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WDF_STATE_NOTIFICATION_TYPE enumeration

[Applies to KMDF 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

For internal use only.

StateNotificationEnterState

The driver is notified immediately before a device's Plug and Play, power, or power policy state machine enters a specified state.

StateNotificationPostProcessState

The driver is notified immediately after a device's Plug and Play, power, or power policy state machine enters a specified state.

StateNotificationLeaveState

The driver is notified immediately before a device's Plug and Play, power, or power policy state machine leaves a specified state.

StateNotificationAllStates

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

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

 

 

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