C++线程操作

定义

std::thread必须明确调用join()或detach()，否则程序终止时会调用std::terminate()

特性	std::thread	std::jthread
‌引入标准‌	C++11	C++20
‌资源管理‌	析构时若仍可汇合（joinable）会‌调用std::terminate终止程序‌	析构时若仍可汇合，会‌**自动调用join()**‌，等待线程结束
‌协作中断‌	‌不支持‌ 原生协作中断机制	‌支持‌，通过 request_stop() 请求停止，线程内可查询停止状态
‌成员函数‌	join(), detach(), get_id(), joinable()等	包含std::thread所有功能，并增加 request_stop(), get_stop_source(), get_stop_token()
‌推荐使用‌	旧代码维护，或需要手动控制线程生命周期	‌新项目首选‌，更安全，资源管理更自动化

void sayHello() {std::this_thread::sleep_for(std::chrono::seconds(3));std::cout << getStringFromU8string(u8"Hello World，子线程, threadId=") + getThreadIdAsString() + "\n";
}int main()
{system("chcp 65001");std::cout << getStringFromU8string(u8"开始主线程，threadId=") << std::this_thread::get_id() << endl;std::thread thread1(sayHello);//std::jthread thread2(sayHello);// thread必须显式调用// thread1.join();// // jthread会自动调用join方法//thread2.join();std::cout << getStringFromU8string(u8"结束主线程，threadId=") << std::this_thread::get_id() << endl;return 0;
}

构造函数

1、通过函数指针

带返回值的函数，需要用到其他方式

#include <iostream>
#include <string>
#include <thread>using namespace std;
std::string getStringFromU8string(const std::u8string& u8str) {return std::string(reinterpret_cast<const char*>(u8str.data()), u8str.size());
}std::u8string getU8stingFromString(const std::string& str) {return std::u8string(reinterpret_cast<const char8_t*>(str.data()), str.size());
}void sayHello() {std::cout << getStringFromU8string(u8"Hello World，子线程, threadId=") << std::this_thread::get_id() << endl;
}void add(int a, int b) {std::cout << getStringFromU8string(u8"Hello World，子线程, threadId=") << std::this_thread::get_id() << " ;a+b=" << (a + b) << endl;
}int main()
{system("chcp 65001");std::cout << getStringFromU8string(u8"开始主线程，threadId=") << std::this_thread::get_id() << endl;// 无参，无返回std::thread thread1(sayHello);// 有参，无返回std::thread thread2(add, 2, 3);// 等待线程结束（阻塞主线程）thread1.join();thread2.join();std::cout << getStringFromU8string(u8"结束主线程，threadId=") << std::this_thread::get_id() << endl;return 0;
}

2、通过Lambda 表达式

int main()
{system("chcp 65001");std::cout << getStringFromU8string(u8"开始主线程，threadId=") << std::this_thread::get_id() << endl;// 无参，无返回std::thread thread1([]() {std::cout << getStringFromU8string(u8"Hello World，子线程, threadId=") << std::this_thread::get_id() << endl; });// 有参，无返回std::thread thread2([](int a, int b) {std::cout << getStringFromU8string(u8"Hello World，子线程, threadId=") << std::this_thread::get_id() << " ;a+b=" << (a + b) << endl; }, 2, 3);// 等待线程结束（阻塞主线程）thread1.join();thread2.join();std::cout << getStringFromU8string(u8"结束主线程，threadId=") << std::this_thread::get_id() << endl;return 0;
}

3、通过成员函数

#include <iostream>
#include <string>
#include <thread>
#include <sstream>using namespace std;
std::string getStringFromU8string(const std::u8string& u8str) {return std::string(reinterpret_cast<const char*>(u8str.data()), u8str.size());
}std::u8string getU8stingFromString(const std::string& str) {return std::u8string(reinterpret_cast<const char8_t*>(str.data()), str.size());
}std::string getThreadIdAsString() {std::stringstream ss;ss << std::this_thread::get_id();return ss.str();
}class Hello {
public:void sayHello() {std::cout << getStringFromU8string(u8"Hello World，子线程, threadId=") + getThreadIdAsString() + "\n";}void add(int a, int b) {std::cout << getStringFromU8string(u8"Hello World，子线程, threadId=") + getThreadIdAsString() + " ;a+b=" + std::to_string(a + b) + "\n";}static void staticAdd(int a, int b) {std::cout << getStringFromU8string(u8"Hello World，子线程, threadId=") + getThreadIdAsString() + " ;a+b=" + std::to_string(a + b) + "\n";}
};int main()
{system("chcp 65001");std::cout << getStringFromU8string(u8"开始主线程，threadId=") << std::this_thread::get_id() << endl;Hello hello;// 无参，无返回std::thread thread1(&Hello::sayHello, &hello);// 有参，无返回std::thread thread2(&Hello::add, &hello, 2, 3);// 有参，无返回（静态方法）std::thread thread3(&Hello::staticAdd, 5, 6);// 等待线程结束（阻塞主线程）thread1.join();thread2.join();thread3.join();std::cout << getStringFromU8string(u8"结束主线程，threadId=") << std::this_thread::get_id() << endl;return 0;
}

4、拷贝构造函数

已删除，不支持

5、移动构造函数

int main()
{system("chcp 65001");std::cout << getStringFromU8string(u8"开始主线程，threadId=") << std::this_thread::get_id() << endl;Hello hello;std::thread thread1(&Hello::sayHello, &hello);// 移动构造函数，原thread1失效不可用了std::thread thread2(std::move(thread1));// 等待线程结束（阻塞主线程）// thread1.join();thread2.join();std::cout << getStringFromU8string(u8"结束主线程，threadId=") << std::this_thread::get_id() << endl;return 0;
}