Java Stream - 如何基准并行流

import java.util.stream.IntStream;

public class Main {
  public static void main(String[] argv) {
    System.out.println("Benchmarking...");
    long t0 = System.nanoTime();

    int a[] = IntStream.range(0, 1_000_000).filter(p -> p % 2 == 0).toArray();
    long t1 = System.nanoTime();

    int b[] = IntStream.range(0, 1_000_000).parallel().filter(p -> p % 2 == 0)
        .toArray();
    long t2 = System.nanoTime();
    
    System.out.printf("serial: %.2fs, parallel %.2fs%n", (t1 - t0) * 1e-9, (t2 - t1) * 1e-9);
  }
}