生產者消費者模型——標誌法

package Thread;
//測試生產者消費者問題2：訊號燈發，標誌位解決
public class PC2Thread {
   public static void main(String[] args) {
     TV tv = new TV();
     new Player(tv).start();
     new Watcher(tv).start();
   }
}
//生產者--》演員
class Player extends  Thread{
TV tv;
public Player(TV tv){
   this.tv = tv;
}
​
   @Override
   public void run() {
    for (int i =0;i<20;i++){
   if (i%2==0){
     this.tv.play("演員表演中");
   }else {
     this.tv.play("插播廣告");
   }
}
}
}
//消費者———》觀眾
class Watcher extends Thread{
   TV tv;
   public Watcher(TV tv){
     this.tv = tv;
   }
​
   @Override
   public void run() {
     for (int i = 0; i < 20; i++) {
       tv.watch();
     }
   }
}
​
//產品——》節目
class TV{
   //演員表演，觀眾等待 T
   //觀眾觀看，演員等待 F
   String voice;//表演的節目
   boolean flag = true;
   //表演
   public synchronized void play(String voice){
     if (!flag){
       try {
         this.wait();
       } catch (InterruptedException e) {
         e.printStackTrace();
       }
     }
     System.out.println("演員表演了："+voice);
     //通知觀眾觀看
     this.notifyAll();
     this.voice = voice;
     this.flag = !this.flag;
   }
public synchronized  void watch(){
     if(flag){
       try {
         this.wait();
       } catch (InterruptedException e) {
         e.printStackTrace();
       }
     }
   System.out.println("觀看了："+voice);
     //通知演員表演
   this.notifyAll();
   this.flag = !this.flag;
}
}