I have been working on updating an old app that makes extensive use of Objective-C's NSTask. Now using Process in Swift, I'm trying to gather updates as the process runs, using readabilityHandler and availableData. However, my process tends to exit before all data has been read. I found this post entitled "Running a Child Process with Standard Input and Output" but it doesn't seem to address gathering output from long-running tasks. Is there a straightforward way to gather ongoing output from a long running task without it prematurely exiting?

I am developing a background application that acts as a metadata server under MacOS written in Swift. Sandboxed clients prompt the user to select URLs which are passed to the server as security scoped bookmarks via an App Group and the metadata will be passed back. I don't want the I/O overhead of passing the complete image file data to the server. All the variations I have tried of creating security scoped bookmarks in the client and reading them from the server fail with error messages such as "The file couldn’t be opened because it isn’t in the correct format." Can anyone guide me in the right direction or is this just not possible?

I abandoned Mac development back around 10.4 when I departed Apple and am playing catch-up, trying to figure out how to register a privileged helper tool that can execute commands as root in the new world order. I am developing on 13.1 and since some of these APIs debuted in 13, I'm wondering if that's ultimately the root of my problem. Starting off with the example code provided here: https://developer.apple.com/documentation/servicemanagement/updating-your-app-package-installer-to-use-the-new-service-management-api Following all build/run instructions in the README to the letter, I've not been successful in getting any part of it to work as documented. When I invoke the register command the test app briefly appears in System Settings for me to enable, but once I slide the switch over, it disappears. Subsequent attempts to invoke the register command are met only with the error message: `Unable to register Error Domain=SMAppServiceErrorDomain Code=1 "Operation not permitted" UserInfo={NSLocalizedFailureReason=Operation not permitted} The app does not re-appear in System Settings on these subsequent invocations. When I invoke the status command the result mysteriously equates to SMAppService.Status.notFound. The plist is in the right place with the right name and it is using the BundleProgram key exactly as supplied in the sample code project. The executable is also in the right place at Contents/Resources/SampleLaunchAgent relative to the app root. The error messaging here is extremely disappointing and I'm not seeing any way for me to dig any further without access to the underlying Objective-C (which the Swift header docs reference almost exclusively, making it fairly clear that this was a... Swift... Port... [Pun intended]).

I implemented BGContinuedProcessingTask in my app and it seems to be working well for everyone except one user (so far) who has reached out to report nothing happens when they tap the Start Processing button. They have an iPhone 12 Pro Max running iOS 26.1. Restarting iPhone does not fix it. When they turn off the background processing feature in the app, it works. In that case my code directly calls the function to start processing instead of waiting for it to be invoked in the register block (or submit catch block). Is this a bug that's possible to occur, maybe device specific? Or have I done something wrong in the implementation? func startProcessingTapped(_ sender: UIButton) { if isBackgroundProcessingEnabled { startBackgroundContinuedProcessing() } else { startProcessing(backgroundTask: nil) } } func startBackgroundContinuedProcessing() { BGTaskScheduler.shared.register(forTaskWithIdentifier: taskIdentifier, using: .main) { @Sendable [weak self] task in guard self != nil else { return } startProcessing(backgroundTask: task as? BGContinuedProcessingTask) } let request = BGContinuedProcessingTaskRequest(identifier: taskIdentifier, title: title, subtitle: subtitle) request.strategy = .fail if BGTaskScheduler.supportedResources.contains(.gpu) { request.requiredResources = .gpu } do { try BGTaskScheduler.shared.submit(request) } catch { startProcessing(backgroundTask: nil) } } func startProcessing(backgroundTask: BGContinuedProcessingTask?) { // FIXME: Never called for this user when isBackgroundProcessingEnabled is true }

