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dragonwell8_jdk
提交 1281ac53 编写于 作者: P psandoz
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8023155: Ensure functional consistency across Random, ThreadLocalRandom, SplittableRandom 

Reviewed-by: mduigou
Contributed-by: NDoug Lea &lt;dl@cs.oswego.edu&gt;, Paul Sandoz <paul.sandoz@oracle.com>
上级 4a714162
隐藏空白更改
内联 并排
Showing with 2427 addition and 213 deletion
src/share/classes/java/util/Random.java
浏览文件 @ 1281ac53
...@@ -26,9 +26,13 @@ ...@@ -26,9 +26,13 @@
package java.util; package java.util;
import java.io.*; import java.io.*;
import java.util.concurrent.atomic.AtomicLong; import java.util.concurrent.atomic.AtomicLong;
import java.util.function.DoubleConsumer;
import java.util.function.IntConsumer;
import java.util.function.LongConsumer;
import java.util.stream.DoubleStream; import java.util.stream.DoubleStream;
import java.util.stream.IntStream; import java.util.stream.IntStream;
import java.util.stream.LongStream; import java.util.stream.LongStream;
import java.util.stream.StreamSupport;
import sun.misc.Unsafe; import sun.misc.Unsafe;
...@@ -85,6 +89,13 @@ class Random implements java.io.Serializable { ...@@ -85,6 +89,13 @@ class Random implements java.io.Serializable {
private static final long addend = 0xBL; private static final long addend = 0xBL;
private static final long mask = (1L << 48) - 1; private static final long mask = (1L << 48) - 1;
private static final double DOUBLE_UNIT = 1.0 / (1L << 53);
// IllegalArgumentException messages
static final String BadBound = "bound must be positive";
static final String BadRange = "bound must be greater than origin";
static final String BadSize = "size must be non-negative";
/** /**
* Creates a new random number generator. This constructor sets * Creates a new random number generator. This constructor sets
* the seed of the random number generator to a value very likely * the seed of the random number generator to a value very likely
...@@ -221,6 +232,82 @@ class Random implements java.io.Serializable { ...@@ -221,6 +232,82 @@ class Random implements java.io.Serializable {
bytes[i++] = (byte)rnd; bytes[i++] = (byte)rnd;
} }
/**
* The form of nextLong used by LongStream Spliterators. If
* origin is greater than bound, acts as unbounded form of
* nextLong, else as bounded form.
*
* @param origin the least value, unless greater than bound
* @param bound the upper bound (exclusive), must not equal origin
* @return a pseudorandom value
*/
final long internalNextLong(long origin, long bound) {
long r = nextLong();
if (origin < bound) {
long n = bound - origin, m = n - 1;
if ((n & m) == 0L) // power of two
r = (r & m) + origin;
else if (n > 0L) { // reject over-represented candidates
for (long u = r >>> 1; // ensure nonnegative
u + m - (r = u % n) < 0L; // rejection check
u = nextLong() >>> 1) // retry
;
r += origin;
}
else { // range not representable as long
while (r < origin || r >= bound)
r = nextLong();
}
}
return r;
}
/**
* The form of nextInt used by IntStream Spliterators.
* For the unbounded case: uses nextInt().
* For the bounded case with representable range: uses nextInt(int bound)
* For the bounded case with unrepresentable range: uses nextInt()
*
* @param origin the least value, unless greater than bound
* @param bound the upper bound (exclusive), must not equal origin
* @return a pseudorandom value
*/
final int internalNextInt(int origin, int bound) {
if (origin < bound) {
int n = bound - origin;
if (n > 0) {
return nextInt(n) + origin;
}
else { // range not representable as int
int r;
do {
r = nextInt();
} while (r < origin || r >= bound);
return r;
}
}
else {
return nextInt();
}
}
/**
* The form of nextDouble used by DoubleStream Spliterators.
*
* @param origin the least value, unless greater than bound
* @param bound the upper bound (exclusive), must not equal origin
* @return a pseudorandom value
*/
final double internalNextDouble(double origin, double bound) {
double r = nextDouble();
if (origin < bound) {
r = r * (bound - origin) + origin;
if (r >= bound) // correct for rounding
r = Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1);
}
return r;
}
/** /**
* Returns the next pseudorandom, uniformly distributed {@code int} * Returns the next pseudorandom, uniformly distributed {@code int}
* value from this random number generator's sequence. The general * value from this random number generator's sequence. The general
...@@ -247,23 +334,23 @@ class Random implements java.io.Serializable { ...@@ -247,23 +334,23 @@ class Random implements java.io.Serializable {
* between 0 (inclusive) and the specified value (exclusive), drawn from * between 0 (inclusive) and the specified value (exclusive), drawn from
* this random number generator's sequence. The general contract of * this random number generator's sequence. The general contract of
* {@code nextInt} is that one {@code int} value in the specified range * {@code nextInt} is that one {@code int} value in the specified range
* is pseudorandomly generated and returned. All {@code n} possible * is pseudorandomly generated and returned. All {@code bound} possible
* {@code int} values are produced with (approximately) equal * {@code int} values are produced with (approximately) equal
* probability. The method {@code nextInt(int n)} is implemented by * probability. The method {@code nextInt(int bound)} is implemented by
* class {@code Random} as if by: * class {@code Random} as if by:
* <pre> {@code * <pre> {@code
* public int nextInt(int n) { * public int nextInt(int bound) {
* if (n <= 0) * if (bound <= 0)
* throw new IllegalArgumentException("n must be positive"); * throw new IllegalArgumentException("bound must be positive");
* *
* if ((n & -n) == n) // i.e., n is a power of 2 * if ((bound & -bound) == bound) // i.e., bound is a power of 2
* return (int)((n * (long)next(31)) >> 31); * return (int)((bound * (long)next(31)) >> 31);
* *
* int bits, val; * int bits, val;
* do { * do {
* bits = next(31); * bits = next(31);
* val = bits % n; * val = bits % bound;
* } while (bits - val + (n-1) < 0); * } while (bits - val + (bound-1) < 0);
* return val; * return val;
* }}</pre> * }}</pre>
* *
...@@ -289,28 +376,28 @@ class Random implements java.io.Serializable { ...@@ -289,28 +376,28 @@ class Random implements java.io.Serializable {
* greatly increases the length of the sequence of values returned by * greatly increases the length of the sequence of values returned by
* successive calls to this method if n is a small power of two. * successive calls to this method if n is a small power of two.
* *
* @param n the bound on the random number to be returned. Must be * @param bound the upper bound (exclusive). Must be positive.
* positive.
* @return the next pseudorandom, uniformly distributed {@code int} * @return the next pseudorandom, uniformly distributed {@code int}
* value between {@code 0} (inclusive) and {@code n} (exclusive) * value between zero (inclusive) and {@code bound} (exclusive)
* from this random number generator's sequence * from this random number generator's sequence
* @throws IllegalArgumentException if n is not positive * @throws IllegalArgumentException if bound is not positive
* @since 1.2 * @since 1.2
*/ */
public int nextInt(int bound) {
if (bound <= 0)
throw new IllegalArgumentException(BadBound);
public int nextInt(int n) { int r = next(31);
if (n <= 0) int m = bound - 1;
throw new IllegalArgumentException("n must be positive"); if ((bound & m) == 0) // i.e., bound is a power of 2
r = (int)((bound * (long)r) >> 31);
if ((n & -n) == n) // i.e., n is a power of 2 else {
return (int)((n * (long)next(31)) >> 31); for (int u = r;
u - (r = u % bound) + m < 0;
int bits, val; u = next(31))
do { ;
bits = next(31); }
val = bits % n; return r;
} while (bits - val + (n-1) < 0);
return val;
} }
/** /**
...@@ -442,8 +529,7 @@ class Random implements java.io.Serializable { ...@@ -442,8 +529,7 @@ class Random implements java.io.Serializable {
* @see Math#random * @see Math#random
*/ */
public double nextDouble() { public double nextDouble() {
return (((long)(next(26)) << 27) + next(27)) return (((long)(next(26)) << 27) + next(27)) * DOUBLE_UNIT;
/ (double)(1L << 53);
} }
private double nextNextGaussian; private double nextNextGaussian;
...@@ -513,57 +599,563 @@ class Random implements java.io.Serializable { ...@@ -513,57 +599,563 @@ class Random implements java.io.Serializable {
} }
} }
// stream methods, coded in a way intended to better isolate for
// maintenance purposes the small differences across forms.
/** /**
* Returns a stream of pseudorandom, uniformly distributed * Returns a stream producing the given {@code streamSize} number of
* {@code integer} values from this random number generator's * pseudorandom {@code int} values.
* sequence. Values are obtained as needed by calling
* {@link #nextInt()}.
* *
* @return an infinite stream of {@code integer} values * <p>A pseudorandom {@code int} value is generated as if it's the result of
* calling the method {@link #nextInt()}.
*
* @param streamSize the number of values to generate
* @return a stream of pseudorandom {@code int} values
* @throws IllegalArgumentException if {@code streamSize} is
* less than zero
* @since 1.8
*/
public IntStream ints(long streamSize) {
if (streamSize < 0L)
throw new IllegalArgumentException(BadSize);
return StreamSupport.intStream
(new RandomIntsSpliterator
(this, 0L, streamSize, Integer.MAX_VALUE, 0),
false);
}
/**
* Returns an effectively unlimited stream of pseudorandom {@code int}
* values.
*
* <p>A pseudorandom {@code int} value is generated as if it's the result of
* calling the method {@link #nextInt()}.
*
* @implNote This method is implemented to be equivalent to {@code
* ints(Long.MAX_VALUE)}.
*
* @return a stream of pseudorandom {@code int} values
* @since 1.8 * @since 1.8
*/ */
public IntStream ints() { public IntStream ints() {
return IntStream.generate(this::nextInt); return StreamSupport.intStream
(new RandomIntsSpliterator
(this, 0L, Long.MAX_VALUE, Integer.MAX_VALUE, 0),
false);
}
/**
* Returns a stream producing the given {@code streamSize} number
* of pseudorandom {@code int} values, each conforming to the given
* origin (inclusive) and bound (exclusive).
*
* <p>A pseudorandom {@code int} value is generated as if it's the result of
* calling the following method with the origin and bound:
* <pre> {@code
* int nextInt(int origin, int bound) {
* int n = bound - origin;
* if (n > 0) {
* return nextInt(n) + origin;
* }
* else { // range not representable as int
* int r;
* do {
* r = nextInt();
* } while (r < origin || r >= bound);
* return r;
* }
* }}</pre>
*
* @param streamSize the number of values to generate
* @param randomNumberOrigin the origin (inclusive) of each random value
* @param randomNumberBound the bound (exclusive) of each random value
* @return a stream of pseudorandom {@code int} values,
* each with the given origin (inclusive) and bound (exclusive)
* @throws IllegalArgumentException if {@code streamSize} is
* less than zero, or {@code randomNumberOrigin}
* is greater than or equal to {@code randomNumberBound}
* @since 1.8
*/
public IntStream ints(long streamSize, int randomNumberOrigin,
int randomNumberBound) {
if (streamSize < 0L)
throw new IllegalArgumentException(BadSize);
if (randomNumberOrigin >= randomNumberBound)
throw new IllegalArgumentException(BadRange);
return StreamSupport.intStream
(new RandomIntsSpliterator
(this, 0L, streamSize, randomNumberOrigin, randomNumberBound),
false);
} }
/** /**
* Returns a stream of pseudorandom, uniformly distributed * Returns an effectively unlimited stream of pseudorandom {@code
* {@code long} values from this random number generator's * int} values, each conforming to the given origin (inclusive) and bound
* sequence. Values are obtained as needed by calling * (exclusive).
