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GetTimeSysInfoFunc callback function (timeprov.h)

  • Article

Retrieves the system time state information.

Syntax

GetTimeSysInfoFunc Gettimesysinfofunc;

HRESULT Gettimesysinfofunc(
  [in]  TimeSysInfo eInfo,
  [out] void *pvInfo
)
{...}

Parameters

[in] eInfo

Requested state information. This parameter can be one of the following values.

Value Meaning
TSI_ClockPrecision
 The pvInfo parameter is a signed __int32 value that specifies the clock precision, in log2 seconds.
TSI_ClockTickSize
 The pvInfo parameter is an unsigned __int64 value that specifies the clock tick size, in (10^-7) seconds.
TSI_CurrentTime
 The pvInfo parameter is an unsigned __int64 value that specifies the current time, in (10^-7) second intervals that have elapsed since 12:00 A.M. January 1, 1601 Coordinated Universal Time (UTC).
TSI_LastSyncTime
 The pvInfo parameter is an unsigned __int64 value that specifies the last synch time, in (10^-7) second intervals that have elapsed since 12:00 A.M. January 1, 1601 Coordinated Universal Time (UTC).
TSI_LeapFlags
 The pvInfo parameter is a BYTE value that indicates an impending leap second or loss of synchronization. The following values are defined:
0 - No change
1 - Add leap second
2 - Subtract leap second
3 - Not synchronized
TSI_PhaseOffset
 The pvInfo parameter is a signed __int64 value that specifies the phase offset used to adjust the clock, in seconds.
TSI_PollInterval
 The pvInfo parameter is a signed __int32 value that specifies the poll interval, in log2 seconds.
TSI_ReferenceIdentifier
 The pvInfo parameter is a DWORD value that specifies the reference identifier for the time source, in NTP format (either an IP address or a four character ASCII string that describes the hardware source, such as Global Positioning System (GPS) or WWVB).
TSI_RootDelay
 The pvInfo parameter is a signed __int64 value that specifies the root delay, in (10^-7) seconds.
TSI_RootDispersion
 The pvInfo parameter is an unsigned __int64 value that specifies, the root dispersion, in (10^-7) seconds.
TSI_Stratum
 The pvInfo parameter is a BYTE value that specifies the number of network hops that separate this computer from the root source. Hardware providers should return zero. NTP providers should return the stratum of the peer that provided the sample.
TSI_TickCount
 The pvInfo parameter is an unsigned __int64 value that specifies the tick count (number of milliseconds since the system was started). This value will eventually wrap, so it should be used only to compare short intervals.
TSI_TSFlags
 The pvInfo parameter is a DWORD value that specifies one of the following time source flags:
TSF_Authenticated
TSF_Hardware
TSF_IPv6

[out] pvInfo

A pointer to a buffer that receives that state information. The format of this data depends on the value of eInfo.

Return value

If the function succeeds, the return value is S_OK. Otherwise, the return value is one of the error codes defined in WinError.h.

Remarks

To ensure accuracy, the time provider should retrieve all time-related information using GetTimeSysInfoFunc. Note that the time values should not be used directly in an NTP packet. They are expressed relative to 12:00 A.M. January 1, 1601, whereas NTP specifies that time values be expressed relative to 12:00 A.M. January 1, 1900.

The TimeProvOpen function returns a pointer to this function.

Examples

For an example, see Sample Time Provider.

Requirements

Requirement Value
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Target Platform Windows
Header timeprov.h