The maximum number of queued operations that can execute at the same time.
- iOS 2.0+
- macOS 10.5+
- Mac Catalyst 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
The value in this property affects only the operations that the current queue has executing at the same time. Other operation queues can also execute their maximum number of operations in parallel.
Reducing the number of concurrent operations does not affect any operations that are currently executing. Specifying the value NSOperationQueueDefaultMaxConcurrentOperationCount (which is recommended) causes the system to set the maximum number of operations based on system conditions.
The default value of this property is
default. You may monitor changes to the value of this property using Key-value observing. Configure an observer to monitor the
max key path of the operation queue.