NWConnection timeout

Question

this is my first post to the community, so please be patient ;-)

I am using Apples Network framework to build a TCP connection to a server. It locks like this:

let testConnection = NWConnection(host: NWEndpoint.Host(server!.serverAddress), port: NWEndpoint.Port(server!.serverPort)!, using: .tcp)
testConnection.stateUpdateHandler = ({ state in
        print("TCP state change to: \(state)")
        switch state {
        case .setup:
            break
        case .waiting(let error):
            print("Waiting Error \(error)")
            testConnection.cancel()
            break
        case .preparing:
            break
        case .ready:
            beginCommunication()
            break
        case .failed(let error):
            print("\(error)")
            break
        case .cancelled:
            break
        default:
            break
        }
    })

The serverAddress and serverPort is entered by the user. I want to test the connection. Now my problem is, that if the user is entering an invalid address / port combination (the service is not offered by the server). I stuck in the preparing state for quite a long time. After that I get to the waiting stage (with error message POSIXErrorCode: Operation timed out).

Is there any way to set the timeout for this first connection process ?

Thanks for your ideas

Answer 1

You can set connection timed out by NWProtocolTCP.Options

lazy var tcpOptions: NWProtocolTCP.Options = {
    let options = NWProtocolTCP.Options()
    options.connectionTimeout = 5 // connection timed out
    return options
}()

lazy var parames: NWParameters = {
    let parames = NWParameters(tls: nil, tcp: self.tcpOptions)
    if let isOption = parames.defaultProtocolStack.internetProtocol as? NWProtocolIP.Options {
        isOption.version = .v4
    }
    parames.preferNoProxies = true
    return parames
}()

lazy var connection: NWConnection = {
    let connection = NWConnection(host: "x.x.x.x", port: xxxx, using: self.parames)
    return connection
}()

When trigger the timed out event, the .waiting state will call back.

2021-08-30 23:05:17.xxxxxx+xxxx Demo[xxxx:xxxxxx] [connection] nw_socket_handle_socket_event [C1:1] Socket SO_ERROR [60: Operation timed out]
The connection is waiting for a network path change with: POSIXErrorCode: Operation timed out

reference from Developer Fourms