Setting priority of a std::thread

set_thread_priority.cpp

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

class thread : public std::thread
{
  public:
    static void setScheduling(std::thread &th, int priority) {
        sched_param sch;
        sch.sched_priority = priority;
        if(pthread_setschedparam(th.native_handle(), SCHED_FIFO, &sch)) {
            std::cerr << "Failed to set Thread scheduling : " << std::strerror(errno) << std::endl;
        }
    }
};

void f(int num) {
    sched_param sch;
    int policy;
    pthread_getschedparam(pthread_self(), &policy, &sch);
    std::cout << "Thread " << num << " priority " << sch.sched_priority << '\n';
}

int main(){
    std::thread t1, t2;
    t1 = std::thread(f, 1);
    t2 = std::thread(f, 2);
    thread::setScheduling(t1, 99);
    t1.join(); t2.join();
}

Compile:
g++ -pthread -Wall -std=c++14 set_thread_priority.cpp -o out.o

Run:
./out.o
If not root then
sudo ./out.o