Platform SDK: Hardware

RequestWakeupLatency

The RequestWakeupLatency function specifies roughly how quickly the computer should enter the working state.

BOOL RequestWakeupLatency(
  LATENCY_TIME latency      // latency requirement
);

Parameters

latency
[in] Specifies the latency requirement on the time is takes to wake the computer. This parameter can be one of the following values.
Value Description
LT_LOWEST_LATENCY PowerSystemSleeping1 state (equivalent to ACPI state S0 and APM state Working).
LT_DONT_CARE Any latency (default).

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. The function will fail if the device does not support wake-up operations or if the system is entering the sleeping state.

Remarks

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.

Requirements

  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Requires Windows 98.
  Header: Declared in Winbase.h; include Windows.h.
  Library: Use Kernel32.lib.

See Also

Power Management Overview, Power Management Functions