线程安全同步代码（卖票）

public class RunnableTest implements Runnable {
private int tick = 60;

@Override
public void run() {
    while (true) {
        synchronized (this) {
            if (tick == 0) {
                break;
            }
            try {
                Thread.sleep(10);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(Thread.currentThread().getName() + "=========" + tick--);
        }
    }
}
public static void main(String[] args) {
    RunnableTest runnableTest=new RunnableTest();
    new Thread(runnableTest).start();
    new Thread(runnableTest).start();


}

}