* {@link #nextLong()}. *
* <p>A pseudorandom {@code int} value is generated as if it's the result of
* calling the following method with the origin and bound:
* <pre> {@code
* int nextInt(int origin, int bound) {
* int n = bound - origin;
* if (n > 0) {
* return nextInt(n) + origin;
* }
* else { // range not representable as int
* int r;
* do {
* r = nextInt();
* } while (r < origin || r >= bound);
* return r;
* }
* }}</pre>
*
* @implNote This method is implemented to be equivalent to {@code
* ints(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
* *
* @return an infinite stream of {@code long} values * @param randomNumberOrigin the origin (inclusive) of each random value
* @param randomNumberBound the bound (exclusive) of each random value
* @return a stream of pseudorandom {@code int} values,
* each with the given origin (inclusive) and bound (exclusive)
* @throws IllegalArgumentException if {@code randomNumberOrigin}
* is greater than or equal to {@code randomNumberBound}
* @since 1.8
*/
public IntStream ints(int randomNumberOrigin, int randomNumberBound) {
if (randomNumberOrigin >= randomNumberBound)
throw new IllegalArgumentException(BadRange);
return StreamSupport.intStream
(new RandomIntsSpliterator
(this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
false);
}
/**
* Returns a stream producing the given {@code streamSize} number of
* pseudorandom {@code long} values.
*
* <p>A pseudorandom {@code long} value is generated as if it's the result
* of calling the method {@link #nextLong()}.
*
* @param streamSize the number of values to generate
* @return a stream of pseudorandom {@code long} values
* @throws IllegalArgumentException if {@code streamSize} is
* less than zero
* @since 1.8
*/
public LongStream longs(long streamSize) {
if (streamSize < 0L)
throw new IllegalArgumentException(BadSize);
return StreamSupport.longStream
(new RandomLongsSpliterator
(this, 0L, streamSize, Long.MAX_VALUE, 0L),
false);
}
/**
* Returns an effectively unlimited stream of pseudorandom {@code long}
* values.
*
* <p>A pseudorandom {@code long} value is generated as if it's the result
* of calling the method {@link #nextLong()}.
*
* @implNote This method is implemented to be equivalent to {@code
* longs(Long.MAX_VALUE)}.
*
* @return a stream of pseudorandom {@code long} values
* @since 1.8 * @since 1.8
*/ */
public LongStream longs() { public LongStream longs() {
return LongStream.generate(this::nextLong); return StreamSupport.longStream
(new RandomLongsSpliterator
(this, 0L, Long.MAX_VALUE, Long.MAX_VALUE, 0L),
false);
}
/**
* Returns a stream producing the given {@code streamSize} number of
* pseudorandom {@code long}, each conforming to the given origin
* (inclusive) and bound (exclusive).
*
* <p>A pseudorandom {@code long} value is generated as if it's the result
* of calling the following method with the origin and bound:
* <pre> {@code
* long nextLong(long origin, long bound) {
* long r = nextLong();
* long n = bound - origin, m = n - 1;
* if ((n & m) == 0L) // power of two
* r = (r & m) + origin;
* else if (n > 0L) { // reject over-represented candidates
* for (long u = r >>> 1; // ensure nonnegative
* u + m - (r = u % n) < 0L; // rejection check
* u = nextLong() >>> 1) // retry
* ;
* r += origin;
* }
* else { // range not representable as long
* while (r < origin || r >= bound)
* r = nextLong();
* }
* return r;
* }}</pre>
*
* @param streamSize the number of values to generate
* @param randomNumberOrigin the origin (inclusive) of each random value
* @param randomNumberBound the bound (exclusive) of each random value
* @return a stream of pseudorandom {@code long} values,
* each with the given origin (inclusive) and bound (exclusive)
* @throws IllegalArgumentException if {@code streamSize} is
* less than zero, or {@code randomNumberOrigin}
* is greater than or equal to {@code randomNumberBound}
* @since 1.8
*/
public LongStream longs(long streamSize, long randomNumberOrigin,
long randomNumberBound) {
if (streamSize < 0L)
throw new IllegalArgumentException(BadSize);
if (randomNumberOrigin >= randomNumberBound)
throw new IllegalArgumentException(BadRange);
return StreamSupport.longStream
(new RandomLongsSpliterator
(this, 0L, streamSize, randomNumberOrigin, randomNumberBound),
false);
}
/**
* Returns an effectively unlimited stream of pseudorandom {@code
* long} values, each conforming to the given origin (inclusive) and bound
* (exclusive).
*
* <p>A pseudorandom {@code long} value is generated as if it's the result
* of calling the following method with the origin and bound:
* <pre> {@code
* long nextLong(long origin, long bound) {
* long r = nextLong();
* long n = bound - origin, m = n - 1;
* if ((n & m) == 0L) // power of two
* r = (r & m) + origin;
* else if (n > 0L) { // reject over-represented candidates
* for (long u = r >>> 1; // ensure nonnegative
* u + m - (r = u % n) < 0L; // rejection check
* u = nextLong() >>> 1) // retry
* ;
* r += origin;
* }
* else { // range not representable as long
* while (r < origin || r >= bound)
* r = nextLong();
* }
* return r;
* }}</pre>
*
* @implNote This method is implemented to be equivalent to {@code
* longs(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
*
* @param randomNumberOrigin the origin (inclusive) of each random value
* @param randomNumberBound the bound (exclusive) of each random value
* @return a stream of pseudorandom {@code long} values,
* each with the given origin (inclusive) and bound (exclusive)
* @throws IllegalArgumentException if {@code randomNumberOrigin}
* is greater than or equal to {@code randomNumberBound}
* @since 1.8
*/
public LongStream longs(long randomNumberOrigin, long randomNumberBound) {
if (randomNumberOrigin >= randomNumberBound)
throw new IllegalArgumentException(BadRange);
return StreamSupport.longStream
(new RandomLongsSpliterator
(this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
false);
} }
/** /**
* Returns a stream of pseudorandom, uniformly distributed * Returns a stream producing the given {@code streamSize} number of
* {@code double} values between {@code 0.0} and {@code 1.0} * pseudorandom {@code double} values, each between zero
* from this random number generator's sequence. Values are * (inclusive) and one (exclusive).
* obtained as needed by calling {@link #nextDouble()}. *
* <p>A pseudorandom {@code double} value is generated as if it's the result
* of calling the method {@link #nextDouble()}}.
* *
* @return an infinite stream of {@code double} values * @param streamSize the number of values to generate
* @return a stream of {@code double} values
* @throws IllegalArgumentException if {@code streamSize} is
* less than zero
* @since 1.8
*/
public DoubleStream doubles(long streamSize) {
if (streamSize < 0L)
throw new IllegalArgumentException(BadSize);
return StreamSupport.doubleStream
(new RandomDoublesSpliterator
(this, 0L, streamSize, Double.MAX_VALUE, 0.0),
false);
}
/**
* Returns an effectively unlimited stream of pseudorandom {@code
* double} values, each between zero (inclusive) and one
* (exclusive).
*
* <p>A pseudorandom {@code double} value is generated as if it's the result
* of calling the method {@link #nextDouble()}}.
*
* @implNote This method is implemented to be equivalent to {@code
* doubles(Long.MAX_VALUE)}.
*
* @return a stream of pseudorandom {@code double} values
* @since 1.8 * @since 1.8
*/ */
public DoubleStream doubles() { public DoubleStream doubles() {
return DoubleStream.generate(this::nextDouble); return StreamSupport.doubleStream
(new RandomDoublesSpliterator
(this, 0L, Long.MAX_VALUE, Double.MAX_VALUE, 0.0),
false);
} }
/** /**
* Returns a stream of pseudorandom, Gaussian ("normally") * Returns a stream producing the given {@code streamSize} number of
* distributed {@code double} values with mean {@code 0.0} * pseudorandom {@code double} values, each conforming to the given origin
* and standard deviation {@code 1.0} from this random number * (inclusive) and bound (exclusive).
* generator's sequence. Values are obtained as needed by *
* calling {@link #nextGaussian()}. * <p>A pseudorandom {@code double} value is generated as if it's the result
* of calling the following method with the origin and bound:
* <pre> {@code
* double nextDouble(double origin, double bound) {
* double r = nextDouble();
* r = r * (bound - origin) + origin;
* if (r >= bound) // correct for rounding
* r = Math.nextDown(bound);
* return r;
* }}</pre>
* *
* @return an infinite stream of {@code double} values * @param streamSize the number of values to generate
* @param randomNumberOrigin the origin (inclusive) of each random value
* @param randomNumberBound the bound (exclusive) of each random value
* @return a stream of pseudorandom {@code double} values,
* each with the given origin (inclusive) and bound (exclusive)
* @throws IllegalArgumentException if {@code streamSize} is
* less than zero
* @throws IllegalArgumentException if {@code randomNumberOrigin}
* is greater than or equal to {@code randomNumberBound}
* @since 1.8 * @since 1.8
*/ */
public DoubleStream gaussians() { public DoubleStream doubles(long streamSize, double randomNumberOrigin,
return DoubleStream.generate(this::nextGaussian); double randomNumberBound) {
if (streamSize < 0L)
throw new IllegalArgumentException(BadSize);
if (!(randomNumberOrigin < randomNumberBound))
throw new IllegalArgumentException(BadRange);
return StreamSupport.doubleStream
(new RandomDoublesSpliterator
(this, 0L, streamSize, randomNumberOrigin, randomNumberBound),
false);
}
/**
* Returns an effectively unlimited stream of pseudorandom {@code
* double} values, each conforming to the given origin (inclusive) and bound
* (exclusive).
*
* <p>A pseudorandom {@code double} value is generated as if it's the result
* of calling the following method with the origin and bound:
* <pre> {@code
* double nextDouble(double origin, double bound) {
* double r = nextDouble();
* r = r * (bound - origin) + origin;
* if (r >= bound) // correct for rounding
* r = Math.nextDown(bound);
* return r;
* }}</pre>
*
* @implNote This method is implemented to be equivalent to {@code
* doubles(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
*
* @param randomNumberOrigin the origin (inclusive) of each random value
* @param randomNumberBound the bound (exclusive) of each random value
* @return a stream of pseudorandom {@code double} values,
* each with the given origin (inclusive) and bound (exclusive)
* @throws IllegalArgumentException if {@code randomNumberOrigin}
* is greater than or equal to {@code randomNumberBound}
* @since 1.8
*/
public DoubleStream doubles(double randomNumberOrigin, double randomNumberBound) {
if (!(randomNumberOrigin < randomNumberBound))
throw new IllegalArgumentException(BadRange);
return StreamSupport.doubleStream
(new RandomDoublesSpliterator
(this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
false);
}
/**
* Spliterator for int streams. We multiplex the four int
* versions into one class by treating a bound less than origin as
* unbounded, and also by treating "infinite" as equivalent to
* Long.MAX_VALUE. For splits, it uses the standard divide-by-two
* approach. The long and double versions of this class are
* identical except for types.
