java Thread yield()方法的理解

  /\*\*

     \* A hint to the scheduler that the current thread is willing to yield

     \* its current use of a processor. The scheduler is free to ignore this

     \* hint.

     \*

     \* <p> Yield is a heuristic attempt to improve relative progression

     \* between threads that would otherwise over-utilise a CPU. Its use

     \* should be combined with detailed profiling and benchmarking to

     \* ensure that it actually has the desired effect.

     \*

     \* <p> It is rarely appropriate to use this method. It may be useful

     \* for debugging or testing purposes, where it may help to reproduce

     \* bugs due to race conditions. It may also be useful when designing

     \* concurrency control constructs such as the ones in the

     \* {@link java.util.concurrent.locks} package.

     \*/

    public static native void yield();

public class Demo3 {

    public static void main(String[] args) throws ExecutionException, InterruptedException {

        Runnable runnable = new Runnable() {

            @Override

            public void run() {

                for (int i = 0; i < 10; i++) {

                    System.out.println("当前线程为: "+ Thread.currentThread().getName()+ i);

                    if (i == 5){

                        Thread.yield();

                    }

                }

            }

        };

 

        Thread thread = new Thread(runnable,"A");

        Thread thread1 = new Thread(runnable,"B");

        thread.start();

        thread1.start();

    }

}