How to Implement Semaphores in iOS Application?

Question

Is it possible to implement Counting Semaphore in ios application?

Answer 1

In Swift 3 you can use a DispatchSemaphore.

// initialization
let semaphore = DispatchSemaphore(value: initialValue)

// wait, decrement the semaphore count (if possible) or wait until count>0
semaphore.wait()

// release, increment the semaphore count
semaphore.signal()