Defines the context type.


typedef enum _TDH_CONTEXT_TYPE {


TDH_CONTEXT_WPP_TMFFILE Null-terminated Unicode string that contains the name of the .tmf file used for parsing the WPP log. Typically, the .tmf file name is picked up from the event GUID so you do not have to specify the file name.
TDH_CONTEXT_WPP_TMFSEARCHPATH Null-terminated Unicode string that contains the path to the .tmf file. You do not have to specify this path if the search path contains the file. Only specify this context information if you also specify the TDH_CONTEXT_WPP_TMFFILE context type. If the file is not found, TDH searches the following locations in the given order:
  • The path specified in the TRACE_FORMAT_SEARCH_PATH environment variable
  • The current folder
TDH_CONTEXT_WPP_GMT A 1-byte Boolean flag that indicates if the WPP event time stamp should be converted to Universal Time Coordinate (UTC). If 1, the time stamp is converted to UTC. If 0, the time stamp is in local time. By default, the time stamp is in local time.
TDH_CONTEXT_POINTERSIZE Size, in bytes, of the pointer data types or size_t data types used in the event. Indicates if the event used 4-byte or 8-byte values. By default, the pointer size is the pointer size of the decoding computer.

To determine the size of the pointer or size_t value, use the PointerSize member of TRACE_LOGFILE_HEADER (the first event you receive in your EventRecordCallback callback contains this header in the data section). However, this value may not be accurate. For example, on a 64-bit computer, a 32-bit application will log 4-byte pointers; however, the session will set PointerSize to 8.

TDH_CONTEXT_PDB_PATH Null-terminated Unicode string that contains the name of the .pdb file for the binary that contains WPP messages. This parameter can be used as an alternative to TDH_CONTEXT_WPP_TMFFILE or TDH_CONTEXT_WPP_TMFSEARCHPATH.
Note  Available only for Windows 8 and Windows Server 2012.


If you are specifying context information for a legacy ETW event, you only need to specify the TDH_CONTEXT_POINTERSIZE type—the other types are used for WPP events and are ignored for legacy ETW events.


Minimum supported client Windows Vista [desktop apps only]
Minimum supported server Windows Server 2008 [desktop apps only]
Header tdh.h

See Also