死锁Demo 

 1 class Demo3 
 2 {
 3     public static void main(String[] args) 
 4     {
 5         System.out.println("Hello World!");
 6         T1 t1 = new T1();
 7         T2 t2 = new T2();
 8         new Thread(t1).start();
 9         new Thread(t2).start();
10     }
11 }
12 class MyLock
13 {
14     static Object obj1 = new Object();
15     static Object obj2 = new Object();
16 }
17 class T1 implements Runnable
18 {
19     public void run(){
20         while(true){
21             synchronized(MyLock.obj1){
22                 System.out.println("t1 obj1");
23                 synchronized(MyLock.obj2){
24                     System.out.println("t1 obj2");
25                 }
26             }
27         }
28     }
29 }
30 class T2 implements Runnable
31 {
32     public void run(){
33         while(true){
34             synchronized(MyLock.obj2){
35                 System.out.println("t2 obj2");
36                 synchronized(MyLock.obj1){
37                     System.out.println("t2 obj1");
38                 }
39             }
40         }
41     }
42 }

造成死锁的原因，同步的嵌套，当持有obj1锁想要拿到obj2锁的时候，恰好另一个类持有obj2锁，想要拿到obj1锁。因为彼此没有完成任务都不释放已拿到的锁，同时又需要对方的锁，所以造成锁死！

 

posted @ 2014-03-05 10:51  一路向北中  阅读(146)  评论(0)    收藏  举报