RtlGetSystemTimePrecise

NTSTATUS __stdcall RtlGetSystemTimePrecise(){
  unsigned __int64 TimeUpdateLock; 
  unsigned int LowPart; 
  unsigned __int64 BaselineSystemTimeQpc; 
  unsigned __int64 QpcSystemTimeIncrement; 
  unsigned __int8 QpcSystemTimeIncrementShift; 
  UINT64 PerformanceCounter; 
  __int64 v6; 

  while( 1 )
  {
    TimeUpdateLock = KUSER_SHARED_DATA.TimeUpdateLock;
    if( (KUSER_SHARED_DATA.TimeUpdateLock & 1) == 0 )
    {
      LowPart = KUSER_SHARED_DATA.SystemTime.LowPart;
      BaselineSystemTimeQpc = KUSER_SHARED_DATA.BaselineSystemTimeQpc;
      QpcSystemTimeIncrement = KUSER_SHARED_DATA.QpcSystemTimeIncrement;
      QpcSystemTimeIncrementShift = KUSER_SHARED_DATA.QpcSystemTimeIncrementShift;
      PerformanceCounter = KeQueryPerformanceCounter(0i64);
      if( KUSER_SHARED_DATA.TimeUpdateLock == TimeUpdateLock )
        break;
    }
    _mm_pause();
  }
  if( PerformanceCounter <= BaselineSystemTimeQpc )
    return LowPart;
  v6 = PerformanceCounter - BaselineSystemTimeQpc - 1;
  if( QpcSystemTimeIncrementShift )
    v6 <<= QpcSystemTimeIncrementShift;
  return(((unsigned __int64)v6 * (unsigned __int128)QpcSystemTimeIncrement) >> 64) + LowPart;
}

Referenced by: