OnJava8-Examples/verifying/BadMicroBenchmark3.java

// verifying/BadMicroBenchmark3.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
// Relying on a common resource
import java.util.*;
import static onjava.TimeIt.*;

public class BadMicroBenchmark3 {
  static final int SIZE = 20_000_000;
  public static void main(String[] args) {
    long[] la = new long[SIZE];
    Random r = new Random();
    System.out.print("parallelSetAll: ");
    timeIt(() ->
      Arrays.parallelSetAll(la, n -> r.nextLong()));
    System.out.print("setAll: ");
    timeIt(() ->
      Arrays.setAll(la, n -> r.nextLong()));
    SplittableRandom sr = new SplittableRandom();
    System.out.print("parallelSetAll: ");
    timeIt(() ->
      Arrays.parallelSetAll(la, n -> sr.nextLong()));
    System.out.print("setAll: ");
    timeIt(() ->
      Arrays.setAll(la, n -> sr.nextLong()));
  }
}
/* Output:
parallelSetAll: 4540
setAll: 1540
parallelSetAll: 398
setAll: 739
*/