Issue:
Background downloads using the flutter_downloader package work perfectly in debug mode and release mode when run directly from Xcode (plugged in).
However, when I create an archive build and install the app separately (via TestFlight or direct IPA install), the background download stops working as soon as the app is minimized.
✅ What I’ve already done
Info.plist
<key>UIBackgroundModes</key>
<array>
<string>remote-notification</string>
<string>fetch</string>
<string>processing</string>
<string>audio</string>
<string>push-to-talk</string>
</array>
AppDelegate.swift
import UIKit
import Flutter
import Firebase
import flutter_downloader
import BackgroundTasks
@main
@objc class AppDelegate: FlutterAppDelegate {
static let backgroundChannel = "com.example.app/background_service"
private var backgroundCompletionHandler: (() -> Void)?
override func application(
_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
) -> Bool {
FirebaseApp.configure()
GeneratedPluginRegistrant.register(with: self)
FlutterDownloaderPlugin.setPluginRegistrantCallback(registerPlugins)
if #available(iOS 10.0, *) {
UNUserNotificationCenter.current().delegate = self
}
if #available(iOS 13.0, *) {
registerBackgroundTask()
}
return super.application(application, didFinishLaunchingWithOptions: launchOptions)
}
@available(iOS 13.0, *)
private func registerBackgroundTask() {
BGTaskScheduler.shared.register(
forTaskWithIdentifier: "com.example.app.process_download_queue",
using: nil
) { [weak self] task in
guard let self = self else { return }
self.handleDownloadQueueTask(task: task as! BGProcessingTask)
}
}
@available(iOS 13.0, *)
private func handleDownloadQueueTask(task: BGProcessingTask) {
scheduleNextDownloadTask()
let headlessEngine = FlutterEngine(name: "BackgroundTaskEngine", project: nil, allowHeadlessExecution: true)
headlessEngine.run()
let channel = FlutterMethodChannel(
name: AppDelegate.backgroundChannel,
binaryMessenger: headlessEngine.binaryMessenger
)
task.expirationHandler = {
channel.invokeMethod("backgroundTaskExpired", arguments: nil)
}
channel.invokeMethod("processNextInBackground", arguments: nil) { result in
task.setTaskCompleted(success: (result as? Bool) ?? false)
}
}
override func application(
_ application: UIApplication,
handleEventsForBackgroundURLSession identifier: String,
completionHandler: @escaping () -> Void
) {
self.backgroundCompletionHandler = completionHandler
super.application(application, handleEventsForBackgroundURLSession: identifier, completionHandler: completionHandler)
}
override func applicationDidEnterBackground(_ application: UIApplication) {
if #available(iOS 13.0, *) {
scheduleNextDownloadTask()
}
}
@available(iOS 10.0, *)
override func userNotificationCenter(
_ center: UNUserNotificationCenter,
willPresent notification: UNNotification,
withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void
) {
if #available(iOS 14.0, *) {
completionHandler([.list, .banner, .badge, .sound])
} else {
completionHandler([.alert, .badge, .sound])
}
}
@available(iOS 10.0, *)
override func userNotificationCenter(
_ center: UNUserNotificationCenter,
didReceive response: UNNotificationResponse,
withCompletionHandler completionHandler: @escaping () -> Void
) {
completionHandler()
}
}
// MARK: - Helper
@available(iOS 13.0, *)
func scheduleNextDownloadTask() {
let request = BGProcessingTaskRequest(identifier: "com.example.app.process_download_queue")
request.requiresNetworkConnectivity = true
request.requiresExternalPower = false
request.earliestBeginDate = Date(timeIntervalSinceNow: 60)
do {
try BGTaskScheduler.shared.submit(request)
print("BGTask: Download queue processing task scheduled successfully.")
} catch {
print("BGTask: Could not schedule download queue task: \(error)")
}
}
private func registerPlugins(registry: FlutterPluginRegistry) {
if !registry.hasPlugin("FlutterDownloaderPlugin") {
FlutterDownloaderPlugin.register(with: registry.registrar(forPlugin: "FlutterDownloaderPlugin")!)