*/
static final class RandomIntsSpliterator implements Spliterator.OfInt {
final Random rng;
long index;
final long fence;
final int origin;
final int bound;
RandomIntsSpliterator(Random rng, long index, long fence,
int origin, int bound) {
this.rng = rng; this.index = index; this.fence = fence;
this.origin = origin; this.bound = bound;
}
public RandomIntsSpliterator trySplit() {
long i = index, m = (i + fence) >>> 1;
return (m <= i) ? null :
new RandomIntsSpliterator(rng, i, index = m, origin, bound);
}
public long estimateSize() {
return fence - index;
}
public int characteristics() {
return (Spliterator.SIZED | Spliterator.SUBSIZED |
Spliterator.NONNULL | Spliterator.IMMUTABLE);
}
public boolean tryAdvance(IntConsumer consumer) {
if (consumer == null) throw new NullPointerException();
long i = index, f = fence;
if (i < f) {
consumer.accept(rng.internalNextInt(origin, bound));
index = i + 1;
return true;
}
return false;
}
public void forEachRemaining(IntConsumer consumer) {
if (consumer == null) throw new NullPointerException();
long i = index, f = fence;
if (i < f) {
index = f;
Random r = rng;
int o = origin, b = bound;
do {
consumer.accept(r.internalNextInt(o, b));
} while (++i < f);
}
}
}
/**
* Spliterator for long streams.
*/
static final class RandomLongsSpliterator implements Spliterator.OfLong {
final Random rng;
long index;
final long fence;
final long origin;
final long bound;
RandomLongsSpliterator(Random rng, long index, long fence,
long origin, long bound) {
this.rng = rng; this.index = index; this.fence = fence;
this.origin = origin; this.bound = bound;
}
public RandomLongsSpliterator trySplit() {
long i = index, m = (i + fence) >>> 1;
return (m <= i) ? null :
new RandomLongsSpliterator(rng, i, index = m, origin, bound);
}
public long estimateSize() {
return fence - index;
}
public int characteristics() {
return (Spliterator.SIZED | Spliterator.SUBSIZED |
Spliterator.NONNULL | Spliterator.IMMUTABLE);
}
public boolean tryAdvance(LongConsumer consumer) {
if (consumer == null) throw new NullPointerException();
long i = index, f = fence;
if (i < f) {
consumer.accept(rng.internalNextLong(origin, bound));
index = i + 1;
return true;
}
return false;
}
public void forEachRemaining(LongConsumer consumer) {
if (consumer == null) throw new NullPointerException();
long i = index, f = fence;
if (i < f) {
index = f;
Random r = rng;
long o = origin, b = bound;
do {
consumer.accept(r.internalNextLong(o, b));
} while (++i < f);
}
}
}
/**
* Spliterator for double streams.
*/
static final class RandomDoublesSpliterator implements Spliterator.OfDouble {
final Random rng;
long index;
final long fence;
final double origin;
final double bound;
RandomDoublesSpliterator(Random rng, long index, long fence,
double origin, double bound) {
this.rng = rng; this.index = index; this.fence = fence;
this.origin = origin; this.bound = bound;
}
public RandomDoublesSpliterator trySplit() {
long i = index, m = (i + fence) >>> 1;
return (m <= i) ? null :
new RandomDoublesSpliterator(rng, i, index = m, origin, bound);
}
public long estimateSize() {
return fence - index;
}
public int characteristics() {
return (Spliterator.SIZED | Spliterator.SUBSIZED |
Spliterator.NONNULL | Spliterator.IMMUTABLE);
}
public boolean tryAdvance(DoubleConsumer consumer) {
if (consumer == null) throw new NullPointerException();
long i = index, f = fence;
if (i < f) {
consumer.accept(rng.internalNextDouble(origin, bound));
index = i + 1;
return true;
}
return false;
}
public void forEachRemaining(DoubleConsumer consumer) {
if (consumer == null) throw new NullPointerException();
long i = index, f = fence;
if (i < f) {
index = f;
Random r = rng;
double o = origin, b = bound;
do {
consumer.accept(r.internalNextDouble(o, b));
} while (++i < f);
}
}
} }
/** /**
......
src/share/classes/java/util/concurrent/ThreadLocalRandom.java
浏览文件 @ 1281ac53
...@@ -37,11 +37,16 @@ package java.util.concurrent; ...@@ -37,11 +37,16 @@ package java.util.concurrent;
import java.io.ObjectStreamField; import java.io.ObjectStreamField;
import java.util.Random; import java.util.Random;
import java.util.Spliterator;
import java.util.concurrent.atomic.AtomicInteger; import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong; import java.util.concurrent.atomic.AtomicLong;
import java.util.function.DoubleConsumer;
import java.util.function.IntConsumer;
import java.util.function.LongConsumer;
import java.util.stream.DoubleStream; import java.util.stream.DoubleStream;
import java.util.stream.IntStream; import java.util.stream.IntStream;
import java.util.stream.LongStream; import java.util.stream.LongStream;
import java.util.stream.StreamSupport;
/** /**
* A random number generator isolated to the current thread. Like the * A random number generator isolated to the current thread. Like the
...@@ -64,6 +69,10 @@ import java.util.stream.LongStream; ...@@ -64,6 +69,10 @@ import java.util.stream.LongStream;
* <p>This class also provides additional commonly used bounded random * <p>This class also provides additional commonly used bounded random
* generation methods. * generation methods.
* *
* <p>Instances of {@code ThreadLocalRandom} are not cryptographically
* secure. Consider instead using {@link java.security.SecureRandom}
* in security-sensitive applications.
*
* @since 1.7 * @since 1.7
* @author Doug Lea * @author Doug Lea
*/ */
...@@ -85,28 +94,26 @@ public class ThreadLocalRandom extends Random { ...@@ -85,28 +94,26 @@ public class ThreadLocalRandom extends Random {
* application-level overhead and footprint of most concurrent * application-level overhead and footprint of most concurrent
* programs. * programs.
* *
* Even though this class subclasses java.util.Random, it uses the
* same basic algorithm as java.util.SplittableRandom. (See its
* internal documentation for explanations, which are not repeated
* here.) Because ThreadLocalRandoms are not splittable
* though, we use only a single 64bit gamma.
*
* Because this class is in a different package than class Thread, * Because this class is in a different package than class Thread,
* field access methods use Unsafe to bypass access control rules. * field access methods use Unsafe to bypass access control rules.
* The base functionality of Random methods is conveniently * To conform to the requirements of the Random superclass
* isolated in method next(bits), that just reads and writes the * constructor, the common static ThreadLocalRandom maintains an
* Thread field rather than its own field. However, to conform to * "initialized" field for the sake of rejecting user calls to
* the requirements of the Random superclass constructor, the * setSeed while still allowing a call from constructor. Note
* common static ThreadLocalRandom maintains an "initialized" * that serialization is completely unnecessary because there is
* field for the sake of rejecting user calls to setSeed while * only a static singleton. But we generate a serial form
* still allowing a call from constructor. Note that * containing "rnd" and "initialized" fields to ensure
* serialization is completely unnecessary because there is only a * compatibility across versions.
* static singleton. But we generate a serial form containing *
* "rnd" and "initialized" fields to ensure compatibility across * Implementations of non-core methods are mostly the same as in
* versions. * SplittableRandom, that were in part derived from a previous
* * version of this class.
* Per-thread initialization is similar to that in the no-arg
* Random constructor, but we avoid correlation among not only
* initial seeds of those created in different threads, but also
* those created using class Random itself; while at the same time
* not changing any statistical properties. So we use the same
* underlying multiplicative sequence, but start the sequence far
* away from the base version, and then merge (xor) current time
* and per-thread probe bits to generate initial values.
* *
* The nextLocalGaussian ThreadLocal supports the very rarely used * The nextLocalGaussian ThreadLocal supports the very rarely used
* nextGaussian method by providing a holder for the second of a * nextGaussian method by providing a holder for the second of a
...@@ -115,24 +122,51 @@ public class ThreadLocalRandom extends Random { ...@@ -115,24 +122,51 @@ public class ThreadLocalRandom extends Random {
* but we provide identical statistical properties. * but we provide identical statistical properties.
*/ */
// same constants as Random, but must be redeclared because private
private static final long multiplier = 0x5DEECE66DL;
private static final long addend = 0xBL;
private static final long mask = (1L << 48) - 1;
private static final int PROBE_INCREMENT = 0x61c88647;
/** Generates the basis for per-thread initial seed values */
private static final AtomicLong seedGenerator =
new AtomicLong(1269533684904616924L);
/** Generates per-thread initialization/probe field */ /** Generates per-thread initialization/probe field */
private static final AtomicInteger probeGenerator = private static final AtomicInteger probeGenerator =
new AtomicInteger(0xe80f8647); new AtomicInteger();
/**
* The next seed for default constructors.
*/
private static final AtomicLong seeder =
new AtomicLong(mix64(System.currentTimeMillis()) ^
mix64(System.nanoTime()));
/**
* The seed increment
*/
private static final long GAMMA = 0x9e3779b97f4a7c15L;
/**
* The increment for generating probe values
*/
private static final int PROBE_INCREMENT = 0x9e3779b9;
/**
* The increment of seeder per new instance
*/
private static final long SEEDER_INCREMENT = 0xbb67ae8584caa73bL;
// Constants from SplittableRandom
private static final double DOUBLE_UNIT = 1.0 / (1L << 53);
private static final float FLOAT_UNIT = 1.0f / (1 << 24);
/** Rarely-used holder for the second of a pair of Gaussians */ /** Rarely-used holder for the second of a pair of Gaussians */
private static final ThreadLocal<Double> nextLocalGaussian = private static final ThreadLocal<Double> nextLocalGaussian =
new ThreadLocal<Double>(); new ThreadLocal<Double>();
private static long mix64(long z) {
z = (z ^ (z >>> 33)) * 0xff51afd7ed558ccdL;
z = (z ^ (z >>> 33)) * 0xc4ceb9fe1a85ec53L;
return z ^ (z >>> 33);
}
private static int mix32(long z) {
z = (z ^ (z >>> 33)) * 0xff51afd7ed558ccdL;
return (int)(((z ^ (z >>> 33)) * 0xc4ceb9fe1a85ec53L) >>> 32);
}
/** /**
* Field used only during singleton initialization. * Field used only during singleton initialization.
* True when constructor completes. * True when constructor completes.
...@@ -155,16 +189,11 @@ public class ThreadLocalRandom extends Random { ...@@ -155,16 +189,11 @@ public class ThreadLocalRandom extends Random {
* rely on (static) atomic generators to initialize the values. * rely on (static) atomic generators to initialize the values.
