ReentrantReadWriteLock——写写互斥（二）

 "读写" 、"写读"、"写写"都是同步的、互斥的 

 

1、Service.java

package ReentrantReadWriteLock;

import java.util.concurrent.locks.ReentrantReadWriteLock;

public class Service {

    private ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
    
    //写写互斥
    public void write(){
        
        try{
            try{
                lock.writeLock().lock();//写锁
                System.out.println("获得写锁"+Thread.currentThread().getName()+" "+System.currentTimeMillis());
                Thread.sleep(10000);
            }finally{
                lock.writeLock().unlock();//解锁
            }
            
        }catch(Exception e){
            e.printStackTrace();
        }
        
    }
    
    
}

可以发现，lock.writeLock()的效果就是同一时间只允许一个线程执行lock()方法后面的代码

 

2、ThreadA.java

package ReentrantReadWriteLock;

public class ThreadA extends Thread{

    private Service service ;
    
    public ThreadA(Service service){
        super();
        this.service = service;
    }
    
    @Override
    public void run(){
        service.write();
    }
    
    
}

 

 

3、ThreadB.java

package ReentrantReadWriteLock;

public class ThreadB extends Thread{

private Service service ;
    
    public ThreadB(Service service){
        super();
        this.service = service;
    }
    
    @Override
    public void run(){
        service.write();
    }
    
    
}

 

 

4、Run.java

package ReentrantReadWriteLock;

public class Run {

    public static void main(String[] args) {
        
        Service service = new Service();
        ThreadA a = new ThreadA(service);
        a.setName("A");
        ThreadB b = new ThreadB(service);
        b.setName("B");
        a.start();
        b.start();
    }
}

 

可以自己更改ThreadA和ThreadB类中的run()方法里的read()、write()方法，实验"读写"、"写读"、"写写"