PFND3DKMT_CREATEALLOCATION callback function (d3dkmthk.h)

Article
02/22/2024

The D3DKMTCreateAllocation function creates allocations of system or video memory.

Syntax

PFND3DKMT_CREATEALLOCATION Pfnd3dkmtCreateallocation;

NTSTATUS Pfnd3dkmtCreateallocation(
  D3DKMT_CREATEALLOCATION *unnamedParam1
)
{...}

Parameters

unnamedParam1

pData [in, out]

A pointer to a D3DKMT_CREATEALLOCATION structure that contains information for creating allocations.

Return value

D3DKMTCreateAllocation returns one of the following values:

Return code	Description
STATUS_SUCCESS	Allocations were successfully created.
STATUS_DEVICE_REMOVED	The graphics adapter was stopped or the display device was reset.
STATUS_INVALID_PARAMETER	Parameters were validated and determined to be incorrect.
STATUS_NO_MEMORY	D3DKMTCreateAllocation could not complete because of insufficient memory.
STATUS_NO_VIDEO_MEMORY	D3DKMTCreateAllocation could not complete because of insufficient video memory. The video memory manager attempts to virtualize video memory; however, if the virtualization fails (such as, when virtual address space runs out), the memory manager might return this error code.

This function might also return other NTSTATUS values.

Remarks

The OpenGL ICD uses the D3DKMTCreateAllocation function to create allocations and resources. An allocation can be associated with a resource, or an allocation can stand alone. The D3DKMTCreateAllocation function can also be used to add additional allocations to a resource at anytime. The only restrictions are that all shared allocations must be associated with a resource and additional allocations cannot be added to an existing shared resource.

Examples

The following code example demonstrates how an OpenGL ICD can use D3DKMTCreateAllocation to create a stand-alone allocation in video memory that is not associated with a resource.

D3DKMT_HANDLE CreateStandAloneAllocation(D3DKMT_HANDLE hDevice, VOID* pPrivateAllocationInfo, UINT Size)
{
    D3DKMT_CREATEALLOCATION CreateAllocation;
    D3DDDI_ALLOCATIONINFO AllocationInfo;

    memset(&CreateAllocation, 0, sizeof(CreateAllocation));
    CreateAllocation.hDevice = hDevice;
    CreateAllocation.NumAllocations = 1;
    CreateAllocation.pAllocationInfo = &AllocationInfo;

    AllocationInfo.hAllocation = NULL;
    AllocationInfo.pSystemMem = NULL;  // Vidmem allocation
    AllocationInfo.pPrivateDriverData = pPrivateAllocationInfo;  // Contains format, size, and so on.
    AllocationInfo.PrivateDriverDataSize = Size;

    if (NT_SUCCESS((*pfnKTCreateAllocation)(&CreateAllocation))) {
        return AllocationInfo.hAllocation;
    }
    return 0;
}

The following code example demonstrates how an OpenGL ICD can use D3DKMTCreateAllocation to create a resource with a single system memory allocation.

HRESULT CreateSysmemResource(D3DKMT_HANDLE hDevice, 
                             UINT AllocationSize, 
                             VOID* pResourceData, 
                             UINT ResourceDataSize,
                             VOID* pAllocationData, 
                             UINT AllocationDataSize,
                             D3DKMT_HANDLE* phResource,
                             D3DKMT_HANDLE* phAllocation)
{
    D3DKMT_CREATEALLOCATION CreateAllocation;
    D3DDDI_ALLOCATIONINFO AllocationInfo;
    VOID* pSysMem;

    *phResource = NULL;
    *phAllocation = NULL;

    // For a sysmem allocation, preallocate the memory.
    pSysMem = MemAlloc(AllocationSize);
    if (pSysMem == NULL) {
        return E_OUTOFMEMORY;
    }
 
    memset(&CreateAllocation, 0, sizeof(CreateAllocation));
    CreateAllocation.hDevice = hDevice;
    CreateAllocation.Flags.CreateResource = TRUE;
    CreateAllocation.pPrivateDriverData = pResourceData;
    CreateAllocation.PrivateDriverDataSize = ResourceDataSize;
    CreateAllocation.NumAllocations = 1;
    CreateAllocation.pAllocationInfo = &AllocationInfo;

    AllocationInfo.hAllocation = NULL;
    AllocationInfo.pSystemMem = pSysMem;
    AllocationInfo.pPrivateDriverData = pAllocationData;
    AllocationInfo.PrivateDriverDataSize = AllocationDataSize;

    if (NT_SUCCESS((*pfnKTCreateAllocation)(&CreateAllocation))) {
        *phResource = CreateAllocation.hResource;
        *phAllocation = AllocationInfo.hAllocation;
        return S_OK;
    }
    MemFree(pSysMem);
    return E_FAIL;
}

Requirements

Requirement	Value
Minimum supported client	Windows Vista
Target Platform	Universal
Header	d3dkmthk.h (include D3dkmthk.h)

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