JAVA经典题--死锁案例

死锁原理: 两个线程相互等待对方释放同步监视器

例子程序:

 public class TestDeadLock implements Runnable {

     public int flag = 1;
     static Object o1 = new Object(), o2 = new Object();

     public void run() {
         if (flag == 1) {
             synchronized (o1) {
                 try {
                     Thread.sleep(500);
                 } catch (Exception e) {
                     e.printStackTrace();
                 }
                 synchronized (o2) {
                     System.out.println("1");
                 }
             }
         }
         if (flag == 0) {
             synchronized (o2) {
                 try {
                     Thread.sleep(500);
                 } catch (Exception 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;
         td2.flag = 0;
         Thread t1 = new Thread(td1);
         Thread t2 = new Thread(td2);
         t1.start();
         t2.start();
     }
 }