同步方法会引起缓存失效

gistfile1.txt

//现在的代码，一秒后停止运行，因为println是同步方法引起本地缓存失效
//把第一条println注释掉，第二条println解除注释，就会一直运行
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

public class Test {
    static boolean b = true;

    public static void main(String[] args) throws InterruptedException {
        new Thread(() -> {
            while (b) {
                System.out.println("running");
                /*try {
                    TimeUnit.MILLISECONDS.sleep(100);
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }*/
            }
//            System.out.println("done");
        }).start();
        TimeUnit.SECONDS.sleep(1);
        b = false;
        //防止jvm退出
        new CountDownLatch(1).await();
    }
}