Dekker's algorithm for mutual exclusion

dekker.swift

import UIKit

var ran: Int = 0;
var favoredProcess: String = "first"
var processOneWantsIn: Bool = false
var processTwoWantsIn: Bool = false

func processOne(task: () -> Void) {
    while ran < 50 {
        processOneWantsIn = true
        
        while processTwoWantsIn {
            if favoredProcess == "second" {
                processOneWantsIn = false
                while favoredProcess == "second" {
                    print("Process one is waiting...")
                }
                processOneWantsIn = true;
            }
        }
        
        task()
        favoredProcess = "second"
        processOneWantsIn = false
    }
}

func processTwo(task: () -> Void) {
    while ran < 50 {
        processTwoWantsIn = true;
        
        while processOneWantsIn {
            if favoredProcess == "first" {
                processTwoWantsIn = false
                while favoredProcess == "first" {
                    print("Process two is waiting...")
                }
                processTwoWantsIn = true
            }
        }
        
        task()
        favoredProcess = "first"
        processTwoWantsIn = false
    }
}

DispatchQueue.global(qos: .userInitiated).async {
    processOne(task: { () -> Void in
        let date = NSDate().timeIntervalSince1970
        print("Process one is running at \(date)")
        ran = ran + 1
    })
}

DispatchQueue.global(qos: .userInitiated).async {
    processTwo(task: { () -> Void in
        let date = NSDate().timeIntervalSince1970
        print("Process two is running at \(date)")
        ran = ran + 1
    })
}