KeRevertToUserGroupAffinityThread

VOID *__stdcall KeRevertToUserGroupAffinityThread(PGROUP_AFFINITY PreviousAffinity){
  PGROUP_AFFINITY p_UserAffinity; 
  _ETHREAD *CurrentThread; 
  VOID *result; 
  UINT8 CurrentIrql; 
  _KPRCB *CurrentPrcb; 
  int IdealProcessor; 
  UINT64 UserIdealProcessor; 
  int v8; 
  int Group; 
  bool v10; 
  UINT64 SpinCount; 
  _SINGLE_LIST_ENTRY ReadyList; 

  p_UserAffinity = PreviousAffinity;
  ReadyList.Next = 0i64;
  CurrentThread = (_ETHREAD *)KeGetCurrentThread();
  result = (VOID *)(unsigned int)CurrentThread->Tcb._bf_0;
  if( ((unsigned __int8)result & 8) != 0
    && !(PreviousAffinity->Reserved[0] | (unsigned __int16)(PreviousAffinity->Reserved[1] | PreviousAffinity->Reserved[2])) )
  {
    if( !PreviousAffinity->Mask
      || (result = (VOID *)KeActiveProcessors.Count,
          Group = PreviousAffinity->Group,
          (unsigned __int16)Group < KeActiveProcessors.Count)
      && (result = (VOID *)KeActiveProcessors.Bitmap[Group],
          v10 = ((unsigned __int64)result & p_UserAffinity->Mask) == 0,
          p_UserAffinity->Mask &= (unsigned __int64)result,
          !v10) )
    {
      CurrentIrql = KeGetCurrentIrql();
      __writecr8(2ui64);
      CurrentPrcb = KeGetCurrentPrcb();
      LODWORD(SpinCount) = 0;
      while( _interlockedbittestandset64((volatile signed __int32 *)&CurrentThread->Tcb.ThreadLock, 0i64) )
      {
        do
          KeYieldProcessorEx(&SpinCount);
        while( CurrentThread->Tcb.ThreadLock );
      }
      IdealProcessor = CurrentThread->Tcb.IdealProcessor;
      if( p_UserAffinity->Mask )
      {
        UserIdealProcessor = 1280i64;
      }
      else
      {
        UserIdealProcessor = CurrentThread->Tcb.UserIdealProcessor;
        p_UserAffinity = &CurrentThread->Tcb.UserAffinity;
        CurrentThread->Tcb._bf_0 &= ~8u;
      }
      KiSetSystemAffinityThread(CurrentPrcb, p_UserAffinity, UserIdealProcessor, &ReadyList);
      v8 = CurrentThread->Tcb.IdealProcessor;
      KiReleaseThreadLockSafe((INT64)CurrentThread);
      if( (xmmword_140CFB490 & 0x8000000) != 0 )
        EtwTraceIdealProcessor((__int64)CurrentThread, 0x546u, IdealProcessor, v8);
      KiProcessDeferredReadyList(CurrentPrcb, &ReadyList, CurrentIrql);
    }
  }
  return result;
}

Referenced by: