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.

Will App be terminated or suspended when updating to incremental version from app store?

On MacOS 26 Tahoe, we are getting a background warning message stating, “App is running in the background…” Is this expected behavior on the new OS? Thanks Asutos

I'm working on implementing file moving with NSFileCoordinator. I'm using the slightly newer asynchronous API with the NSFileAccessIntents. My question is, how do I go about notifying the coordinator about the item move? Should I simply create a new instance in the asynchronous block? Or does it need to be the same coordinator instance? let writeQueue = OperationQueue() public func saveAndMove(data: String, to newURL: URL) { let oldURL = presentedItemURL! let sourceIntent = NSFileAccessIntent.writingIntent(with: oldURL, options: .forMoving) let destinationIntent = NSFileAccessIntent.writingIntent(with: newURL, options: .forReplacing) let coordinator = NSFileCoordinator() coordinator.coordinate(with: [sourceIntent, destinationIntent], queue: writeQueue) { error in if let error { return } do { // ERROR: Can't access NSFileCoordinator because it is not Sendable (Swift 6) coordinator.item(at: oldURL, willMoveTo: newURL) try FileManager.default.moveItem(at: oldURL, to: newURL) coordinator.item(at: oldURL, didMoveTo: newURL) } catch { print("Failed to move to \(newURL)") } } }

Service Management framework supports installing and uninstalling services, including Service Management login items, launchd agents, and launchd daemons. General: Forums subtopic: App & System Services > Processes & Concurrency Forums tag: Service Management Service Management framework documentation Daemons and Services Programming Guide archived documentation Technote 2083 Daemons and Agents — It hasn’t been updated in… well… decades, but it’s still remarkably relevant. EvenBetterAuthorizationSample sample code — This has been obviated by SMAppService. SMJobBless sample code — This has been obviated by SMAppService. Sandboxing with NSXPCConnection sample code WWDC 2022 Session 10096 What’s new in privacy introduces the new SMAppService facility, starting at 07˸07 BSD Privilege Escalation on macOS forums post Getting Started with SMAppService forums post Background items showing up with the wrong name forums post Related forums tags include: XPC, Apple’s preferred inter-process communication (IPC) mechanism Inter-process communication, for other IPC mechanisms Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

General: DevForums subtopic: App & System Services > Processes & Concurrency Processes & concurrency covers a number of different technologies: Background Tasks Resources Concurrency Resources — This includes Swift concurrency. Service Management Resources XPC Resources Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

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)?

Desired Behavior I want the app to be able to handle multiple Push-to-Start notifications even when it is completely terminated. Each Live Activity should: Be successfully displayed upon receiving a Push-to-Start notification. Trigger background tasks to send its update token to the server, regardless of the time interval between notifications. Problem I am facing an issue with iOS Live Activities when using Push-to-Start notifications to trigger Live Activities in an app that has been completely terminated. Here’s the detailed scenario: When the app is completely terminated and I send the first Push-to-Start notification: The Live Activity is successfully displayed. didFinishLaunchingWithOptions` is triggered, and background tasks execute correctly, including sending the update token to the server. When I send consecutive Push-to-Start notifications in quick succession (e.g., within a few seconds or minutes): Both notifications successfully display their respective Live Activities. Background tasks are executed correctly for both notifications. However, when there is a longer interval (e.g., 10 minutes) between two Push-to-Start notifications: The first notification works perfectly—it displays the Live Activity, triggers didFinishLaunchingWithOptions, and executes background tasks. The second notification successfully displays the Live Activity but fails to execute any background tasks, such as sending the update token to the server. My HypothesisI suspect that iOS might impose a restriction where background runtime for Push-to-Start notifications can only be granted once within a certain time frame after the app has been terminated. Any insights into why this issue might be occurring or how to ensure consistent background task execution for multiple Push-to-Start notifications would be greatly appreciated!

