java例程练习（多线程[死锁问题]）

/*
*死锁产生有2个原因：
*1，资源竞争
*2，进程间的推进顺序非法
*
*程序模拟的是第一个情况
*/
public class TestDeadLock implements Runnable {
public int flag = 1;

static Object o1 = new Object();
static Object o2 = new Object();

public void run() {
System.out.println("flag=" + flag);
if(flag == 1) {
synchronized(o1) {
try {
Thread.sleep(500);
} catch(InterruptedException e) {
e.printStackTrace();
}
synchronized(o2) {
System.out.println("1");
}

}
}

if(flag == 0) {
synchronized(o2) {
try {
Thread.sleep(500);
} catch(InterruptedException e) {
e.printStackTrace();
}
synchronized(o1) {
System.out.println("0");
}

}
}
}

public static void main(String[] args) {
TestDeadLock td1 = new TestDeadLock();
TestDeadLock td2 = new TestDeadLock();
td1.flag = 1;//用flag区分不同的线程
td2.flag = 0;
Thread t1 = new Thread(td1);
Thread t2 = new Thread(td2);
t1.start();
t2.start();

}

}