C++ mutex互斥锁使用教程

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

std::mutex mtx;  // 全局互斥锁

mtx.lock();
// 操作共享资源
std::cout << "Thread " << std::this_thread::get_id() 
          << " is working\n";
mtx.unlock();

void print_data() {
    std::lock_guard<std::mutex> guard(mtx);
    std::cout << "Thread " << std::this_thread::get_id() 
              << " is working\n";
    // 函数结束时，guard 析构，自动释放锁
}

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

int counter = 0;
std::mutex mtx;

void increment(int id) {
    for (int i = 0; i < 100000; ++i) {
        std::lock_guard<std::mutex> guard(mtx);
        ++counter;  // 安全地修改共享变量
    }
    std::cout << "Thread " << id << " done.\n";
}

int main() {
    std::thread t1(increment, 1);
    std::thread t2(increment, 2);

    t1.join();
    t2.join();

    std::cout << "Final counter value: " << counter << "\n";
    return 0;
}