*/ */
static final void localInit() { static final void localInit() {
int p = probeGenerator.getAndAdd(PROBE_INCREMENT); int p = probeGenerator.addAndGet(PROBE_INCREMENT);
int probe = (p == 0) ? 1 : p; // skip 0 int probe = (p == 0) ? 1 : p; // skip 0
long current, next; long seed = mix64(seeder.getAndAdd(SEEDER_INCREMENT));
do { // same sequence as j.u.Random but different initial value
current = seedGenerator.get();
next = current * 181783497276652981L;
} while (!seedGenerator.compareAndSet(current, next));
long r = next ^ ((long)probe << 32) ^ System.nanoTime();
Thread t = Thread.currentThread(); Thread t = Thread.currentThread();
UNSAFE.putLong(t, SEED, r); UNSAFE.putLong(t, SEED, seed);
UNSAFE.putInt(t, PROBE, probe); UNSAFE.putInt(t, PROBE, probe);
} }
...@@ -191,124 +220,264 @@ public class ThreadLocalRandom extends Random { ...@@ -191,124 +220,264 @@ public class ThreadLocalRandom extends Random {
throw new UnsupportedOperationException(); throw new UnsupportedOperationException();
} }
protected int next(int bits) { final long nextSeed() {
Thread t; long r; // read and update per-thread seed Thread t; long r; // read and update per-thread seed
UNSAFE.putLong UNSAFE.putLong(t = Thread.currentThread(), SEED,
(t = Thread.currentThread(), SEED, r = UNSAFE.getLong(t, SEED) + GAMMA);
r = (UNSAFE.getLong(t, SEED) * multiplier + addend) & mask); return r;
return (int) (r >>> (48-bits));
} }
// We must define this, but never use it.
protected int next(int bits) {
return (int)(mix64(nextSeed()) >>> (64 - bits));
}
// IllegalArgumentException messages
static final String BadBound = "bound must be positive";
static final String BadRange = "bound must be greater than origin";
static final String BadSize = "size must be non-negative";
/** /**
* Returns a pseudorandom, uniformly distributed value between the * The form of nextLong used by LongStream Spliterators. If
* given least value (inclusive) and bound (exclusive). * origin is greater than bound, acts as unbounded form of
* nextLong, else as bounded form.
* *
* @param least the least value returned * @param origin the least value, unless greater than bound
* @param bound the upper bound (exclusive) * @param bound the upper bound (exclusive), must not equal origin
* @throws IllegalArgumentException if least greater than or equal * @return a pseudorandom value
* to bound */
* @return the next value final long internalNextLong(long origin, long bound) {
*/ long r = mix64(nextSeed());
public int nextInt(int least, int bound) { if (origin < bound) {
if (least >= bound) long n = bound - origin, m = n - 1;
throw new IllegalArgumentException(); if ((n & m) == 0L) // power of two
return nextInt(bound - least) + least; r = (r & m) + origin;
} else if (n > 0L) { // reject over-represented candidates
for (long u = r >>> 1; // ensure nonnegative
/** u + m - (r = u % n) < 0L; // rejection check
* Returns a pseudorandom, uniformly distributed value u = mix64(nextSeed()) >>> 1) // retry
* between 0 (inclusive) and the specified value (exclusive). ;
* r += origin;
* @param n the bound on the random number to be returned. Must be }
* positive. else { // range not representable as long
* @return the next value while (r < origin || r >= bound)
* @throws IllegalArgumentException if n is not positive r = mix64(nextSeed());
*/ }
public long nextLong(long n) {
if (n <= 0)
throw new IllegalArgumentException("n must be positive");
// Divide n by two until small enough for nextInt. On each
// iteration (at most 31 of them but usually much less),
// randomly choose both whether to include high bit in result
// (offset) and whether to continue with the lower vs upper
// half (which makes a difference only if odd).
long offset = 0;
while (n >= Integer.MAX_VALUE) {
int bits = next(2);
long half = n >>> 1;
long nextn = ((bits & 2) == 0) ? half : n - half;
if ((bits & 1) == 0)
offset += n - nextn;
n = nextn;
} }
return offset + nextInt((int) n); return r;
} }
@Override /**
public IntStream ints() { * The form of nextInt used by IntStream Spliterators.
return IntStream.generate(() -> current().nextInt()); * Exactly the same as long version, except for types.
*
* @param origin the least value, unless greater than bound
* @param bound the upper bound (exclusive), must not equal origin
* @return a pseudorandom value
*/
final int internalNextInt(int origin, int bound) {
int r = mix32(nextSeed());
if (origin < bound) {
int n = bound - origin, m = n - 1;
if ((n & m) == 0)
r = (r & m) + origin;
else if (n > 0) {
for (int u = r >>> 1;
u + m - (r = u % n) < 0;
u = mix32(nextSeed()) >>> 1)
;
r += origin;
}
else {
while (r < origin || r >= bound)
r = mix32(nextSeed());
}
}
return r;
} }
@Override /**
public LongStream longs() { * The form of nextDouble used by DoubleStream Spliterators.
return LongStream.generate(() -> current().nextLong()); *
* @param origin the least value, unless greater than bound
* @param bound the upper bound (exclusive), must not equal origin
* @return a pseudorandom value
*/
final double internalNextDouble(double origin, double bound) {
double r = (nextLong() >>> 11) * DOUBLE_UNIT;
if (origin < bound) {
r = r * (bound - origin) + origin;
if (r >= bound) // correct for rounding
r = Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1);
}
return r;
} }
@Override /**
public DoubleStream doubles() { * Returns a pseudorandom {@code int} value.
return DoubleStream.generate(() -> current().nextDouble()); *
* @return a pseudorandom {@code int} value
*/
public int nextInt() {
return mix32(nextSeed());
} }
@Override /**
public DoubleStream gaussians() { * Returns a pseudorandom {@code int} value between zero (inclusive)
return DoubleStream.generate(() -> current().nextGaussian()); * and the specified bound (exclusive).
*
* @param bound the upper bound (exclusive). Must be positive.
* @return a pseudorandom {@code int} value between zero
* (inclusive) and the bound (exclusive)
* @throws IllegalArgumentException if {@code bound} is not positive
*/
public int nextInt(int bound) {
if (bound <= 0)
throw new IllegalArgumentException(BadBound);
int r = mix32(nextSeed());
int m = bound - 1;
if ((bound & m) == 0) // power of two
r &= m;
else { // reject over-represented candidates
for (int u = r >>> 1;
u + m - (r = u % bound) < 0;
u = mix32(nextSeed()) >>> 1)
;
}
return r;
} }
/** /**
* Returns a pseudorandom, uniformly distributed value between the * Returns a pseudorandom {@code int} value between the specified
* given least value (inclusive) and bound (exclusive). * origin (inclusive) and the specified bound (exclusive).
* *
* @param least the least value returned * @param origin the least value returned
* @param bound the upper bound (exclusive) * @param bound the upper bound (exclusive)
* @return the next value * @return a pseudorandom {@code int} value between the origin
* @throws IllegalArgumentException if least greater than or equal * (inclusive) and the bound (exclusive)
* to bound * @throws IllegalArgumentException if {@code origin} is greater than
* or equal to {@code bound}
*/ */
public long nextLong(long least, long bound) { public int nextInt(int origin, int bound) {
if (least >= bound) if (origin >= bound)
throw new IllegalArgumentException(); throw new IllegalArgumentException(BadRange);
return nextLong(bound - least) + least; return internalNextInt(origin, bound);
} }
/** /**
* Returns a pseudorandom, uniformly distributed {@code double} value * Returns a pseudorandom {@code long} value.
* between 0 (inclusive) and the specified value (exclusive).
* *
* @param n the bound on the random number to be returned. Must be * @return a pseudorandom {@code long} value
* positive.
* @return the next value
* @throws IllegalArgumentException if n is not positive
*/ */
public double nextDouble(double n) { public long nextLong() {
if (n <= 0) return mix64(nextSeed());
throw new IllegalArgumentException("n must be positive");
return nextDouble() * n;
} }
/** /**
* Returns a pseudorandom, uniformly distributed value between the * Returns a pseudorandom {@code long} value between zero (inclusive)
* given least value (inclusive) and bound (exclusive). * and the specified bound (exclusive).
* *
* @param least the least value returned * @param bound the upper bound (exclusive). Must be positive.
* @return a pseudorandom {@code long} value between zero
* (inclusive) and the bound (exclusive)
* @throws IllegalArgumentException if {@code bound} is not positive
*/
public long nextLong(long bound) {
if (bound <= 0)
throw new IllegalArgumentException(BadBound);
long r = mix64(nextSeed());
long m = bound - 1;
if ((bound & m) == 0L) // power of two
r &= m;
else { // reject over-represented candidates
for (long u = r >>> 1;
u + m - (r = u % bound) < 0L;
u = mix64(nextSeed()) >>> 1)
;
}
return r;
}
/**
* Returns a pseudorandom {@code long} value between the specified
* origin (inclusive) and the specified bound (exclusive).
*
* @param origin the least value returned
* @param bound the upper bound (exclusive) * @param bound the upper bound (exclusive)
* @return the next value * @return a pseudorandom {@code long} value between the origin
* @throws IllegalArgumentException if least greater than or equal * (inclusive) and the bound (exclusive)
* to bound * @throws IllegalArgumentException if {@code origin} is greater than
* or equal to {@code bound}
*/
public long nextLong(long origin, long bound) {
if (origin >= bound)
throw new IllegalArgumentException(BadRange);
return internalNextLong(origin, bound);
}
/**
* Returns a pseudorandom {@code double} value between zero
* (inclusive) and one (exclusive).
*
* @return a pseudorandom {@code double} value between zero
* (inclusive) and one (exclusive)
*/
public double nextDouble() {
return (mix64(nextSeed()) >>> 11) * DOUBLE_UNIT;
}
/**
* Returns a pseudorandom {@code double} value between 0.0
* (inclusive) and the specified bound (exclusive).
*
* @param bound the upper bound (exclusive). Must be positive.
* @return a pseudorandom {@code double} value between zero
* (inclusive) and the bound (exclusive)
* @throws IllegalArgumentException if {@code bound} is not positive
*/
public double nextDouble(double bound) {
if (!(bound > 0.0))
throw new IllegalArgumentException(BadBound);
double result = (mix64(nextSeed()) >>> 11) * DOUBLE_UNIT * bound;
return (result < bound) ? result : // correct for rounding
Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1);
}
/**
* Returns a pseudorandom {@code double} value between the specified
* origin (inclusive) and bound (exclusive).
*
* @param origin the least value returned
* @param bound the upper bound (exclusive)
* @return a pseudorandom {@code double} value between the origin
* (inclusive) and the bound (exclusive)
* @throws IllegalArgumentException if {@code origin} is greater than
* or equal to {@code bound}
*/
public double nextDouble(double origin, double bound) {
if (!(origin < bound))
throw new IllegalArgumentException(BadRange);
return internalNextDouble(origin, bound);
}
/**
* Returns a pseudorandom {@code boolean} value.
*
* @return a pseudorandom {@code boolean} value
*/ */
public double nextDouble(double least, double bound) { public boolean nextBoolean() {
if (least >= bound) return mix32(nextSeed()) < 0;
throw new IllegalArgumentException(); }
return nextDouble() * (bound - least) + least;
/**
* Returns a pseudorandom {@code float} value between zero
* (inclusive) and one (exclusive).
*
* @return a pseudorandom {@code float} value between zero
* (inclusive) and one (exclusive)
*/
public float nextFloat() {
return (mix32(nextSeed()) >>> 8) * FLOAT_UNIT;
} }
public double nextGaussian() { public double nextGaussian() {
...@@ -329,6 +498,445 @@ public class ThreadLocalRandom extends Random { ...@@ -329,6 +498,445 @@ public class ThreadLocalRandom extends Random {
return v1 * multiplier; return v1 * multiplier;
} }
// stream methods, coded in a way intended to better isolate for
// maintenance purposes the small differences across forms.
