Bewerken

Delen via

TraceLogging Wrapper Macros

  • Artikel

The TraceLoggingWrite and TraceLoggingWriteActivity macros emit TraceLogging events configured according to the macro parameters. Each of these macros accept a set of required parameters followed by up to 99 optional parameters. Each optional parameter either configures the event or adds a field to the event. Each optional parameter must be one of the TraceLogging Wrapper macros described on this page.

For example:

TraceLoggingWrite(
    g_hProvider,
    "MyEvent1",
    TraceLoggingLevel(WINEVENT_LEVEL_WARNING), // Levels defined in <winmeta.h>
    TraceLoggingKeyword(MyNetworkingKeyword),
    TraceLoggingString(operationName), // Adds an "operationName" field.
    TraceLoggingHResult(hr, "NetStatus")); // Adds a "NetStatus" field.

In this example, g_hProvider and "MyEvent1" are the required parameters. They specify the provider to use for the event and the event's name. Each of the remaining parameters is a wrapper macro. The TraceLoggingLevel and TraceLoggingKeyword parameters configure the event. The TraceLoggingString and TraceLoggingHResult parameters add fields to the event.

Event Configuration macros

The following macros configure the event.

If a particular configuration macro is not provided in the TraceLoggingWrite, a default is used for that event. For example, if no TraceLoggingLevel parameter is used for an event, the event uses a default level of 5 (VERBOSE).

  • TraceLoggingLevel sets the event's level. The level is an 8-bit value indicating event severity. Levels from 1 (WINEVENT_LEVEL_CRITICAL) to 5 (WINEVENT_LEVEL_VERBOSE) are defined in <winmeta.h>. If not specified, the event defaults to level 5 (VERBOSE). Level is an important part of ETW event routing and filtering, so all events should have a meaningful non-zero level.
  • TraceLoggingKeyword sets the event's keyword. A keyword is a 64-bit value with each bit indicating a category to which the event belongs. The low 48 bits of the keyword are defined by the owner of the provider while the high 16 bits of the keyword are defined by Microsoft. For example, you might decide that all providers with name "MyCompany.MyComponent" will use keyword 0x1 to mean "Networking". If not specified, the event defaults to keyword 0x0 (None). Keyword is an important part of ETW event routing and filtering, so all events should have a meaningful non-zero keyword.
  • TraceLoggingOpcode sets the event's opcode. The opcode is an 8-bit value indicating special semantics for the event, e.g. that the event records the beginning (WINEVENT_OPCODE_START) or end (WINEVENT_OPCODE_STOP) of an ETW activity (a group of related events). If not specified, the event defaults to opcode 0 (WINEVENT_OPCODE_INFO) indicating that no special semantics are required.
  • TraceLoggingChannel sets the event's channel. The channel is an 8-bit value that is used for various purposes. If not specified, the event defaults to channel 11 (WINEVENT_CHANNEL_TRACELOGGING). Most events do not need to change the event's channel and should not use TraceLoggingChannel.
  • TraceLoggingEventTag sets the event's tag. The tag is a 28-bit value with provider-defined semantics. For example, a provider might define tag bit 0x1000000 to indicate that the event potentially contains personally-identifiable information and should receive special treatment from provider-specific event processing tools. If not specified, the tag defaults to 0.
  • TraceLoggingDescription sets the event's description. The description is a string literal with a human-readable description of the event. This serves as a comment about the event purpose, and the description is also recorded as an annotation in your component's debug symbols (PDB). If not specified, the description defaults to "".
  • TraceLoggingCustomAttribute adds a key-value annotation to the component's debug symbols (PDB).

Field macros

TraceLogging supports many wrapper macros for adding fields to an event. Each field is a name-value pair. For example, TraceLoggingInt32(argc, "ArgCount") would add an INT32 field named "ArgCount" with value argc.

