How to deal with shared resources in multi-threading in C++?

Use mutex (mutex) in C++ to handle multi-threaded shared resources: create a mutex through std::mutex. Use mtx.lock() to obtain a mutex for exclusive access to shared resources. Use mtx.unlock() to release the mutex.

Handling shared resources in multi-threading in C++

Introduction

In In multi-threaded programming, when multiple threads access shared resources concurrently, thread safety issues will arise. Mutex (mutex) is a synchronization mechanism that ensures that only one thread accesses shared resources at the same time, thereby preventing data competition and corruption.

The syntax and usage of mutex

In C++, you can use std::mutex to create a mutex:

std::mutex mtx;

To have exclusive access to shared resources, you need to use lock() and unlock() Methods:

mtx.lock(); // 获取互斥量
// 对共享资源进行操作
mtx.unlock(); // 释放互斥量

Practical case

The following is a practical case of using a mutex to protect shared resources:

#include <iostream>
#include <thread>
#include <mutex>

std::mutex mtx;
int shared_resource = 0;

void increment_resource() {
    mtx.lock();
    shared_resource++;
    mtx.unlock();
}

int main() {
    std::vector<std::thread> threads;

    // 创建多个线程并行执行 increment_resource() 函数
    for (int i = 0; i < 1000; i++) {
        threads.push_back(std::thread(increment_resource));
    }

    // 等待所有线程执行完毕
    for (auto& thread : threads) {
        thread.join();
    }

    // 打印共享资源的最终值，此时的值应该是 1000
    std::cout << shared_resource << std::endl;

    return 0;
}

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