深入同步语法

1. 深入synchronized关键字

class Service{
    public void fun1(){
        synchronized(this){
            try{
                Thread.sleep(3000); //休眠3秒; 可能会异常
            }
            catch(Exception e){
                System.out.println(e);
            }
               System.out.println("fun1");
        }
    }
    public void fun2(){
        synchronized(this){
            System.out.println("fun2");
        }
    }
}

class MyThread1 implements Runnable{{
    private Service service;
    
    public MyThread1(Service service){
        this.service = service;
    }
    
    public void run(){
        service.fun1();
    }
}

class MyThread2 implements Runnable{{
    private Service service;
    
    public MyThread2(Service service){
        this.service = service;
    }
    
    public void run(){
        service.fun2();
    }
}

class Test{
    public static void main(String args []){
        Service service = new Service();
           //共用service对象
        Thread t1 = new Thread(new MyThread1(service));
        Thread t2 = new Thread(new MyThread2(service));
        
        t1.start();
        t2.start();
    }
}

        t1.start(); ---> service.fun1(); ---> synchronized(this),其中this代表new Thread(new MyThread1(service));中传入的service---> 进入fun1就休眠, 则会执行

        fun2, fun2还是但同步锁还是锁住this,即service, service被线程fun1锁住在,

        

        一旦某一对象获得线程同步锁, 对象上所有被同步的代码统统不能执行