ParallelServiceCaller

// http://stackoverflow.com/a/28800828/5552518

import Foundation
import Alamofire

class ParallelServiceCaller {
    var firstServiceCallComplete = false
    var secondServiceCallComplete = false

    func startServiceCalls() {
        let firstRequest = Alamofire.request(.GET, "http://httpbin.org/get", parameters: ["first": "request"])
        firstRequest.responseString { request, response, dataString, error in
            self.firstServiceCallComplete = true
            self.handleServiceCallCompletion()
        }

        let secondRequest = Alamofire.request(.GET, "http://httpbin.org/get", parameters: ["second": "request"])
        secondRequest.responseString { request, response, dataString, error in
            self.secondServiceCallComplete = true
            self.handleServiceCallCompletion()
        }
    }

    private func handleServiceCallCompletion() {
        if self.firstServiceCallComplete && self.secondServiceCallComplete {
            // Handle the fact that you're finished
        }
    }
}