PdhOpenQueryA function

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_FUNCTION PdhOpenQueryA(
  LPCSTR     szDataSource,
  DWORD_PTR  dwUserData,
  PDH_HQUERY *phQuery
);

Parameters

szDataSource

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

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

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.

Requirements

   
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Target Platform Windows
Header pdh.h
Library Pdh.lib
DLL Pdh.dll

See also

PdhCloseQuery

PdhGetCounterInfo

PdhIsRealTimeQuery

PdhOpenQueryH

PdhSetDefaultRealTimeDataSource