XPC is the preferred inter-process communication (IPC) mechanism on Apple platforms. XPC has three APIs: The high-level NSXPCConnection API, for Objective-C and Swift The low-level Swift API, introduced with macOS 14 The low-level C API, which, while callable from all languages, works best with C-based languages General: Forums subtopic: App & System Services > Processes & Concurrency Forums tag: XPC Creating XPC services documentation NSXPCConnection class documentation Low-level API documentation XPC has extensive man pages — For the low-level API, start with the xpc man page; this is the original source for the XPC C API documentation and still contains titbits that you can’t find elsewhere. Also read the xpcservice.plist man page, which documents the property list format used by XPC services. Daemons and Services Programming Guide archived documentation WWDC 2012 Session 241 Cocoa Interprocess Communication with XPC — This is no longer available from the Apple Developer website )-: Technote 2083 Daemons and Agents — It hasn’t been updated in… well… decades, but it’s still remarkably relevant. TN3113 Testing and Debugging XPC Code With an Anonymous Listener XPC and App-to-App Communication forums post Validating Signature Of XPC Process forums post This forums post summarises the options for bidirectional communication This forums post explains the meaning of privileged flag Related tags include: Inter-process communication, for other IPC mechanisms Service Management, for installing and uninstalling Service Management login items, launchd agents, and launchd daemons Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

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!

Some users of my Mac app are complaining of redrawing delays. Based on what I see in logs, my GCD timer event handlers are not being run in a timely manner although the runloop is still pumping events: sometimes 500ms pass before a 15ms timer runs. During this time, many keypresses are routed through -[NSApplication sendEvent:], which is how I know it's not locked up in synchronous code. This issue has not been reported in older versions of macOS. I start the timer like this: _gcdUpdateTimer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, dispatch_get_main_queue()); dispatch_source_set_timer(_gcdUpdateTimer, dispatch_time(DISPATCH_TIME_NOW, period * NSEC_PER_SEC), period * NSEC_PER_SEC, 0.0005 * NSEC_PER_SEC); dispatch_source_set_event_handler(_gcdUpdateTimer, ^{ …redraw… });

I have an app that I'm using for my own purposes and is not in the app store. I would like to run an http server in the background for more than the allotted 3 minutes to allow persistent communications with a connected Bluetooth device. The Bluetooth device would poll the service at intervals. Is this possible to do? This app does not need app store approval since it's only for personal use.

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!

Hi all, Our company has an application that runs on several machines, this app is launched via a deamon that keeps it alive. One of the feature of this app, is to start a headless electron application to run some tests. When spawning this electron application with the new arm64 OS, we are getting this issue: Silent Test Agent Worker exited with code: 133 [ERROR] [75873:0205/135842.347044:ERROR:mach_port_rendezvous.cc(384)] bootstrap_look_up com.hivestreaming.silenttestagent.MachPortRendezvousServer.1: Permission denied (1100) [ERROR] [75873:0205/135842.347417:ERROR:shared_memory_switch.cc(237)] No rendezvous client, terminating process (parent died?) [ERROR] [75872:0205/135842.347634:ERROR:mach_port_rendezvous.cc(384)] bootstrap_look_up com.hivestreaming.silenttestagent.MachPortRendezvousServer.1: Permission denied (1100) [ERROR] [75872:0205/135842.347976:ERROR:shared_memory_switch.cc(237)] No rendezvous client, terminating process (parent died?) Both application (main app and electron one) are signed and notarized, but it seems that there is some other permission issue. If we run the electron application manually, all runs as expected. I added the crash report as attachment CrashReport.log

