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.ArrayList;
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();
        Runnable[] throwingActions = {
            () -> sr.nextInt(-17),
            () -> sr.nextInt(0),
            () -> sr.nextInt(Integer.MIN_VALUE),
        };
        assertThrows(IllegalArgumentException.class, throwingActions);
    }

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

    /**
     * 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();
        Runnable[] throwingActions = {
            () -> sr.nextLong(-17L),
            () -> sr.nextLong(0L),
            () -> sr.nextLong(Long.MIN_VALUE),
        };
        assertThrows(IllegalArgumentException.class, throwingActions);
    }

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

    /**
     * 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();
        Runnable[] throwingActions = {
            () -> sr.nextDouble(-17.0d),
            () -> sr.nextDouble(0.0d),
            () -> sr.nextDouble(-Double.MIN_VALUE),
            () -> sr.nextDouble(Double.NEGATIVE_INFINITY),
            () -> sr.nextDouble(Double.NaN),
        };
        assertThrows(IllegalArgumentException.class, throwingActions);
    }

    /**
     * nextDouble(! (least < bound)) throws IllegalArgumentException
     */
    public void testNextDoubleBadBounds() {
        SplittableRandom sr = new SplittableRandom();
        Runnable[] throwingActions = {
            () -> 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),
        };
        assertThrows(IllegalArgumentException.class, throwingActions);
    }

    // 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();
        Runnable[] throwingActions = {
            () -> { 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); },
        };
        assertThrows(IllegalArgumentException.class, throwingActions);
    }

    /**
     * Invoking bounded ints, long, doubles, with illegal bounds throws
     * IllegalArgumentException
     */
    public void testBadStreamBounds() {
        SplittableRandom r = new SplittableRandom();
        Runnable[] throwingActions = {
            () -> { 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); },
        };
        assertThrows(IllegalArgumentException.class, throwingActions);
    }

    /**
     * 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:	1.23
Committed:	Fri Oct 13 02:34:59 2017 UTC (6 years, 7 months ago) by jsr166
Branch:	MAIN
Changes since 1.22:	+15 -1 lines
Log Message:	improve nextBytes tests
#	Content
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	import java.util.Arrays;
8	import java.util.ArrayList;
9	import java.util.List;
10	import java.util.SplittableRandom;
11	import java.util.concurrent.atomic.AtomicInteger;
12	import java.util.concurrent.atomic.LongAdder;
13	import java.lang.reflect.Method;
14	import java.util.function.Predicate;
15	import java.util.stream.Collectors;
16
17	import junit.framework.Test;
18	import junit.framework.TestSuite;
19
20	public class SplittableRandomTest extends JSR166TestCase {
21
22	public static void main(String[] args) {
23	main(suite(), args);
24	}
25	public static Test suite() {
26	return new TestSuite(SplittableRandomTest.class);
27	}
28
29	/*
30	* Testing coverage notes:
31	*
32	* 1. Many of the test methods are adapted from ThreadLocalRandomTest.
33	*
34	* 2. These tests do not check for random number generator quality.
35	* But we check for minimal API compliance by requiring that
36	* repeated calls to nextX methods, up to NCALLS tries, produce at
37	* least two distinct results. (In some possible universe, a
38	* "correct" implementation might fail, but the odds are vastly
39	* less than that of encountering a hardware failure while running
40	* the test.) For bounded nextX methods, we sample various
41	* intervals across multiples of primes. In other tests, we repeat
42	* under REPS different values.
43	*/
44
45	// max numbers of calls to detect getting stuck on one value
46	static final int NCALLS = 10000;
47
48	// max sampled int bound
49	static final int MAX_INT_BOUND = (1 << 26);
50
51	// max sampled long bound
52	static final long MAX_LONG_BOUND = (1L << 40);
53
54	// Number of replications for other checks
55	static final int REPS =
56	Integer.getInteger("SplittableRandomTest.reps", 4);
57
58	/**
59	* Repeated calls to nextInt produce at least two distinct results
60	*/
61	public void testNextInt() {
62	SplittableRandom sr = new SplittableRandom();
63	int f = sr.nextInt();
64	int i = 0;
65	while (i < NCALLS && sr.nextInt() == f)
66	++i;
67	assertTrue(i < NCALLS);
68	}
69
70	/**
71	* Repeated calls to nextLong produce at least two distinct results
72	*/
73	public void testNextLong() {
74	SplittableRandom sr = new SplittableRandom();
75	long f = sr.nextLong();
76	int i = 0;
77	while (i < NCALLS && sr.nextLong() == f)
78	++i;
79	assertTrue(i < NCALLS);
80	}
81
82	/**
83	* Repeated calls to nextDouble produce at least two distinct results
84	*/
85	public void testNextDouble() {
86	SplittableRandom sr = new SplittableRandom();
87	double f = sr.nextDouble();
88	int i = 0;
89	while (i < NCALLS && sr.nextDouble() == f)
90	++i;
91	assertTrue(i < NCALLS);
92	}
93
94	/**
95	* Two SplittableRandoms created with the same seed produce the
96	* same values for nextLong.
