runoob_17_mutex

/*
 * @Author: by777
 * @Date: 2025-03-24 14:47:17
 * @LastEditors: by777
 * @LastEditTime: 2025-03-24 14:57:52
 * @FilePath: /cxx_stl/runoob_17.cpp
 * @Description: https://www.runoob.com/cplusplus/cpp-libs-mutex.html
 * 
 * Copyright (c) 2025 by by777, All Rights Reserved. 
 */
#include <iostream>
#include <thread>
#include <mutex> // 用于在多线程程序中实现线程间的同步和互斥
using namespace std;

// 1. std::mutex 基本的互斥锁
std::mutex mtx;
int shared_resource = 0;
void increment(){
    for(int i=0; i< 10000; i++){
        mtx.lock();
        ++shared_resource;
        mtx.unlock();
    }
}
// 2. std:;recursive_mutex: 递归互斥锁，允许同一线程多次锁定
std::recursive_mutex rmtx;
int shared_resource_2 = 0;
void recursive_increment(int count){
    if(count<0) return;
    std::lock_guard<std::recursive_mutex> lock(rmtx);
    ++shared_resource_2;
    cout<<"Increment shared_resource_2 to "<<shared_resource_2<<" (count="<<count<<")"<<endl;
    //递归调用
    recursive_increment(count-1);
}
// 3. std::timed_mutex：具有超时功能的互斥锁
// 4. std::recursive_timed_mutex:具有超时功能的递归互斥锁

int main(int argc, const char** argv) {
    // 1. std::mutex 基本的互斥锁
    {
        thread t1(increment);
        thread t2(increment);
        t1.join();
        t2.join();
        cout<<"Final value: "<<shared_resource<<endl;        

    }


    // 2. std:;recursive_mutex: 递归互斥锁，允许同一线程多次锁定
    {
        thread t1(recursive_increment, 3);
        thread t2(recursive_increment, 3);
        t1.join();
        t2.join();
        cout<<"Final value: "<<shared_resource_2<<endl;        


    }
    // 3. std::timed_mutex：具有超时功能的互斥锁
    // 4. std::recursive_timed_mutex:具有超时功能的递归互斥锁

    return 0;
}