WDF_REQUEST_COMPLETION_PARAMS structure

[Applies to KMDF and UMDF]

The WDF_REQUEST_COMPLETION_PARAMS structure contains parameters that are associated with the completion of an I/O request.

Syntax

typedef struct _WDF_REQUEST_COMPLETION_PARAMS {
  ULONG            Size;
  WDF_REQUEST_TYPE Type;
  IO_STATUS_BLOCK  IoStatus;
  union {
    struct {
      WDFMEMORY Buffer;
      size_t    Length;
      size_t    Offset;
    } Write;
    struct {
      WDFMEMORY Buffer;
      size_t    Length;
      size_t    Offset;
    } Read;
    struct {
      ULONG  IoControlCode;
      struct {
        WDFMEMORY Buffer;
        size_t    Offset;
      } Input;
      struct {
        WDFMEMORY Buffer;
        size_t    Offset;
        size_t    Length;
      } Output;
    } Ioctl;
    struct {
      union {
        PVOID     Ptr;
        ULONG_PTR Value;
      } Argument1;
      union {
        PVOID     Ptr;
        ULONG_PTR Value;
      } Argument2;
      union {
        PVOID     Ptr;
        ULONG_PTR Value;
      } Argument3;
      union {
        PVOID     Ptr;
        ULONG_PTR Value;
      } Argument4;
    } Others;
    struct {
      PWDF_USB_REQUEST_COMPLETION_PARAMS Completion;
    } Usb;
  } Parameters;
} WDF_REQUEST_COMPLETION_PARAMS, *PWDF_REQUEST_COMPLETION_PARAMS;

Members

Size

The size, in bytes, of this structure.

Type

A WDF_REQUEST_TYPE value that identifies the request type.

IoStatus

An IO_STATUS_BLOCK structure for the request.

Parameters

Request-specific values for the request.

Write

For write requests, this member identifies the buffer that the driver specified when it formatted the request and sent it to an I/O target.

Read

For read requests, this member identifies the buffer that the driver specified when it formatted the request and sent it to an I/O target.

Ioctl

Input

For device control requests, this member identifies the input buffer that the driver specified when it formatted the request and sent it to an I/O target.

Output

For device control requests, this member identifies the output buffers that the driver specified when it formatted the request and sent it to an I/O target.

Others

Argument1

Use of this member is defined by the driver stack.

Argument2

Use of this member is defined by the driver stack.

Argument3

Use of this member is defined by the driver stack.

Argument4

Use of this member is defined by the driver stack.

Usb

For USB devices, this member contains a pointer to a WDF_USB_REQUEST_COMPLETION_PARAMS structure.

Remarks

The WDF_REQUEST_COMPLETION_PARAMS structure is used as input to the WdfRequestGetCompletionParams method and a driver's CompletionRoutine callback function.

In both cases, the completion parameters structure contains valid information only if the driver has formatted the request by calling one of the WdfIoTargetFormatXxx methods. For example, see WdfIoTargetFormatRequestForRead.

Your driver must call WDF_REQUEST_COMPLETION_PARAMS_INIT to initialize the WDF_REQUEST_COMPLETION_PARAMS structure before the driver calls WdfRequestGetCompletionParams.

Requirements

See also

WdfRequestGetCompletionParams

WDF_REQUEST_COMPLETION_PARAMS_INIT

IO_STATUS_BLOCK

WDF_REQUEST_TYPE

CompletionRoutine

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