Hello, I'm trying to adopt the new BGContinuedProcessingTask API, but I'm having a little trouble imagining how the API authors intended it be used. I saw the WWDC talk, but it lacked higher-level details about how to integrate this API, and I can't find a sample project. I notice that we can list wildcard background task identifiers in our Info.plist files now, and it appears this is to be used with continued tasks - a user might start one video encoding, then while it is ongoing, enqueue another one from the same app, and these tasks would have identifiers such as "MyApp.VideoEncoding.ABCD" and "MyApp.VideoEncoding.EFGH" to distinguish them. When it comes to implementing this, is the expectation that we: a) Register a single handler for the wildcard pattern, which then figures out how to fulfil each request from the identifier of the passed-in task instance? Or b) Register a unique handler for each instance of the wildcard pattern? Since you can't unregister handlers, any resources captured by the handler would be leaked, so you'd need to make sure you only register immediately before submission - in other words register + submit should always be called as a pair. Of course, I'd like to design my application to use this API as the authors intended it be used, but I'm just not entirely sure what that is. When I try to register a single handler for a wildcard pattern, the system rejects it at runtime (while allowing registrations for each instance of the pattern, indicating that at least my Info.plist is configured correctly). That points towards option B. If it is option B, it's potentially worth calling that out in documentation - or even better, perhaps introduce a new call just for BGContinuedProcessingTask instead of the separate register + submit calls? Thanks for your insight. K Aside: Also, it would be really nice if the handler closure would be async. Currently if you need to await on something, you need to launch an unstructured Task, but that causes issues since BGContinuedProcessingTask is not Sendable, so you can't pass it in to that Task to do things like update the title or mark the BGTask as complete.

We would be creating N NWListener objects and M NWConnection objects in our process' communication subsystem to create server sockets, accepted client sockets on server and client sockets on clients. Both NWConnection and NWListener rely on DispatchQueue to deliver state changes, incoming connections, send/recv completions etc. What DispatchQueues should I use and why? Global Concurrent Dispatch Queue (and which QoS?) for all NWConnection and NWListener One custom concurrent queue (which QoS?) for all NWConnection and NWListener? (Does that anyways get targetted to one of the global queues?) One custom concurrent queue per NWConnection and NWListener though all targetted to Global Concurrent Dispatch Queue (and which QoS?)? One custom concurrent queue per NWConnection and NWListener though all targetted to single target custom concurrent queue? For every option above, how am I impacted in terms of parallelism, concurrency, throughput & latency and how is overall system impacted (with other processes also running)? Seperate questions (sorry for the digression): Are global concurrent queues specific to a process or shared across all processes on a device? Can I safely use setSpecific on global dispatch queues in our app?

I am encountering an issue with my application, BloxOneEndpoint.pkg, which includes two services: rc_service_infoblox – Runs as the root user. Controller Application – Runs as a normal user. Although a thread within rc_service_infoblox is running fine and performing its expected tasks, I notice that the service appears as "Not Responding" in Activity Monitor. Despite normal functionality, this status is concerning, as it may indicate some issue to customer. I would appreciate any insights into why this might be happening and how to resolve it. Is there a specific API or mechanism I should use to ensure the service remains in a "Running" state in Activity Monitor? Thank you for your guidance.