/**
* Returns a stream producing the given {@code streamSize} number of
* pseudorandom {@code int} values.
*
* @param streamSize the number of values to generate
* @return a stream of pseudorandom {@code int} values
* @throws IllegalArgumentException if {@code streamSize} is
* less than zero
* @since 1.8
*/
public IntStream ints(long streamSize) {
if (streamSize < 0L)
throw new IllegalArgumentException(BadSize);
return StreamSupport.intStream
(new RandomIntsSpliterator
(0L, streamSize, Integer.MAX_VALUE, 0),
false);
}
/**
* Returns an effectively unlimited stream of pseudorandom {@code int}
* values.
*
* @implNote This method is implemented to be equivalent to {@code
* ints(Long.MAX_VALUE)}.
*
* @return a stream of pseudorandom {@code int} values
* @since 1.8
*/
public IntStream ints() {
return StreamSupport.intStream
(new RandomIntsSpliterator
(0L, Long.MAX_VALUE, Integer.MAX_VALUE, 0),
false);
}
/**
* Returns a stream producing the given {@code streamSize} number
* of pseudorandom {@code int} values, each conforming to the given
* origin (inclusive) and bound (exclusive).
*
* @param streamSize the number of values to generate
* @param randomNumberOrigin the origin (inclusive) of each random value
* @param randomNumberBound the bound (exclusive) of each random value
* @return a stream of pseudorandom {@code int} values,
* each with the given origin (inclusive) and bound (exclusive)
* @throws IllegalArgumentException if {@code streamSize} is
* less than zero, or {@code randomNumberOrigin}
* is greater than or equal to {@code randomNumberBound}
* @since 1.8
*/
public IntStream ints(long streamSize, int randomNumberOrigin,
int randomNumberBound) {
if (streamSize < 0L)
throw new IllegalArgumentException(BadSize);
if (randomNumberOrigin >= randomNumberBound)
throw new IllegalArgumentException(BadRange);
return StreamSupport.intStream
(new RandomIntsSpliterator
(0L, streamSize, randomNumberOrigin, randomNumberBound),
false);
}
/**
* Returns an effectively unlimited stream of pseudorandom {@code
* int} values, each conforming to the given origin (inclusive) and bound
* (exclusive).
*
* @implNote This method is implemented to be equivalent to {@code
* ints(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
*
* @param randomNumberOrigin the origin (inclusive) of each random value
* @param randomNumberBound the bound (exclusive) of each random value
* @return a stream of pseudorandom {@code int} values,
* each with the given origin (inclusive) and bound (exclusive)
* @throws IllegalArgumentException if {@code randomNumberOrigin}
* is greater than or equal to {@code randomNumberBound}
* @since 1.8
*/
public IntStream ints(int randomNumberOrigin, int randomNumberBound) {
if (randomNumberOrigin >= randomNumberBound)
throw new IllegalArgumentException(BadRange);
return StreamSupport.intStream
(new RandomIntsSpliterator
(0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
false);
}
/**
* Returns a stream producing the given {@code streamSize} number of
* pseudorandom {@code long} values.
*
* @param streamSize the number of values to generate
* @return a stream of pseudorandom {@code long} values
* @throws IllegalArgumentException if {@code streamSize} is
* less than zero
* @since 1.8
*/
public LongStream longs(long streamSize) {
if (streamSize < 0L)
throw new IllegalArgumentException(BadSize);
return StreamSupport.longStream
(new RandomLongsSpliterator
(0L, streamSize, Long.MAX_VALUE, 0L),
false);
}
/**
* Returns an effectively unlimited stream of pseudorandom {@code long}
* values.
*
* @implNote This method is implemented to be equivalent to {@code
* longs(Long.MAX_VALUE)}.
*
* @return a stream of pseudorandom {@code long} values
* @since 1.8
*/
public LongStream longs() {
return StreamSupport.longStream
(new RandomLongsSpliterator
(0L, Long.MAX_VALUE, Long.MAX_VALUE, 0L),
false);
}
/**
* Returns a stream producing the given {@code streamSize} number of
* pseudorandom {@code long}, each conforming to the given origin
* (inclusive) and bound (exclusive).
*
* @param streamSize the number of values to generate
* @param randomNumberOrigin the origin (inclusive) of each random value
* @param randomNumberBound the bound (exclusive) of each random value
* @return a stream of pseudorandom {@code long} values,
* each with the given origin (inclusive) and bound (exclusive)
* @throws IllegalArgumentException if {@code streamSize} is
* less than zero, or {@code randomNumberOrigin}
* is greater than or equal to {@code randomNumberBound}
* @since 1.8
*/
public LongStream longs(long streamSize, long randomNumberOrigin,
long randomNumberBound) {
if (streamSize < 0L)
throw new IllegalArgumentException(BadSize);
if (randomNumberOrigin >= randomNumberBound)
throw new IllegalArgumentException(BadRange);
return StreamSupport.longStream
(new RandomLongsSpliterator
(0L, streamSize, randomNumberOrigin, randomNumberBound),
false);
}
/**
* Returns an effectively unlimited stream of pseudorandom {@code
* long} values, each conforming to the given origin (inclusive) and bound
* (exclusive).
*
* @implNote This method is implemented to be equivalent to {@code
* longs(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
*
* @param randomNumberOrigin the origin (inclusive) of each random value
* @param randomNumberBound the bound (exclusive) of each random value
* @return a stream of pseudorandom {@code long} values,
* each with the given origin (inclusive) and bound (exclusive)
* @throws IllegalArgumentException if {@code randomNumberOrigin}
* is greater than or equal to {@code randomNumberBound}
* @since 1.8
*/
public LongStream longs(long randomNumberOrigin, long randomNumberBound) {
if (randomNumberOrigin >= randomNumberBound)
throw new IllegalArgumentException(BadRange);
return StreamSupport.longStream
(new RandomLongsSpliterator
(0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
false);
}
/**
* Returns a stream producing the given {@code streamSize} number of
* pseudorandom {@code double} values, each between zero
* (inclusive) and one (exclusive).
*
* @param streamSize the number of values to generate
* @return a stream of {@code double} values
* @throws IllegalArgumentException if {@code streamSize} is
* less than zero
* @since 1.8
*/
public DoubleStream doubles(long streamSize) {
if (streamSize < 0L)
throw new IllegalArgumentException(BadSize);
return StreamSupport.doubleStream
(new RandomDoublesSpliterator
(0L, streamSize, Double.MAX_VALUE, 0.0),
false);
}
/**
* Returns an effectively unlimited stream of pseudorandom {@code
* double} values, each between zero (inclusive) and one
* (exclusive).
*
* @implNote This method is implemented to be equivalent to {@code
* doubles(Long.MAX_VALUE)}.
*
* @return a stream of pseudorandom {@code double} values
* @since 1.8
*/
public DoubleStream doubles() {
return StreamSupport.doubleStream
(new RandomDoublesSpliterator
(0L, Long.MAX_VALUE, Double.MAX_VALUE, 0.0),
false);
}
/**
* Returns a stream producing the given {@code streamSize} number of
* pseudorandom {@code double} values, each conforming to the given origin
* (inclusive) and bound (exclusive).
*
* @param streamSize the number of values to generate
* @param randomNumberOrigin the origin (inclusive) of each random value
* @param randomNumberBound the bound (exclusive) of each random value
* @return a stream of pseudorandom {@code double} values,
* each with the given origin (inclusive) and bound (exclusive)
* @throws IllegalArgumentException if {@code streamSize} is
* less than zero
* @throws IllegalArgumentException if {@code randomNumberOrigin}
* is greater than or equal to {@code randomNumberBound}
* @since 1.8
*/
public DoubleStream doubles(long streamSize, double randomNumberOrigin,
double randomNumberBound) {
if (streamSize < 0L)
throw new IllegalArgumentException(BadSize);
if (!(randomNumberOrigin < randomNumberBound))
throw new IllegalArgumentException(BadRange);
return StreamSupport.doubleStream
(new RandomDoublesSpliterator
(0L, streamSize, randomNumberOrigin, randomNumberBound),
false);
}
/**
* Returns an effectively unlimited stream of pseudorandom {@code
* double} values, each conforming to the given origin (inclusive) and bound
* (exclusive).
*
* @implNote This method is implemented to be equivalent to {@code
* doubles(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
*
* @param randomNumberOrigin the origin (inclusive) of each random value
* @param randomNumberBound the bound (exclusive) of each random value
* @return a stream of pseudorandom {@code double} values,
* each with the given origin (inclusive) and bound (exclusive)
* @throws IllegalArgumentException if {@code randomNumberOrigin}
* is greater than or equal to {@code randomNumberBound}
* @since 1.8
*/
public DoubleStream doubles(double randomNumberOrigin, double randomNumberBound) {
if (!(randomNumberOrigin < randomNumberBound))
throw new IllegalArgumentException(BadRange);
return StreamSupport.doubleStream
(new RandomDoublesSpliterator
(0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
false);
}
/**
* Spliterator for int streams. We multiplex the four int
* versions into one class by treating a bound less than origin as
* unbounded, and also by treating "infinite" as equivalent to
* Long.MAX_VALUE. For splits, it uses the standard divide-by-two
* approach. The long and double versions of this class are
* identical except for types.
*/
static final class RandomIntsSpliterator implements Spliterator.OfInt {
long index;
final long fence;
final int origin;
final int bound;
RandomIntsSpliterator(long index, long fence,
int origin, int bound) {
this.index = index; this.fence = fence;
this.origin = origin; this.bound = bound;
}
public RandomIntsSpliterator trySplit() {
long i = index, m = (i + fence) >>> 1;
return (m <= i) ? null :
new RandomIntsSpliterator(i, index = m, origin, bound);
}
public long estimateSize() {
return fence - index;
}
public int characteristics() {
return (Spliterator.SIZED | Spliterator.SUBSIZED |
Spliterator.NONNULL | Spliterator.IMMUTABLE);
}
public boolean tryAdvance(IntConsumer consumer) {
if (consumer == null) throw new NullPointerException();
long i = index, f = fence;
if (i < f) {
consumer.accept(ThreadLocalRandom.current().internalNextInt(origin, bound));
index = i + 1;
return true;
}
return false;
}
public void forEachRemaining(IntConsumer consumer) {
if (consumer == null) throw new NullPointerException();
long i = index, f = fence;
if (i < f) {
index = f;
int o = origin, b = bound;
ThreadLocalRandom rng = ThreadLocalRandom.current();
do {
consumer.accept(rng.internalNextInt(o, b));
} while (++i < f);
}
}
}
/**
* Spliterator for long streams.
*/
static final class RandomLongsSpliterator implements Spliterator.OfLong {
long index;
final long fence;
final long origin;
final long bound;
RandomLongsSpliterator(long index, long fence,
long origin, long bound) {
this.index = index; this.fence = fence;
this.origin = origin; this.bound = bound;
}
public RandomLongsSpliterator trySplit() {
long i = index, m = (i + fence) >>> 1;
return (m <= i) ? null :
new RandomLongsSpliterator(i, index = m, origin, bound);
}
public long estimateSize() {
return fence - index;
}
public int characteristics() {
return (Spliterator.SIZED | Spliterator.SUBSIZED |
Spliterator.NONNULL | Spliterator.IMMUTABLE);
}
public boolean tryAdvance(LongConsumer consumer) {
if (consumer == null) throw new NullPointerException();
long i = index, f = fence;
if (i < f) {
consumer.accept(ThreadLocalRandom.current().internalNextLong(origin, bound));
index = i + 1;
return true;
}
return false;
}
public void forEachRemaining(LongConsumer consumer) {
if (consumer == null) throw new NullPointerException();
long i = index, f = fence;
if (i < f) {
index = f;
long o = origin, b = bound;
ThreadLocalRandom rng = ThreadLocalRandom.current();
do {
consumer.accept(rng.internalNextLong(o, b));
} while (++i < f);
}
}
}
/**
* Spliterator for double streams.
