VOID EngQueryPerformanceFrequency(
| LONGLONG *pFrequency | |
| ); |
EngQueryPerformanceFrequency queries the frequency of the performance counter.
Parameters
pFrequency
Pointer to a location in which the performance counter frequency is returned.
Comments
The resolution of the timer is 1/x, where x is the value returned in the location to which pFrequency points. For example, if the value returned in pFrequency is 2 million, each tick is 1/2 millionth of a second. Each 1/x millionth increment of the count corresponds to one second of elapsed time.
A driver should call this routine sparingly. Frequent calls to EngQueryPerformanceFrequency can degrade the I/O performance for the calling driver and for the system as a whole.
See Also