D3D12DDI_BARRIER_SYNC enumeration (d3d12umddi.h)

2024-05-22

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_INDEX_INPUT = 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_CLEAR_UNORDERED_ACCESS_VIEW = 0x8000,
  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_INDEX_INPUT` Value: 0x4 Maps to D3D12DDI_BARRIER_SYNC_INPUT_ASSEMBLER.
`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_CLEAR_UNORDERED_ACCESS_VIEW` Value: 0x8000 Synchronize against execution to a UAV.
`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

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