*/
static final class RandomDoublesSpliterator implements Spliterator.OfDouble {
long index;
final long fence;
final double origin;
final double bound;
RandomDoublesSpliterator(long index, long fence,
double origin, double bound) {
this.index = index; this.fence = fence;
this.origin = origin; this.bound = bound;
}
public RandomDoublesSpliterator trySplit() {
long i = index, m = (i + fence) >>> 1;
return (m <= i) ? null :
new RandomDoublesSpliterator(i, index = m, origin, bound);
}
public long estimateSize() {
return fence - index;
}
public int characteristics() {
return (Spliterator.SIZED | Spliterator.SUBSIZED |
Spliterator.NONNULL | Spliterator.IMMUTABLE);
}
public boolean tryAdvance(DoubleConsumer consumer) {
if (consumer == null) throw new NullPointerException();
long i = index, f = fence;
if (i < f) {
consumer.accept(ThreadLocalRandom.current().internalNextDouble(origin, bound));
index = i + 1;
return true;
}
return false;
}
public void forEachRemaining(DoubleConsumer consumer) {
if (consumer == null) throw new NullPointerException();
long i = index, f = fence;
if (i < f) {
index = f;
double o = origin, b = bound;
ThreadLocalRandom rng = ThreadLocalRandom.current();
do {
consumer.accept(rng.internalNextDouble(o, b));
} while (++i < f);
}
}
}
// Within-package utilities // Within-package utilities
/* /*
...@@ -401,23 +1009,26 @@ public class ThreadLocalRandom extends Random { ...@@ -401,23 +1009,26 @@ public class ThreadLocalRandom extends Random {
*/ */
private static final ObjectStreamField[] serialPersistentFields = { private static final ObjectStreamField[] serialPersistentFields = {
new ObjectStreamField("rnd", long.class), new ObjectStreamField("rnd", long.class),
new ObjectStreamField("initialized", boolean.class) new ObjectStreamField("initialized", boolean.class),
}; };
/** /**
* Saves the {@code ThreadLocalRandom} to a stream (that is, serializes it). * Saves the {@code ThreadLocalRandom} to a stream (that is, serializes it).
* @param s the stream
* @throws java.io.IOException if an I/O error occurs
*/ */
private void writeObject(java.io.ObjectOutputStream out) private void writeObject(java.io.ObjectOutputStream s)
throws java.io.IOException { throws java.io.IOException {
java.io.ObjectOutputStream.PutField fields = out.putFields(); java.io.ObjectOutputStream.PutField fields = s.putFields();
fields.put("rnd", UNSAFE.getLong(Thread.currentThread(), SEED)); fields.put("rnd", UNSAFE.getLong(Thread.currentThread(), SEED));
fields.put("initialized", true); fields.put("initialized", true);
out.writeFields(); s.writeFields();
} }
/** /**
* Returns the {@link #current() current} thread's {@code ThreadLocalRandom}. * Returns the {@link #current() current} thread's {@code ThreadLocalRandom}.
* @return the {@link #current() current} thread's {@code ThreadLocalRandom}
*/ */
private Object readResolve() { private Object readResolve() {
return current(); return current();
......
test/java/util/Random/RandomStreamTest.java
浏览文件 @ 1281ac53
...@@ -82,13 +82,6 @@ public class RandomStreamTest { ...@@ -82,13 +82,6 @@ public class RandomStreamTest {
assertEquals(destination.size(), count); assertEquals(destination.size(), count);
} }
@Test(dataProvider = "suppliers")
public void testRandomGaussianStream(final Random random, final int count) {
final List<Double> destination = new ArrayList<>(count);
random.gaussians().limit(count).forEach(destination::add);
assertEquals(destination.size(), count);
}
@Test @Test
public void testIntStream() { public void testIntStream() {
final long seed = System.currentTimeMillis(); final long seed = System.currentTimeMillis();
...@@ -131,20 +124,6 @@ public class RandomStreamTest { ...@@ -131,20 +124,6 @@ public class RandomStreamTest {
assertEquals(a, b); assertEquals(a, b);
} }
@Test
public void testGaussianStream() {
final long seed = System.currentTimeMillis();
final Random r1 = new Random(seed);
final double[] a = new double[SIZE];
for (int i=0; i < SIZE; i++) {
a[i] = r1.nextGaussian();
}
final Random r2 = new Random(seed); // same seed
final double[] b = r2.gaussians().limit(SIZE).toArray();
assertEquals(a, b);
}
@Test @Test
public void testThreadLocalIntStream() throws InterruptedException, ExecutionException, TimeoutException { public void testThreadLocalIntStream() throws InterruptedException, ExecutionException, TimeoutException {
ThreadLocalRandom tlr = ThreadLocalRandom.current(); ThreadLocalRandom tlr = ThreadLocalRandom.current();
...@@ -163,12 +142,6 @@ public class RandomStreamTest { ...@@ -163,12 +142,6 @@ public class RandomStreamTest {
testRandomResultSupplierConcurrently(() -> tlr.doubles().limit(SIZE).boxed().collect(toList())); testRandomResultSupplierConcurrently(() -> tlr.doubles().limit(SIZE).boxed().collect(toList()));
} }
@Test
public void testThreadLocalGaussianStream() throws InterruptedException, ExecutionException, TimeoutException {
ThreadLocalRandom tlr = ThreadLocalRandom.current();
testRandomResultSupplierConcurrently(() -> tlr.gaussians().limit(SIZE).boxed().collect(toList()));
}
<T> void testRandomResultSupplierConcurrently(Supplier<T> s) throws InterruptedException, ExecutionException, TimeoutException { <T> void testRandomResultSupplierConcurrently(Supplier<T> s) throws InterruptedException, ExecutionException, TimeoutException {
// Produce 10 completable future tasks // Produce 10 completable future tasks
final int tasks = 10; final int tasks = 10;
......
test/java/util/Random/RandomTest.java 0 → 100644
浏览文件 @ 1281ac53
/*
* Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
import org.testng.Assert;
import org.testng.annotations.Test;
import java.util.Random;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.LongAdder;
import java.util.function.BiConsumer;
import static org.testng.Assert.*;
/**
* @test
* @run testng RandomTest
* @summary test methods on Random
*/
@Test
public class RandomTest {
// Note: this test was adapted from the 166 TCK ThreadLocalRandomTest test
// and modified to be a TestNG test
/*
* Testing coverage notes:
*
* We don't test randomness properties, but only that repeated
* calls, up to NCALLS tries, produce at least one different
* result. For bounded versions, we sample various intervals
* across multiples of primes.
*/
// 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 << 28);
// max sampled long bound
static final long MAX_LONG_BOUND = (1L << 42);
// Number of replications for other checks
static final int REPS = 20;
/**
* Repeated calls to nextInt produce at least two distinct results
*/
public void testNextInt() {
Random r = new Random();
int f = r.nextInt();
int i = 0;
while (i < NCALLS && r.nextInt() == f)
++i;
assertTrue(i < NCALLS);
}
/**
* Repeated calls to nextLong produce at least two distinct results
*/
public void testNextLong() {
Random r = new Random();
long f = r.nextLong();
int i = 0;
while (i < NCALLS && r.nextLong() == f)
++i;
assertTrue(i < NCALLS);
}
/**
* Repeated calls to nextBoolean produce at least two distinct results
*/
public void testNextBoolean() {
Random r = new Random();
boolean f = r.nextBoolean();
int i = 0;
while (i < NCALLS && r.nextBoolean() == f)
++i;
assertTrue(i < NCALLS);
}
/**
* Repeated calls to nextFloat produce at least two distinct results
*/
public void testNextFloat() {
Random r = new Random();
float f = r.nextFloat();
int i = 0;
while (i < NCALLS && r.nextFloat() == f)
++i;
assertTrue(i < NCALLS);
}
/**
* Repeated calls to nextDouble produce at least two distinct results
*/
public void testNextDouble() {
Random r = new Random();
double f = r.nextDouble();
int i = 0;
while (i < NCALLS && r.nextDouble() == f)
++i;
assertTrue(i < NCALLS);
}
/**
* Repeated calls to nextGaussian produce at least two distinct results
*/
public void testNextGaussian() {
Random r = new Random();
double f = r.nextGaussian();
int i = 0;
while (i < NCALLS && r.nextGaussian() == f)
++i;
assertTrue(i < NCALLS);
}
/**
* nextInt(negative) throws IllegalArgumentException
*/
@Test(expectedExceptions = IllegalArgumentException.class)
public void testNextIntBoundedNeg() {
Random r = new Random();
int f = r.nextInt(-17);
}
/**
* nextInt(bound) returns 0 <= value < bound; repeated calls produce at
* least two distinct results
*/
public void testNextIntBounded() {
Random r = new Random();
// sample bound space across prime number increments
for (int bound = 2; bound < MAX_INT_BOUND; bound += 524959) {
int f = r.nextInt(bound);
assertTrue(0 <= f && f < bound);
int i = 0;
int j;
while (i < NCALLS &&
(j = r.nextInt(bound)) == f) {
assertTrue(0 <= j && j < bound);
++i;
}
assertTrue(i < NCALLS);
}
}
/**
* Invoking sized ints, long, doubles, with negative sizes throws
* IllegalArgumentException
*/
public void testBadStreamSize() {
Random r = new Random();
executeAndCatchIAE(() -> r.ints(-1L));
executeAndCatchIAE(() -> r.ints(-1L, 2, 3));
executeAndCatchIAE(() -> r.longs(-1L));
executeAndCatchIAE(() -> r.longs(-1L, -1L, 1L));
executeAndCatchIAE(() -> r.doubles(-1L));
executeAndCatchIAE(() -> r.doubles(-1L, .5, .6));
}
/**
* Invoking bounded ints, long, doubles, with illegal bounds throws
* IllegalArgumentException
*/
public void testBadStreamBounds() {
Random r = new Random();
executeAndCatchIAE(() -> r.ints(2, 1));
executeAndCatchIAE(() -> r.ints(10, 42, 42));
executeAndCatchIAE(() -> r.longs(-1L, -1L));
executeAndCatchIAE(() -> r.longs(10, 1L, -2L));
testDoubleBadOriginBound((o, b) -> r.doubles(10, o, b));
}
// An arbitrary finite double value
static final double FINITE = Math.PI;
void testDoubleBadOriginBound(BiConsumer<Double, Double> bi) {
executeAndCatchIAE(() -> bi.accept(17.0, 2.0));
executeAndCatchIAE(() -> bi.accept(0.0, 0.0));
executeAndCatchIAE(() -> bi.accept(Double.NaN, FINITE));
executeAndCatchIAE(() -> bi.accept(FINITE, Double.NaN));
executeAndCatchIAE(() -> bi.accept(Double.NEGATIVE_INFINITY, Double.NEGATIVE_INFINITY));
// Returns NaN
// executeAndCatchIAE(() -> bi.accept(Double.NEGATIVE_INFINITY, FINITE));
// executeAndCatchIAE(() -> bi.accept(Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY));
executeAndCatchIAE(() -> bi.accept(FINITE, Double.NEGATIVE_INFINITY));
// Returns Double.MAX_VALUE
// executeAndCatchIAE(() -> bi.accept(FINITE, Double.POSITIVE_INFINITY));
executeAndCatchIAE(() -> bi.accept(Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY));
executeAndCatchIAE(() -> bi.accept(Double.POSITIVE_INFINITY, FINITE));
executeAndCatchIAE(() -> bi.accept(Double.POSITIVE_INFINITY, Double.POSITIVE_INFINITY));
}
private void executeAndCatchIAE(Runnable r) {
executeAndCatch(IllegalArgumentException.class, r);
}
private void executeAndCatch(Class<? extends Exception> expected, Runnable r) {
Exception caught = null;
try {
r.run();
}
catch (Exception e) {
caught = e;
}
assertNotNull(caught,
String.format("No Exception was thrown, expected an Exception of %s to be thrown",
expected.getName()));
Assert.assertTrue(expected.isInstance(caught),
String.format("Exception thrown %s not an instance of %s",
caught.getClass().getName(), expected.getName()));
}
/**
* A sequential sized stream of ints generates the given number of values
*/
public void testIntsCount() {
LongAdder counter = new LongAdder();
Random r = new Random();
long size = 0;
for (int reps = 0; reps < REPS; ++reps) {
counter.reset();
r.ints(size).forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
size += 524959;
}
}
/**
* A sequential sized stream of longs generates the given number of values
*/
public void testLongsCount() {
LongAdder counter = new LongAdder();
Random r = new Random();
long size = 0;
for (int reps = 0; reps < REPS; ++reps) {
counter.reset();
r.longs(size).forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
size += 524959;
}
}
/**
* A sequential sized stream of doubles generates the given number of values
*/
public void testDoublesCount() {
LongAdder counter = new LongAdder();
Random r = new Random();
long size = 0;
for (int reps = 0; reps < REPS; ++reps) {
counter.reset();
r.doubles(size).forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
size += 524959;
}
}
/**
* Each of a sequential sized stream of bounded ints is within bounds
*/
public void testBoundedInts() {
AtomicInteger fails = new AtomicInteger(0);
Random r = new Random();
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).
