An identifier for the type of system object being monitored by a dispatch source.
- iOS 4.0+
- macOS 10.6+
- Mac Catalyst 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
Constants of this type represent the class of low-level system object that is being monitored by the dispatch source. Constants of this type are passed as a parameter to
dispatch and determine how the handle argument is interpreted (as a file descriptor, mach port, signal number, process identifier, etc.) and how the mask argument is interpreted. See Dispatch Source Type Constants for details about source type constants.