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One challenging aspect of Swift concurrency is flow control, aka backpressure. I was explaining this to someone today and thought it better to post that explanation here, for the benefit of all. If you have questions or comments, start a new thread in App & System Services > Processes & Concurrency and tag with Swift and Concurrency. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" Why is flow control important? In Swift concurrency you often want to model data flows using AsyncSequence. However, that’s not without its challenges. A key issue is flow control, aka backpressure. Imagine you have a network connection with a requests property that returns an AsyncSequence of Request values. The core of your networking code might be a loop like this: func processRequests(connection: Connection) async throws { for try await request in connection.requests { let response = responseForRequest(request) try await connection.reply(with: response) } } Flow control is important in both the inbound and outbound cases. Let’s start with the inbound case. If the remote peer is generating requests very quickly, the network is fast, and responseForRequest(_:) is slow, it’s easy to fall foul of unbounded memory growth. For example, if you use AsyncStream to implement the requests property, its default buffering policy is .unbounded. So the code receiving requests from the connection will continue to receive them, buffering them in the async stream, without any bound. In the worst case scenario that might run your process out of memory. In a more typical scenario it might result in a huge memory spike. The outbound case is similar. Imagine that the remote peer keeps sending requests but stops receiving them. If the reply(with:) method isn’t implemented correctly, this might also result in unbounded memory growth. The solution to this problem is flow control. This flow control operates independently on the send and receive side: On the send side, the code sending responses should notice that the network connection has asserted flow control and stop sending responses until that flow control lifts. In an async method, like the reply(with:) example shown above, it can simply not return until the network connection has space to accept the reply. On the receive side, the code receiving requests from the connection should monitor how many are buffered. If that gets too big, it should stop receiving. That causes the requests to pile up in the connection itself. If the network connection implements flow control properly [1], this will propagate to the remote peer, which should stop generating requests. [1] TCP and QUIC both implement flow control. Use them! If you’re tempted to implement your own protocol directly on top of UDP, consider how it should handle flow control. Flow control and Network framework Network framework has built-in support for flow control. On the send side, it uses a ‘push’ model. When you call send(content:contentContext:isComplete:completion:) the connection buffers the message. However, it only calls the completion handler when it’s passed that message to the network for transmission [2]. If you send a message and don’t receive this completion callback, it’s time to stop sending more messages. On the receive side, Network framework uses a ‘pull’ model. The receiver calls a receive method, like receiveMessage(completion:), which calls a completion handler when there’s a message available. If you’ve already buffered too many messages, just stop calling this receive method. These techniques are readily adaptable to Swift concurrency using Swift’s CheckedContinuation type. That works for both send and receive, but there’s a wrinkle. If you want to model receive as an AsyncSequence, you can’t use AsyncStream. That’s because AsyncStream doesn’t support flow control. So, you’ll need to come up with your own AsyncSequence implementation [3]. [2] Note that this doesn’t mean that the data has made it to the remote peer, or has even been sent on the wire. Rather, it says that Network framework has successfully passed the data to the transport protocol implementation, which is then responsible for getting it to the remote peer. [3] There’s been a lot of discussion on Swift Evolution about providing such an implementation but none of that has come to fruition yet. Specifically: The Swift Async Algorithms package provides AsyncChannel, but my understanding is that this is not yet ready for prime time. I believe that the SwiftNIO folks have their own infrastructure for this. They’re driving this effort to build such support into Swift Async Algorithms. Avoid the need for flow control In some cases you can change your design to avoid the need for control. Imagine that your UI needs to show the state of a remote button. The network connection sends you a message every time the button is depressed or released. However, your UI only cares about the current state. If you forward every messages from the network to your UI, you have to worried about flow control. To eliminate that worry: Have your networking code translate the message to reflect the current state. Use AsyncStream with a buffering policy of .bufferingNewest(1). That way there’s only ever one value in the stream and, if the UI code is slow for some reason, while it might miss some transitions, it always knows about the latest state. 2024-12-13 Added a link to the MultiProducerSingleConsumerChannel PR. 2024-12-10 First posted.

I have an app, that when enters the background schedules a task to run. The earliest possible time value is set, as is the completion handler when the task eventually runs. It seems to run pretty reliably for the 1st few interations and then (from looking at the streaming Console logs), doesn't seem to reach a high CP score to execute next time around. eg '......background.task:EDBC23' CurrentScore: 0.648418, ThresholdScore: 0.808034 DecisionToRun:0 looking at the previous entries before this, I can see the breakdown... {name: Application Policy, policyWeight: 50.000, response: {0, 0.35}} {name: Device Activity Policy, policyWeight: 5.000, response: {0, 0.50}} ], Decision: CP Score: 0.648418} and I understand certain elements are outside of our control; however, is there a preferred method to get a background task (which ultimately runs an API call) to trigger consistently? The silent-push method has come up a few times - but of course, if the user disables / doesn't consent to push notifications, that fails Any suggestions?

Hello, I am trying to implement a subscriber which specifies its own demand for how many elements it wants to receive from a publisher. My code is below: import Combine var array = [1, 2, 3, 4, 5, 6, 7] struct ArraySubscriber<T>: Subscriber { typealias Input = T typealias Failure = Never let combineIdentifier = CombineIdentifier() func receive(subscription: any Subscription) { subscription.request(.max(4)) } func receive(_ input: T) -> Subscribers.Demand { print("input,", input) return .max(4) } func receive(completion: Subscribers.Completion<Never>) { switch completion { case .finished: print("publisher finished normally") case .failure(let failure): print("publisher failed due to, ", failure) } } } let subscriber = ArraySubscriber<Int>() array.publisher.subscribe(subscriber) According to Apple's documentation, I specify the demand inside the receive(subscription: any Subscription) method, see link. But when I run this code I get the following output: input, 1 input, 2 input, 3 input, 4 input, 5 input, 6 input, 7 publisher finished normally Instead, I expect the subscriber to only "receive" elements 1, 2, 3, 4 from the array. How can I accomplish this?