forEach(x -> {
if (x < lo || x >= hi)
fails.getAndIncrement();
});
}
}
assertEquals(fails.get(), 0);
}
/**
* Each of a sequential sized stream of bounded longs is within bounds
*/
public void testBoundedLongs() {
AtomicInteger fails = new AtomicInteger(0);
Random r = new Random();
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).
forEach(x -> {
if (x < lo || x >= hi)
fails.getAndIncrement();
});
}
}
assertEquals(fails.get(), 0);
}
/**
* Each of a sequential sized stream of bounded doubles is within bounds
*/
public void testBoundedDoubles() {
AtomicInteger fails = new AtomicInteger(0);
Random r = new Random();
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).
forEach(x -> {
if (x < lo || x >= hi)
fails.getAndIncrement();
});
}
}
assertEquals(fails.get(), 0);
}
/**
* A parallel unsized stream of ints generates at least 100 values
*/
public void testUnsizedIntsCount() {
LongAdder counter = new LongAdder();
Random r = new Random();
long size = 100;
r.ints().limit(size).parallel().forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
}
/**
* A parallel unsized stream of longs generates at least 100 values
*/
public void testUnsizedLongsCount() {
LongAdder counter = new LongAdder();
Random r = new Random();
long size = 100;
r.longs().limit(size).parallel().forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
}
/**
* A parallel unsized stream of doubles generates at least 100 values
*/
public void testUnsizedDoublesCount() {
LongAdder counter = new LongAdder();
Random r = new Random();
long size = 100;
r.doubles().limit(size).parallel().forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
}
/**
* A sequential unsized stream of ints generates at least 100 values
*/
public void testUnsizedIntsCountSeq() {
LongAdder counter = new LongAdder();
Random r = new Random();
long size = 100;
r.ints().limit(size).forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
}
/**
* A sequential unsized stream of longs generates at least 100 values
*/
public void testUnsizedLongsCountSeq() {
LongAdder counter = new LongAdder();
Random r = new Random();
long size = 100;
r.longs().limit(size).forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
}
/**
* A sequential unsized stream of doubles generates at least 100 values
*/
public void testUnsizedDoublesCountSeq() {
LongAdder counter = new LongAdder();
Random r = new Random();
long size = 100;
r.doubles().limit(size).forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
}
}
test/java/util/SplittableRandom/SplittableRandomTest.java
浏览文件 @ 1281ac53
...@@ -25,8 +25,10 @@ import org.testng.Assert; ...@@ -25,8 +25,10 @@ import org.testng.Assert;
import org.testng.annotations.Test; import org.testng.annotations.Test;
import java.util.SplittableRandom; import java.util.SplittableRandom;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.atomic.AtomicInteger; import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.LongAdder; import java.util.concurrent.atomic.LongAdder;
import java.util.function.BiConsumer;
import static org.testng.Assert.assertEquals; import static org.testng.Assert.assertEquals;
import static org.testng.Assert.assertNotNull; import static org.testng.Assert.assertNotNull;
...@@ -272,6 +274,53 @@ public class SplittableRandomTest { ...@@ -272,6 +274,53 @@ public class SplittableRandomTest {
} }
} }
/**
* nextDouble(bound) throws IllegalArgumentException
*/
public void testNextDoubleBadBound() {
SplittableRandom sr = new SplittableRandom();
executeAndCatchIAE(() -> sr.nextDouble(0.0));
executeAndCatchIAE(() -> sr.nextDouble(-0.0));
executeAndCatchIAE(() -> sr.nextDouble(+0.0));
executeAndCatchIAE(() -> sr.nextDouble(-1.0));
executeAndCatchIAE(() -> sr.nextDouble(Double.NaN));
executeAndCatchIAE(() -> sr.nextDouble(Double.NEGATIVE_INFINITY));
// Returns Double.MAX_VALUE
// executeAndCatchIAE(() -> r.nextDouble(Double.POSITIVE_INFINITY));
}
/**
* nextDouble(origin, bound) throws IllegalArgumentException
*/
public void testNextDoubleBadOriginBound() {
testDoubleBadOriginBound(new SplittableRandom()::nextDouble);
}
// An arbitrary finite double value
static final double FINITE = Math.PI;
void testDoubleBadOriginBound(BiConsumer<Double, Double> bi) {
executeAndCatchIAE(() -> bi.accept(17.0, 2.0));
executeAndCatchIAE(() -> bi.accept(0.0, 0.0));
executeAndCatchIAE(() -> bi.accept(Double.NaN, FINITE));
executeAndCatchIAE(() -> bi.accept(FINITE, Double.NaN));
executeAndCatchIAE(() -> bi.accept(Double.NEGATIVE_INFINITY, Double.NEGATIVE_INFINITY));
// Returns NaN
// executeAndCatchIAE(() -> bi.accept(Double.NEGATIVE_INFINITY, FINITE));
// executeAndCatchIAE(() -> bi.accept(Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY));
executeAndCatchIAE(() -> bi.accept(FINITE, Double.NEGATIVE_INFINITY));
// Returns Double.MAX_VALUE
// executeAndCatchIAE(() -> bi.accept(FINITE, Double.POSITIVE_INFINITY));
executeAndCatchIAE(() -> bi.accept(Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY));
executeAndCatchIAE(() -> bi.accept(Double.POSITIVE_INFINITY, FINITE));
executeAndCatchIAE(() -> bi.accept(Double.POSITIVE_INFINITY, Double.POSITIVE_INFINITY));
}
/** /**
* nextDouble(least, bound) returns least <= value < bound; * nextDouble(least, bound) returns least <= value < bound;
* repeated calls produce at least two distinct results * repeated calls produce at least two distinct results
...@@ -318,8 +367,8 @@ public class SplittableRandomTest { ...@@ -318,8 +367,8 @@ public class SplittableRandomTest {
executeAndCatchIAE(() -> r.ints(10, 42, 42)); executeAndCatchIAE(() -> r.ints(10, 42, 42));
executeAndCatchIAE(() -> r.longs(-1L, -1L)); executeAndCatchIAE(() -> r.longs(-1L, -1L));
executeAndCatchIAE(() -> r.longs(10, 1L, -2L)); executeAndCatchIAE(() -> r.longs(10, 1L, -2L));
executeAndCatchIAE(() -> r.doubles(0.0, 0.0));
executeAndCatchIAE(() -> r.doubles(10, .5, .4)); testDoubleBadOriginBound((o, b) -> r.doubles(10, o, b));
} }
private void executeAndCatchIAE(Runnable r) { private void executeAndCatchIAE(Runnable r) {
......
test/java/util/concurrent/ThreadLocalRandom/ThreadLocalRandomTest.java 0 → 100644
浏览文件 @ 1281ac53
/*
* Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
import org.testng.Assert;
import org.testng.annotations.Test;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.LongAdder;
import java.util.function.BiConsumer;
import static org.testng.Assert.*;
/**
* @test
* @run testng ThreadLocalRandomTest
* @summary test methods on ThreadLocalRandom
*/
@Test
public class ThreadLocalRandomTest {
// Note: this test was copied from the 166 TCK ThreadLocalRandomTest test
// and modified to be a TestNG test
/*
* Testing coverage notes:
*
* We don't test randomness properties, but only that repeated
* calls, up to NCALLS tries, produce at least one different
* result. For bounded versions, we sample various intervals
* across multiples of primes.
