DXGKDDI_DESCRIBEALLOCATION callback function (d3dkmddi.h)

The DxgkDdiDescribeAllocation function retrieves information about an existing allocation that is not otherwise available to the Microsoft DirectX graphics kernel subsystem.

Syntax

DXGKDDI_DESCRIBEALLOCATION DxgkddiDescribeallocation;

NTSTATUS DxgkddiDescribeallocation(
  [in]     IN_CONST_HANDLE hAdapter,
  [in/out] INOUT_PDXGKARG_DESCRIBEALLOCATION pDescribeAllocation
)
{...}

Parameters

[in] hAdapter

A handle to a context block that is associated with a display adapter. The display miniport driver previously provided this handle to the DirectX graphics kernel subsystem in the MiniportDeviceContext output parameter of the DxgkDdiAddDevice function.

[in/out] pDescribeAllocation

A pointer to a DXGKARG_DESCRIBEALLOCATION structure that describes an existing allocation.

Return value

DxgkDdiDescribeAllocation returns STATUS_SUCCESS if it succeeds; otherwise, it returns one of the error codes defined in Ntstatus.h.

Remarks

Because the DirectX graphics kernel subsystem does not necessarily maintain records of allocations, the graphics kernel subsystem calls DxgkDdiDescribeAllocation to request that the display miniport driver return information about existing allocations. Currently, the display miniport driver must be able to return this information for the following allocations:

• Allocations that are also primaries (that is, allocations that the user-mode display driver created by setting the Primary bit-field flag in the Flags member of the D3DDDI_ALLOCATIONINFO structure in a call to the pfnAllocateCb function).
• Allocations that might be the source of a presentation (that is, allocations that are represented by the hSource member of the DXGKARG_PRESENT structure in a call to the display miniport driver's DxgkDdiPresent function).

Requirements

See also

D3DDDI_ALLOCATIONINFO

DXGKARG_DESCRIBEALLOCATION

DxgkDdiAddDevice

DxgkDdiPresent

pfnAllocateCb