死锁举例

public class DeadLockDemo implements Runnable{

public int flag=1;
static Object o1=new Object();
static Object o2=new Object();
public static void main(String[] args) {
DeadLockDemo d1=new DeadLockDemo();
d1.flag=1;
DeadLockDemo d2=new DeadLockDemo();
d2.flag=2;
Thread t1=new Thread(d1);

Thread t2=new Thread(d2);
t1.start();
t2.start();
}
@Override
public void run() {
 if(flag==1){
 synchronized (o1) {
System.out.println("o1 "+flag);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
synchronized(o2){
System.out.println("o2 "+flag);
}
}
 }
 if(flag==2){
 synchronized (o2) {
 try {
 System.out.println("o2 "+flag);
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
synchronized(o1){
System.out.println("o1"+flag);
}

}
 }
 }
}

t1请求02锁，但是02锁被太占用，t1等待，t2请求o1锁，但是o1锁被t1占用，这样t1和t2都在互相等待彼此资源的状态，而且还不释放锁，就这样一直处于等待下去