- iOS 8.0+
- macOS 10.10+
- Mac Catalyst 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
_BLOCK _ASSIGN _CURRENT
Set the attributes of the work item to match the attributes of the current execution context.
Cause the work item to act as a barrier block when submitted to a concurrent queue.
Disassociate the work item's attributes from the current execution context.
_BLOCK _ENFORCE _QOS _CLASS
Prefer the quality-of-service class associated with the block.
_BLOCK _INHERIT _QOS _CLASS
Prefer the quality-of-service class associated with the current execution context.
_BLOCK _NO _QOS _CLASS
Execute the work item without assigning a quality-of-service class.
Creates a new dispatch block on the heap using an existing block and the given flags.
_block _create _with _qos _class
Creates a new dispatch block from an existing block and the given flags, and assigns it the specified quality-of-service class and relative priority.
The prototype of blocks submitted to dispatch queues, which take no arguments and have no return value.
This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.Learn more about using Apple's beta software