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KsEnableEvent function

The KsEnableEvent function enables events requested through IOCTL_KS_ENABLE_EVENT. It responds to all event identifiers defined by the sets. This function can only be called at PASSIVE_LEVEL.


NTSTATUS KsEnableEvent(
  _In_      PIRP Irp,
  _In_      ULONG EventSetsCount,
  _In_      const KSEVENT_SET *EventSet,
  _Inout_   PLIST_ENTRY EventsList,
  _In_opt_  KSEVENTS_LOCKTYPE EventsFlags,
  _In_opt_  PVOID EventsLock


Irp [in]

Specifies the IRP with the enable request being handled. The file object associated with the IRP is stored with the event for later comparison when disabling the event.

EventSetsCount [in]

Indicates the number of event set structures being passed.

EventSet [in]

Specifies a pointer to the list of event set information.

EventsList [in, out]

If the enabling event's KSEVENT_SET.AddHandler for the event set is NULL, it must point to the head of the list of KSEVENT_ENTRY items on which the event is to be added. This function assumes a single list for at least a subset of events.

EventsFlags [in, optional]

Specifies KSEVENTS_LOCKTYPE flags specifying the type of exclusion lock to be used in accessing the event list, if any. If no flag is set, then no lock is taken. If a handler is specified already, this parameter is ignored.

EventsLock [in, optional]

If the KSEVENT_SET.AddHandler for the event set containing the event being enabled is NULL, then this is used to synchronize access to the list. This value can be NULL if no flag is set in EventsFlags.

Return value

The KsEnableEvent function returns STATUS_SUCCESS if successful, or an error specific to the event being enabled if unsuccessful. The function always sets the IO_STATUS_BLOCK.Information field of the PIRP.IoStatus element within the IRP to zero. It does not set the IO_STATUS_BLOCK.Status field, nor does it complete the IRP.


Minidrivers do not call KsEnableEvent. Only a pure KS driver or a class driver should call this routine.



Ks.h (include Ks.h)



See also




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