*/
// 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 << 28);
// max sampled long bound
static final long MAX_LONG_BOUND = (1L << 42);
// Number of replications for other checks
static final int REPS = 20;
/**
* setSeed throws UnsupportedOperationException
*/
@Test(expectedExceptions = UnsupportedOperationException.class)
public void testSetSeed() {
ThreadLocalRandom.current().setSeed(17);
}
/**
* Repeated calls to nextInt produce at least two distinct results
*/
public void testNextInt() {
int f = ThreadLocalRandom.current().nextInt();
int i = 0;
while (i < NCALLS && ThreadLocalRandom.current().nextInt() == f)
++i;
assertTrue(i < NCALLS);
}
/**
* Repeated calls to nextLong produce at least two distinct results
*/
public void testNextLong() {
long f = ThreadLocalRandom.current().nextLong();
int i = 0;
while (i < NCALLS && ThreadLocalRandom.current().nextLong() == f)
++i;
assertTrue(i < NCALLS);
}
/**
* Repeated calls to nextBoolean produce at least two distinct results
*/
public void testNextBoolean() {
boolean f = ThreadLocalRandom.current().nextBoolean();
int i = 0;
while (i < NCALLS && ThreadLocalRandom.current().nextBoolean() == f)
++i;
assertTrue(i < NCALLS);
}
/**
* Repeated calls to nextFloat produce at least two distinct results
*/
public void testNextFloat() {
float f = ThreadLocalRandom.current().nextFloat();
int i = 0;
while (i < NCALLS && ThreadLocalRandom.current().nextFloat() == f)
++i;
assertTrue(i < NCALLS);
}
/**
* Repeated calls to nextDouble produce at least two distinct results
*/
public void testNextDouble() {
double f = ThreadLocalRandom.current().nextDouble();
int i = 0;
while (i < NCALLS && ThreadLocalRandom.current().nextDouble() == f)
++i;
assertTrue(i < NCALLS);
}
/**
* Repeated calls to nextGaussian produce at least two distinct results
*/
public void testNextGaussian() {
double f = ThreadLocalRandom.current().nextGaussian();
int i = 0;
while (i < NCALLS && ThreadLocalRandom.current().nextGaussian() == f)
++i;
assertTrue(i < NCALLS);
}
/**
* nextInt(negative) throws IllegalArgumentException
*/
@Test(expectedExceptions = IllegalArgumentException.class)
public void testNextIntBoundedNeg() {
int f = ThreadLocalRandom.current().nextInt(-17);
}
/**
* nextInt(least >= bound) throws IllegalArgumentException
*/
@Test(expectedExceptions = IllegalArgumentException.class)
public void testNextIntBadBounds() {
int f = ThreadLocalRandom.current().nextInt(17, 2);
}
/**
* nextInt(bound) returns 0 <= value < bound; repeated calls produce at
* least two distinct results
*/
public void testNextIntBounded() {
// sample bound space across prime number increments
for (int bound = 2; bound < MAX_INT_BOUND; bound += 524959) {
int f = ThreadLocalRandom.current().nextInt(bound);
assertTrue(0 <= f && f < bound);
int i = 0;
int j;
while (i < NCALLS &&
(j = ThreadLocalRandom.current().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() {
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 = ThreadLocalRandom.current().nextInt(least, bound);
assertTrue(least <= f && f < bound);
int i = 0;
int j;
while (i < NCALLS &&
(j = ThreadLocalRandom.current().nextInt(least, bound)) == f) {
assertTrue(least <= j && j < bound);
++i;
}
assertTrue(i < NCALLS);
}
}
}
/**
* nextLong(negative) throws IllegalArgumentException
*/
@Test(expectedExceptions = IllegalArgumentException.class)
public void testNextLongBoundedNeg() {
long f = ThreadLocalRandom.current().nextLong(-17);
}
/**
* nextLong(least >= bound) throws IllegalArgumentException
*/
@Test(expectedExceptions = IllegalArgumentException.class)
public void testNextLongBadBounds() {
long f = ThreadLocalRandom.current().nextLong(17, 2);
}
/**
* nextLong(bound) returns 0 <= value < bound; repeated calls produce at
* least two distinct results
*/
public void testNextLongBounded() {
for (long bound = 2; bound < MAX_LONG_BOUND; bound += 15485863) {
long f = ThreadLocalRandom.current().nextLong(bound);
assertTrue(0 <= f && f < bound);
int i = 0;
long j;
while (i < NCALLS &&
(j = ThreadLocalRandom.current().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() {
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 = ThreadLocalRandom.current().nextLong(least, bound);
assertTrue(least <= f && f < bound);
int i = 0;
long j;
while (i < NCALLS &&
(j = ThreadLocalRandom.current().nextLong(least, bound)) == f) {
assertTrue(least <= j && j < bound);
++i;
}
assertTrue(i < NCALLS);
}
}
}
/**
* nextDouble(bound) throws IllegalArgumentException
*/
public void testNextDoubleBadBound() {
ThreadLocalRandom r = ThreadLocalRandom.current();
executeAndCatchIAE(() -> r.nextDouble(0.0));
executeAndCatchIAE(() -> r.nextDouble(-0.0));
executeAndCatchIAE(() -> r.nextDouble(+0.0));
executeAndCatchIAE(() -> r.nextDouble(-1.0));
executeAndCatchIAE(() -> r.nextDouble(Double.NaN));
executeAndCatchIAE(() -> r.nextDouble(Double.NEGATIVE_INFINITY));
// Returns Double.MAX_VALUE
// executeAndCatchIAE(() -> r.nextDouble(Double.POSITIVE_INFINITY));
}
/**
* nextDouble(origin, bound) throws IllegalArgumentException
*/
public void testNextDoubleBadOriginBound() {
testDoubleBadOriginBound(ThreadLocalRandom.current()::nextDouble);
}
// An arbitrary finite double value
static final double FINITE = Math.PI;
void testDoubleBadOriginBound(BiConsumer<Double, Double> bi) {
executeAndCatchIAE(() -> bi.accept(17.0, 2.0));
executeAndCatchIAE(() -> bi.accept(0.0, 0.0));
executeAndCatchIAE(() -> bi.accept(Double.NaN, FINITE));
executeAndCatchIAE(() -> bi.accept(FINITE, Double.NaN));
executeAndCatchIAE(() -> bi.accept(Double.NEGATIVE_INFINITY, Double.NEGATIVE_INFINITY));
// Returns NaN
// executeAndCatchIAE(() -> bi.accept(Double.NEGATIVE_INFINITY, FINITE));
// executeAndCatchIAE(() -> bi.accept(Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY));
executeAndCatchIAE(() -> bi.accept(FINITE, Double.NEGATIVE_INFINITY));
// Returns Double.MAX_VALUE
// executeAndCatchIAE(() -> bi.accept(FINITE, Double.POSITIVE_INFINITY));
executeAndCatchIAE(() -> bi.accept(Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY));
executeAndCatchIAE(() -> bi.accept(Double.POSITIVE_INFINITY, FINITE));
executeAndCatchIAE(() -> bi.accept(Double.POSITIVE_INFINITY, Double.POSITIVE_INFINITY));
}
/**
* nextDouble(least, bound) returns least <= value < bound; repeated calls
* produce at least two distinct results
*/
public void testNextDoubleBounded2() {
for (double least = 0.0001; least < 1.0e20; least *= 8) {
for (double bound = least * 1.001; bound < 1.0e20; bound *= 16) {
double f = ThreadLocalRandom.current().nextDouble(least, bound);
assertTrue(least <= f && f < bound);
int i = 0;
double j;
while (i < NCALLS &&
(j = ThreadLocalRandom.current().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() {
ThreadLocalRandom r = ThreadLocalRandom.current();
executeAndCatchIAE(() -> r.ints(-1L));
executeAndCatchIAE(() -> r.ints(-1L, 2, 3));
executeAndCatchIAE(() -> r.longs(-1L));
executeAndCatchIAE(() -> r.longs(-1L, -1L, 1L));
executeAndCatchIAE(() -> r.doubles(-1L));
executeAndCatchIAE(() -> r.doubles(-1L, .5, .6));
}
/**
* Invoking bounded ints, long, doubles, with illegal bounds throws
* IllegalArgumentException
*/
public void testBadStreamBounds() {
ThreadLocalRandom r = ThreadLocalRandom.current();
executeAndCatchIAE(() -> r.ints(2, 1));
executeAndCatchIAE(() -> r.ints(10, 42, 42));
executeAndCatchIAE(() -> r.longs(-1L, -1L));
executeAndCatchIAE(() -> r.longs(10, 1L, -2L));
testDoubleBadOriginBound((o, b) -> r.doubles(10, o, b));
}
private void executeAndCatchIAE(Runnable r) {
executeAndCatch(IllegalArgumentException.class, r);
}
private void executeAndCatch(Class<? extends Exception> expected, Runnable r) {
Exception caught = null;
try {
r.run();
}
catch (Exception e) {
caught = e;
}
assertNotNull(caught,
String.format("No Exception was thrown, expected an Exception of %s to be thrown",
expected.getName()));
Assert.assertTrue(expected.isInstance(caught),
String.format("Exception thrown %s not an instance of %s",
caught.getClass().getName(), expected.getName()));
}
/**
* A parallel sized stream of ints generates the given number of values
*/
public void testIntsCount() {
LongAdder counter = new LongAdder();
ThreadLocalRandom r = ThreadLocalRandom.current();
long size = 0;
for (int reps = 0; reps < REPS; ++reps) {
counter.reset();
r.ints(size).parallel().forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
size += 524959;
}
}
/**
* A parallel sized stream of longs generates the given number of values
*/
public void testLongsCount() {
LongAdder counter = new LongAdder();
ThreadLocalRandom r = ThreadLocalRandom.current();
long size = 0;
for (int reps = 0; reps < REPS; ++reps) {
counter.reset();
r.longs(size).parallel().forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
size += 524959;
}
}
/**
* A parallel sized stream of doubles generates the given number of values
*/
public void testDoublesCount() {
LongAdder counter = new LongAdder();
ThreadLocalRandom r = ThreadLocalRandom.current();
long size = 0;
for (int reps = 0; reps < REPS; ++reps) {
counter.reset();
r.doubles(size).parallel().forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
size += 524959;
}
}
/**
* Each of a parallel sized stream of bounded ints is within bounds
*/
public void testBoundedInts() {
AtomicInteger fails = new AtomicInteger(0);
ThreadLocalRandom r = ThreadLocalRandom.current();
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(fails.get(), 0);
}
/**
* Each of a parallel sized stream of bounded longs is within bounds
*/
public void testBoundedLongs() {
AtomicInteger fails = new AtomicInteger(0);
ThreadLocalRandom r = ThreadLocalRandom.current();
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(fails.get(), 0);
}
/**
* Each of a parallel sized stream of bounded doubles is within bounds
*/
public void testBoundedDoubles() {
AtomicInteger fails = new AtomicInteger(0);
ThreadLocalRandom r = ThreadLocalRandom.current();
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(fails.get(), 0);
}
/**
* A parallel unsized stream of ints generates at least 100 values
*/
public void testUnsizedIntsCount() {
LongAdder counter = new LongAdder();
ThreadLocalRandom r = ThreadLocalRandom.current();
long size = 100;
r.ints().limit(size).parallel().forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
}
/**
* A parallel unsized stream of longs generates at least 100 values
*/
public void testUnsizedLongsCount() {
LongAdder counter = new LongAdder();
ThreadLocalRandom r = ThreadLocalRandom.current();
long size = 100;
r.longs().limit(size).parallel().forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
}
/**
* A parallel unsized stream of doubles generates at least 100 values
*/
public void testUnsizedDoublesCount() {
LongAdder counter = new LongAdder();
ThreadLocalRandom r = ThreadLocalRandom.current();
long size = 100;
r.doubles().limit(size).parallel().forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
}
/**
* A sequential unsized stream of ints generates at least 100 values
*/
public void testUnsizedIntsCountSeq() {
LongAdder counter = new LongAdder();
ThreadLocalRandom r = ThreadLocalRandom.current();
long size = 100;
r.ints().limit(size).forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
}
/**
* A sequential unsized stream of longs generates at least 100 values
*/
public void testUnsizedLongsCountSeq() {
LongAdder counter = new LongAdder();
ThreadLocalRandom r = ThreadLocalRandom.current();
long size = 100;
r.longs().limit(size).forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
}
/**
* A sequential unsized stream of doubles generates at least 100 values
*/
public void testUnsizedDoublesCountSeq() {
LongAdder counter = new LongAdder();
ThreadLocalRandom r = ThreadLocalRandom.current();
long size = 100;
r.doubles().limit(size).forEach(x -> {
counter.increment();
});
assertEquals(counter.sum(), size);
}
}
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