I am encountering an issue when making an API call using URLSession with DispatchQueue.global(qos: .background).async on a real device running tvOS 18. The code works as expected on tvOS 17 and in the simulator for tvOS 18, but when I remove the debug mode, After the API call it takes few mintues or 5 to 10 min to load the data on the real device.
Code: Here’s the code I am using for the API call:
appconfig.getFeedURLData(feedUrl: feedUrl, timeOut: kRequestTimeOut, apiMethod: ApiMethod.POST.rawValue) { (result) in
self.EpisodeItems = Utilities.sharedInstance.getEpisodeArray(data: result)
}
func getFeedURLData(feedUrl: String, timeOut: Int, apiMethod: String, completion: @escaping (_ result: Data?) -> ()) {
guard let validUrl = URL(string: feedUrl) else { return }
var request = URLRequest(url: validUrl, cachePolicy: .useProtocolCachePolicy, timeoutInterval: TimeInterval(timeOut))
let userPasswordString = "\(KappSecret):\(KappPassword)"
let userPasswordData = userPasswordString.data(using: .utf8)
let base64EncodedCredential = userPasswordData!.base64EncodedString(options: .lineLength64Characters)
let authString = "Basic \(base64EncodedCredential)"
let headers = [
"authorization": authString,
"cache-control": "no-cache",
"user-agent": "TN-CTV-\(kPlateForm)-\(kAppVersion)"
]
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.httpMethod = apiMethod
request.allHTTPHeaderFields = headers
let response = URLSession.requestSynchronousData(request as URLRequest)
if response.1 != nil {
do {
guard let parsedData = try JSONSerialization.jsonObject(with: response.1!, options: .mutableContainers) as? AnyObject else {
print("Error parsing data")
completion(nil)
return
}
print(parsedData)
completion(response.1)
return
} catch let error {
print("Error: \(error.localizedDescription)")
completion(response.1)
return
}
}
completion(response.1)
}
import Foundation
public extension URLSession {
public static func requestSynchronousData(_ request: URLRequest) -> (URLResponse?, Data?) {
var data: Data? = nil
var responseData: URLResponse? = nil
let semaphore = DispatchSemaphore(value: 0)
let task = URLSession.shared.dataTask(with: request) { taskData, response, error in
data = taskData
responseData = response
if data == nil, let error = error {
print(error)
}
semaphore.signal()
}
task.resume()
_ = semaphore.wait(timeout: .distantFuture)
return (responseData, data)
}
public static func requestSynchronousDataWithURLString(_ requestString: String) -> (URLResponse?, Data?) {
guard let url = URL(string: requestString.checkValidUrl()) else { return (nil, nil) }
let request = URLRequest(url: url)
return URLSession.requestSynchronousData(request)
}
}
Issue Description: Working scenario: The API call works fine on tvOS 17 and in the simulator for tvOS 18. Problem: When running on a real device with tvOS 18, the API call takes time[enter image description here] when debug mode is disabled, but works fine when debug mode is enabled, Data is loading after few minutes.
Error message: Error Domain=WKErrorDomain Code=11 "Timed out while loading attributed string content" UserInfo={NSLocalizedDescription=Timed out while loading attributed string content} NSURLConnection finished with error - code -1001 nw_read_request_report [C4] Receive failed with error "Socket is not connected" Snapshot request 0x30089b3c0 complete with error: <NSError: 0x3009373f0; domain: BSActionErrorDomain; code: 1 ("response-not-possible")> tcp_input [C7.1.1.1:3] flags=[R] seq=817957096, ack=0, win=0 state=CLOSE_WAIT rcv_nxt=817957096, snd_una=275546887
Environment: Xcode version: 16.1 Real device: Model A1625 (32GB) tvOS version: 18.1
Debugging steps I’ve taken: I’ve verified that the issue does not occur in debug mode. I’ve confirmed that the API call works fine on tvOS 17 and in the simulator (tvOS 18). The error suggests a network timeout (-1001) and a socket connection issue ("Socket is not connected").
Questions:
Is this a known issue with tvOS 18 on real devices? Are there any specific settings or configurations in tvOS 18 that could be causing the timeout error in non-debug mode? Could this be related to how URLSession or networking behaves differently in release mode? I would appreciate any help or insights into this issue!
You’ve combined a number of anti-patterns:
-
Don’t use Dispatch global concurrent queues. See Avoid Dispatch Global Concurrent Queues for an explanation as to why.
-
Using the
.backgroundQoS is tricky, because work on such queues can be delayed for a long time [1]. -
Don’t try to convert asynchronous code to synchronous code using a semaphore, or any other concurrency primitive for that matter.
Given the above, it’s hard to say exactly what’s going wrong. I recommend that you fix all of these issues and then post back if you continue to have problems.
Of these, only the last one is potentially challenging. However, I don’t think that’s a problem in your specific case. You have a getFeedURLData(…) routine that calls your requestSynchronousData(…) method and then processes the result. However, you don’t need to call URLSession synchronously here, because getFeedURLData(…) is already asynchronous, that is, it has a completion handler. So instead of this:
func getFeedURLData(…) {
…
let response = URLSession.requestSynchronousData(…)
… process response …
completion(response.1)
}
do this:
func getFeedURLData(…) {
…
let response = make an asynchronous request {
… process response …
completion(response.1)
}
}
Alternatively, you could adopt Swift concurrency for this part of your project, allowing you to write linear code that acts asynchronously.
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"
[1] Most notably, an iPhone in Low Power Mode won’t run work on background queues.