Most of the field wrapper macros accept similar parameters:

  • value: An expression that will be evaluated at runtime to determine the data to include in the field. Most field wrapper macros use a single parameter to specify the value, but some macros require multiple parameters for the field value, e.g. a pointer and a length. The value parameter(s) are always required.
    • In some cases, the field value is specified as pszValue, in which case it is a pointer to a 0-terminated string of characters to include in the field. pszValue may be NULL, in which case the field value will be an empty string "".
    • In some cases, the field value is specified as pchValue, in which case it is a pointer to a string of cchValue characters to include in the field. pchValue may be NULL only if cchValue is 0.
    • In some cases, the field value is specified as pValue with an automatically-determined size (no cbValue parameter), in which case it is a pointer to the value to include in the field. pValue may not be NULL.
    • In some cases, the field value is specified as pValue with a cbValue parameter to specify the size (in bytes) of the data to include in the field. pValue may be NULL only if cbValue is 0.
  • name: A string literal (compile-time constant) with the name to use for the field. Most field wrapper macros do not require a name parameter. If you omit the name parameter, the field's name is determined based on the preprocessor text of the macro's value, pszValue, pchValue, or pValue parameter. For example, TraceLoggingInt32(x[4] + y) is equivalent to TraceLoggingInt32(x[4] + y, "x[4] + y"). Both would add a field named "x[4] + y" to the event with a value determined by evaluating the expression x[4] + y.
  • description: A string literal (compile-time constant) with a description to use for the field. This is mostly used as a convenient place to put a comment for the field, but the description is also recorded as an annotation in the component's debug symbols (PDB). The description is optional. If the description parameter is omitted, the field's description defaults to "".
  • tag: A 28-bit integer (compile-time constant) with provider-defined semantics. For example, a provider might define tag 0x2 to indicate that the field contains a telephone number and should receive special treatment from provider-specific event processing tools. If the tag parameter is omitted, the field's tag defaults to 0.

For example, the following wrapper macro invocations all have the same effect:

  • TraceLoggingInt32(argc)
  • TraceLoggingInt32(argc, "argc")
  • TraceLoggingInt32(argc, "argc", "")
  • TraceLoggingInt32(argc, "argc", "", 0)

Scalars

  • TraceLoggingValue(value, [name, ...]):

    Adds a field with a type that is automatically-deduced from the type of the value parameter. (C++ only)

  • TraceLoggingInt8(value, [name, ...]):

    Adds a field with an INT8 value.

  • TraceLoggingUInt8(value, [name, ...]):

    Adds a field with a UINT8 value.

  • TraceLoggingInt16(value, [name, ...]):

    Adds a field with an INT16 value.

  • TraceLoggingUInt16(value, [name, ...]):

    Adds a field with a UINT16 value.

  • TraceLoggingInt32(value, [name, ...]):

    Adds a field with an INT32 value.

  • TraceLoggingUInt32(value, [name, ...]):

    Adds a field with a UINT32 value.

  • TraceLoggingInt64(value, [name, ...]):

    Adds a field with an INT64 value.

  • TraceLoggingUInt64(value, [name, ...]):

    Adds a field with a UINT64 value.

  • TraceLoggingIntPtr(value, [name, ...]):

    Adds a field with an INT_PTR value (signed integer with the same size as a pointer).

  • TraceLoggingUIntPtr(value, [name, ...]):

    Adds a field with a UINT_PTR value (unsigned integer with the same size as a pointer).

  • TraceLoggingLong(value, [name, ...]):

    Adds a field with a LONG value (signed long int, 32-bits on Windows platforms).

  • TraceLoggingULong(value, [name, ...]):

    Adds a field with a ULONG value (unsigned long int, 32-bits on Windows platforms).

  • TraceLoggingHexInt8(value, [name, ...]):

    Adds a field with an INT8 value with a hexadecimal formatting hint.

  • TraceLoggingHexUInt8(value, [name, ...]):

    Adds a field with a UINT8 value with a hexadecimal formatting hint.

  • TraceLoggingHexInt16(value, [name, ...]):

    Adds a field with an INT16 value with a hexadecimal formatting hint.

