NSThread object posts this notification when it receives the
exit() message, before the thread exits. Observer methods invoked to receive this notification execute in the exiting thread, before it exits.
- iOS 2.0+
- macOS 10.0+
- tvOS 9.0+
- watchOS 2.0+
The notification object is the exiting
NSThread object. This notification does not contain a
static let NSWillBecomeMultiThreaded: NSNotification.Name
Posted when the first thread is detached from the current thread. The
NSThread class posts this notification at most once—the first time a thread is detached using
detachNewThreadSelector(_:toTarget:with:) or the
start() method. Subsequent invocations of those methods do not post this notification. Observers of this notification have their notification method invoked in the main thread, not the new thread. The observer notification methods always execute before the new thread begins executing.