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DeadLockDemo.java
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47 lines (42 loc) · 1.44 KB
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package concurrent.lock;
/**
* 一个死锁例子
* <p>
* 通过flag区别线程A和B、线程A获得AAA对象的锁，继续执行，此时如果能拿到对象BBB的锁，run（）执行完毕，
* 线程1就可以顺利结束，然后释放对两个对象的锁现在的问题是，如果在线程A获得对象BBB的锁之前，线程B已经获得对象BBB的锁，那么线程B
* 就会寻求对象AAA的锁，显然是无法得到的。这就导致两个线程都无法释放自己的锁。
*/
public class DeadLockDemo {
public static void main(String[] args) {
LockDemo A = new LockDemo(true);
LockDemo B = new LockDemo(false);
new Thread(A).start();
new Thread(B).start();
}
}
class LockDemo implements Runnable {
public static final Object AAA = new Object();
public static final Object BBB = new Object();
boolean flag;
public LockDemo(boolean flag) {
this.flag = flag;
}
@Override
public void run() {
if (flag) {
synchronized (AAA) {
System.out.println("if lock AAA");
synchronized (BBB) {
System.out.println("if lock BBB");
}
}
} else {
synchronized (BBB) {
System.out.println("else lock BBB");
synchronized (AAA) {
System.out.println("else lock AAA");
}
}
}
}
}