Java并发：join与wait

　　//java.lang.Thread

    public final synchronized void join(long millis)
    throws InterruptedException {
        long base = System.currentTimeMillis();
        long now = 0;

        if (millis < 0) {
            throw new IllegalArgumentException("timeout value is negative");
        }

        if (millis == 0) {
            while (isAlive()) {
                wait(0);
            }
        } else {
            while (isAlive()) {
                long delay = millis - now;
                if (delay <= 0) {
                    break;
                }
                wait(delay);
                now = System.currentTimeMillis() - base;
            }
        }
    }

public class Program{
    public static void main(String[] args) throws Exception{
        MyThread myThread = new Thread(new Runnable(){
            @Override
            public void run() {
                //this就是当前对象myThread，同步获取到myThread锁
                synchronized (this) {
                    this.notify();//唤醒在myThread锁上等待的单个线程。即main主线程从waitting变成runnable，main方法继续执行
                }
            }
        });
        myThread.setName("myThread");
        myThread.start();
        //同步获取到myThread锁
        synchronized (myThread) {
            //使当前线程（main）从runnable进入waitting状态，等待其他某个线程调用myThread锁的 notify方法
            myThread.wait();
        }
}