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D3D12DDI_BARRIER_ACCESS enumeration (d3d12umddi.h)

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A D3D12DDI_BARRIER_ACCESS value is a bit-wise OR of the following fields that specify resource access with respect to a barrier.

Syntax

typedef enum D3D12DDI_BARRIER_ACCESS {
  D3D12DDI_BARRIER_ACCESS_COMMON = 0x0,
  D3D12DDI_BARRIER_ACCESS_VERTEX_BUFFER = 0x1,
  D3D12DDI_BARRIER_ACCESS_CONSTANT_BUFFER = 0x2,
  D3D12DDI_BARRIER_ACCESS_INDEX_BUFFER = 0x4,
  D3D12DDI_BARRIER_ACCESS_RENDER_TARGET = 0x8,
  D3D12DDI_BARRIER_ACCESS_UNORDERED_ACCESS = 0x10,
  D3D12DDI_BARRIER_ACCESS_DEPTH_STENCIL_WRITE = 0x20,
  D3D12DDI_BARRIER_ACCESS_DEPTH_STENCIL_READ = 0x40,
  D3D12DDI_BARRIER_ACCESS_SHADER_RESOURCE = 0x80,
  D3D12DDI_BARRIER_ACCESS_STREAM_OUTPUT = 0x100,
  D3D12DDI_BARRIER_ACCESS_INDIRECT_ARGUMENT = 0x200,
  D3D12DDI_BARRIER_ACCESS_PREDICATION = 0x200,
  D3D12DDI_BARRIER_ACCESS_COPY_DEST = 0x400,
  D3D12DDI_BARRIER_ACCESS_COPY_SOURCE = 0x800,
  D3D12DDI_BARRIER_ACCESS_RESOLVE_DEST = 0x1000,
  D3D12DDI_BARRIER_ACCESS_RESOLVE_SOURCE = 0x2000,
  D3D12DDI_BARRIER_ACCESS_RAYTRACING_ACCELERATION_STRUCTURE_READ = 0x4000,
  D3D12DDI_BARRIER_ACCESS_RAYTRACING_ACCELERATION_STRUCTURE_WRITE = 0x8000,
  D3D12DDI_BARRIER_ACCESS_SHADING_RATE_SOURCE = 0x10000,
  D3D12DDI_BARRIER_ACCESS_VIDEO_DECODE_READ = 0x20000,
  D3D12DDI_BARRIER_ACCESS_VIDEO_DECODE_WRITE = 0x40000,
  D3D12DDI_BARRIER_ACCESS_VIDEO_PROCESS_READ = 0x80000,
  D3D12DDI_BARRIER_ACCESS_VIDEO_PROCESS_WRITE = 0x100000,
  D3D12DDI_BARRIER_ACCESS_VIDEO_ENCODE_READ = 0x200000,
  D3D12DDI_BARRIER_ACCESS_VIDEO_ENCODE_WRITE = 0x400000,
  D3D12DDI_BARRIER_ACCESS_NO_ACCESS = 0x80000000
} ;

Constants

 
D3D12DDI_BARRIER_ACCESS_COMMON
Value: 0x0
The default initial access for all resources in a given ExecuteCommandLists scope. Supports any type of access compatible with current layout and resource properties, including no more than one write access. For buffers and textures using D3D12DDI_BARRIER_LAYOUT_COMMON, D3D12DDI_BARRIER_ACCESS_COMMON supports concurrent read and write accesses.

When used as AccessAfter, D3D12DDI_BARRIER_ACCESS_COMMON can be used to return a resource back to common accessibility. Note that this might force unnecessary cache flushes if used incorrectly. When possible, AccessAfter should be limited to explicit access bits.

