timeTest2.cpp

#include <iostream>
#include <chrono>
#include <thread>
#include <atomic>

using namespace std::literals;

// compile command
// g++ -lpthread -std=c++14 -march=native -O3 timeTest.cpp -o timeTest

// use thread safe increment this value each ms
typedef std::atomic_int_fast64_t clocktype;
clocktype g_tick_counter(0);

auto const one_Tick = std::chrono::milliseconds(1000);

static int runclock() {
  auto timeout = std::chrono::high_resolution_clock::now();
  while (1) {
    std::this_thread::sleep_for(one_Tick);
    auto now = std::chrono::high_resolution_clock::now();
    while (timeout < now) {
      g_tick_counter++;
      timeout += one_Tick;
    }
  }
}
static std::uint_fast64_t get_ms_time() { return g_tick_counter; }

int main() {
  std::thread t1(runclock);
  uint64_t times = 0;
  uint64_t slowcounter = 0;
  while (get_ms_time() == 0) {
    // wait timer to start running
    std::this_thread::sleep_for(1ms);
  }

  auto lastTime = get_ms_time();
  while (1) {
    times += 1;
    auto now = get_ms_time();
    if (now > lastTime) {
      slowcounter += 1;
      std::cout << times / slowcounter /
                       std::chrono::duration_cast<std::chrono::milliseconds>(
                           one_Tick).count() << " ops per ms" << std::endl;
      lastTime = now;
    }
  }
}