97	*/
98	public void testSeedConstructor() {
99	for (long seed = 2; seed < MAX_LONG_BOUND; seed += 15485863) {
100	SplittableRandom sr1 = new SplittableRandom(seed);
101	SplittableRandom sr2 = new SplittableRandom(seed);
102	for (int i = 0; i < REPS; ++i)
103	assertEquals(sr1.nextLong(), sr2.nextLong());
104	}
105	}
106
107	/**
108	* A SplittableRandom produced by split() of a default-constructed
109	* SplittableRandom generates a different sequence
110	*/
111	public void testSplit1() {
112	SplittableRandom sr = new SplittableRandom();
113	for (int reps = 0; reps < REPS; ++reps) {
114	SplittableRandom sc = sr.split();
115	int i = 0;
116	while (i < NCALLS && sr.nextLong() == sc.nextLong())
117	++i;
118	assertTrue(i < NCALLS);
119	}
120	}
121
122	/**
123	* A SplittableRandom produced by split() of a seeded-constructed
124	* SplittableRandom generates a different sequence
125	*/
126	public void testSplit2() {
127	SplittableRandom sr = new SplittableRandom(12345);
128	for (int reps = 0; reps < REPS; ++reps) {
129	SplittableRandom sc = sr.split();
130	int i = 0;
131	while (i < NCALLS && sr.nextLong() == sc.nextLong())
132	++i;
133	assertTrue(i < NCALLS);
134	}
135	}
136
137	/**
138	* nextInt(non-positive) throws IllegalArgumentException
139	*/
140	public void testNextIntBoundNonPositive() {
141	SplittableRandom sr = new SplittableRandom();
142	Runnable[] throwingActions = {
143	() -> sr.nextInt(-17),
144	() -> sr.nextInt(0),
145	() -> sr.nextInt(Integer.MIN_VALUE),
146	};
147	assertThrows(IllegalArgumentException.class, throwingActions);
148	}
149
150	/**
151	* nextInt(least >= bound) throws IllegalArgumentException
152	*/
153	public void testNextIntBadBounds() {
154	SplittableRandom sr = new SplittableRandom();
155	Runnable[] throwingActions = {
156	() -> sr.nextInt(17, 2),
157	() -> sr.nextInt(-42, -42),
158	() -> sr.nextInt(Integer.MAX_VALUE, Integer.MIN_VALUE),
159	};
160	assertThrows(IllegalArgumentException.class, throwingActions);
161	}
162
163	/**
164	* nextInt(bound) returns 0 <= value < bound;
165	* repeated calls produce at least two distinct results
166	*/
167	public void testNextIntBounded() {
168	SplittableRandom sr = new SplittableRandom();
169	for (int i = 0; i < 2; i++) assertEquals(0, sr.nextInt(1));
170	// 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	* repeated calls produce at least two distinct results
188	*/
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	* nextLong(non-positive) throws IllegalArgumentException
209	*/
210	public void testNextLongBoundNonPositive() {
211	SplittableRandom sr = new SplittableRandom();
212	Runnable[] throwingActions = {
213	() -> sr.nextLong(-17L),
214	() -> sr.nextLong(0L),
215	() -> sr.nextLong(Long.MIN_VALUE),
216	};
217	assertThrows(IllegalArgumentException.class, throwingActions);
218	}
219
220	/**
221	* nextLong(least >= bound) throws IllegalArgumentException
222	*/
223	public void testNextLongBadBounds() {
224	SplittableRandom sr = new SplittableRandom();
225	Runnable[] throwingActions = {
226	() -> sr.nextLong(17L, 2L),
227	() -> sr.nextLong(-42L, -42L),
228	() -> sr.nextLong(Long.MAX_VALUE, Long.MIN_VALUE),
229	};
230	assertThrows(IllegalArgumentException.class, throwingActions);
231	}
232
233	/**
234	* nextLong(bound) returns 0 <= value < bound;
235	* repeated calls produce at least two distinct results
236	*/
237	public void testNextLongBounded() {
238	SplittableRandom sr = new SplittableRandom();
239	for (int i = 0; i < 2; i++) assertEquals(0L, sr.nextLong(1L));
240	for (long bound = 2; bound < MAX_LONG_BOUND; bound += 15485863) {
241	long f = sr.nextLong(bound);
242	assertTrue(0 <= f && f < bound);
243	int i = 0;
244	long j;
245	while (i < NCALLS &&
