# dispatch_block_flags_t Flags to pass to the [`dispatch_block_create`](/documentation/Dispatch/dispatch_block_create) and [`dispatch_block_create_with_qos_class`](/documentation/Dispatch/dispatch_block_create_with_qos_class) functions. ``` typedef enum { ... } dispatch_block_flags_t; ``` ## Topics ### Flags [`DISPATCH_BLOCK_ASSIGN_CURRENT`](/documentation/Dispatch/dispatch_block_flags_t/DISPATCH_BLOCK_ASSIGN_CURRENT) Set the attributes of the work item to match the attributes of the current execution context. [`DISPATCH_BLOCK_BARRIER`](/documentation/Dispatch/dispatch_block_flags_t/DISPATCH_BLOCK_BARRIER) Cause the work item to act as a barrier block when submitted to a concurrent queue. [`DISPATCH_BLOCK_DETACHED`](/documentation/Dispatch/dispatch_block_flags_t/DISPATCH_BLOCK_DETACHED) Disassociate the work item’s attributes from the current execution context. [`DISPATCH_BLOCK_ENFORCE_QOS_CLASS`](/documentation/Dispatch/dispatch_block_flags_t/DISPATCH_BLOCK_ENFORCE_QOS_CLASS) Prefer the quality-of-service class associated with the block. [`DISPATCH_BLOCK_INHERIT_QOS_CLASS`](/documentation/Dispatch/dispatch_block_flags_t/DISPATCH_BLOCK_INHERIT_QOS_CLASS) Prefer the quality-of-service class associated with the current execution context. [`DISPATCH_BLOCK_NO_QOS_CLASS`](/documentation/Dispatch/dispatch_block_flags_t/DISPATCH_BLOCK_NO_QOS_CLASS) Execute the work item without assigning a quality-of-service class. --- 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)