}
}
🧩 Observations
Background download works correctly when:
The app is plugged in and run via Xcode (release/debug)
It stops working when:
The app is installed from an archived build (IPA/TestFlight) and minimized
All entitlements and background modes are properly added.
Provisioning profile includes required background modes.
❓Question
Is there any known limitation or signing difference between Xcode run and archived release builds that could cause URLSession background tasks not to trigger?
Has anyone faced a similar issue when using flutter_downloader on iOS 13+ with BGTaskScheduler or URLSession background configuration?
Any help or working setup example for production/TestFlight would be appreciated.
Processes & Concurrency
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I am considering to use the BGAppRefreshTask mechanism, and while I think I have read and understood all documentation and hints in this forum about it (especially the limitations), the one thing I do not understand is: how can I debug it? I cannot find a way to trigger the BGAppRefreshTask execution reliably and immediately. I would have expected the Xcode Debug->Simulate Background Fetch menu to do this for me, but it only sends the app into the background.
I am working with the unmodified (except for a few added print()) ColorFeed sample code project from Apple, which schedules a task 15min into the future when it goes to the background. Using a real device, I have not managed to trigger execution of the BGAppRefreshTask more often than once a day so far.
Surely, there must be a way to trigger it much more often solely for debugging and development purposes (I am totally happy with all restrictions for the final app).
So what detail am I missing here?
Hello everyone,
I’m a new developer still learning as I go. I’m building a simple watchOS app that tracks Apple Watch battery consumption, records hourly usage data, and uses that information to predict battery life in hours.
I’ve run into an issue where background refresh completely stalls after charging and never recovers, regardless of what I do. The only way to restore normal behavior is to restart the watch.
Background refresh can work fine for days, but if the watch is charging and a scheduled background refresh tries to run during that period, it appears to be deferred—and then remains in that deferred state indefinitely. Even reopening the app or scheduling new refreshes doesn’t recover it.
Has anyone else encountered this behavior? Is there a reliable workaround?
I’ve seen a few reports suggesting that there may be a regression in scheduleBackgroundRefresh() on watchOS 26, where tasks are never delivered after certain states.
Any insights or confirmations would be greatly appreciated. Thank you!
I have implemented a XPC server using C APIs. I want to write unit tests for it.
I came across the following links that use Swift APIs-
Testing and Debugging XPC Code With an Anonymous Listener
TN3113
I have tried to write anonymous listener code and the client code in the same file, using C APIs-
#include <unistd.h>
#include <syslog.h>
#include <pthread.h>
#include <stdio.h>
#include <xpc/xpc.h>
#include <xpc/connection.h>
#include <CoreFoundation/CoreFoundation.h>
static void Anon_Client_Connection_Handler(xpc_connection_t connection, xpc_object_t clientMessage)
{
const char *description = xpc_copy_description(clientMessage);
printf("Event received - %s\n", description);
free((void *)description);
xpc_type_t type = xpc_get_type(clientMessage);
if (type == XPC_TYPE_ERROR)
{
if (clientMessage == XPC_ERROR_CONNECTION_INVALID)
printf("Client_Connection_Handler received invalid connection n");
else if (clientMessage == XPC_ERROR_TERMINATION_IMMINENT)
printf("Client_Connection_Handler received termination notice n");
}
else
{
const char *clientMsg = xpc_dictionary_get_string(clientMessage, "message");
printf("Received from client: %s ", clientMsg);
}
}
static void Anon_Listener_Connection_Handler(xpc_connection_t connection)
{
printf("Anon_Listener_Connection_Handler called, setting up event handler \n");
xpc_connection_set_event_handler(connection, ^(xpc_object_t clientMessage) {
printf("Processing the connection! \n");
Anon_Client_Connection_Handler(connection, clientMessage);
});
xpc_connection_resume(connection);
}
int main(int argc, const char *argv[])
{
xpc_connection_t anon_listener = xpc_connection_create(NULL, NULL);
xpc_connection_set_event_handler(anon_listener, ^(xpc_object_t clientConnection) {
printf("Client tried to connect \n");
Anon_Listener_Connection_Handler(clientConnection);
});
xpc_connection_resume(anon_listener);
printf("\nINFO Anonymous connection resumed");
xpc_object_t anon_endpoint = xpc_endpoint_create(anon_listener);
xpc_connection_t clientConnection = xpc_connection_create_from_endpoint(anon_endpoint);
xpc_object_t message = xpc_dictionary_create(NULL, NULL, 0);
xpc_dictionary_set_string(message, "message", "client's message");
xpc_connection_send_message_with_reply(clientConnection, message, dispatch_get_main_queue(), ^(xpc_object_t event) {
printf("\nINFO inside reply");
const char *description = xpc_copy_description(event);
printf("\nINFO %s",description);
free((void *)description);
});
xpc_release(message);
xpc_release(anon_listener);
printf("\nINFO Releasing listener");
xpc_release(anon_endpoint);
printf("\nINFO Releasing endpoint");
// dispatch_main();
return 0;
}
and this is the output I get
INFO Anonymous connection resumed
INFO Releasing listener
INFO Releasing endpoint
I am not able to connect to the client and exchange messages. Where am I going wrong?
