WdfChildListCreate function (wdfchildlist.h)

Article
04/18/2022

[Applies to KMDF only]

The WdfChildListCreate method creates a child list for a specified parent device.

Syntax

NTSTATUS WdfChildListCreate(
  [in]           WDFDEVICE              Device,
  [in]           PWDF_CHILD_LIST_CONFIG Config,
  [in, optional] PWDF_OBJECT_ATTRIBUTES ChildListAttributes,
  [out]          WDFCHILDLIST           *ChildList
);

Parameters

[in] Device

A handle to a framework device object that represents the parent device.

[in] Config

A pointer to a WDF_CHILD_LIST_CONFIG structure that contains driver-supplied configuration information for the child list.

[in, optional] ChildListAttributes

A pointer to a WDF_OBJECT_ATTRIBUTES structure that contains driver-supplied object attributes for the framework child-list object. (The structure's ParentObject member must be NULL.)

[out] ChildList

A pointer to a caller-allocated location that receives a handle to a framework child-list object.

Return value

WdfChildListCreate returns STATUS_SUCCESS, or another status value for which NT_SUCCESS(status) equals TRUE, if the operation succeeds. Otherwise, this method might return one of the following values:

Return code	Description
STATUS_INVALID_PARAMETER	An input parameter was invalid.
STATUS_INSUFFICIENT_RESOURCES	An object could not be allocated.

This method might also return other NTSTATUS values.

A system bug check occurs if the driver supplies an invalid object handle.

Remarks

The framework creates a default child list for each framework device object that represents a functional device object (FDO). To use the default child list, the driver calls WdfFdoGetDefaultChildList. If your driver requires additional child lists, it can call WdfChildListCreate to create them.

The parent of each child-list object is the device's framework device object. The driver cannot change this parent, and the ParentObject member or the WDF_OBJECT_ATTRIBUTES structure must be NULL.

Your driver cannot delete the child-list object that WdfChildListCreate creates. The framework deletes the object at the proper time.

For more information about child lists, see Dynamic Enumeration.

Examples

The following code example initializes a WDF_CHILD_LIST_CONFIG structure and then calls WdfChildListCreate.

WDF_CHILD_LIST_CONFIG listConfig;

WDF_CHILD_LIST_CONFIG_INIT(
                           &listConfig,
                           sizeof(PDO_IDENTIFICATION_DESCRIPTION),
                           My_EvtDeviceListCreatePdo
                           );

listConfig.AddressDescriptionSize = sizeof(PDO_ADDRESS_DESCRIPTION);

listConfig.EvtChildListScanForChildren = My_EvtChildListScanForChildren;

listConfig.EvtChildListIdentificationDescriptionDuplicate = My_EvtChildListIdentificationDescriptionDuplicate;
listConfig.EvtChildListIdentificationDescriptionCompare = My_EvtChildListIdentificationDescriptionCompare;
listConfig.EvtChildListIdentificationDescriptionCleanup = My_EvtChildListIdentificationDescriptionCleanup;

status = WdfChildListCreate(
                            device,
                            &listConfig,
                            WDF_NO_OBJECT_ATTRIBUTES,
                            &ParentDeviceContext->ChildList
                            );
if (!NT_SUCCESS(status)) {
    return status;
}

Requirements

Requirement	Value
Target Platform	Universal
Minimum KMDF version	1.0
Header	wdfchildlist.h (include Wdf.h)
Library	Wdf01000.sys (see Framework Library Versioning.)
IRQL	PASSIVE_LEVEL
DDI compliance rules	DriverCreate(kmdf), KmdfIrql(kmdf), KmdfIrql2(kmdf), KmdfIrqlExplicit(kmdf)

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