RequestWakeupLatency function (winbase.h)

[RequestWakeupLatency is available for use in the operating systems specified in the Requirements section. It may be altered or unavailable in subsequent versions.]

Has no effect and returns STATUS_NOT_SUPPORTED. This function is provided only for compatibility with earlier versions of Windows.

Windows Server 2008 and Windows Vista:  Has no effect and always returns success.


BOOL RequestWakeupLatency(
  [in] LATENCY_TIME latency


[in] latency

The latency requirement for the time is takes to wake the computer. This parameter can be one of the following values.

Value Meaning
PowerSystemSleeping1 state (equivalent to ACPI state S0 and APM state Working).
Any latency (default).

Return value

The return value is nonzero.


The system uses the wake-up latency requirement when choosing a sleeping state. The latency is not guaranteed because wake-up time is determined by the hardware design of the particular computer.

To cancel a latency request, call RequestWakeupLatency with LT_DONT_CARE.


Requirement Value
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Target Platform Windows
Header winbase.h (include Windows.h)
Library Kernel32.lib
DLL Kernel32.dll

See also

Power Management Functions