I am writing an app which mainly is used to update data used by other apps on the device. After the user initializes some values in the app, they almost never have to return to it (occasionally to add a "friend"). The app needs to run a background task at least daily, however, without the user's intervention (or even awareness, once they've given permission). My understanding of background refresh tasks is that if the user doesn't activate the app in the foreground periodically, the scheduled background tasks may never run. If this is true, do I want to use a background processing task instead, or is there a better solution (or have I misunderstood entirely)?
Topic:
App & System Services
SubTopic:
Processes & Concurrency
So i am pretty new to Xcode, but i have been using Python and other language for some while. But I am quite new to the game of view and view control. So it may be that i have over complicated this a bit - and it may be that I have some wrong understanding of the dependencies and appcontroller (that i thought would be a good idea). So here we have a main file we call it app.swift, we have a startupmanager.swift, a appcoordinator and a dependeciescontainer. But it may be that this is either a overkill - or that I am doing it wrong.
So my thought was that i had a dependeciecontainer, a appcoordinator for the views and a startupmanager that controll the initialized fetching. I have controlled the memory when i run it - checking if it is higher, lower eg - but it was first when i did my 2 days profile i saw a lot of new errors, like this: Fikser(7291,0x204e516c0) malloc: xzm: failed to initialize deferred reclamation buffer (46). and i also get macro errors, probably from the @Query in my feedview.
So my thought was that a depencecie manager and a startupmanager was a good idea together with a app coordinator.
But maybe I am wrong - maybe this is not a good idea? Or maybe I am doing some things twice? I have added a lot of prints and debugs for checking. But it seems that it starts off to heavy?
import SwiftUI
import Combine
@MainActor
class AppCoordinator: ObservableObject {
@Published var isLoggedIn: Bool = false
private var authManager: AuthenticationManager = .shared
private var cancellables = Set<AnyCancellable>()
private let startupManager: StartupManager
private let container: DependencyContainer
@Published var path = NavigationPath()
enum Screen: Hashable, Identifiable {
case profile
case activeJobs
case offers
case message
var id: Self { self }
}
init(container: DependencyContainer) {
self.container = container
self.startupManager = container.makeStartupManager()
setupObserving()
startupManager.start()
print("AppCoordinator initialized!")
