# std::jthread::native_handle

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< cpp‎ | thread‎ | jthread

[[nodiscard]] native_handle_type native_handle(); |  | (since C++20) (not always present)

Returns the implementation defined underlying thread handle.

### Parameters

(none)

### Return value

implementation defined handle type representing the thread.

### Exceptions

May throw implementation-defined exceptions.

### Example

Uses `native_handle` to enable realtime scheduling of C++ threads on a POSIX system

Run this code

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

    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

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