  • TraceLoggingHexUInt16(value, [name, ...]):

    Adds a field with a UINT16 value with a hexadecimal formatting hint.

  • TraceLoggingHexInt32(value, [name, ...]):

    Adds a field with an INT32 value with a hexadecimal formatting hint.

  • TraceLoggingHexUInt32(value, [name, ...]):

    Adds a field with a UINT32 value with a hexadecimal formatting hint.

  • TraceLoggingHexInt64(value, [name, ...]):

    Adds a field with an INT64 value with a hexadecimal formatting hint.

  • TraceLoggingHexUInt64(value, [name, ...]):

    Adds a field with a UINT64 value with a hexadecimal formatting hint.

  • TraceLoggingHexIntPtr(value, [name, ...]):

    Adds a field with an INT_PTR value with a hexadecimal formatting hint.

  • TraceLoggingHexUIntPtr(value, [name, ...]):

    Adds a field with a UINT_PTR value with a hexadecimal formatting hint.

  • TraceLoggingHexLong(value, [name, ...]):

    Adds a field with a LONG value with a hexadecimal formatting hint.

  • TraceLoggingHexULong(value, [name, ...]):

    Adds a field with a ULONG value with a hexadecimal formatting hint.

  • TraceLoggingFloat32(value, [name, ...]):

    Adds a field with a FLOAT (32-bit floating point) value.

  • TraceLoggingFloat64(value, [name, ...]):

    Adds a field with a DOUBLE (64-bit floating point) value.

  • TraceLoggingBoolean(value, [name, ...]):

    Adds a field with an 8-bit Boolean value (Win32 BOOLEAN or C++ bool).

  • TraceLoggingBool(value, [name, ...]):

    Adds a field with a 32-bit Boolean value (Win32 BOOL).

  • TraceLoggingChar(value, [name, ...]):

    Adds a field with a char value (8-bit integer with string formatting hint, typically treated as code page 1252).

  • TraceLoggingChar16(value, [name, ...]):

    Adds a field with a char16_t value (16-bit integer with string formatting hint, typically treated as UCS-2).

  • TraceLoggingWChar(value, [name, ...]):

    Adds a field with a wchar_t value (same as char16_t on Windows platforms).

  • TraceLoggingPointer(value, [name, ...]):

    Adds a field with a void* value (pointer-sized value with a hexadecimal formatting hint).

  • TraceLoggingCodePointer(value, [name, ...]):

    Adds a field with a void* value (pointer-sized value with a code-pointer formatting hint).

  • TraceLoggingPid(value, [name, ...]):

    Adds a field with an INT32 value with a process ID formatting hint.

  • TraceLoggingTid(value, [name, ...]):

    Adds a field with an INT32 value with a thread ID formatting hint.

  • TraceLoggingIPv4Address(value, [name, ...]):

    Adds a field with a UINT32 value with an IPv4 formatting hint (network byte order).

  • TraceLoggingIPv6Address(pValue, [name, ...]):

    Adds a field with a 16-byte binary value with an IPv6 formatting hint.

  • TraceLoggingPort(value, [name, ...]):

    Adds a field with a UINT16 value with an IP port formatting hint (network byte order).

  • TraceLoggingSocketAddress(pValue, cbValue, [name, ...]):

    Adds a field with a SOCKADDR value.

  • TraceLoggingWinError(value, [name, ...]):

    Adds a field with a UINT32 value with a Win32 error code formatting hint.

  • TraceLoggingNTStatus(value, [name, ...]):

    Adds a field with an NTSTATUS (LONG) value with a WinNT error code formatting hint.

  • TraceLoggingHResult(value, [name, ...]):

    Adds a field with an HRESULT (LONG) value with a Windows HRESULT formatting hint.

  • TraceLoggingFileTime(value, [name, ...]):

    Adds a field with a FILETIME value. When used in C code, the value parameter must be an lvalue expression.

  • TraceLoggingFileTimeUtc(value, [name, ...]):

    Adds a field with a FILETIME value with a UTC time zone formatting hint. When used in C code, the value parameter must be an lvalue expression.

