volatile

# 關於volatile的相關知識，主要閱讀了一些文章

文章1 文章2 文章3

這幾篇文章須要結合起來看，各有優勢，其中文章1有一個地方有一些筆誤的錯別字，我當時看的時候有點迷惑，可是文章2相同的部分講的很清楚

# 可是閱讀了這些文章以後，總想着本身寫寫代碼驗證一下

public class QQ {

    private static String name = "init";

    private static boolean flag = false;

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

        Thread thread1 = new Thread(() -> {
            System.out.println("thread1 start");
            name = "yukong";
            flag = true;
            System.out.println("thread1 end");
        });

        Thread thread2 = new Thread(() -> {
            while (true) {
                if (flag) {
                    System.out.println("flag = " + flag + ", name=" + name);
                    break;
                }
            }
        });

        thread2.start();
        Thread.sleep(1000);
        thread1.start();

    }

}

　　- 上面代碼的執行結果是thread1執行完成，thread2無輸出，且一直在運行

# 咱們使用上volatile

public class QQ {

    private static String name = "init";

    private volatile static boolean flag = false;

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

        Thread thread1 = new Thread(() -> {
            System.out.println("thread1 start");
            name = "yukong";
            flag = true;
            System.out.println("thread1 end");
        });

        Thread thread2 = new Thread(() -> {
            while (true) {
                if (flag) {
                    System.out.println("flag = " + flag + ", name=" + name);
                    break;
                }
            }
        });

        thread2.start();
        Thread.sleep(1000);
        thread1.start();

    }
}