2.2.4.2 Extrinsic Events

Extrinsic events are events generated by a component outside the implementation. In WMI, extrinsic events are represented as instances of a class that is derived from the __ExtrinsicEvent class. If any component wants to generate an event, the component defines a class that is derived from the __ExtrinsicEvent class. Instances of the derived class defined by the component, represented by using IWbemClassObject (section 2.2.4), are used to send events.

__ExtrinsicEvent class is defined by WMI as shown in the following MOF text.

  
 [abstract]
 class __SystemClass
 {
 };
  
 [abstract]
 class __IndicationRelated : __SystemClass
 {
 };
  
  [abstract: DisableOverride ToInstance ToSubClass]
 class __Event : __IndicationRelated
 {
     uint64 TIME_CREATED;
     uint8 SECURITY_DESCRIPTOR[];
 };
  
 class __ExtrinsicEvent : __Event
 {
 };
  
  

Where TIME_CREATED is the time at which the event is generated, represented as a 64-bit value that represents the number of 100-nanosecond intervals since January 1, 1601 (UTC), and SECURITY_DESCRIPTOR is a security descriptor, as defined in [MS-DTYP], represented as an array of bytes. The security descriptor MUST specify security for events as specified in section 5.2.