  • TraceLoggingSystemTime(value, [name, ...]):

    Adds a field with a SYSTEMTIME value. When used in C code, the value parameter must be an lvalue expression.

  • TraceLoggingSystemTimeUtc(value, [name, ...]):

    Adds a field with a SYSTEMTIME value with a UTC time zone formatting hint. When used in C code, the value parameter must be an lvalue expression.

  • TraceLoggingGuid(value, [name, ...]):

    Adds a field with a GUID value. When used in C code, the value parameter must be an lvalue expression.

  • TraceLoggingString(pszValue, [name, ...]):

    Adds a field with a 0-terminated char string (typically treated as code page 1252). If pszValue is NULL, an empty string "" is used as the field value.

  • TraceLoggingUtf8String(pszValue, [name, ...]):

    Adds a field with a 0-terminated char string with a UTF-8 formatting hint. If pszValue is NULL, an empty string "" is used as the field value.

  • TraceLoggingString16(pszValue, [name, ...]):

    Adds a field with a 0-terminated char16_t string (UTF-16). If pszValue is NULL, an empty string u"" is used as the field value.

  • TraceLoggingWideString(pszValue, [name, ...]):

    Adds a field with a 0-terminated wchar_t string (UTF-16 on Windows). If pszValue is NULL, an empty string L"" is used as the field value.

  • TraceLoggingCountedString(pchValue, cchValue, [name, ...]):

    Adds a field with a counted char string (typically treated as code page 1252). pchValue may be NULL only if cchValue is 0.

  • TraceLoggingCountedUtf8String(pchValue, cchValue, [name, description, tag]):

    Adds a field with a counted char string with a UTF-8 formatting hint. pchValue may be NULL only if cchValue is 0.

  • TraceLoggingCountedString16(pchValue, cchValue, [name, ...]):

    Adds a field with a counted char16_t string (UTF-16). pchValue may be NULL only if cchValue is 0.

  • TraceLoggingCountedWideString(pchValue, cchValue, [name, description, tag]):

    Adds a field with a counted wchar_t string (UTF-16 on Windows). pchValue may be NULL only if cchValue is 0.

  • TraceLoggingAnsiString(pValue, [name, ...]):

    Adds a field with an ANSI_STRING value. The pValue pointer must not be NULL.

  • TraceLoggingUnicodeString(pValue, [name, ...]):

    Adds a field with a UNICODE_STRING value. The pValue pointer must not be NULL.

  • TraceLoggingSid(pValue, [name, ...]):

    Adds a field with a SID value. The pValue pointer must not be NULL and must point at a properly-initialized SID (Revision and SubAuthorityCount must be valid).

  • TraceLoggingBinary(pValue, cbValue, [name, ...]):

    Adds a field with binary data.

  • TraceLoggingBinaryEx(pValue, cbValue, outType, [name, ...]):

    Adds a field with binary data with the formatting hint specified by outType.

  • TraceLoggingBinaryBuffer(pValue, StructType, [name, ...]):

    Adds a field with binary data. pValue must be a non-NULL pointer to a StructType struct. pValue->Buffer must point at the start of the data and pValue->Length must be the number of bytes of data to be included in the field.

  • TraceLoggingBinaryBufferEx(pValue, StructType, outType, name, description, tag):

    Adds a field with binary data with the formatting hint specified by outType. pValue must be a non-NULL pointer to a StructType struct. pValue->Buffer must point at the start of the data and pValue->Length must be the number of bytes of data to be included in the field.

  • TraceLoggingCustom(pValue, cbValue, protocol, bSchema, cbSchema, [name, ...]):

    Adds a field with binary data that has been serialized according to a serialization protocol. Compile-time constant decoding information will be included along with the event to allow deserialization by the event decoder.

Structures

You can use the TraceLoggingStruct(fieldCount, name, [...]) macro to create a named structure (group of fields). The fieldCount parameter indicates how many of the subsequent fields should be counted as part of the structure. Structures may be nested, in which case each nested structure and its contained fields counts as a single field for the purpose of defining the parent struct.

