package book.thread;

/**
 * 一個線程死鎖的例子
 */
public class DeadLock {
	public static void main(String[] args) {
		// 2個資源
		final Object resource1 = "resource1";
		final Object resource2 = "resource2";
		// 第一個線程，想先占有resource1，再嘗試著占有resource2
		Thread t1 = new Thread() {
			public void run() {
				//嘗試占有了resource1
				synchronized (resource1) {
					//成功占有resource1
					System.out.println("Thread 1: locked resource 1");
					//休眠一段時間
					try {
						Thread.sleep(50);
					} catch (InterruptedException e) {
					}
					// 嘗試著占有resource2，如果不能占有，該線程會一直等待
					synchronized (resource2) {
						System.out.println("Thread 1: locked resource 2");
					}
				}
			}
		};

		// 第二個線程，想先占有resource2，再占有resource1
		Thread t2 = new Thread() {
			public void run() {
				// 嘗試著占有resource2
				synchronized (resource2) {
					// 成功占有resource2
					System.out.println("Thread 2: locked resource 2");
					// 休眠一段時間
					try {
						Thread.sleep(50);
					} catch (InterruptedException e) {
					}
					// 嘗試占有resource1，如果不能占有，該線程會一直等待
					synchronized (resource1) {
						System.out.println("Thread 2: locked resource 1");
					}
				}
			}
		};
		// 啟動兩個線程
		t1.start();
		t2.start();
	}
}