4.2 synchronized解决方案

4.2 synchronized解决方案

面向对象改进: 把需要保护的共享变量放入一个类

class Room {
    int value = 0;

    public void increment() {
        synchronized (this) {
            value++;
        }
    }

    public void decrement() {
        synchronized (this) {
            value--;
        }
    }

    public int get() {
        synchronized (this) {
            return value;
        }
    }
}

@Slf4j
public class TestCounterOop {

    public static void main(String[] args) throws InterruptedException {
        Room room = new Room();
        
        Thread t1 = new Thread(() -> {
            for (int j = 0; j < 5000; j++) {
                room.increment();
            }
        }, "t1");

        Thread t2 = new Thread(() -> {
            for (int j = 0; j < 5000; j++) {
                room.decrement();
            }
        }, "t2");
        t1.start();
        t2.start();

        t1.join();
        t2.join();
        log.debug("count: {}" , room.get());
    }
}