Arrays

You can create a field that contains an array of scalar (single) values. For example, you add an array of GUIDs as a single field in your event.

Note

While the TraceLogging protocol supports arrays of all types, TraceLoggingProvider.h only provides wrapper macros for arrays of simple values, e.g. it provides macros for arrays of INT32 and GUID but it does not provide macros for arrays of String or arrays of structures. It is possible to create events with arrays of complex values by marshaling the data into a buffer and then using the TraceLoggingPacked macros described below.

TraceLogging supports fixed-length and variable-length arrays.

  • Use the Array macro in cases where the array length is not known at compile-time and may be different each time the event is generated.
  • Use the FixedArray macro in cases where the array length is known at compile-time (i.e. when the array length is a constant). This communicates to the event consumer that all events with a particular event name will have the same number of items in the array field.

All of the array macros require the pValues and cValues parameters to be specified, with pValues pointing to the start of the array content and cValues set to the number of items in the array. pValues may be NULL only if cValues is 0.

All of the array macros optionally accept name, description, and tag parameters as described for the Scalar macros. If name is not specified, the field name is determined from the preprocessor text of pValues. If description is not specified, the field description will be "". If tag is not specified, the field tag will be 0.

Note

To ensure ETW does not drop your events, avoid creating events with large arrays. ETW does not support events that are larger than 64KB. Any such events will be silently dropped by ETW. In addition, events that are larger than the consumer session's BufferSize will also be dropped by ETW. The event size is based on the sum of the event's headers, metadata (provider, event, and field names), and data (field values).

  • TraceLoggingInt8Array(pValues, cValues, [name, ...])
  • TraceLoggingInt8FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingUInt8Array(pValues, cValues, [name, ...])
  • TraceLoggingUInt8FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingInt16Array(pValues, cValues, [name, ...])
  • TraceLoggingInt16FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingUInt16Array(pValues, cValues, [name, ...])
  • TraceLoggingUInt16FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingInt32Array(pValues, cValues, [name, ...])
  • TraceLoggingInt32FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingUInt32Array(pValues, cValues, [name, ...])
  • TraceLoggingUInt32FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingInt64Array(pValues, cValues, [name, ...])
  • TraceLoggingInt64FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingUInt64Array(pValues, cValues, [name, ...])
  • TraceLoggingUInt64FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingIntPtrArray(pValues, cValues, [name, ...])
  • TraceLoggingIntPtrFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingUIntPtrArray(pValues, cValues, [name, ...])
  • TraceLoggingUIntPtrFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingLongArray(pValues, cValues, [name, ...])
  • TraceLoggingLongFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingULongArray(pValues, cValues, [name, ...])
  • TraceLoggingULongFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingHexInt8Array(pValues, cValues, [name, ...])
  • TraceLoggingHexInt8FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingHexUInt8Array(pValues, cValues, [name, ...])
  • TraceLoggingHexUInt8FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingHexInt16Array(pValues, cValues, [name, ...])
  • TraceLoggingHexInt16FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingHexUInt16Array(pValues, cValues, [name, ...])
  • TraceLoggingHexUInt16FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingHexInt32Array(pValues, cValues, [name, ...])
  • TraceLoggingHexInt32FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingHexUInt32Array(pValues, cValues, [name, ...])
  • TraceLoggingHexUInt32FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingHexInt64Array(pValues, cValues, [name, ...])
  • TraceLoggingHexInt64FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingHexUInt64Array(pValues, cValues, [name, ...])
  • TraceLoggingHexUInt64FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingHexIntPtrArray(pValues, cValues, [name, ...])
  • TraceLoggingHexIntPtrFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingHexUIntPtrArray(pValues, cValues, [name, ...])
  • TraceLoggingHexUIntPtrFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingHexLongArray(pValues, cValues, [name, ...])
  • TraceLoggingHexLongFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingHexULongArray(pValues, cValues, [name, ...])
  • TraceLoggingHexULongFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingFloat32Array(pValues, cValues, [name, ...])
  • TraceLoggingFloat32FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingFloat64Array(pValues, cValues, [name, ...])
  • TraceLoggingFloat64FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingBooleanArray(pValues, cValues, [name, ...])
  • TraceLoggingBooleanFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingBoolArray(pValues, cValues, [name, ...])
  • TraceLoggingBoolFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingCharArray(pValues, cValues, [name, ...])
  • TraceLoggingCharFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingChar16Array(pValues, cValues, [name, ...])
  • TraceLoggingChar16FixedArray(pValues, cValues, [name, ...])
  • TraceLoggingWCharArray(pValues, cValues, [name, ...])
  • TraceLoggingWCharFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingPointerArray(pValues, cValues, [name, ...])
  • TraceLoggingPointerFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingCodePointerArray(pValues, cValues, [name, ...])
  • TraceLoggingCodePointerFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingFileTimeArray(pValues, cValues, [name, ...])
  • TraceLoggingFileTimeFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingFileTimeUtcArray(pValues, cValues, [name, ...])
  • TraceLoggingFileTimeUtcFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingSystemTimeArray(pValues, cValues, [name, ...])
  • TraceLoggingSystemTimeFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingSystemTimeUtcArray(pValues, cValues, [name, ...])
  • TraceLoggingSystemTimeUtcFixedArray(pValues, cValues, [name, ...])
  • TraceLoggingGuidArray(pValues, cValues, [name, ...])
  • TraceLoggingGuidFixedArray(pValues, cValues, [name, ...])

