从头认识多线程-2.3 synchronized持有对象锁与类锁的不同点

这一章节我们来讨论游戏，synchronized持有对象锁与类锁的不同点-两种锁是并行的东西，没有交集。

1.同步持有对象锁或者类锁

package com.ray.deepintothread.ch02.topic_3;

public class SynchInstance5 {
	public static void main(String[] args) throws InterruptedException {
		MyTestObjectFive myTestObjectFive = new MyTestObjectFive();
		for (int i = 0; i < 2; i++) {
			ThreadFive threadFive = new ThreadFive(myTestObjectFive);
			Thread thread = new Thread(threadFive);
			thread.setName("" + i);
			thread.start();
		}
	}
}

class ThreadFive implements Runnable {

	private MyTestObjectFive myTestObjectFive;

	public ThreadFive(MyTestObjectFive myTestObjectFive) {
		this.myTestObjectFive = myTestObjectFive;
	}

	@Override
	public void run() {
		try {
			if (Integer.parseInt(Thread.currentThread().getName()) % 2 == 0) {
				myTestObjectFive.test1();
			} else {
				myTestObjectFive.test2();
			}

		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
}

class MyTestObjectFive {
	public synchronized void test1() throws InterruptedException {
		for (int i = 0; i < 5; i++) {
			System.out.println(i);
			Thread.sleep(100);
		}
	}

	public synchronized void test2() throws InterruptedException {
		for (int i = 0; i < 5; i++) {
			System.out.println(i);
			Thread.sleep(100);
		}
	}
}

输出：

0
1
2
3
4
0
1
2
3
4

package com.ray.deepintothread.ch02.topic_3;

public class SynchInstance6 {
	public static void main(String[] args) throws InterruptedException {
		for (int i = 0; i < 2; i++) {
			ThreadSix threadSix = new ThreadSix();
			Thread thread = new Thread(threadSix);
			thread.setName("" + i);
			thread.start();
		}
	}
}

class ThreadSix implements Runnable {

	@Override
	public void run() {
		try {
			if (Integer.parseInt(Thread.currentThread().getName()) % 2 == 0) {
				MyTestObjectSix.test1();
			} else {
				MyTestObjectSix.test2();
			}

		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
}

class MyTestObjectSix {
	public static synchronized void test1() throws InterruptedException {
		for (int i = 0; i < 5; i++) {
			System.out.println(i);
			Thread.sleep(100);
		}
	}

	public static synchronized void test2() throws InterruptedException {
		for (int i = 0; i < 5; i++) {
			System.out.println(i);
			Thread.sleep(100);
		}
	}
}

输出：

0
1
2
3
4
0
1
2
3
4

像前面章节一样，当我们同步持有对象锁或者类锁，输出的是按照顺序的

2.当同时持有对象锁和类锁

package com.ray.deepintothread.ch02.topic_3;

public class SynchInstance4 {
	public static void main(String[] args) throws InterruptedException {
		MyTestObjectFour myTestObjectThree = new MyTestObjectFour();
		for (int i = 0; i < 2; i++) {
			ThreadFour threadFour = new ThreadFour(myTestObjectThree);
			Thread thread = new Thread(threadFour);
			thread.setName("" + i);
			thread.start();
		}
	}
}

class ThreadFour implements Runnable {

	private MyTestObjectFour myTestObjectThree;

	public ThreadFour(MyTestObjectFour myTestObjectThree) {
		this.myTestObjectThree = myTestObjectThree;
	}

	@Override
	public void run() {
		try {
			if (Integer.parseInt(Thread.currentThread().getName()) % 2 == 0) {
				myTestObjectThree.test1();
			} else {
				MyTestObjectFour.test2();
			}

		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
}

class MyTestObjectFour {
	public synchronized void test1() throws InterruptedException {
		for (int i = 0; i < 5; i++) {
			System.out.println(i);
			Thread.sleep(100);
		}
	}

	public static synchronized void test2() throws InterruptedException {
		for (int i = 0; i < 5; i++) {
			System.out.println(i);
			Thread.sleep(100);
		}
	}
}

输出：

0
0
1
1
2
2
3
3
4
4

从输出可以看见，两者就像平行的关系，没有交集，交替的出现。但也是有秩序的。

总结：这一章节讨论了synchronized持有对象锁与类锁的不同点

这一章节就到这里，谢谢

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我的github：https://github.com/raylee2015/DeepIntoThread

目录：http://blog.youkuaiyun.com/raylee2007/article/details/51204573