C++实现读写锁

参考链接：https://blog.csdn.net/ojshilu/article/details/25244389

#include 
#include 
#include 
#include 
#include 
using namespace std;

class Read_Write_Lock{
    private:
        mutex read_mutex;  //其实这个是用来控制 read_mutex_count 的
        mutex write_mutex;
        int read_mutex_count = 0; //写锁肯定是只能有一个，所以只需要记录读锁的个数

    public:
        void readLock(){
            read_mutex.lock();
            //如果加了读锁之后，read_mutex_count的数量刚好为1，
            //这就说明当前资源是无锁状态，要对资源加写锁之后再读
            if(++read_mutex_count == 1){
                write_mutex.lock();
            }
            read_mutex.unlock();
        }

        void readUnLock(){
            read_mutex.lock();
            if(read_mutex_count == 1){
                write_mutex.unlock();
                read_mutex_count-- ;
            }
            read_mutex.unlock();
        }

        void writeLock(){
            write_mutex.lock();
        }

        void writeUnLock(){
            write_mutex.unlock();
        }
};

volatile int var = 10;
Read_Write_Lock rwLock;


void Write() {
    rwLock.writeLock();
    var += 10;
    std::cout<< "tid : " <
    rwLock.readLock();
    std::cout<< "tid: "<
    vector writers;
    vector readers;
    for (int i = 0; i < 10; i++) {  // 10 个写线程
        writers.push_back(std::thread(Write)); 
    }
    for (int i = 0; i < 100; i++) {   // 100 个读线程
        readers.push_back(std::thread(Read));
    }
    for (auto& t : writers) {   // 写线程启动
        t.join();
    }
    for (auto& t : readers) {   // 读线程启动
        t.join();
    }
    std::cin.get();
}