I understand that GCD and it's underlying implementations have evolved over time. And many things have not been shared explicitly in Apple documentation. The most concepts of DispatchQueue (serial and concurrent queues), DispatchQoS, target queue and system provided queues: main and globals etc. I have some doubts & questions to clarify: [Main Dispatch Queue] [Link] Because the main queue doesn't behave entirely like a regular serial queue, it may have unwanted side-effects when used in processes that are not UI apps (daemons). For such processes, the main queue should be avoided. What does it mean? Can you elaborate? [Global Concurrent Dispatch Queues] Are they global to a process or across processes on a device. I believe it is the first case but just wanted to be sure. [Global Concurrent Dispatch Queues] Does system create 4 (for each QoS) * 2 (over-commiting and non-overcommiting queues) = 8 queues in all. When does which type of queue comes into play? [Custom Queue][Target Queue concept] [swift-corelibs-libdispatch/man/dispatch_queue_create.3] QUOTE The default target queue of all dispatch objects created by the application is the default priority global concurrent queue. UNQUOTE Is this stil true? We could not find a mention of this in any latest official apple documentation (though some old forum threads (one more) and github code documentation indicate the same). The official documentation only says: [dispatch_set_target_queue] QUOTE If you want the system to provide a queue that is appropriate for the current object UNQUOTE [dispatch_queue_create_with_target] QUOTE Specify DISPATCH_TARGET_QUEUE_DEFAULT to set the target queue to the default type for the current dispatch queue.UNQUOTE [Dispatch>DispatchQueue>init] QUOTE Specify DISPATCH_TARGET_QUEUE_DEFAULT if you want the system to provide a queue that is appropriate for the current object. UNQUOTE What is the difference between passing target queue as 'nil' vs 'DISPATCH_TARGET_QUEUE_DEFAULT' to DispatchQueue init? [Custom Queue][Target Queue concept] [dispatch_set_target_queue] QUOTE The system doesn't allocate threads to the dispatch queue if it has a target queue, unless that target queue is a global concurrent queue. UNQUOTE The system does allocate threads to the custom dispatch queues that have global concurrent queue as the default target. What does that mean? Why does targetting to global concurrent queues mean in that case? [System / GCD Thread Pool] that excutes work items from DispatchQueue: Is this thread pool per queue? or across queues per process? or across processes per device?

Hi, I have a couple questions about background app refresh. First, is the function RefreshAppContentsOperation() where to implement code that needs to be run in the background? Second, despite importing BackgroundTasks, I am getting the error "cannot find operationQueue in scope". What can I do to resolve that? Thank you. func scheduleAppRefresh() { let request = BGAppRefreshTaskRequest(identifier: "peaceofmindmentalhealth.RoutineRefresh") // Fetch no earlier than 15 minutes from now. request.earliestBeginDate = Date(timeIntervalSinceNow: 15 * 60) do { try BGTaskScheduler.shared.submit(request) } catch { print("Could not schedule app refresh: \(error)") } } func handleAppRefresh(task: BGAppRefreshTask) { // Schedule a new refresh task. scheduleAppRefresh() // Create an operation that performs the main part of the background task. let operation = RefreshAppContentsOperation() // Provide the background task with an expiration handler that cancels the operation. task.expirationHandler = { operation.cancel() } // Inform the system that the background task is complete // when the operation completes. operation.completionBlock = { task.setTaskCompleted(success: !operation.isCancelled) } // Start the operation. operationQueue.addOperation(operation) } func RefreshAppContentsOperation() -> Operation { }

I've been seeing a high number of BGTaskScheduler related crashes, all of them coming from iOS 18.4. I've encountered this myself once on launch upon installing my app, but haven't been able to reproduce it since, even after doing multiple relaunches and reinstalls. Crash report attached at the bottom of this post. I am not even able to symbolicate the reports despite having the archive on my MacBook: Does anyone know if this is an iOS 18.4 bug or am I doing something wrong when scheduling the task? Below is my code for scheduling the background task on the view that appears when my app launches: .onChange(of: scenePhase) { newPhase in if newPhase == .active { #if !os(macOS) let request = BGAppRefreshTaskRequest(identifier: "notifications") request.earliestBeginDate = Calendar.current.date(byAdding: .hour, value: 3, to: Date()) do { try BGTaskScheduler.shared.submit(request) Logger.notifications.log("Background task scheduled. Earliest begin date: \(request.earliestBeginDate?.description ?? "nil", privacy: .public)") } catch let error { // print("Scheduling Error \(error.localizedDescription)") Logger.notifications.error("Error scheduling background task: \(error.localizedDescription, privacy: .public)") } #endif ... } 2025-02-23_19-53-50.2294_+0000-876d2b8ec083447af883961da90398f00562f781.crash