本帖最后由 李道福 于 2013-4-4 21:13 编辑
- class Ticket4 implements Runnable
- {
- private int tick = 100;
- private boolean flag=true;
- Object obj = new Object();
- public void run()
- {
- while(true)
- {
- if(flag)
- synchronized(obj)
- {
- if(tick>0)
- {
- System.out.println("-obj-"+Thread.currentThread().getName()+"---");
- System.out.println("Ticket:"+tick--);
- flag=false;
- }
- }else
- show();
- }
- }
- public synchronized void show(){
- if(tick>0){
- System.out.println("-show-"+Thread.currentThread().getName()+"---");
- System.out.println("Ticket:"+tick--);
- flag=true;
- }
- }
- }
- class TestTicket4
- {
- public static void main(String[] args)
- {
-
- Ticket4 t = new Ticket4();
-
- Thread t1 = new Thread(t);
- Thread t2 = new Thread(t);
- Thread t3 = new Thread(t);
- Thread t4 = new Thread(t);
- t1.start();
- t2.start();
- t3.start();
- t4.start();
- }
- }
- 这个代码有什么问题嘛?所有的线程都是在执行时都是同一把锁,为什么在输出时还会输出0;并且输出的结果也不是按我想的那样同步代码块和同步方法
- 互换依次输出?
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