Class ThreadLocalRandom

  • All Implemented Interfaces:
    java.io.Serializable

    class ThreadLocalRandom
    extends java.util.Random
    Copied directly from the JSR-166 project.
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private static long addend  
      (package private) boolean initialized
      Initialization flag to permit calls to setSeed to succeed only while executing the Random constructor.
      private static java.lang.ThreadLocal<ThreadLocalRandom> localRandom
      The actual ThreadLocal
      private static long mask  
      private static long multiplier  
      private long pad0  
      private long pad1  
      private long pad2  
      private long pad3  
      private long pad4  
      private long pad5  
      private long pad6  
      private long pad7  
      private long rnd
      The random seed.
      private static long serialVersionUID  
    • Constructor Summary

      Constructors 
      Constructor Description
      ThreadLocalRandom()
      Constructor called only by localRandom.initialValue.
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      static ThreadLocalRandom current()
      Returns the current thread's ThreadLocalRandom.
      protected int next​(int bits)  
      double nextDouble​(double n)
      Returns a pseudorandom, uniformly distributed double value between 0 (inclusive) and the specified value (exclusive).
      double nextDouble​(double least, double bound)
      Returns a pseudorandom, uniformly distributed value between the given least value (inclusive) and bound (exclusive).
      int nextInt​(int least, int bound)
      Returns a pseudorandom, uniformly distributed value between the given least value (inclusive) and bound (exclusive).
      long nextLong​(long n)
      Returns a pseudorandom, uniformly distributed value between 0 (inclusive) and the specified value (exclusive).
      long nextLong​(long least, long bound)
      Returns a pseudorandom, uniformly distributed value between the given least value (inclusive) and bound (exclusive).
      void setSeed​(long seed)
      Throws UnsupportedOperationException.
      • Methods inherited from class java.util.Random

        doubles, doubles, doubles, doubles, ints, ints, ints, ints, longs, longs, longs, longs, nextBoolean, nextBytes, nextDouble, nextFloat, nextGaussian, nextInt, nextInt, nextLong
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • rnd

        private long rnd
        The random seed. We can't use super.seed.
      • initialized

        boolean initialized
        Initialization flag to permit calls to setSeed to succeed only while executing the Random constructor. We can't allow others since it would cause setting seed in one part of a program to unintentionally impact other usages by the thread.
      • pad0

        private long pad0
      • pad1

        private long pad1
      • pad2

        private long pad2
      • pad3

        private long pad3
      • pad4

        private long pad4
      • pad5

        private long pad5
      • pad6

        private long pad6
      • pad7

        private long pad7
      • localRandom

        private static final java.lang.ThreadLocal<ThreadLocalRandom> localRandom
        The actual ThreadLocal
    • Constructor Detail

      • ThreadLocalRandom

        ThreadLocalRandom()
        Constructor called only by localRandom.initialValue.
    • Method Detail

      • current

        public static ThreadLocalRandom current()
        Returns the current thread's ThreadLocalRandom.
        Returns:
        the current thread's ThreadLocalRandom
      • setSeed

        public void setSeed​(long seed)
        Throws UnsupportedOperationException. Setting seeds in this generator is not supported.
        Overrides:
        setSeed in class java.util.Random
        Throws:
        java.lang.UnsupportedOperationException - always
      • next

        protected int next​(int bits)
        Overrides:
        next in class java.util.Random
      • nextInt

        public int nextInt​(int least,
                           int bound)
        Returns a pseudorandom, uniformly distributed value between the given least value (inclusive) and bound (exclusive).
        Parameters:
        least - the least value returned
        bound - the upper bound (exclusive)
        Returns:
        the next value
        Throws:
        java.lang.IllegalArgumentException - if least greater than or equal to bound
      • nextLong

        public long nextLong​(long n)
        Returns a pseudorandom, uniformly distributed value between 0 (inclusive) and the specified value (exclusive).
        Parameters:
        n - the bound on the random number to be returned. Must be positive.
        Returns:
        the next value
        Throws:
        java.lang.IllegalArgumentException - if n is not positive
      • nextLong

        public long nextLong​(long least,
                             long bound)
        Returns a pseudorandom, uniformly distributed value between the given least value (inclusive) and bound (exclusive).
        Parameters:
        least - the least value returned
        bound - the upper bound (exclusive)
        Returns:
        the next value
        Throws:
        java.lang.IllegalArgumentException - if least greater than or equal to bound
      • nextDouble

        public double nextDouble​(double n)
        Returns a pseudorandom, uniformly distributed double value between 0 (inclusive) and the specified value (exclusive).
        Parameters:
        n - the bound on the random number to be returned. Must be positive.
        Returns:
        the next value
        Throws:
        java.lang.IllegalArgumentException - if n is not positive
      • nextDouble

        public double nextDouble​(double least,
                                 double bound)
        Returns a pseudorandom, uniformly distributed value between the given least value (inclusive) and bound (exclusive).
        Parameters:
        least - the least value returned
        bound - the upper bound (exclusive)
        Returns:
        the next value
        Throws:
        java.lang.IllegalArgumentException - if least greater than or equal to bound