dl	1.2	}
502
503			/**
504			* A sequential unsized stream of longs generates at least 100 values
505			*/
506			public void testUnsizedLongsCountSeq() {
507			LongAdder counter = new LongAdder();
508			SplittableRandom r = new SplittableRandom();
509			long size = 100;
510	jsr166	1.6	r.longs().limit(size).forEach(x -> counter.increment());
511	jsr166	1.4	assertEquals(size, counter.sum());
512	dl	1.2	}
513
514			/**
515			* A sequential unsized stream of doubles generates at least 100 values
516			*/
517			public void testUnsizedDoublesCountSeq() {
518			LongAdder counter = new LongAdder();
519			SplittableRandom r = new SplittableRandom();
520			long size = 100;
521	jsr166	1.6	r.doubles().limit(size).forEach(x -> counter.increment());
522	jsr166	1.4	assertEquals(size, counter.sum());
523	dl	1.2	}
524
525	jsr166	1.22	/**
526			* SplittableRandom should implement most of Random's public methods
527			*/
528			public void testShouldImplementMostRandomMethods() throws Throwable {
529			Predicate<Method> wasForgotten = method -> {
530			String name = method.getName();
531			// some methods deliberately not implemented
532			if (name.equals("setSeed")) return false;
533			if (name.equals("nextFloat")) return false;
534			if (name.equals("nextGaussian")) return false;
535			try {
536			SplittableRandom.class.getMethod(
537			method.getName(), method.getParameterTypes());
538			} catch (ReflectiveOperationException ex) {
539			return true;
540			}
541			return false;
542			};
543			List<Method> forgotten =
544			Arrays.stream(java.util.Random.class.getMethods())
545			.filter(wasForgotten)
546			.collect(Collectors.toList());
547			if (!forgotten.isEmpty())
548			throw new AssertionError("Please implement: " + forgotten);
549			}
550
551			/**
552			* Repeated calls to nextBytes produce at least values of different signs for every byte
553			*/
554			public void testNextBytes() {
555			SplittableRandom sr = new SplittableRandom();
556	jsr166	1.23	int n = sr.nextInt(1, 20);
557	jsr166	1.22	byte[] bytes = new byte[n];
558			outer:
559			for (int i = 0; i < n; i++) {
560			for (int tries = NCALLS; tries-->0; ) {
561			byte before = bytes[i];
562			sr.nextBytes(bytes);
563			byte after = bytes[i];
564			if (after * before < 0)
565			continue outer;
566			}
567			fail("not enough variation in random bytes");
568			}
569			}
570
571	jsr166	1.23	/**
572			* Filling an empty array with random bytes succeeds without effect.
573			*/
574			public void testNextBytes_emptyArray() {
575			new SplittableRandom().nextBytes(new byte[0]);
576			}
577
578			public void testNextBytes_nullArray() {
579			try {
580			new SplittableRandom().nextBytes(null);
581			shouldThrow();
582			} catch (NullPointerException success) {}
583			}
584
585	dl	1.1	}