package com.cpucode.java.aqs;

import java.util.HashMap;

import java.util.Map;

import java.util.concurrent.locks.Lock;

import java.util.concurrent.locks.ReentrantReadWriteLock;

/**

* @author : cpucode

* @date : 2021/7/30

* @time : 15:22

* @github : https://github.com/CPU-Code

* @csdn : https://blog.csdn.net/qq_44226094

*/

public class RWLock {

static Map<Integer,Object> cacheMap = new HashMap<>();

static ReentrantReadWriteLock rwl = new ReentrantReadWriteLock();

static Lock read = rwl.readLock();

static Lock write = rwl.writeLock();

public static final Object get(Integer key) {

System.out.println("开始读取数据");

// 读锁

read.lock();

try {

return cacheMap.get(key);

}finally {

read.unlock();

}

}

public static final Object put(Integer key,Object value){

System.out.println("开始写数据");

write.lock();

try{

return cacheMap.put(key, value);

}finally {

write.unlock();

}

}

public static void main(String[] args) {

for (int i = 0; i < 11; i++) {

int finalI = i;

new Thread(()->{

put(finalI, finalI);

}).start();

new Thread(()->{

get(finalI);

}).start();

}

//读->读是可以共享

//读->写 互斥

//写->写 互斥

//读多写少的场景

}

}