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PdhAddEnglishCounterA function (pdh.h)

  • Article

Adds the specified language-neutral counter to the query.

Syntax

PDH_FUNCTION PdhAddEnglishCounterA(
  [in]  PDH_HQUERY   hQuery,
  [in]  LPCSTR       szFullCounterPath,
  [in]  DWORD_PTR    dwUserData,
  [out] PDH_HCOUNTER *phCounter
);

Parameters

[in] hQuery

Handle to the query to which you want to add the counter. This handle is returned by the PdhOpenQuery function.

[in] szFullCounterPath

Null-terminated string that contains the counter path. For details on the format of a counter path, see Specifying a Counter Path. The maximum length of a counter path is PDH_MAX_COUNTER_PATH.

[in] dwUserData

User-defined value. This value becomes part of the counter information. To retrieve this value later, call the PdhGetCounterInfo function and access the dwQueryUserData member of the PDH_COUNTER_INFO structure.

[out] phCounter

Handle to the counter that was added to the query. You may need to reference this handle in subsequent calls.

Return value

Return ERROR_SUCCESS if the function succeeds.

If the function fails, the return value is a system error code or a PDH error code. The following are possible values.

Return code Description
PDH_CSTATUS_BAD_COUNTERNAME
 The counter path could not be parsed or interpreted.
PDH_CSTATUS_NO_COUNTER
 Unable to find the specified counter on the computer or in the log file.
PDH_CSTATUS_NO_COUNTERNAME
 The counter path is empty.
PDH_CSTATUS_NO_MACHINE
 The path did not contain a computer name and the function was unable to retrieve the local computer name.
PDH_CSTATUS_NO_OBJECT
 Unable to find the specified object on the computer or in the log file.
PDH_FUNCTION_NOT_FOUND
 Unable to determine the calculation function to use for this counter.
PDH_INVALID_ARGUMENT
 One or more arguments are not valid.
PDH_INVALID_HANDLE
 The query handle is not valid.
PDH_MEMORY_ALLOCATION_FAILURE
 Unable to allocate memory required to complete the function.

Remarks

This function provides a language-neutral way to add performance counters to the query. In contrast, the counter path that you specify in the PdhAddCounter function must be localized.

If a counter instance is specified that does not yet exist, PdhAddEnglishCounter does not report an error condition. Instead, it returns ERROR_SUCCESS. The reason for this behavior is that it is not known whether a nonexistent counter instance has been specified or whether one will exist but has not yet been created.

To remove the counter from the query, use the PdhRemoveCounter function.

Note  If the counter path contains a wildcard character, the non-wildcard portions of the path will be localized, but wildcards will not be expanded before adding the localized counter path to the query. In this case, you will need use the following procedure to add all matching counter names to the query.
  1. Make a query
  2. Use PdhAddEnglishCounter with the string containing wildcards
  3. Use PdhGetCounterInfo on the counter handle returned by PdhAddEnglishCounter to get a localized full path (szFullPath.) This string still contains wildcards, but the non-wildcard parts are now localized.
  4. Use PdhExpandWildCardPath to expand the wildcards.
  5. Use PdhAddCounter on each of the resulting paths
 

Note

The pdh.h header defines PdhAddEnglishCounter as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement Value
Minimum supported client Windows Vista [desktop apps only]
Minimum supported server Windows Server 2008 [desktop apps only]
Target Platform Windows
Header pdh.h
Library Pdh.lib
DLL Pdh.dll

See also

PdhAddCounter

PdhBrowseCounters

PdhMakeCounterPath

PdhOpenQuery

PdhRemoveCounter