PiUEventNotifyClientPendingEvent

void __fastcall PiUEventNotifyClientPendingEvent(__int64 a1){
  ExAcquireFastMutex(*(FAST_MUTEX **)(a1 + 16));
  PiUEventEstimateRequiredClientBufferSize(a1);
  KeReleaseGuardedMutex(*(_FAST_MUTEX **)(a1 + 16));
  ZwUpdateWnfStateData();
}

Referenced by:

PiUEventHandleGetEvent
PiUEventNotifyClient