uint64_t getChronometerTime() in ms

main.cpp

#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
LARGE_INTEGER frequency; // init with QueryPerformanceFrequency(&frequency) e.g. at beginning of main()
#endif                   // or go wild and put that in the constructor of a dedicated static object

#ifndef _WIN32
#if defined (CLOCK_MONOTONIC)
#include <time.h>
#else
#include <sys/time.h>
#endif
#endif

static uint64_t getChronometerTime()
{
#ifdef _WIN32
  LARGE_INTEGER t;
  QueryPerformanceCounter(&t);

  return t.QuadPart * 1000 / frequency.QuadPart;
#else
#if defined (CLOCK_MONOTONIC)
  struct timespec t;

  clock_gettime(CLOCK_MONOTONIC, &t);
  return t.tv_sec * 1000 + round(t.tv_nsec / 1000000.0);
#else
  struct timeval t;

  gettimeofday(&t, 0);
  return t.tv_sec * 1000 + round(t.tv_usec / 1000.0);
#endif
#endif
}