C++20 std::jthread

C++20 `std::jthread`

std::jthread 表示 joining thread , 与C++11里面的std::thread不同std::jthread 自动join, 并且可以被外部终止

自动`join`

std::thread

#include <iostream>
#include <thread>
using namespace std;int main(int argc, char* argv[])
{std::cout << std::boolalpha << std::endl;std::thread thr{[] { cout << "joinable std::thread<<" << std::endl; }};std::cout << thr.joinable() << std::endl;
}

执行后会发生:

std::jthread

#include <iostream>
#include <thread>
using namespace std;int main(int argc, char* argv[])
{std::cout << std::boolalpha << std::endl;std::jthread thr{[] { cout << "joinable std::thread" << std::endl; }};std::cout << thr.joinable() << std::endl;
}

可以正常运行

外部请求终止

请求终止,不是强制终止, 是否终止由线程本身决定 ,保证终止前能调用析构函数, 遵循RALL

#include <iostream>
#include <thread>
using namespace std;int main(int argc, char* argv[])
{std::jthread nonInterruptable([](){int counter{0};while (counter < 10){ // 不可以接收终止请求std::this_thread::sleep_for(0.2s); // CPP真是越来越好用了std::cerr << "non-interruptable thread: " << counter << '\n';++counter;}});std::jthread interrupttible([](std::stop_token stoken){int counter{0};while (counter < 10){std::this_thread::sleep_for(0.2s);if (stoken.stop_requested()) return; // 可以接收终止请求std::cerr << "interruptible" << counter << endl;++counter;}});std::this_thread::sleep_for(1s);std::cerr << endl;nonInterruptable.request_stop(); // 发送终止请求,但是并没有用interrupttible.request_stop(); // 发送终止请求,成功让线程终止cout << endl;
}