程序名称:DeadLock.java
程序内容:
package thread;
/**
* 死锁现象: 两个或多个线程均锁定了对方需要使用的对象;
* 解决方法: 降低所的粒度,即 锁定整个对象
* @author web
*
*/
public class DeadLock implements Runnable {
public int flag = 1;
static Object o1 = new Object();
static Object o2 = new Object();
public static void main(String[] args) {
DeadLock d1 = new DeadLock();
DeadLock d2 = new DeadLock();
d1.flag = 1;
d2.flag = 2;
Thread t1 = new Thread(d1);
Thread t2 = new Thread(d2);
t1.start();
t2.start();
}
//使用 flag 来模拟两个线程
@Override
public void run() {
System.out.println("flag : " + flag);
if(flag == 1) {
synchronized (o1) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
synchronized (o2) {
System.out.println("2");
}
}
}
if(flag == 2) {
synchronized (o2) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
synchronized (o1) {
System.out.println("1");
}
}
}
}
}