I have followed these steps as mentioned in this link :(https://developer.apple.com/forums/thread/721737) My projects app bundle structure is like this : TWGUI.app TWGUI.app/Contents TWGUI.app/Contents/_CodeSignature TWGUI.app/Contents/_CodeSignature/CodeResources TWGUI.app/Contents/MacOS TWGUI.app/Contents/MacOS/TWAgent TWGUI.app/Contents/MacOS/TWGUI TWGUI.app/Contents/Resources TWGUI.app/Contents/Library TWGUI.app/Contents/Library/LaunchAgents TWGUI.app/Contents/Library/LaunchAgents/com.example.TWGUI.agent.plist TWGUI.app/Contents/Info.plist TWGUI.app/Contents/PkgInfo TWGUI is my main GUI App , i which i want to embed TWAgent (a command line tool target) and register it using SMAppServices so that launchd can launch it. In TWGUI, code for registering to launchd using SMAppServices is structure as follow : import SwiftUI import ServiceManagement struct ContentView: View { let agent = SMAppService.agent(plistName: "com.example.TWGUI.agent.plist") var body: some View { VStack { Button("Register Agent") { RegisterAgent () } .padding() Button("Unregister Agent") { UnregisterAgent () } .padding() } } func RegisterAgent() { DispatchQueue.global(qos: .background).async { do { print("Registering Agent. Status: \(agent.status.rawValue)") try agent.register() print("Agent registered") } catch { print("Failed to register agent: \(error)") } } } func UnregisterAgent() { DispatchQueue.global(qos: .background).async { do { print("Unregistering Agent. Status: \(agent.status.rawValue)") try agent.unregister() print("Agent unregistered") } catch { print("Failed to unregister agent: \(error)") } } } } com.example.TWGUI.agent.plist : &lt;?xml version="1.0" encoding="UTF-8"?&gt; &lt;!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs$ &lt;plist version="1.0"&gt; &lt;dict&gt; &lt;key&gt;Label&lt;/key&gt; &lt;string&gt;com.example.TWGUI.agent&lt;/string&gt; &lt;key&gt;ProgramArguments&lt;/key&gt; &lt;array&gt; &lt;string&gt;Contents/MacOS/TWAgent&lt;/string&gt; &lt;/array&gt; &lt;key&gt;RunAtLoad&lt;/key&gt; &lt;true/&gt; &lt;key&gt;KeepAlive&lt;/key&gt; &lt;true/&gt; &lt;/dict&gt; &lt;/plist&gt; I have used ProgramArguements instead of using Program in above plist because i was getting this error when i was using Program earlier : Registering Agent. Status: 3 Failed to register agent: Error Domain=SMAppServiceErrorDomain Code=111 "Invalid or missing Program/ProgramArguments" UserInfo={NSLocalizedFailureReason=Invalid or missing Program/ProgramArguments} TWGUI apps Info.plist is : &lt;?xml version="1.0" encoding="UTF-8"?&gt; &lt;!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"&gt; &lt;plist version="1.0"&gt; &lt;dict&gt; &lt;key&gt;BuildMachineOSBuild&lt;/key&gt; &lt;string&gt;23C71&lt;/string&gt; &lt;key&gt;CFBundleDevelopmentRegion&lt;/key&gt; &lt;string&gt;en&lt;/string&gt; &lt;key&gt;CFBundleExecutable&lt;/key&gt; &lt;string&gt;TWGUI&lt;/string&gt; &lt;key&gt;CFBundleIdentifier&lt;/key&gt; &lt;string&gt;com.example.TWAgent&lt;/string&gt; &lt;key&gt;CFBundleInfoDictionaryVersion&lt;/key&gt; &lt;string&gt;6.0&lt;/string&gt; &lt;key&gt;CFBundleName&lt;/key&gt; &lt;string&gt;TWGUI&lt;/string&gt; &lt;key&gt;CFBundlePackageType&lt;/key&gt; &lt;string&gt;APPL&lt;/string&gt; &lt;key&gt;CFBundleShortVersionString&lt;/key&gt; &lt;string&gt;1.0&lt;/string&gt; &lt;key&gt;CFBundleSupportedPlatforms&lt;/key&gt; &lt;array&gt; &lt;string&gt;MacOSX&lt;/string&gt; &lt;/array&gt; &lt;key&gt;CFBundleVersion&lt;/key&gt; &lt;string&gt;1&lt;/string&gt; &lt;key&gt;DTCompiler&lt;/key&gt; &lt;string&gt;com.apple.compilers.llvm.clang.1_0&lt;/string&gt; &lt;key&gt;DTPlatformBuild&lt;/key&gt; &lt;string&gt;&lt;/string&gt; &lt;key&gt;DTPlatformName&lt;/key&gt; &lt;string&gt;macosx&lt;/string&gt; &lt;key&gt;DTPlatformVersion&lt;/key&gt; &lt;string&gt;14.2&lt;/string&gt; &lt;key&gt;DTSDKBuild&lt;/key&gt; &lt;string&gt;23C53&lt;/string&gt; &lt;key&gt;DTSDKName&lt;/key&gt; &lt;string&gt;macosx14.2&lt;/string&gt; &lt;key&gt;DTXcode&lt;/key&gt; &lt;string&gt;1510&lt;/string&gt; &lt;key&gt;DTXcodeBuild&lt;/key&gt; &lt;string&gt;15C65&lt;/string&gt; &lt;key&gt;LSMinimumSystemVersion&lt;/key&gt; &lt;string&gt;14.2&lt;/string&gt; &lt;/dict&gt; &lt;/plist&gt; TWAgent target has main.swift file which does this : import Foundation let startTime = CFAbsoluteTimeGetCurrent() func logTimeSinceStart() { let elapsedTime = CFAbsoluteTimeGetCurrent() - startTime NSLog("Time since program started: \(elapsedTime) seconds") } func startLoggingTime() { Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { _ in logTimeSinceStart() } } // Start logging time startLoggingTime() // Keep the run loop running CFRunLoopRun() I followed these exact same steps in another project earlier and my agent was getting registered, although i lost that project due to some reasons. But now i am getting this error when i am registering or unregistering agent using SMAppServices from the code above : Registering Agent. Status: 3 Failed to register agent: Error Domain=SMAppServiceErrorDomain Code=1 "Operation not permitted" UserInfo={NSLocalizedFailureReason=Operation not permitted} I tried diffrent fixes for like this : Moved app bundle to /applications folder Gave permission for full disc access to this app . Code sign again (both agent and TWGUI ... But nothing seems to work , getting same error. I tried to launch agent using : Launchctl load com.example.TWGUI.agent.plist and it worked , so there is no issue with my plist implementation. Can someone help me understand how can i solve this issue ? or if i am following right steps ? Can give steps need to follow to implement this and steps so that i can register and start my agent using SMAppServices? And i also tried the project give in apples official documentation : [https://developer.apple.com/documentation/servicemanagement/updating-your-app-package-installer-to-use-the-new-service-management-api) but got same error in this project as well .

