Retrieves the frequency of the performance counter. The frequency of the performance counter is fixed at system boot and is consistent across all processors. Therefore, the frequency need only be queried upon application initialization, and the result can be cached.
BOOL QueryPerformanceFrequency( LARGE_INTEGER *lpFrequency );
A pointer to a variable that receives the current performance-counter frequency, in counts per second. If the installed hardware doesn't support a high-resolution performance counter, this parameter can be zero (this will not occur on systems that run Windows XP or later).
If the installed hardware supports a high-resolution performance counter, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError. On systems that run Windows XP or later, the function will always succeed and will thus never return zero.
For more info about this function and its usage, see Acquiring high-resolution time stamps.
|Minimum supported client||Windows 2000 Professional [desktop apps | UWP apps]|
|Minimum supported server||Windows 2000 Server [desktop apps | UWP apps]|
|Header||profileapi.h (include Windows.h)|