}
private func setupObserving() {
authManager.$isAuthenticated
.receive(on: RunLoop.main)
.sink { [weak self] isAuthenticated in
self?.isLoggedIn = isAuthenticated
}
.store(in: &cancellables)
}
func userDidLogout() {
authManager.logout()
path.removeLast(path.count)
}
func showProfile() {
path.append(Screen.profile)
}
func showActiveJobs() {
path.append(Screen.activeJobs)
}
func showOffers() {
path.append(Screen.offers)
}
func showMessage() {
path.append(Screen.message)
}
@ViewBuilder
func viewForDestination(_ destination: Screen) -> some View {
switch destination {
case .profile:
ProfileView()
case .activeJobs:
ActiveJobsView()
case .offers:
OffersView()
case .message:
ChatView()
}
}
@ViewBuilder
func viewForJob(_ job: Job) -> some View {
PostDetailView(
job: job,
jobUserDetailsRepository: container.makeJobUserDetailsRepository()
)
}
@ViewBuilder
func viewForProfileSubview(_ destination: ProfileView.ProfileSubviews) -> some View {
switch destination{
case .personalSettings:
PersonalSettingView()
case .historicData:
HistoricDataView()
case .transactions:
TransactionView()
case .helpCenter:
HelpcenterView()
case .helpContract:
HelpContractView()
}
}
enum HomeBarDestinations: Hashable, Identifiable {
case postJob
case jobPosting
var id: Self { self }
}
@ViewBuilder
func viewForHomeBar(_ destination: HomeBarView.HomeBarDestinations) -> some View {
switch destination {
case .postJob:
PostJobView()
}
}
}
import Apollo
import FikserAPI
import SwiftData
class DependencyContainer {
static var shared: DependencyContainer!
private let modelContainer: ModelContainer
static func initialize(with modelContainer: ModelContainer) {
shared = DependencyContainer(modelContainer: modelContainer)
}
private init(modelContainer: ModelContainer) {
self.modelContainer = modelContainer
print("DependencyContainer being initialized at ")
}
@MainActor
private lazy var userData: UserData = {
return UserData(apollo: Network.shared.apollo)
}()
@MainActor
private lazy var userDetailsRepository: UserDetailsRepository = {
return UserDetailsRepository(userData: makeUserData())
}()
@MainActor
private lazy var jobData: JobData = {
return JobData(apollo: Network.shared.apollo)
}()
@MainActor
private lazy var jobRepository: JobRepository = {
return JobRepository(jobData: makeJobData(), modelContainer: modelContainer)
}()
@MainActor
func makeUserData() -> UserData {
return userData
}
@MainActor
func makeUserDetailsRepository() -> UserDetailsRepository {
return userDetailsRepository
}
@MainActor
func makeStartupManager() -> StartupManager {
return StartupManager(
userDetailsRepository: makeUserDetailsRepository(),
jobRepository: makeJobRepository(),
authManager: AuthenticationManager.shared,
lastUpdateRepository: makeLastUpdateRepository()
)
}
@MainActor
func makeJobData() -> JobData {
return jobData
}
@MainActor
func makeJobRepository() -> any JobRepositoryProtocol {
return jobRepository
}
@MainActor
private lazy var jobUserData: JobUserData = {
return JobUserData(apollo: Network.shared.apollo)
}()
@MainActor
private lazy var jobUserDetailsRepository: JobUserDetailsRepository = {
return JobUserDetailsRepository(jobUserData: makeJobUserData())
}()
@MainActor
func makeJobUserData() -> JobUserData {
return jobUserData
}
@MainActor
func makeJobUserDetailsRepository() -> JobUserDetailsRepository {
return jobUserDetailsRepository
}
@MainActor
private lazy var lastUpdateData: LastUpdateData = {
return LastUpdateData(apollo: Network.shared.apollo)
}()
@MainActor
private lazy var lastUpdateRepository: LastUpdateRepository = {
return LastUpdateRepository(lastUpdateData: makeLastUpdateData())
}()
@MainActor
func makeLastUpdateData() -> LastUpdateData {
return lastUpdateData
}
@MainActor
func makeLastUpdateRepository() -> LastUpdateRepository {
return lastUpdateRepository
}
}```
Topic:
App & System Services
SubTopic:
Processes & Concurrency
I'm working on a Mac app that receives a process ID via NSXPCConnection, and I'm trying to figure out the best way to determine whether that process is a native macOS app like Safari—with bundles and all—or just a script launched by something like Node or Python. The executable is signed with a Team ID using codesign.
I was thinking about getting the executable's path as one way to handle it, but I’m wondering if there’s a more reliable method than relying on the folder structure.
