# barrier(afterEncoderStages:beforeEncoderStages:visibilityOptions:) Encodes an intra-pass barrier. ``` func barrier(afterEncoderStages: MTLStages, beforeEncoderStages: MTLStages, visibilityOptions: MTL4VisibilityOptions = [ .device ]) ``` ## Parameters `afterEncoderStages` [`MTLStages`](/documentation/Metal/MTLStages) mask that represents the stages of work to wait for. This argument only applies to subsequent work you encode in the current command encoder. `beforeEncoderStages` [`MTLStages`](/documentation/Metal/MTLStages) mask that represents the stages of work that wait. This argument only applies to work you encode in the current command encoder prior to this barrier. `visibilityOptions` [`MTL4VisibilityOptions`](/documentation/Metal/MTL4VisibilityOptions) of the barrier, controlling cache flush behavior. ## Discussion Encode a barrier that guarantees that any subsequent work you encode in the *current command encoder*, corresponding to `beforeEncoderStages`, doesn’t begin until all prior commands in this command encoder, corresponding to `afterEncoderStages`, completes. When calling this method, it’s your responsibility to ensure parameters `afterEncoderStages` and `beforeEncoderStages` contain a combination of [`MTLStages`](/documentation/Metal/MTLStages) for which this encoder can encode commands. For example, for a [`MTL4ComputeCommandEncoder`](/documentation/Metal/MTL4ComputeCommandEncoder) instance, you can provide any combination of [`dispatch`](/documentation/Metal/MTLStages/dispatch), [`blit`](/documentation/Metal/MTLStages/blit) and [`accelerationStructure`](/documentation/Metal/MTLStages/accelerationStructure). --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)