Edit

D3D12DDI_BARRIER_SYNC enumeration (d3d12umddi.h)

  • Article

Important

Some information relates to a prerelease product which may be substantially modified before it's commercially released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

A D3D12DDI_BARRIER_SYNC value is a bit-wise OR of the following fields that specify the synchronization scope of GPU work with respect to the barrier.

Syntax

typedef enum D3D12DDI_BARRIER_SYNC {
  D3D12DDI_BARRIER_SYNC_NONE = 0x0,
  D3D12DDI_BARRIER_SYNC_ALL = 0x1,
  D3D12DDI_BARRIER_SYNC_DRAW = 0x2,
  D3D12DDI_BARRIER_SYNC_INPUT_ASSEMBLER = 0x4,
  D3D12DDI_BARRIER_SYNC_VERTEX_SHADING = 0x8,
  D3D12DDI_BARRIER_SYNC_PIXEL_SHADING = 0x10,
  D3D12DDI_BARRIER_SYNC_DEPTH_STENCIL = 0x20,
  D3D12DDI_BARRIER_SYNC_RENDER_TARGET = 0x40,
  D3D12DDI_BARRIER_SYNC_COMPUTE_SHADING = 0x80,
  D3D12DDI_BARRIER_SYNC_RAYTRACING = 0x100,
  D3D12DDI_BARRIER_SYNC_COPY = 0x200,
  D3D12DDI_BARRIER_SYNC_RESOLVE = 0x400,
  D3D12DDI_BARRIER_SYNC_EXECUTE_INDIRECT = 0x800,
  D3D12DDI_BARRIER_SYNC_PREDICATION = 0x800,
  D3D12DDI_BARRIER_SYNC_ALL_SHADING = 0x1000,
  D3D12DDI_BARRIER_SYNC_NON_PIXEL_SHADING = 0x2000,
  D3D12DDI_BARRIER_SYNC_EMIT_RAYTRACING_ACCELERATION_STRUCTURE_POSTBUILD_INFO = 0x4000,
  D3D12DDI_BARRIER_SYNC_VIDEO_DECODE = 0x100000,
  D3D12DDI_BARRIER_SYNC_VIDEO_PROCESS = 0x200000,
  D3D12DDI_BARRIER_SYNC_VIDEO_ENCODE = 0x400000,
  D3D12DDI_BARRIER_SYNC_BUILD_RAYTRACING_ACCELERATION_STRUCTURE = 0x800000,
  D3D12DDI_BARRIER_SYNC_COPY_RAYTRACING_ACCELERATION_STRUCTURE = 0x1000000,
  D3D12DDI_BARRIER_SYNC_SPLIT = 0x80000000
} ;

Constants

 
D3D12DDI_BARRIER_SYNC_NONE
Value: 0x0
Synchronization is not needed either before or after a barrier. When used, D3D12DDI_BARRIER_SYNC_NONE must be the only bit set.

A SyncBefore value of D3D12DDI_BARRIER_SYNC_NONE implies there has been no preceding barriers or accesses made to the resource in the same ExecuteCommandLists scope.

A SyncAfter value of D3D12DDI_BARRIER_SYNC_NONE implies that the corresponding subresources are not accessed after the barrier in the same ExecuteCommandLists scope.

In both cases, AccessAfter must be D3D12DDI_BARRIER_ACCESS_NO_ACCESS.
D3D12DDI_BARRIER_SYNC_ALL
Value: 0x1
A SyncBefore value of D3D12DDI_BARRIER_SYNC_ALL indicates all preceding work must complete before executing the barrier.

A SyncAfter value of D3D12DDI_BARRIER_SYNC_ALL indicates all subsequent work must wait for the barrier to complete.
D3D12DDI_BARRIER_SYNC_DRAW
Value: 0x2
This value is an umbrella scope for all Draw pipeline stages. Synchronize against the following GPU workloads:

* DrawInstanced
* DrawIndexedInstanced
* SetGraphicsRootDescriptorTable
* SetGraphicsRootShaderResource
* SetGraphicsRootUnorderedAccessView
* SetGraphicsRootConstantBufferView

The SetGraphicsRootXxx synchronization is required to support D3D12DDI_DESCRIPTOR_RANGE_FLAG_0013_DATA_STATIC_WHILE_SET_AT_EXECUTE descriptors.

