Applies to: desktop apps only

Creates a new query that is used to manage the collection of performance data.

To use handles to data sources, use the PdhOpenQueryH function.

Syntax

PDH_STATUS PdhOpenQuery(
  __in   LPCTSTR szDataSource,
  __in   DWORD_PTR dwUserData,
  __out  PDH_HQUERY *phQuery
);

Parameters

szDataSource [in]

Null-terminated string that specifies the name of the log file from which to retrieve performance data. If NULL, performance data is collected from a real-time data source.

dwUserData [in]

User-defined value to associate with this query. To retrieve the user data later, call PdhGetCounterInfo and access the dwQueryUserData member of PDH_COUNTER_INFO.

phQuery [out]

Handle to the query. You use this handle in subsequent calls.

Return value

If the function succeeds, it returns ERROR_SUCCESS.

If the function fails, the return value is a system error code or a PDH error code.

Examples

For an example, see Reading Performance Data from a Log File or Writing Performance Data to a Log File.

Requirements

See also

PdhCloseQuery

PdhGetCounterInfo

PdhIsRealTimeQuery

PdhOpenQueryH

PdhSetDefaultRealTimeDataSource

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Build date: 2/3/2012