iOS / Swift: Set timeout for opening Streams - ios

Question

I am working on an iOS app (Swift 4) that connects to a server via
Stream.getStreamsToHost(withName: self.host!, port: self.port!, inputStream: &self.inputStream, outputStream: &self.outputStream)
if let instream = self.inputStream, let outstream = self.outputStream {
instream.delegate = self
outstream.delegate = self
instream.schedule(in: .current, forMode: .commonModes)
outstream.schedule(in: .current, forMode: .commonModes)
instream.open()
outstream.open()
}
In case I have a bad internet connection / no connection / server is not reachable for some reason, I want to show the user an error message. This already works but it takes almost a minute until the error "The operation couldn’t be completed. Operation timed out" happens.
Can I somehow reduce the timeout in my app or is this a system-wide timeout that cannot be changed?
The constants for Stream.setProperty do not seam to contain any timeout-related stuff: https://developer.apple.com/documentation/foundation/stream#1666775
A workaround I can imagine is to manually schedule a function after X seconds and if the connection is not established then, to cancel it. Is this the best-practice to achieve a custom timeout?

Answer 1

After reading a few threads about this problem I decided to use a Timer that checks for a successful connection after n seconds:
Stream.getStreamsToHost(withName: self.host!, port: self.port!, inputStream: &self.inputStream, outputStream: &self.outputStream)
if let instream = self.inputStream, let outstream = self.outputStream {
instream.delegate = self
outstream.delegate = self
instream.schedule(in: .current, forMode: .commonModes)
outstream.schedule(in: .current, forMode: .commonModes)
instream.open()
outstream.open()
self.connectionTimer = Timer.scheduledTimer(withTimeInterval: self.CONNECTION_TIMEOUT, repeats: false) { _ in
if !self.instreamReady || !self.outstreamReady {
self.errorHandler(NetworkingError.Timeout("Timeout \(self.CONNECTION_TIMEOUT)s exeeded"))
self.disconnect()
}
self.connectionTimer?.invalidate()
self.connectionTimer = nil
}
}
Works :)

Answer 2

var continue = true
var countin = 0
var inp :InputStream?
var out :OutputStream?
let testData = mesaj
Stream.getStreamsToHost(withName: addr, port: port, inputStream: &inp, outputStream: &out)
let stream = out!
print( stream.streamStatus.rawValue)
Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { (timer) in
guard continue == true else{
timer.invalidate()
return
}
if (counting == 0){
DispatchQueue.global(qos: .utility).async() {
stream.open()
var position = 0
print( stream.streamStatus.rawValue)
while position < testData.count {
let length = min(4096, testData.count - position)
let amount = testData[position...].withUnsafeBytes {
stream.write($0.bindMemory(to: UInt8.self).baseAddress!, maxLength: length)
}
if amount <= 0 {
// Error or EOF
break
}
position += amount
}
stream.close()
DispatchQueue.main.sync {
self.durumTF.text = "Send to PC"
self.durumTF.textColor = .blue
}
continue=false
}
}
if (counting == 3){
print(stream.streamStatus.rawValue)
if stream.streamStatus.rawValue == 7 {
stream.close()
self.durumTF.text = "Couldn't connect to PC"
self.durumTF.textColor = .red
}
if stream.streamStatus.rawValue == 1 {
stream.close()
self.durumTF.text = "Run server on pc"
self.durumTF.textColor = .red
}
continue = false
}
counting += 1
}