OnJava8-Examples/validating/jmh/JMH1.java

// validating/jmh/JMH1.java
// (c)2021 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
package validating.jmh;
import java.util.*;
import org.openjdk.jmh.annotations.*;
import java.util.concurrent.TimeUnit;

@State(Scope.Thread)
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.MICROSECONDS)
// Increase these three for more accuracy:
@Warmup(iterations = 5)
@Measurement(iterations = 5)
@Fork(1)
public class JMH1 {
  private long[] la;
  @Setup
  public void setup() {
    la = new long[250_000_000];
  }
  @Benchmark
  public void setAll() {
    Arrays.setAll(la, n -> n);
  }
  @Benchmark
  public void parallelSetAll() {
    Arrays.parallelSetAll(la, n -> n);
  }
}