D3D12DDI_WORK_GRAPH_DESC_0108 structure (d3d12umddi.h)

The D3D12DDI_WORK_GRAPH_DESC_0108 structure defines the state subobject of type D3D12DDI_STATE_SUBOBJECT_TYPE_WORK_GRAPH.

Syntax

typedef struct D3D12DDI_WORK_GRAPH_DESC_0108 {
  LPCWSTR                             ProgramName;
  UINT                                Version;
  D3D12DDI_WORK_GRAPH_FLAGS_0108      Flags;
  UINT                                NumNodes;
  const D3D12DDI_NODE_LIST_ENTRY_0108 *pNodes;
  UINT                                NumEntrypoints;
  const D3D12DDI_NODE_LIST_ENTRY_0108 *pEntrypoints;
} D3D12DDI_WORK_GRAPH_DESC_0108;

Members

ProgramName

Name of the work graph. This name is unique in the given state object.

Version

The version number of this work graph, starting at 0. When PFND3D12DDI_ADD_TO_STATE_OBJECT_0072 is being used, this value increments for new versions.

If a state object that has had a few additions in it to other parts of it (perhaps other work graphs) gets a newly created work graph added, Version will be 0 for the initial appearance of the new work graph, even though the state object itself has had a few iterations. Similarly if additions are made to other parts of a state object but a particular work graph in it is left alone, its version doesn't change until the next time an addition is made to the work graph itself. The Version value is the same numbering used in the VersionAdded field of D3D12DDI_NODE_0108.

Flags

A D3D12DDI_WORK_GRAPH_FLAGS_0108 enumeration that specifies flags that control the behavior of the work graph.

NumNodes

The number of nodes within the work graph, including already existing ones if an addition is happening. This value determines the number of elements in the pNodes array.

pNodes

Pointer to an array of D3D12DDI_NODE_LIST_ENTRY_0108 structures, where each entry represents a node definition in the work graph.

Even with the D3D12DDI_WORK_GRAPH_FLAG_ADD_TO_EXISTING_WORK_GRAPH flag, pNodes points to a list of all nodes in the graph. New nodes appear at the start of the list.

NumEntrypoints

Number of entrypoints including already existing ones if an addition is happening. This value determines the number of elements in the pEntrypoints array.

pEntrypoints

Pointer to an array of D3D12DDI_NODE_LIST_ENTRY_0108 structures, where each entry represents an entry point in the work graph.

Even with the D3D12DDI_WORK_GRAPH_FLAG_ADD_TO_EXISTING_WORK_GRAPH flag, pEntryPoints points to a list of all entrypoints. New entrypoints appear at the start of the list and continue entrypoint index numbering after previous versions. For example, suppose the initial version of a graph has two entrypoints. This list would have two entries, and the driver must infer that they have entry point indices [0] and [1] respectively for record assignments from PFND3D12DDI_DISPATCH_GRAPH_0108. If an addition happens, with 3 new entrypoints, the list for the new graph version would have 5 entry point entries, with the new entries at the start of the list. The driver must infer the entrypoint indices of the 3 new entries at the start of the list (the entries with the new Version), so the full list would be [2], [3], [4], [0], [1]. Ideally these assignments would have been provided by the runtime in the DDI so the driver wouldn't have to figure this out, but this was missed and deemed not important enough to fix.

Remarks

The D3D12DDI_WORK_GRAPH_DESC_0108 structure describes a work graph. The work graph itself is a collection of nodes, where each node represents a unit of work or a task. Nodes can have dependencies on one another, which define the execution order. Entry points are the nodes where execution can begin and are typically the nodes without dependencies or those that can be run immediately.

The runtime provides conveniences at the API level, like being able to define a work graph just by listing entrypoints or even by asking for all available nodes to be used. The runtime takes the API work graph definition, validates it, and gives the driver the final set of nodes in the graph, depicted in this D3D12DDI_WORK_GRAPH_DESC_0108 structure.

For more information, see Work graphs.

Requirements

See also

D3D12DDI_NODE_LIST_ENTRY_0108

D3D12DDI_STATE_SUBOBJECT_TYPE

D3D12DDI_WORK_GRAPH_FLAGS_0108

PFND3D12DDI_ADD_TO_STATE_OBJECT_0072

PFND3D12DDI_CREATE_STATE_OBJECT_0054

PFND3D12DDI_DISPATCH_GRAPH_0108