Importance of Thread.onSpinWait() method in Java 9?

Thread.onSpinWait() method has been introduced in Java 9. It is a static method of Thread class and can be optionally called in busy-waiting loops. It allows the JVM to issue processor instructions on some system architectures to improve reaction time in such spin-wait loops, and also reduce the power consumed by the core thread. It can benefit the overall power consumption of a java program and allows other core threads to execute at faster speeds within the same power consumption envelope.

Syntax

public static void onSpinWait()

Example

public class ThreadOnSpinWaitTest {    public static void main(final String args[]) throws InterruptedException {       final NormalTask task1 = new NormalTask();       final SpinWaitTask task2 = new SpinWaitTask();       final Thread thread1 = new Thread(task1);       thread1.start();       final Thread thread2 = new Thread(task2);       thread2.start();       new Thread(() -> {          try {             Thread.sleep(1000);          } catch(final InterruptedException e) {             e.printStackTrace();          } finally {             task1.start();             task2.sta*rt();          }       }).start();       thread1.join();       thread2.join();    }    private abstract static class Task implements Runnable {       volatile boolean canStart;       void start() {          this.canStart = true;       }    }    private static class NormalTask extends Task {       @Override       public void run() {          while(!this.canStart) {          }          System.out.println("Done!");       }    }    private static class SpinWaitTask extends Task {       @Override       public void run() {          while(!this.canStart) {             Thread.onSpinWait();          }          System.out.println("Done!");       }    } }

Output

Done! Done!