//TestTea.java --- by tsaiwn@csie.nctu.edu.tw
///This program demostrates how to use Thread in Java.
///But there are two problems:
///(1) stop() is unsafe. This might crash the program.(多 Run 幾次試試)
///    We should tell thread to die by using a flag instead of
///    using stop( ) to kill the thread.
///(2)concurrent access to TestTea.n might cause synchronization problem.
///   Codes access to the same variable should be monitored by using
///   a synchronized block to mark as a Critical Section.
public class TestTea {
    protected static long n = 0;
    public static void main(String[]x) throws Exception{
        Tea t1 = new Tea();
        Coffee t2 = new Coffee();
        t1.start();
        t2.start();
        while(true){
           Thread.sleep(13);
           if(n > 10){
              t1.stop(); t2.stop();
              break;
           }
        } // while
        System.out.println("Thank you and Bye!");
    }
}
class Coffee extends Thread{
    public void run(){
        while(true){
           System.out.println("Drink Coffee "+  ++TestTea.n);
           // yield();
        }
    } // run
}
class Tea extends Thread{
    public void run(){
        while(true){
           System.out.println("Drink Tea "+  ++TestTea.n);
           // yield();
        }
    } // run
}