A SyncBefore value of D3D12DDI_BARRIER_SYNC_DRAW indicates all preceding Draw work must complete before executing the barrier.

A SyncAfter value of D3D12DDI_BARRIER_SYNC_DRAW indicates all subsequent Draw work must wait for the barrier to complete.
D3D12DDI_BARRIER_SYNC_INPUT_ASSEMBLER
Value: 0x4
Synchronize against Input Assembler stage execution.
D3D12DDI_BARRIER_SYNC_VERTEX_SHADING
Value: 0x8
Synchronize against all vertex shading stages, including vertex, domain, hull, tessellation, geometry, amplification and mesh shading.
D3D12DDI_BARRIER_SYNC_PIXEL_SHADING
Value: 0x10
Synchronize against pixel shader execution.
D3D12DDI_BARRIER_SYNC_DEPTH_STENCIL
Value: 0x20
Synchronize against depth/stencil read/write operations. This includes depth-stencil view (DSV) accesses during Draw* and ClearRenderTargetView.
D3D12DDI_BARRIER_SYNC_RENDER_TARGET
Value: 0x40
Synchronize against render target read/write operations. This includes render-target view (RTV) writes during Draw* and ClearRenderTargetView.
D3D12DDI_BARRIER_SYNC_COMPUTE_SHADING
Value: 0x80
Synchronize against the following GPU workloads:

* Dispatch
* SetComputeRootDescriptorTable
* SetComputeRootShaderResource
* SetComputeRootUnorderedAccessView
* SetComputeRootConstantBufferView

The SetComputeRootXxx synchronization is required to support D3D12DDI_DESCRIPTOR_RANGE_FLAG_DATA_STATIC_WHILE_SET_AT_EXECUTION descriptors.
D3D12DDI_BARRIER_SYNC_RAYTRACING
Value: 0x100
Synchronize against raytracing execution.
D3D12DDI_BARRIER_SYNC_COPY
Value: 0x200
Synchronize against Copy commands.
D3D12DDI_BARRIER_SYNC_RESOLVE
Value: 0x400
Synchronize against Resolve commands.
D3D12DDI_BARRIER_SYNC_EXECUTE_INDIRECT
Value: 0x800
Synchronize against ExecuteIndirect execution.
D3D12DDI_BARRIER_SYNC_PREDICATION
Value: 0x800
Synchronize against Predication commands. Aliased with D3D12DDI_BARRIER_SYNC_EXECUTE_INDIRECT*.
D3D12DDI_BARRIER_SYNC_ALL_SHADING
Value: 0x1000
Synchronize against all shader execution.
D3D12DDI_BARRIER_SYNC_NON_PIXEL_SHADING
Value: 0x2000
Synchronize against shader execution except pixel shading. Exists for compatibility with the legacy ResourceBarrier API.
D3D12DDI_BARRIER_SYNC_EMIT_RAYTRACING_ACCELERATION_STRUCTURE_POSTBUILD_INFO
Value: 0x4000
Synchronize against PFND3D12DDI_EMIT_RAYTRACING_ACCELERATION_STRUCTURE_POSTBUILD_INFO_0054 work.
D3D12DDI_BARRIER_SYNC_VIDEO_DECODE
Value: 0x100000
Synchronize against Video Decode execution.
D3D12DDI_BARRIER_SYNC_VIDEO_PROCESS
Value: 0x200000
Synchronize against Video Process execution.
D3D12DDI_BARRIER_SYNC_VIDEO_ENCODE
Value: 0x400000
Synchronize against Video Encode execution.
D3D12DDI_BARRIER_SYNC_BUILD_RAYTRACING_ACCELERATION_STRUCTURE
Value: 0x800000
Synchronize against PFND3D12DDI_BUILD_RAYTRACING_ACCELERATION_STRUCTURE_0054 work.

