---
title: DISPATCH_BLOCK_BARRIER
framework: dispatch
role: symbol
role_heading: Enumeration Case
path: dispatch/dispatch_block_flags_t/dispatch_block_barrier
---

# DISPATCH_BLOCK_BARRIER

Cause the work item to act as a barrier block when submitted to a concurrent queue.

## Declaration

```occ
DISPATCH_BLOCK_BARRIER
```

## Discussion

Discussion Indicates that a dispatch block should act as a barrier block when submitted to a DISPATCH_QUEUE_CONCURRENT queue. See dispatch_barrier_async for details. This flag has no effect when the dispatch block is invoked directly.

## See Also

### Flags

- [DISPATCH_BLOCK_ASSIGN_CURRENT](dispatch/dispatch_block_flags_t/dispatch_block_assign_current.md)
- [DISPATCH_BLOCK_DETACHED](dispatch/dispatch_block_flags_t/dispatch_block_detached.md)
- [DISPATCH_BLOCK_ENFORCE_QOS_CLASS](dispatch/dispatch_block_flags_t/dispatch_block_enforce_qos_class.md)
- [DISPATCH_BLOCK_INHERIT_QOS_CLASS](dispatch/dispatch_block_flags_t/dispatch_block_inherit_qos_class.md)
- [DISPATCH_BLOCK_NO_QOS_CLASS](dispatch/dispatch_block_flags_t/dispatch_block_no_qos_class.md)