concurrency5.swift

class ViewController: UIViewController {
    let concurrent = DispatchQueue(label: "com.besher.concurrent", attributes: .concurrent)
    let isolation = DispatchQueue(label: "com.besher.isolation", attributes: .concurrent)
    private var _array = [1,2,3,4,5]
    
    var threadSafeArray: [Int] {
        get {
            return isolation.sync {
                _array
            }
        }
        set {
            isolation.async(flags: .barrier) {
                self._array = newValue
            }
        }
    }
    
    override func viewDidLoad() {
        for _ in 0...15 {
            race()
        }
    }
    
    func race() {
        concurrent.async {
            for i in self.threadSafeArray {
                print(i)
            }
        }
        
        concurrent.async {
            for i in 0..<10 {
                self.threadSafeArray.append(i)
            }
        }
    }
}