I am developing a macOS non-interactive macOS application which does not show any ui. i want to block main thread and do all the work on worker thread . Once done with work in worker thread, want to unblock main thread by exiting event loop to terminate application. Because i dont want to show any UI or use any Foundation/Cocoa functionality, i am thinking of using CFRunLoop to block main thread from exiting until i finish my work in worker thread. When i tried this in a project, I am able to finish work in worker thread after block main thread using CFRunLoop. I also want this application to be a bundled application, which can be launched by double clicking on application bundle . But when i tried it in my xcode project by launching it using double clicking on application bundle, application keeps on toggling/bouncing in the dock menu with a status "Not responding". Although i am able to complete my work in worker thread. import Foundation let runLoop = CFRunLoopGetCurrent() func workerTask() { DispatchQueue.global().async { print("do its work") sleep(5) // do some work print("calling exit event loop") CFRunLoopStop(runLoop) print ("unblocking main thread") } } workerTask () // blocking main thread print ("blocked main thread") CFRunLoopRun() print ("exit") Why i am getting this application bouncing in doc menu behavior ? I tried by using NSApplicationMain instead of CFRunLoop in my project, in that case i didnt get this behavior . Does NSApplicationMain does some extra work before starting NSRunLoop which i am not doing while using CFRunLoop, which is showing this toggling/Bouncing application icon in Dock menu ? or Is this bouncing app icon issue is related to run loop i am using which is CFRunLoop ? Note : If i dont use a bundled application and use a commandline application then i am able to do all steps in worker thread and exit main thread as i wanted after finishing my work . But i need to do all this in application which can be launched using double clicking (bundled applcation). If not by using CFRunLoop, then how can i achive this ? - Create a application which shows no UI and do all work in worker thread while main thread is blocked. Once work is done unblock main thread and exit. And user should be able to launch application using double click the application icon.