std::jthread::native_handle

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< cpp‎ | thread‎ | jthread

 
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std::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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