ReadWriteLock：读写锁

一、

/*
* 1. ReadWriteLock : 读写锁
*
* 写写/读写 需要“互斥”
* 读读 不需要互斥
*
*/
public class TestReadWriteLock {

public static void main(String[] args) {
ReadWriteLockDemo rw = new ReadWriteLockDemo();

new Thread(new Runnable() {

@Override
public void run() {
rw.set((int)(Math.random() * 101));
}
}, "Write:").start();

for (int i = 0; i < 100; i++) {
new Thread(new Runnable() {

@Override
public void run() {
rw.get();
}
}).start();
}
}

}

class ReadWriteLockDemo{

private int number = 0;

private ReadWriteLock lock = new ReentrantReadWriteLock();

//读
public void get(){
lock.readLock().lock(); //上锁

try{
System.out.println(Thread.currentThread().getName() + " : " + number);
}finally{
lock.readLock().unlock(); //释放锁
}
}

//写
public void set(int number){
lock.writeLock().lock();

try{
System.out.println(Thread.currentThread().getName());
this.number = number;
}finally{
lock.writeLock().unlock();
}
}
}