WmiTraceMessageVa function (wdm.h)

The WmiTraceMessageVa routine adds a message to the output log of a WPP software tracing session.

Syntax

NTSTATUS WmiTraceMessageVa(
  [in] TRACELOGGER_HANDLE LoggerHandle,
  [in] ULONG              MessageFlags,
  [in] LPCGUID            MessageGuid,
  [in] USHORT             MessageNumber,
  [in] va_list            MessageArgList
);

Parameters

[in] LoggerHandle

Specifies a trace handle for a software tracing session.

[in] MessageFlags

Specifies a bitwise OR of one or more message flags. See the Remarks section for details.

[in] MessageGuid

Specifies a GUID that identifies a software trace class.

[in] MessageNumber

Identifies the message subtype. The meaning of subtypes is specific to the software trace class and the provider.

[in] MessageArgList

Provides a required list of message parameters that specify a set of message parts. The parameters are organized as a sequence of parameter pairs, where each pair specifies one part of the complete message. Each parameter pair consists of a PVOID pointer to data, followed immediately by a ULONG value that specifies the length of the data. The parameter list must be terminated by a NULL PVOID pointer followed by a ULONG(0).

Return value

WmiTraceMessageVa returns one of the following values:

Return code Description
STATUS_SUCCESS
The operation completed successfully.
STATUS_INVALID_HANDLE
LoggerHandle is not a valid software trace handle.
STATUS_NO_MEMORY
There is insufficient buffer memory to log the message. See the Remarks section for more information.
Other NTSTATUS value
An internal error occurred.

Remarks

A caller can use WmiTraceMessage or WmiTraceMessageVa to add a message to the output log of a WPP software tracing session. WmiTraceMessage simplifies a caller's code by handling the variable list mechanism before calling WmiTraceMessageVa.

A caller can set the following message flags:

Flag Description
TRACE_MESSAGE_SEQUENCE Include a sequence number in the message. Message sequencing can only be used if it is enabled for the software tracing session specified by LoggerHandle.
TRACE_MESSAGE_GUID MessageGuid specifies a GUID that identifies a software trace class. This flag must be set.
TRACE_MESSAGE_TIMESTAMP Include a time stamp in the message.
TRACE_MESSAGE_PERFORMANCE_TIMESTAMP This flag is not implemented and is obsolete. It must not be used.
TRACE_MESSAGE_SYSTEMINFO Include the thread identifier (TID) and process identifier (PID) in the message.
 

WmiTraceMessageVa does not log the message if one of the following is true:

  • The total size, in bytes, of the message data and the message header is greater than the size of individual message buffers allocated for a software tracing session. (The maximum message header size is 48 bytes.)
  • All message buffers allocated to software tracing session are full.
WmiTraceMessageVa runs at the IRQL of the caller.

Requirements

Requirement Value
Minimum supported client Available in Windows XP and later versions of Windows.
Target Platform Universal
Header wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
Library NtosKrnl.lib
DLL NtosKrnl.exe
IRQL See Remarks section.

See also

IoWmiWriteEvent

TRACE_INFORMATION_CLASS

WmiFireEvent

WmiQueryTraceInformation

WmiTraceMessage