Package org.cloudbus.cloudsim.distributions

Class JDKThreadLocalRandomGenerator

java.lang.Object
org.cloudbus.cloudsim.distributions.JDKThreadLocalRandomGenerator
All Implemented Interfaces:
org.apache.commons.math3.random.RandomGenerator
public final class JDKThreadLocalRandomGenerator extends Object implements org.apache.commons.math3.random.RandomGenerator
A RandomGenerator that internally uses the ThreadLocalRandom, a very fast Pseudo-Random Number Generator (PRNG) with higher performance than Random, mainly in concurrent environments. The ThreadLocalRandom also has much better performance than PRNGs available in org.apache.commons.math3, despite it probably has worse statistical properties.

This generator has some drawbacks. It only generates the seed internally and doesn't allow setting an explicit seed. Calling the setSeed() methods will throw an UnsupportedOperationException and there is no way to get the generated seed. This later issue makes it impossible to reproduce a simulation experiment to verify the generated results if the seed is unknown.

Finally, it doesn't allow applying the Antithetic Variates Technique in order to try reducing variance of experiments using the generated numbers. Classes such as UniformDistr provide such a feature if the underlying PRNG allows setting a seed. That is explained because the technique is applied when multiple runs of the same simulation are executed. In such scenario, the second half of experiments have to use the seeds from the first half.

Since:
CloudSim Plus 4.3.9
Author:
Manoel Campos da Silva Filho

  • Method Details

    • getInstance

      public static JDKThreadLocalRandomGenerator getInstance()

    • setSeed

      public void setSeed(int seed)
      Specified by:
      setSeed in interface org.apache.commons.math3.random.RandomGenerator

    • setSeed

      public void setSeed(int[] seed)
      Specified by:
      setSeed in interface org.apache.commons.math3.random.RandomGenerator

    • setSeed

      public void setSeed(long seed)
      Specified by:
      setSeed in interface org.apache.commons.math3.random.RandomGenerator

    • nextBytes

      public void nextBytes(byte[] bytes)
      Specified by:
      nextBytes in interface org.apache.commons.math3.random.RandomGenerator

    • nextInt

      public int nextInt()
      Specified by:
      nextInt in interface org.apache.commons.math3.random.RandomGenerator

    • nextInt

      public int nextInt(int bound)
      Specified by:
      nextInt in interface org.apache.commons.math3.random.RandomGenerator

    • nextLong

      public long nextLong()
      Specified by:
      nextLong in interface org.apache.commons.math3.random.RandomGenerator

    • nextBoolean

      public boolean nextBoolean()
      Specified by:
      nextBoolean in interface org.apache.commons.math3.random.RandomGenerator

    • nextFloat

      public float nextFloat()
      Specified by:
      nextFloat in interface org.apache.commons.math3.random.RandomGenerator

    • nextDouble

      public double nextDouble()
      Specified by:
      nextDouble in interface org.apache.commons.math3.random.RandomGenerator

    • nextGaussian

      public double nextGaussian()
      Specified by:
      nextGaussian in interface org.apache.commons.math3.random.RandomGenerator