Swift 2 to 3 Migration dispatch_get_global_queue [duplicate]

Answer 1

Try this it will work.

DispatchQueue.global(qos: .background).async {

    DispatchQueue.main.async {

    }
})

If you still need any help feel free to ask here.

Answer 2

Actually, a closer and simpler approach to your question would be:

DispatchQueue.global(qos: .default).async { ... }