QueryPerformanceFrequency

QueryPerformanceFrequency retrieves the frequency of the high-resolution performance counter, if one exists. The frequency cannot change while the system is running.

Syntax

BOOL QueryPerformanceFrequency(
    LARGE_INTEGER* lpFrequency
);

Parameters

lpFrequency

Pointer to a variable that receives the current performance-counter frequency, in counts per second. If the installed hardware does not support a high-resolution performance counter, this parameter can be zero.

Return Value

A non-zero value if the installed hardware supports a high-resolution performance counter, 0 (zero) if the function fails

For example, if the installed hardware does not support a high-resolution performance counter, the function fails.

To get extended error information, call GetLastError.

Remarks

The frequency of the high-resolution performance counter is not the processor speed.

Requirements

Minimum Supported Version	RTX64 2013
Header	windows.h
Library	Rtx_Rtss.lib

In Windows applications, this function is available by including rtapi.h and linking to rtapi.lib.