WDF_STATE_NOTIFICATION_TYPE enumeration (wdfdevice.h)

[Applies to KMDF only]

Note

This enumeration is for Microsoft internal use only.

The WDF_STATE_NOTIFICATION_TYPE enumeration identifies the type of Plug and Play, power, or power policy notification that a framework-based driver will receive.

Syntax

typedef enum _WDF_STATE_NOTIFICATION_TYPE {
  StateNotificationInvalid = 0x0000,
  StateNotificationEnterState = 0x0001,
  StateNotificationPostProcessState = 0x0002,
  StateNotificationLeaveState = 0x0004,
  StateNotificationAllStates = StateNotificationEnterState | StateNotificationPostProcessState | StateNotificationLeaveState
} WDF_STATE_NOTIFICATION_TYPE;

Constants

 
StateNotificationInvalid
Value: 0x0000
For internal use only.
StateNotificationEnterState
Value: 0x0001
The driver is notified immediately before a device's Plug and Play, power, or power policy state machine enters a specified state.
StateNotificationPostProcessState
Value: 0x0002
The driver is notified immediately after a device's Plug and Play, power, or power policy state machine enters a specified state.
StateNotificationLeaveState
Value: 0x0004
The driver is notified immediately before a device's Plug and Play, power, or power policy state machine leaves a specified state.
StateNotificationAllStates
Value: StateNotificationEnterState
The driver receives enter-state, postprocess-state, and leave-state notifications.

Remarks

When the framework's state machine for a driver's device changes from state a to state b, the framework notifies the driver (if the driver registered an appropriate event callback function), in the following sequence:

  1. Calls state a's leave-state notification callback function.
  2. Calls state b's enter-state notification callback function.
  3. Changes the device's state from a to b.
  4. Calls state b's postprocess-state notification callback function.
To register for notification of a change in state, the driver can call the following methods:

Requirements

Requirement Value
Minimum KMDF version 1.0
Header wdfdevice.h (include Wdf.h)

See also

WDF_DEVICE_PNP_NOTIFICATION_DATA

WDF_DEVICE_POWER_NOTIFICATION_DATA

WDF_DEVICE_POWER_POLICY_NOTIFICATION_DATA