用Java寫一個死鎖

寫一個由於多變量的synchronized順序使用不當引起的死鎖。

public class BadLock {
	public static void main(String[] args) {
		Locklock locklock = new Locklock();
		Thread thread1 = new Test1(locklock);
		Thread thread2 = new Test2(locklock);
		thread1.start();
		thread2.start();
		if (thread1.isAlive() && thread2.isAlive()) {
			System.out.println("all thread has alive and running..");
		}
	}

}

class Locklock {
	private Object obj1 = new Object();
	private Object obj2 = new Object();

	public void lockObj1() throws InterruptedException {
		synchronized (obj1) {
			// sleep並不釋放鎖
			Thread.sleep(1);
			synchronized (obj2) {
				while (true) {
					System.out.println(Thread.currentThread().getName());
				}
			}
		}
	}

	public void lockObj2() throws InterruptedException {
		synchronized (obj2) {
			// sleep並不釋放鎖
			Thread.sleep(1);
			synchronized (obj1) {
				while (true) {
					System.out.println(Thread.currentThread().getName());
				}
			}
		}
	}
}

class Test1 extends Thread {
	Locklock locklock1;

	public Test1(Locklock locklock1) {
		// TODO Auto-generated constructor stub
		this.locklock1 = locklock1;
		Thread.currentThread().setName("thread1");
	}

	@Override
	public void run() {
		try {
			locklock1.lockObj1();
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	};
}

class Test2 extends Thread {
	Locklock locklock;

	public Test2(Locklock locklock) {
		// TODO Auto-generated constructor stub
		this.locklock = locklock;
		Thread.currentThread().setName("thread2");
	}

	@Override
	public void run() {
		try {
			locklock.lockObj2();
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	};
}