Edit

AcxCircuitInitAssignAcxRequestPreprocessCallback function (acxcircuit.h)

  • Article

The AcxCircuitInitAssignAcxRequestPreprocessCallback function add a WDFREQUEST preprocess callback.

Syntax

NTSTATUS AcxCircuitInitAssignAcxRequestPreprocessCallback(
  PACXCIRCUIT_INIT                  CircuitInit,
  PFN_ACX_OBJECT_PREPROCESS_REQUEST EvtObjectAcxRequestPreprocess,
  ACXCONTEXT                        DriverContext,
  ACX_REQUEST_TYPE                  RequestType,
  const GUID                        *Set,
  ULONG                             Id
);

Parameters

CircuitInit

The ACXCIRCUIT_INIT structure that defines the circuit initialization. ACXCIRCUIT_INIT is an opaque object used for circuit initialization. Use AcxCircuitInitAllocate to initialize the ACXCIRCUIT_INIT structure.

EvtObjectAcxRequestPreprocess

A pointer to a EVT_ACX_OBJECT_PREPROCESS_REQUEST callback.

DriverContext

The driver context defined by the ACXCONTEXT object. For more information about ACX objects, see Summary of ACX Objects.

RequestType

An ACX_REQUEST_TYPE enum that defines different request types, such as AcxRequestTypeAny, AcxRequestTypeProperty, etc.

Set

Optional GUID to identify a specific item set ID.

Id

An ID to identify a specific item in the specified set ID.

Return value

Returns STATUS_SUCCESS if the call was successful. Otherwise, it returns an appropriate error code. For more information, see Using NTSTATUS Values.

Remarks

The driver can invoke this DDI multiple times to setup different preprocess callbacks. ACX invokes the first it finds that matches the specific incoming WDFREQUEST type.

Example

Example usage is shown below.

    // Render callbacks.

    EVT_ACX_OBJECT_PREPROCESS_REQUEST   CodecR_EvtCircuitRequestPreprocess;


    //
    // Add circuit type.
    //
    AcxCircuitInitSetCircuitType(circuitInit, AcxCircuitTypeRender);

    //
    // Assign the circuit's pnp-power callbacks.
    //
    ACX_CIRCUIT_PNPPOWER_CALLBACKS_INIT(&powerCallbacks);
    powerCallbacks.EvtAcxCircuitPowerUp = CodecR_EvtCircuitPowerUp;
    powerCallbacks.EvtAcxCircuitPowerDown = CodecR_EvtCircuitPowerDown;
    AcxCircuitInitSetAcxCircuitPnpPowerCallbacks(circuitInit, &powerCallbacks);


    //
    // Set circuit-callbacks.
    //
    status = AcxCircuitInitAssignAcxRequestPreprocessCallback(
                                            circuitInit, 
                                            CodecR_EvtCircuitRequestPreprocess,
                                            (ACXCONTEXT)AcxRequestTypeAny, // dbg only
                                            AcxRequestTypeAny,
                                            NULL, 
                                            AcxItemIdNone);

ACX requirements

Minimum ACX version: 1.0

For more information about ACX versions, see ACX version overview.

Requirements

Requirement Value
Header acxcircuit.h
IRQL PASSIVE_LEVEL

See also