std::jthrea...ative_handle(3)

🌸 NAME 🌸

okay so this page is from the C++ Standard Libary manual, and the main character is std::jthread::native_handle. iykyk 💅

• std::jthread::native_handle - std::jthread::native_handle

✨ Synopsis ✨

[[nodiscard]] native_handle_type native_handle();

• since C++20 — yes bestie, this one is a C++20 thing.
• not always present — literally not always present, fr fr.

It returns the implementation defined underlying thread handle. that's the whole vibe.

🎀 Parameters 🎀

• (none) — literally none, bestie. zero parameters. 🫶

💖 Return value 💖

• Implementation defined handle type representing the thread. that's it. that's the return. iconic.

😭 Exceptions 😭

• May throw implementation-defined exceptions. so yeah, implementation-defined exceptions are allowed. ngl that's the entire caveat. 💀

🦋 Example 🦋

This example uses native_handle to enable realtime scheduling of C++ threads on a POSIX system.

// Run this code — and then this code, exactly:

        #include <chrono>
        #include <cstring>
        #include <iostream>
        #include <mutex>
        #include <pthread.h>
        #include <thread>

        std::mutex iomutex;
        void f(int num)
        {
            std::this_thread::sleep_for(std::chrono::seconds(1));

            sched_param sch;
            int policy;
            pthread_getschedparam(pthread_self(), &policy, &sch);
            std::lock_guard<std::mutex> lk(iomutex);
            std::cout << "Thread " << num << " is executing at priority "
                      << sch.sched_priority << '\n';
        }

        int main()
        {
            std::jthread t1(f, 1), t2(f, 2);

            sched_param sch;
            int policy;
            pthread_getschedparam(t1.native_handle(), &policy, &sch);
            sch.sched_priority = 20;
            if (pthread_setschedparam(t1.native_handle(), SCHED_FIFO, &sch))
                std::cout << "Failed to setschedparam: " <<
       std::strerror(errno) << '\n';

        }

🌈 Output 🌈

Thread 2 is executing at priority 0
Thread 1 is executing at priority 20

mwah 💖 this page is from http://cppreference.com, version/date 2024.06.10, and the footer says std::jthrea...ative_handle(3). periodt. 🎀