PcGetTimeInterval function (portcls.h)
The PcGetTimeInterval function returns the time elapsed since a specified time. Time is measured in 100-nanosecond units.
Syntax
PORTCLASSAPI ULONGLONG PcGetTimeInterval(
[in] ULONGLONG Since
);
Parameters
[in] Since
Specifies the time from which to measure the interval. Typically, this function is called once with a "since" of zero to get the current time, and is called subsequently with a "since" of the recorded current time to get time intervals from that time.
Return value
PcGetTimeInterval returns the current time minus Since.
Remarks
The value that is specified in parameter Since is measured in 100-nanosecond units. If Since is zero, the time returned is the number of 100-nanosecond ticks since January 1, 1601. The time units are the same as those used to specify the system time in the KeQuerySystemTime function.
The following macros from portcls.h are useful for converting seconds, milliseconds, and microseconds to 100-millisecond units:
GTI_SECONDS
GTI_MILLISECONDS
GTI_MICROSECONDS
This function can be used for timing purposes by first saving the current time,
ULONGLONG ullTime = PcGetTimeInterval(0);
and then checking to see whether the required interval has passed
if (PcGetTimeInterval(ullTime) >= GTI_MILLISECONDS(5))
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | The PortCls system driver implements the PcGetTimeInterval function in Microsoft Windows 98/Me and in Windows 2000 and later operating systems. |
| Target Platform | Universal |
| Header | portcls.h (include Portcls.h) |
| Library | Portcls.lib |
| IRQL | Any level |