IWbemUnboundObjectSink::IndicateToConsumer method (wbemprov.h)

The IWbemUnboundObjectSink::IndicateToConsumer method is called by WMI to actually deliver events to a consumer. From an implementation standpoint, IndicateToConsumer contains the code for processing events that the sink receives.


HRESULT IndicateToConsumer(
  [in] IWbemClassObject *pLogicalConsumer,
  [in] long             lNumObjects,
  [in] IWbemClassObject **apObjects


[in] pLogicalConsumer

Pointer to the logical consumer object for which this set of objects is delivered.

[in] lNumObjects

Number of objects delivered in the array that follows.

[in] apObjects

Pointer to an array of IWbemClassObject instances which represent the events delivered. Because each object in the array corresponds to a separate event, an implementation of IndicateToConsumer must treat each object separately.

Return value

This method returns WBEM_S_NO_ERROR if successful. Otherwise, the implementation should return an appropriate error code.


WMI typically obtains the IWbemUnboundObjectSink pointer for a particular logical consumer from a event consumer provider which implements the IWbemEventConsumerProvider interface. Then, Windows Management calls IndicateToConsumer to deliver the actual event objects.

Most implementations of IndicateToConsumer assume that the notification is asynchronous. To support synchronous notification, a sink must complete event processing in less than 20 milliseconds. Extremely fast event consumer providers that support synchronous notification must not hold the pointer to the IWbemClassObject interface or increment the pointer reference count in IndicateToConsumer. If IndicateToConsumer requires the class object defined by IWbemClassObject beyond the lifetime of the IndicateToConsumer call, make a copy of the object. However, if there must be long-term access to the information pointed to by the IWbemClassObject pointer, it is recommended that the event consumer provider not support synchronous notification. Event consumer providers indicate the type of notification that they support when they complete their registration.


Requirement Value
Minimum supported client Windows Vista
Minimum supported server Windows Server 2008
Target Platform Windows
Header wbemprov.h (include Wbemidl.h)
Library Wbemuuid.lib
DLL Fastprox.dll

See also