246	(j = sr.nextLong(bound)) == f) {
247	assertTrue(0 <= j && j < bound);
248	++i;
249	}
250	assertTrue(i < NCALLS);
251	}
252	}
253
254	/**
255	* nextLong(least, bound) returns least <= value < bound;
256	* repeated calls produce at least two distinct results
257	*/
258	public void testNextLongBounded2() {
259	SplittableRandom sr = new SplittableRandom();
260	for (long least = -86028121; least < MAX_LONG_BOUND; least += 982451653L) {
261	for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) {
262	long f = sr.nextLong(least, bound);
263	assertTrue(least <= f && f < bound);
264	int i = 0;
265	long j;
266	while (i < NCALLS &&
267	(j = sr.nextLong(least, bound)) == f) {
268	assertTrue(least <= j && j < bound);
269	++i;
270	}
271	assertTrue(i < NCALLS);
272	}
273	}
274	}
275
276	/**
277	* nextDouble(non-positive) throws IllegalArgumentException
278	*/
279	public void testNextDoubleBoundNonPositive() {
280	SplittableRandom sr = new SplittableRandom();
281	Runnable[] throwingActions = {
282	() -> sr.nextDouble(-17.0d),
283	() -> sr.nextDouble(0.0d),
284	() -> sr.nextDouble(-Double.MIN_VALUE),
285	() -> sr.nextDouble(Double.NEGATIVE_INFINITY),
286	() -> sr.nextDouble(Double.NaN),
287	};
288	assertThrows(IllegalArgumentException.class, throwingActions);
289	}
290
291	/**
292	* nextDouble(! (least < bound)) throws IllegalArgumentException
293	*/
294	public void testNextDoubleBadBounds() {
295	SplittableRandom sr = new SplittableRandom();
296	Runnable[] throwingActions = {
297	() -> sr.nextDouble(17.0d, 2.0d),
298	() -> sr.nextDouble(-42.0d, -42.0d),
299	() -> sr.nextDouble(Double.MAX_VALUE, Double.MIN_VALUE),
300	() -> sr.nextDouble(Double.NaN, 0.0d),
301	() -> sr.nextDouble(0.0d, Double.NaN),
302	};
303	assertThrows(IllegalArgumentException.class, throwingActions);
304	}
305
306	// TODO: Test infinite bounds!
307	//() -> sr.nextDouble(Double.NEGATIVE_INFINITY, 0.0d),
308	//() -> sr.nextDouble(0.0d, Double.POSITIVE_INFINITY),
309
310	/**
311	* nextDouble(least, bound) returns least <= value < bound;
312	* repeated calls produce at least two distinct results
313	*/
314	public void testNextDoubleBounded2() {
315	SplittableRandom sr = new SplittableRandom();
316	for (double least = 0.0001; least < 1.0e20; least *= 8) {
317	for (double bound = least * 1.001; bound < 1.0e20; bound *= 16) {
318	double f = sr.nextDouble(least, bound);
319	assertTrue(least <= f && f < bound);
320	int i = 0;
321	double j;
322	while (i < NCALLS &&
323	(j = sr.nextDouble(least, bound)) == f) {
324	assertTrue(least <= j && j < bound);
325	++i;
326	}
327	assertTrue(i < NCALLS);
328	}
329	}
330	}
331
332	/**
333	* Invoking sized ints, long, doubles, with negative sizes throws
334	* IllegalArgumentException
335	*/
336	public void testBadStreamSize() {
337	SplittableRandom r = new SplittableRandom();
338	Runnable[] throwingActions = {
339	() -> { java.util.stream.IntStream x = r.ints(-1L); },
340	() -> { java.util.stream.IntStream x = r.ints(-1L, 2, 3); },
341	() -> { java.util.stream.LongStream x = r.longs(-1L); },
342	() -> { java.util.stream.LongStream x = r.longs(-1L, -1L, 1L); },
343	() -> { java.util.stream.DoubleStream x = r.doubles(-1L); },
344	() -> { java.util.stream.DoubleStream x = r.doubles(-1L, .5, .6); },
345	};
346	assertThrows(IllegalArgumentException.class, throwingActions);
347	}
348
349	/**
350	* Invoking bounded ints, long, doubles, with illegal bounds throws
351	* IllegalArgumentException
352	*/
353	public void testBadStreamBounds() {
354	SplittableRandom r = new SplittableRandom();
355	Runnable[] throwingActions = {
356	() -> { java.util.stream.IntStream x = r.ints(2, 1); },
357	() -> { java.util.stream.IntStream x = r.ints(10, 42, 42); },