The corresponding barrier AccessBefore or AccessAfter field must have the D3D12DDI_BARRIER_ACCESS_RAYTRACING_ACCELERATION_STRUCTURE_WRITE bit set.
D3D12DDI_BARRIER_SYNC_COPY_RAYTRACING_ACCELERATION_STRUCTURE
Value: 0x1000000
Synchronize against PFND3D12DDI_BUILD_RAYTRACING_ACCELERATION_STRUCTURE_0054 work.

The corresponding barrier AccessBefore or AccessAfter field must have the D3D12DDI_BARRIER_ACCESS_RAYTRACING_ACCELERATION_STRUCTURE_WRITE bit set.
D3D12DDI_BARRIER_SYNC_SPLIT
Value: 0x80000000
Special sync bit indicating a split barrier. Used as a SyncAfter value to indicate the start of a split barrier. The application must provide a matching barrier with SyncBefore set to D3D12DDI_BARRIER_SYNC_SPLIT. See Remarks.

Remarks

A split barrier is a hint to the driver that a state transition must occur between two points in a command stream, even cross ExecuteCommandLists boundaries. Drivers can complete the required layout transitions and cache flushes any time between the start and end of a split barrier.

Enhanced Barrier APIs allow SPLIT synchronization. Split barriers are represented by a pair of barriers where the initial barrier uses a D3D12DDI_BARRIER_SYNC_SPLIT SyncAfter value, and the final barrier uses a D3D12DDI_BARRIER_SYNC_SPLIT SyncBefore value.

Split barrier pairs must use identical LayoutBefore, LayoutAfter, AccessBefore, and AccessAfter values for both the initial and final barriers. Split barrier pairs must be sequential with no other intervening barriers on the same resource. The following code snippet is an application-level example.

// BEGIN split from compute shader UAV to pixel shader SRV
splitBarrierBegin.SyncBefore = D3D12_BARRIER_SYNC_COMPUTE
splitBarrierBegin.SyncAfter = D3D12_BARRIER_SYNC_SPLIT
splitBarrierBegin.AccessBefore = D3D12_BARRIER_ACCESS_UNORDERED_ACCESS
splitBarrierBegin.AccessAfter = D3D12_BARRIER_ACCESS_DIRECT_QUEUE_SHADER_RESOURCE
splitBarrierBegin.LayoutBefore = D3D12_BARRIER_LAYOUT_UNORDERED_ACCESS
splitBarrierBegin.LayoutAfter = D3D12_BARRIER_LAYOUT_DIRECT_QUEUE_SHADER_RESOURCE

// END split from compute shader UAV to pixel shader SRV
splitBarrierEnd.SyncBefore = D3D12_BARRIER_SYNC_SPLIT
splitBarrierEnd.SyncAfter = D3D12_BARRIER_SYNC_PIXEL_SHADING
splitBarrierEnd.AccessBefore = D3D12_BARRIER_ACCESS_UNORDERED_ACCESS
splitBarrierEnd.AccessAfter = D3D12_BARRIER_ACCESS_DIRECT_QUEUE_SHADER_RESOURCE
splitBarrierEnd.LayoutBefore = D3D12_BARRIER_LAYOUT_UNORDERED_ACCESS
splitBarrierEnd.LayoutAfter = D3D12_BARRIER_LAYOUT_DIRECT_QUEUE_SHADER_RESOURCE

Split barriers across ExecuteCommandLists boundaries are allowed. In this case all AccessBefore and AccessAfter values are effectively ignored since the ExecuteCommandLists boundaries takes care of any cache flushing. Essentially, cross-ExecuteCommandLists split barriers are layout-only barriers. Therefore, splitting a buffer barrier or a simultaneous-access texture barrier across ExecuteCommandLists boundaries serves no purpose. An unmatched BEGIN or END split barrier on a buffer or simultaneous-access texture in a given ExecuteCommandLists scope is effectively unused and the Debug Layer produces a warning.

Requirements

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

See also

D3D12DDI_BARRIER_ACCESS

D3D12DDI_BUFFER_BARRIER_0088

D3D12DDI_GLOBAL_BARRIER_0088

D3D12DDI_RANGED_BARRIER_0088

D3D12DDI_TEXTURE_BARRIER_0088