EVENT_TRACE structure

The EVENT_TRACE structure is used to deliver event information to an event trace consumer.

Syntax

typedef struct _EVENT_TRACE {
  EVENT_TRACE_HEADER Header;
  ULONG              InstanceId;
  ULONG              ParentInstanceId;
  GUID               ParentGuid;
  PVOID              MofData;
  ULONG              MofLength;
  union {
    ULONG              ClientContext;
    ETW_BUFFER_CONTEXT BufferContext;
  } DUMMYUNIONNAME;
} EVENT_TRACE, *PEVENT_TRACE;

Members

        `Header`

        An 

EVENT_TRACE_HEADER structure that contains standard event tracing information.

        `InstanceId`

        Instance identifier. Contains valid data when the 

provider calls the TraceEventInstance function to generate the event. Otherwise, the value is zero.

        `ParentInstanceId`

        Instance identifier for a parent event. Contains valid data when the 

provider calls the TraceEventInstance function to generate the event. Otherwise, the value is zero.

        `ParentGuid`

        Class GUID of the parent event. Contains valid data when the 

provider calls the TraceEventInstance function to generate the event. Otherwise, the value is zero.

        `MofData`

        Pointer to the beginning of the event-specific data for this event.
    
    
        `MofLength`

        Number of bytes to which <b>MofData</b> points.
    
    
        `DUMMYUNIONNAME`

        
    
    
        `DUMMYUNIONNAME.ClientContext`

        Reserved.
    
    
        `DUMMYUNIONNAME.BufferContext`

        Provides information about the event such as the session identifier and processor number of the CPU on which the provider process ran. For details, see the <a href="https://docs.microsoft.com/windows/desktop/api/relogger/ns-relogger-etw_buffer_context">ETW_BUFFER_CONTEXT</a> structure.

Prior to Windows Vista:  Not supported.

## Remarks
    ETW passes this structure to the 

consumer's EventCallback callback function.

Requirements

   
Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Header evntrace.h
## See Also

    <a href="https://docs.microsoft.com/windows/desktop/ETW/eventcallback">EventCallback</a>

EventClassCallback