Portable way of setting std::thread priority in C++11

Question

What is the correct way in the post C++11 world for setting the priority of an instance of std::thread

Is there a portable way of doing this that works at least in Windows and POSIX (Linux) environments?

Or is it a matter of getting a handle and using whatever native calls are available for the particular OS?

Answer 1

There's no way to set thread priorities via the C++11 library. I don't think this is going to change in C++14, and my crystal ball is too hazy to comment on versions after that.

In POSIX, pthread_setschedparam(thread.native_handle(), policy, {priority});

In Win32 BOOL SetThreadPriority(HANDLE hThread,int nPriority)

Answer 2

My quick implementation...

#include <thread> #include <pthread.h> #include <iostream> #include <cstring>  class thread : public std::thread {   public:     thread() {}     static void setScheduling(std::thread &th, int policy, int priority) {         sch_params.sched_priority = priority;         if(pthread_setschedparam(th.native_handle(), policy, &sch_params)) {             std::cerr << "Failed to set Thread scheduling : " << std::strerror(errno) << std::endl;         }     }   private:     sched_param sch_params; }; 

and this is how I use it...

// create thread std::thread example_thread(example_function);  // set scheduling of created thread thread::setScheduling(example_thread, SCHED_RR, 2);