Make a synchronous operation synchronous. Abstracts away the details of dispatch_semaphore_wait et al. so you don't have to worry about it.

import Later

let later = Later(3) // default delay is 5s

someAsyncOperation() {
  
  // async operation is complete, so finish the later.
  later.done()
}

later.wait() // while the async operation is completing, let's chill for up to 3s

A delay timeout of 0 means wait forever.

Add Later to your Package.swift file:

import PackageDescription

let package = Package(
    name: "YourPackageName",
    dependencies: [
        .Package(url: "https://github.com/coryalder/Later.git", majorVersion: 0),
    ]
)