---
title: "DispatchPredicate.onQueueAsBarrier(_:)"
framework: dispatch
role: symbol
role_heading: Case
path: "dispatch/dispatchpredicate/onqueueasbarrier(_:)"
---

# DispatchPredicate.onQueueAsBarrier(_:)

A predicate that indicates the evaluated context is the associated dispatch queue as part of a barrier operation.

## Declaration

```swift
case onQueueAsBarrier(DispatchQueue)
```

## Discussion

Discussion For more information about barrier operations, see `barrier`.

## See Also

### Predicates

- [DispatchPredicate.onQueue(_:)](dispatch/dispatchpredicate/onqueue(_:).md)
- [DispatchPredicate.notOnQueue(_:)](dispatch/dispatchpredicate/notonqueue(_:).md)