358	() -> { java.util.stream.LongStream x = r.longs(-1L, -1L); },
359	() -> { java.util.stream.LongStream x = r.longs(10, 1L, -2L); },
360	() -> { java.util.stream.DoubleStream x = r.doubles(0.0, 0.0); },
361	() -> { java.util.stream.DoubleStream x = r.doubles(10, .5, .4); },
362	};
363	assertThrows(IllegalArgumentException.class, throwingActions);
364	}
365
366	/**
367	* A parallel sized stream of ints generates the given number of values
368	*/
369	public void testIntsCount() {
370	LongAdder counter = new LongAdder();
371	SplittableRandom r = new SplittableRandom();
372	long size = 0;
373	for (int reps = 0; reps < REPS; ++reps) {
374	counter.reset();
375	r.ints(size).parallel().forEach(x -> counter.increment());
376	assertEquals(size, counter.sum());
377	size += 524959;
378	}
379	}
380
381	/**
382	* A parallel sized stream of longs generates the given number of values
383	*/
384	public void testLongsCount() {
385	LongAdder counter = new LongAdder();
386	SplittableRandom r = new SplittableRandom();
387	long size = 0;
388	for (int reps = 0; reps < REPS; ++reps) {
389	counter.reset();
390	r.longs(size).parallel().forEach(x -> counter.increment());
391	assertEquals(size, counter.sum());
392	size += 524959;
393	}
394	}
395
396	/**
397	* A parallel sized stream of doubles generates the given number of values
398	*/
399	public void testDoublesCount() {
400	LongAdder counter = new LongAdder();
401	SplittableRandom r = new SplittableRandom();
402	long size = 0;
403	for (int reps = 0; reps < REPS; ++reps) {
404	counter.reset();
405	r.doubles(size).parallel().forEach(x -> counter.increment());
406	assertEquals(size, counter.sum());
407	size += 524959;
408	}
409	}
410
411	/**
412	* Each of a parallel sized stream of bounded ints is within bounds
413	*/
414	public void testBoundedInts() {
415	AtomicInteger fails = new AtomicInteger(0);
416	SplittableRandom r = new SplittableRandom();
417	long size = 12345L;
418	for (int least = -15485867; least < MAX_INT_BOUND; least += 524959) {
419	for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 67867967) {
420	final int lo = least, hi = bound;
421	r.ints(size, lo, hi).parallel().forEach(
422	x -> {
423	if (x < lo \|\| x >= hi)
424	fails.getAndIncrement(); });
425	}
426	}
427	assertEquals(0, fails.get());
428	}
429
430	/**
431	* Each of a parallel sized stream of bounded longs is within bounds
432	*/
433	public void testBoundedLongs() {
434	AtomicInteger fails = new AtomicInteger(0);
435	SplittableRandom r = new SplittableRandom();
436	long size = 123L;
437	for (long least = -86028121; least < MAX_LONG_BOUND; least += 1982451653L) {
438	for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) {
439	final long lo = least, hi = bound;
440	r.longs(size, lo, hi).parallel().forEach(
441	x -> {
442	if (x < lo \|\| x >= hi)
443	fails.getAndIncrement(); });
444	}
445	}
446	assertEquals(0, fails.get());
447	}
448
449	/**
450	* Each of a parallel sized stream of bounded doubles is within bounds
451	*/
452	public void testBoundedDoubles() {
453	AtomicInteger fails = new AtomicInteger(0);
454	SplittableRandom r = new SplittableRandom();
455	long size = 456;
456	for (double least = 0.00011; least < 1.0e20; least *= 9) {
457	for (double bound = least * 1.0011; bound < 1.0e20; bound *= 17) {
458	final double lo = least, hi = bound;
459	r.doubles(size, lo, hi).parallel().forEach(
460	x -> {
461	if (x < lo \|\| x >= hi)
462	fails.getAndIncrement(); });
463	}
464	}
465	assertEquals(0, fails.get());
466	}
467
468	/**
469	* A parallel unsized stream of ints generates at least 100 values
470	*/
471	public void testUnsizedIntsCount() {
472	LongAdder counter = new LongAdder();
473	SplittableRandom r = new SplittableRandom();
474	long size = 100;
