KeRemoveQueueApc

INT8 __fastcall KeRemoveQueueApc(INT64 a1){
  INT64 v1; 
  unsigned __int8 CurrentIrql; 
  INT8 v4; 
  UINT64 SpinCount; 

  v1 = *(_QWORD *)(a1 + 8);
  CurrentIrql = KeGetCurrentIrql();
  __writecr8(2ui64);
  LODWORD(SpinCount) = 0;
  while( _interlockedbittestandset64((volatile signed __int32 *)(v1 + 64), 0i64) )
  {
    do
      KeYieldProcessorEx(&SpinCount);
    while( *(_QWORD *)(v1 + 64) );
  }
  v4 = KiRemoveQueueApc((_KAPC *)a1);
  KiReleaseThreadLockSafe(v1);
  __writecr8(CurrentIrql);
  return v4;
}

Referenced by:

CmNotifyRunDown
EtwpCancelPendingStackwalkApcs
EtwpCovSampCaptureCancelApcs
EtwpQueueStackWalkApc
EtwpTraceThreadRundownWithStack
ExpCancelTimer
ExpSetTimerObject