Packed macros

TraceLoggingProvider.h only provides field macros for blittable field types, i.e. fields where each field macro corresponds to a single field and a single contiguous region of memory with the field's value.

TraceLoggingProvider.h does not provide direct support for more complex cases such as:

  • Logging an array of a variable-length type such as an array of strings.
  • Logging an array of structures.
  • Passing multiple fields to ETW via a single buffer to reduce event logging overhead.

To support these scenarios, TraceLoggingProvider.h defines several TraceLoggingPacked macros that allow you to directly manipulate the event definition (metadata) and field values (data) of the event.

Warning

The TraceLoggingPacked macros are tricky to use correctly and require a good understanding of how TraceLogging events are created. If used incorrectly they will result in corrupt events that do not decode correctly.

For details on the use of these macros, refer to the comments in the TraceLoggingProvider.h header.

  • TraceLoggingPackedField(pValue, cbValue, inType, [name, description, tags]):

    Adds field data (pValue, cbValue) and field metadata (name, inType).

  • TraceLoggingPackedFieldEx(pValue, cbValue, inType, outType, [name, ...]):

    Adds field data (pValue, cbValue) and field metadata (name, inType) along with a formatting hint (outType).

  • TraceLoggingPackedMetadata(inType, [name, ...]):

    Adds field metadata (name, inType) without adding field data. Corresponding field data must be added via TraceLoggingPackedData.

  • TraceLoggingPackedMetadataEx(inType, outType, [name, ...]):

    Adds field metadata (name, inType) and a formatting hint (outType) without adding field data. Corresponding field data must be added via TraceLoggingPackedData.

  • TraceLoggingPackedStruct(fieldCount, name, [...]):

    Adds field metadata (name, fieldCount) for a struct.

  • TraceLoggingPackedStructArray(fieldCount, [name, ...]):

    Adds field metadata (name, fieldCount) for a variable-length array of struct. The array length must be specified via TraceLoggingPackedData.

  • TraceLoggingPackedData(pValue, cbValue):

    Adds field data to an event without adding any field metadata. Corresponding metadata must be added via the Metadata macros.

  • TraceLoggingPackedDataEx(pValue, cbValue, dataDescType):

    Adds field data to an event without adding any field metadata, using a specific Type in the EVENT_DATA_DESCRIPTOR for the data. Corresponding metadata must be added via the Metadata macros.