475	r.ints().limit(size).parallel().forEach(x -> counter.increment());
476	assertEquals(size, counter.sum());
477	}
478
479	/**
480	* A parallel unsized stream of longs generates at least 100 values
481	*/
482	public void testUnsizedLongsCount() {
483	LongAdder counter = new LongAdder();
484	SplittableRandom r = new SplittableRandom();
485	long size = 100;
486	r.longs().limit(size).parallel().forEach(x -> counter.increment());
487	assertEquals(size, counter.sum());
488	}
489
490	/**
491	* A parallel unsized stream of doubles generates at least 100 values
492	*/
493	public void testUnsizedDoublesCount() {
494	LongAdder counter = new LongAdder();
495	SplittableRandom r = new SplittableRandom();
496	long size = 100;
497	r.doubles().limit(size).parallel().forEach(x -> counter.increment());
498	assertEquals(size, counter.sum());
499	}
500
501	/**
502	* A sequential unsized stream of ints generates at least 100 values
503	*/
504	public void testUnsizedIntsCountSeq() {
505	LongAdder counter = new LongAdder();
506	SplittableRandom r = new SplittableRandom();
507	long size = 100;
508	r.ints().limit(size).forEach(x -> counter.increment());
509	assertEquals(size, counter.sum());
510	}
511
512	/**
513	* A sequential unsized stream of longs generates at least 100 values
514	*/
515	public void testUnsizedLongsCountSeq() {
516	LongAdder counter = new LongAdder();
517	SplittableRandom r = new SplittableRandom();
518	long size = 100;
519	r.longs().limit(size).forEach(x -> counter.increment());
520	assertEquals(size, counter.sum());
521	}
522
523	/**
524	* A sequential unsized stream of doubles generates at least 100 values
525	*/
526	public void testUnsizedDoublesCountSeq() {
527	LongAdder counter = new LongAdder();
528	SplittableRandom r = new SplittableRandom();
529	long size = 100;
530	r.doubles().limit(size).forEach(x -> counter.increment());
531	assertEquals(size, counter.sum());
532	}
533
534	/**
535	* SplittableRandom should implement most of Random's public methods
536	*/
537	public void testShouldImplementMostRandomMethods() throws Throwable {
538	Predicate<Method> wasForgotten = method -> {
539	String name = method.getName();
540	// some methods deliberately not implemented
541	if (name.equals("setSeed")) return false;
542	if (name.equals("nextFloat")) return false;
543	if (name.equals("nextGaussian")) return false;
544	try {
545	SplittableRandom.class.getMethod(
546	method.getName(), method.getParameterTypes());
547	} catch (ReflectiveOperationException ex) {
548	return true;
549	}
550	return false;
551	};
552	List<Method> forgotten =
553	Arrays.stream(java.util.Random.class.getMethods())
554	.filter(wasForgotten)
555	.collect(Collectors.toList());
556	if (!forgotten.isEmpty())
557	throw new AssertionError("Please implement: " + forgotten);
558	}
559
560	/**
561	* Repeated calls to nextBytes produce at least values of different signs for every byte
562	*/
563	public void testNextBytes() {
564	SplittableRandom sr = new SplittableRandom();
565	int n = sr.nextInt(1, 20);
566	byte[] bytes = new byte[n];
567	outer:
568	for (int i = 0; i < n; i++) {
569	for (int tries = NCALLS; tries-->0; ) {
570	byte before = bytes[i];
571	sr.nextBytes(bytes);
572	byte after = bytes[i];
573	if (after * before < 0)
574	continue outer;
575	}
576	fail("not enough variation in random bytes");
577	}
578	}
579
580	/**
581	* Filling an empty array with random bytes succeeds without effect.
582	*/
583	public void testNextBytes_emptyArray() {
584	new SplittableRandom().nextBytes(new byte[0]);
585	}
586
587	public void testNextBytes_nullArray() {
588	try {
589	new SplittableRandom().nextBytes(null);
590	shouldThrow();
591	} catch (NullPointerException success) {}
592	}
593
594	}