线程中死锁的demo

/*
虽然同步的出现解决了线程安全问题。
但是也带来了一些弊端：
1，效率会降低。
2，容易引发死锁。

死锁经常出现的状况为：同步嵌套。

*/

class Test implements Runnable
{
	private boolean flag;
	Test(boolean flag)
	{
		this.flag = flag;
	}
	public void run()
	{
		if(flag)
		{
			while(true)
			{
				synchronized(MyLock.locka)
				{
					System.out.println(Thread.currentThread().getName()+"...if......locka");
					synchronized(MyLock.lockb)
					{
						System.out.println(Thread.currentThread().getName()+"...if......lockb");
						
					}
				}
			}
		}
		else
		{
			while(true)
			{
				synchronized(MyLock.lockb)
				{
					System.out.println(Thread.currentThread().getName()+"...else..........lockb");
					synchronized(MyLock.locka)
					{
						System.out.println(Thread.currentThread().getName()+"...else..........locka");
						
					}
				}
			}
		}
	}

}

class MyLock
{
	public static Object locka = new Object();
	public static Object lockb = new Object();
}


class DeadLockTest 
{
	public static void main(String[] args) 
	{
		Test t1 = new Test(true);
		Test t2 = new Test(false);

		Thread th1 = new Thread(t1,"С?");
		Thread th2 = new Thread(t2,"κ?");

		th1.start();
		th2.start();
	}
}