windows_ports.cpp

#ifdef _WINDOWS

#include "windows_ports.h"

LARGE_INTEGER getFILETIMEoffset(){
  SYSTEMTIME s;
  FILETIME f;
  LARGE_INTEGER t;

  s.wYear = 1970;
  s.wMonth = 1;
  s.wDay = 1;
  s.wHour = 0;
  s.wMinute = 0;
  s.wSecond = 0;
  s.wMilliseconds = 0;
  SystemTimeToFileTime(&s, &f);
  t.QuadPart = f.dwHighDateTime;
  t.QuadPart <<= 32;
  t.QuadPart |= f.dwLowDateTime;
  return (t);
}

int clock_gettime(int X, struct timespec *tv){
    LARGE_INTEGER           t;
    FILETIME            f;
    double                  microseconds;
    static LARGE_INTEGER    offset;
    static double           frequencyToMicroseconds;
    static int              initialized = 0;
    static BOOL             usePerformanceCounter = 0;

    if (!initialized) {
        LARGE_INTEGER performanceFrequency;
        initialized = 1;
        usePerformanceCounter = QueryPerformanceFrequency(&performanceFrequency);
        if (usePerformanceCounter) {
            QueryPerformanceCounter(&offset);
            frequencyToMicroseconds = (double)performanceFrequency.QuadPart / 1000000.;
        } else {
            offset = getFILETIMEoffset();
            frequencyToMicroseconds = 10.;
        }
    }
    if (usePerformanceCounter) QueryPerformanceCounter(&t);
    else {
        GetSystemTimeAsFileTime(&f);
        t.QuadPart = f.dwHighDateTime;
        t.QuadPart <<= 32;
        t.QuadPart |= f.dwLowDateTime;
    }

    t.QuadPart -= offset.QuadPart;
    microseconds = (double)t.QuadPart / frequencyToMicroseconds;
    t.QuadPart = microseconds;
    tv->tv_sec = t.QuadPart / 1000000;
    tv->tv_nsec = t.QuadPart % 1000000000;
    return (0);
}

#endif