Topic:
App & System Services
SubTopic:
Processes & Concurrency
Tags:
XPC
Inter-process communication
Testing Environment:
iOS Version: 26.0 Beta 7
Xcode Version: 17.0 Beta 6
Device: iPhone 16 Pro
Description:
We are implementing the new BGContinuedProcessingTask API and are using the wildcard identifier notation as described in the official documentation. Our Info.plist is correctly configured with a permitted identifier pattern, such as com.our-bundle.export.*.
We then register a single launch handler for this exact wildcard pattern. We are performing this registration within a UIViewController, which is a supported pattern as BGContinuedProcessingTask is explicitly exempt from the "register before applicationDidFinishLaunching" requirement, according to the BGTaskScheduler.h header file. The register method correctly returns true, indicating the registration was successful.
However, when we then try to submit a task with a unique identifier that matches this pattern (e.g., com.our-bundle.export.UUID), the BGTaskScheduler.shared.submit() call throws an NSInternalInconsistencyException and terminates the app. The error reason is: 'No launch handler registered for task with identifier com.our-bundle.export.UUID'.
This indicates that the system is not correctly matching the specific, unique identifier from the submit call to the registered wildcard pattern handler. This behavior contradicts the official documentation.
Steps to Reproduce:
Create a new Xcode project.
In Signing & Capabilities, add "Background Modes" (with "Background processing" checked) and "Background GPU Access".
Add a permitted identifier (e.g., "com.company.test.*") to BGTaskSchedulerPermittedIdentifiers in Info.plist.
In a UIViewController's viewDidLoad, register a handler for the wildcard pattern. Check that the register method returns true.
Immediately after, try to submit a BGContinuedProcessingTaskRequest with a unique identifier that matches the pattern.
Expected Results:
The submit call should succeed without crashing, and the task should be scheduled.
Actual Results:
The app crashes immediately upon calling submit(). The console shows an uncaught NSInternalInconsistencyException with the reason: 'No launch handler registered for task with identifier com.company.test.UUID'.
Workaround:
The issue can be bypassed if we register a new handler for each unique identifier immediately before submitting a request with that same unique identifier. This strongly suggests the bug is in the system's wildcard pattern-matching logic.
In iOS Background Execution limits, I see this:
When the user ‘force quits’ an app by swiping up in the multitasking UI, iOS interprets that to mean that the user doesn’t want the app running at all. iOS also sets a flag that prevents the app from being launched in the background. That flag gets cleared when the user next launches the app manually.
However, I see that when I close an app on iPadOS 26 with the red X, the app doesn't appear in the multitasking UI. So are they treated as force closes and prevented from running background tasks?
Hello, I am programming a CLI tool to partition USB disks. I am calling diskutil to do the work, but I am hitting issues with permissions, it seems.
Here is a trial run of the same command running diskutil directly on the terminal vs running from my code:
Calling diskutil directly (works as expected)
% /usr/sbin/diskutil partitionDisk /dev/disk2 MBR Free\ Space gap 2048S fat32 f-fix 100353S Free\ Space tail 0
Started partitioning on disk2
Unmounting disk
Creating the partition map
Waiting for partitions to activate
Formatting disk2s1 as MS-DOS (FAT32) with name f-fix
512 bytes per physical sector
/dev/rdisk2s1: 98784 sectors in 98784 FAT32 clusters (512 bytes/cluster)
bps=512 spc=1 res=32 nft=2 mid=0xf8 spt=32 hds=16 hid=2079 drv=0x80 bsec=100360 bspf=772 rdcl=2 infs=1 bkbs=6
Mounting disk
Finished partitioning on disk2
/dev/disk2 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: FDisk_partition_scheme +104.9 MB disk2
1: DOS_FAT_32 F-FIX 51.4 MB disk2s1
Calling diskutil programmatically (error -69877)
% sudo ./f-fix
DEBUG: /usr/sbin/diskutil partitionDisk /dev/disk2 MBR Free Space gap 2048S fat32 f-fix 100353S Free Space tail 0
Started partitioning on disk2
Unmounting disk
Error: -69877: Couldn't open device
(Is a disk in use by a storage system such as AppleRAID, CoreStorage, or APFS?)
