package lock;

/*
方式三：
  Lock鎖
synchronized和lock的不同
1.sychronized在執(zhí)行完相應(yīng)代碼塊以后屬于自動(dòng)釋放同步監(jiān)視器，lock需要手動(dòng)啟動(dòng)同步
建議優(yōu)先使用lock->同步方法塊->同步方法(在方法體之外)

實(shí)現(xiàn)Runnable對(duì)象被三個(gè)線程調(diào)用，然后這個(gè)對(duì)象的run方法里貢獻(xiàn)資源操作器被lock上鎖了

@author zsben
@create 2020-01-03 23:55
*/

import java.util.concurrent.locks.ReentrantLock;

class Window implements Runnable{

  private int ticket = 100;

  //1.實(shí)例化lock
  private ReentrantLock lock = new ReentrantLock(true);//fair=true:公平鎖，線程先來后到

  @Override
  public void run() {
    while(true){
      try{
        //2.調(diào)用lock方法
        lock.lock();

        if(ticket>0){

          try {
            Thread.sleep(100);
          } catch (InterruptedException e) {
            e.printStackTrace();
          }

          System.out.println(Thread.currentThread().getName()+": "+ticket);
          ticket--;
        }else break;
      }
      finally {
        //3.調(diào)用解鎖方法
        lock.unlock();
      }
    }
  }
}

public class LockTest {

  public static void main(String[] args) {
    Window w = new Window();

    Thread t1 = new Thread(w);
    Thread t2 = new Thread(w);
    Thread t3 = new Thread(w);

    t1.start();
    t2.start();
    t3.start();

  }
}