获取sleep一毫秒的真实时间

                    double t0,t1;
                    __int64 Freq = 0;
                    __int64 Count = 0;
                    if (QueryPerformanceFrequency((LARGE_INTEGER*)&Freq)&& Freq > 0&& QueryPerformanceCounter((LARGE_INTEGER*)&Count)){
                        t0=(double)Count / (double)Freq * 1000.0;
                    }
                    Sleep(1);
                    if (QueryPerformanceFrequency((LARGE_INTEGER*)&Freq) && Freq > 0 && QueryPerformanceCounter((LARGE_INTEGER*)&Count)) {
                        t1 = (double)Count / (double)Freq * 1000.0;
                    }
TRACE(_T("Sleep=%.3lf	"),t1-t0);