Failed to fix drive `/dev/disk2'
Source Code
The relevant code from my program is this:
char *args[16]; int n = 0;
args[n++] = "/usr/sbin/diskutil";
args[n++] = "partitionDisk";
args[n++] = (char *)disk;
args[n++] = (char *)scheme;
(...)
args[n++] = NULL;
char **parent_env = *_NSGetEnviron();
if (posix_spawnp(&pid, args[0], NULL, NULL, args, parent_env) != 0)
return 1;
if (waitpid(pid, &status, 0) < 0)
return 1;
return 0;
Question
Are there any system protections against running it like so? What could I be missing? Is this a Disk Arbitration issue?
How can you force cancel a task that doesn't need cleanup and doesn't check for cancellation?
If this cannot be done, would this be a useful addition to Swift?
Here is the situation:
The async method doesn't check for cancellation since it is not doing anything repetively (for example in a loop). For example, the method may be doing "try JSONDecoder().decode(Dictionary<String, ...>.self, from: data)" where data is a large amount.
The method doesn't need cleanup.
I would like the force cancellation to throw an error. I am already handling errors for the async method.
My intended situation if that the user request the async method to get some JSON encoded data, but since it is taking longer that they are willing to wait, they would tap a cancellation button that the app provides.
After logging in to the main App, turn on screen recording, then switch to the interface of another App to perform operations. After about ten-odd minutes, when returning to the main App, it was found that the app was forcefully quit by the system, and subsequent operations could not be carried out.
Hello im creating an expo module using this new API, but the problem i found currently testing this functionality is that when the task fails, the notification error doesn't go away and is always showing the failed task notification even if i start a new task and complete that one.
I want to implement this module into the production app but i feel like having always the notification error might confuse our users or find it a bit bothersome.
Is there a way for the users to remove this notification?
Best regards!
Just trying to understand the documentation.
Obviously, we can send a request to the service to return all the data at once. Can the data arrive in pieces, involving either multiple async callbacks or a Combine Publisher?
Hi,
I have requirement in iOS where application needs to run in the background
It can be a simple hello world program running in the background.
could you shed some light on what is the expected behaviour and is it allowed in iOS.
I'm using flutter's inappwebview. All functions work on my simulator and phone, but when I submit for review, I get an answer saying infinite loading. How did it happen? I don't know what the problem is.
Topic:
App & System Services
SubTopic:
Processes & Concurrency
How to execute code on main app when interacted with a live activity, given that they are already interactable.
is there a way without opening the app?
what are the best ways?
Topic:
App & System Services
SubTopic:
Processes & Concurrency
Tags:
Extensions
WidgetKit
ActivityKit
Dear Apple:
We are developing an app for file sharing between mobile devices. We want to create an iOS app that can continue sharing files with other devices even when it is running in the background. We are using WLAN channels for file sharing. Could you please advise on which background persistence measures we should use to ensure the iOS app can maintain file transfer when it goes to the background? Thank you.
My app is for personal use currently, so distribution won't be a problem. It registers a privileged helper using SMAppService, and I was wondering whether there is a way to customize the authorization dialog that the system presents to the user.
我在开发 Mac应用完成 后 通过Xcode 上传二进制文件的过程中, 出现了错误, 错误提示: App里面用到的 com.apple.security.application-groups 权限里面 有 group.*** 和 开发者组ID.*** 导致校验失败, 当我单独使用 group.xxx的时候, 我的程序会崩溃 , 因为里面用到了 MachPortRende 进程间通信问题, 这里默认了 开发者组ID.*** 这个路径, 错误详情: 在尝试启动 QuickFox 应用时,程序因权限问题而崩溃。具体的错误信息 bootstrap_check_in 组ID.xxxx.MachPortRendezvousServer.82392: Permission denied (1100) 显示,应用在尝试使用 Mach 端口进行进程间通信时,没有获得足够的权限, 因此 我需要您们的帮助, 如果单独用开发者组ID.*** 我们又没有权限 将数据写入 组ID.xxx里面的文件
Topic:
App & System Services
SubTopic:
Processes & Concurrency
Tags:
Entitlements
Inter-process communication