Signals (increments) a semaphore.
SDKs
- iOS 8.0+
- macOS 10.10+
- UIKit for Mac 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
- Xcode 8.0+
Framework
- Dispatch
Declaration
@discardableResult func signal() -> Int
Parameters
dsemaThe counting semaphore. This parameter cannot be
NULL.
Return Value
This function returns non-zero if a thread is woken. Otherwise, zero is returned.
Discussion
Increment the counting semaphore. If the previous value was less than zero, this function wakes a thread currently waiting in dispatch.