posix系统线程调度-设置线程优先级

#include <thread>
#include <mutex>
#include <iostream>
#include <chrono>
#include <cstring>
#include <pthread.h>
 
std::mutex iomutex;
void thread_func(int num)
{
    while(true) {
        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 << '
';

        std::this_thread::sleep_for(std::chrono::seconds(2));
    }
}

int main(int argc,char* argv[])
{
    std::thread thd_1(thread_func, 1);
 
    sched_param sch;
    int policy; 
    pthread_getschedparam(thd_1.native_handle(), &policy, &sch);
    sch.sched_priority = 20;
    policy=SCHED_FIFO;
    //policy=SCHED_RR;
    //policy=SCHED_OTHER;
    if (pthread_setschedparam(thd_1.native_handle(),policy, &sch)) {
        std::cout << "Failed to setschedparam: " << std::strerror(errno) << '
';
    }
 
    thd_1.join();

    return 0;
}