Avoid using D3D12DDI_BARRIER_ACCESS_COMMON as a barrier AccessBefore value. Any read-after-write or write-after-write hazards are best handled using explicit AccessBefore bits.
D3D12DDI_BARRIER_ACCESS_VERTEX_BUFFER
Value: 0x1
A buffer resource is accessible as a vertex buffer in the current execution queue.
D3D12DDI_BARRIER_ACCESS_CONSTANT_BUFFER
Value: 0x2
A buffer resource is accessible as a constant buffer in the current execution queue.
D3D12DDI_BARRIER_ACCESS_INDEX_BUFFER
Value: 0x4
A buffer resource is accessible as an index buffer in the current execution queue.
D3D12DDI_BARRIER_ACCESS_RENDER_TARGET
Value: 0x8
A resource is accessible as a render target.
D3D12DDI_BARRIER_ACCESS_UNORDERED_ACCESS
Value: 0x10
A resource is accessible as an unordered access resource.
D3D12DDI_BARRIER_ACCESS_DEPTH_STENCIL_WRITE
Value: 0x20
A resource is accessible as a writeable depth/stencil resource.
D3D12DDI_BARRIER_ACCESS_DEPTH_STENCIL_READ
Value: 0x40
A resource is accessible as a read-only depth/stencil resource.
D3D12DDI_BARRIER_ACCESS_SHADER_RESOURCE
Value: 0x80
A resource is accessible as a shader resource.
D3D12DDI_BARRIER_ACCESS_STREAM_OUTPUT
Value: 0x100
A buffer is accessible as a stream output target.
D3D12DDI_BARRIER_ACCESS_INDIRECT_ARGUMENT
Value: 0x200
A buffer is accessible as an indirect argument buffer.
D3D12DDI_BARRIER_ACCESS_PREDICATION
Value: 0x200
A buffer is accessible as a predication buffer. Aliased with D3D12DDI_BARRIER_ACCESS_INDIRECT_ARGUMENT.
D3D12DDI_BARRIER_ACCESS_COPY_DEST
Value: 0x400
A resource is accessible as a copy destination.
D3D12DDI_BARRIER_ACCESS_COPY_SOURCE
Value: 0x800
A resource is accessible as a copy source.
D3D12DDI_BARRIER_ACCESS_RESOLVE_DEST
Value: 0x1000
A resource is accessible as a resolve destination.
D3D12DDI_BARRIER_ACCESS_RESOLVE_SOURCE
Value: 0x2000
A resource is accessible as a resolve source.
D3D12DDI_BARRIER_ACCESS_RAYTRACING_ACCELERATION_STRUCTURE_READ
Value: 0x4000
A resource is accessible for read as a ray tracing acceleration structure. The resource must have been created using an initial state of D3D12DDI_RESOURCE_STATE_RAYTRACING_ACCELERATION_STRUCTURE.
D3D12DDI_BARRIER_ACCESS_RAYTRACING_ACCELERATION_STRUCTURE_WRITE
Value: 0x8000
A resource is accessible for write as a ray tracing acceleration structure. The resource must have been created using an initial state of D3D12DDI_RESOURCE_STATE_RAYTRACING_ACCELERATION_STRUCTURE.
D3D12DDI_BARRIER_ACCESS_SHADING_RATE_SOURCE
Value: 0x10000
A resource is accessible as a shading rate source.
D3D12DDI_BARRIER_ACCESS_VIDEO_DECODE_READ
Value: 0x20000
A resource is accessible for read-only access in a video decode queue.
D3D12DDI_BARRIER_ACCESS_VIDEO_DECODE_WRITE
Value: 0x40000
A resource is accessible for write access in a video decode queue.
D3D12DDI_BARRIER_ACCESS_VIDEO_PROCESS_READ
Value: 0x80000
A resource is accessible for read-only access in a video process queue.
D3D12DDI_BARRIER_ACCESS_VIDEO_PROCESS_WRITE
Value: 0x100000
A resource is accessible for write access in a video process queue.
D3D12DDI_BARRIER_ACCESS_VIDEO_ENCODE_READ
Value: 0x200000
A resource is accessible for read-only access in a video encode queue.
D3D12DDI_BARRIER_ACCESS_VIDEO_ENCODE_WRITE
Value: 0x400000
A resource is accessible for write access in a video encode queue.
D3D12DDI_BARRIER_ACCESS_NO_ACCESS
Value: 0x80000000
A resource is inaccessible for read or write. Once a subresource access has been transitioned to D3D12DDI_BARRIER_ACCESS_NO_ACCESS, it must be reactivated by a barrier with AccessBefore set to D3D12DDI_BARRIER_ACCESS_NO_ACCESS before using in the same ExecuteCommandLists scope.

D3D12DDI_BARRIER_ACCESS_NO_ACCESS can only be used in conjunction with D3D12DDI_BARRIER_SYNC_NONE or D3D12DDI_BARRIER_SYNC_SPLIT.

D3D12DDI_BARRIER_ACCESS_NO_ACCESS cannot be set with other access bits. D3D12DDI_BARRIER_ACCESS_NO_ACCESS indicates a resource is not expected to be accessed until some subsequent barrier or the next ECL scope.

This value is useful in aliasing barriers when a subresource is not needed for a sufficiently long time that it makes sense to purge the subresource from any read cache.

It is also useful for initiating a layout transition as the final act on a resource before the end of an ExecuteCommandLists scope. If SyncAfter is D3D12DDI_BARRIER_SYNC_NONE, then AccessAfter MUST be D3D12DDI_BARRIER_ACCESS_NO_ACCESS.

Requirements

Requirement Value
Minimum supported client Windows 11 (WDDM 3.0)
Header d3d12umddi.h

See also

D3D12DDI_BARRIER_SYNC

D3D12DDI_BUFFER_BARRIER_0088

D3D12DDI_GLOBAL_BARRIER_0088

D3D12DDI_RANGED_BARRIER_0088

D3D12DDI_TEXTURE_BARRIER_0088