线程死锁示例

代码如下：

public class DeadLock {
	
	private OtherDeadLock otherDeadLock; 
	
	private final Object LOCK = new Object();
	
	public DeadLock(OtherDeadLock otherDeadLock) {
		this.otherDeadLock = otherDeadLock;
	}

	public void m1() {
		synchronized (LOCK) {
			System.out.println("m1");
			otherDeadLock.o1();
		}
	}
	
	public void m2() {
		synchronized (LOCK) {
			System.out.println("m2");
		}
	}
}

public class OtherDeadLock {
	
	private final Object LOCK = new Object();
	
	private DeadLock deadLock;

	public void o1() {
		synchronized (LOCK) {
			System.out.println("--------------------o1---");
		}
	}
	
	public void o2() {
		synchronized (LOCK) {
			System.out.println("--------------------o2---");
			deadLock.m2();
		}
	}
	
	public void set(DeadLock deadLock) {
		this.deadLock = deadLock;
	}
}

public class Test {

	public static void main(String[] args) {
		final OtherDeadLock otherDeadLock = new OtherDeadLock();
		final DeadLock deadLock = new DeadLock(otherDeadLock);
		otherDeadLock.set(deadLock);
		new Thread() {
			@Override
			public void run() {
				while(true) {
					deadLock.m1();
				}
			}
		}.start();
		
		
		new Thread() {
			@Override
			public void run() {
				while(true) {
					otherDeadLock.o2();
				}
			}
		}.start();
	}
}

运行结果：

m1
--------------------o1---
m1
--------------------o1---
m1
--------------------o1---
m1
--------------------o1---
m1
--------------------o1---
m1
--------------------o1---
m1
--------------------o1---
m1
--------------------o1---
m1
--------------------o1---
m1
--------------------o1---
m1
--------------------o1---
m1
--------------------o1---
m1
--------------------o1---
m1
--------------------o1---
m1
--------------------o2---

运行一会就会卡在那，我们可以通过【jstack pid】将线程堆栈信息导出

我们会发现两个线程彼此持有锁，并且互相等待对方的锁，发生了死锁。