QueryInterruptTimePrecise function (realtimeapiset.h)

Article
10/13/2021

Gets the current interrupt-time count, in a more precise form than QueryInterruptTime does.

Syntax

void QueryInterruptTimePrecise(
  [out] PULONGLONG lpInterruptTimePrecise
);

Parameters

[out] lpInterruptTimePrecise

A pointer to a ULONGLONG in which to receive the interrupt-time count in system time units of 100 nanoseconds. Divide by ten million, or 1e7, to get seconds (there are 1e9 nanoseconds in a second, so there are 1e7 100-nanoseconds in a second).

Return value

None

Remarks

QueryInterruptTimePrecise is similar to the QueryInterruptTime routine, but is more precise. The interrupt time reported by QueryInterruptTime is based on the latest tick of the system clock timer. The system clock timer is the hardware timer that periodically generates interrupts for the system clock. The uniform period between system clock timer interrupts is referred to as a system clock tick, and is typically in the range of 0.5 milliseconds to 15.625 milliseconds, depending on the hardware platform. The interrupt time value retrieved by QueryInterruptTime is accurate within a system clock tick.

To provide a system time value that is more precise than that of QueryInterruptTime, QueryInterruptTimePrecise reads the timer hardware directly, therefore a QueryInterruptTimePrecise call can be slower than a QueryInterruptTime call.

Call the KeQueryTimeIncrement routine to determine the duration of a system clock tick.

Also see Remarks in QueryInterruptTime.

Note The QueryInterruptTimePrecise function produces different results on debug ("checked") builds of Windows, because the interrupt-time count and tick count are advanced by approximately 49 days. This helps to identify bugs that might not occur until the system has been running for a long time. The checked build is available to MSDN subscribers through the Microsoft Developer Network (MSDN) Web site.

To compile an application that uses this function, define _WIN32_WINNT as 0x0601 or later. For more information, see Using the Windows Headers.

Requirements

Requirement	Value
Minimum supported client	Windows 10 [desktop apps \| UWP apps]
Minimum supported server	Windows Server 2016 [desktop apps \| UWP apps]
Target Platform	Windows
Header	realtimeapiset.h
Library	Mincore.lib
DLL	Kernel32.dll