Dear Apple Support Team, My app, io.cylonix.sase, has a BGAppRefreshTask (io.cylonix.sase.ios.refresh) that is canceled by dasd ~9ms after submission from a Network Extension. Please help identify the cause and suggest a solution. App Details: App ID: io.cylonix.sase iOS Version: 17.1.1 (iPhone Xs Max) Network Extension: saseWgNetworkExtension with packet-tunnel-provider entitlement Use Case: VPN app; Network Extension records file receipts in shared group UserDefaults and schedules BGAppRefreshTask to wake the main app. App Usage: High (frequently used) System State: Sufficient resources (not low on battery or memory) Issue: The task is submitted but canceled immediately with priority 10. It has never run, so rate-limiting is not an issue. ` debug 22:09:37.952749-0700 dasd Best binding found for evaluator 0x16d541720: <private> debug 22:09:37.954483-0700 dasd Invoking selector backgroundTaskSchedulerPermittedIdentifiersWithContext:tableID:unitID:unitBytes: on <LSApplicationRecord 0x724844650> default 22:09:37.955563-0700 dasd CANCELED: bgRefresh-io.cylonix.sase.ios.refresh:ABDAFA at priority 10 <private>!

When I search, it's always people trying to do stuff in the background. I want my app to only do stuff when it is active. And this post https://developer.apple.com/forums/thread/685525 seems to have prevented replies from the start. Which means it's just a documentation page and does not belong in the discussion forums at all, because it prevents all discussion.

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.

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?

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

Hello! I'm writing a System Extension that is an Endpoint Security client. And I want to Deny/Allow executing some XPC Service processes (using the ES_EVENT_TYPE_AUTH_EXEC event) depending on characteristics of a process that starts the XPC Service. For this purpose, I need an API that could allow me to obtain an execution context of the XPC Service process. I can obtain this information using the "sudo launchctl procinfo <pid>" command (e.g. I can use the "domain = pid/3428" part of the output for this purpose). Also, I know that when the xpcproxy process is started, it gets as the arguments a service name and a pid of the process that requests the service so I can grasp the execution context from xpcproxy launching. But are these ways to obtain this info legitimate?

Hi everyone, I’m Jaswanth. My friends and I are students working on a project where we’ve developed a website and a companion app. Here’s the key functionality: When two users enter a virtual room, one of them is prompted to download a desktop app. The app is built with Python and uses psutil to check for certain running processes. It does not send any data over the internet. It has a GUI that clearly shows the system is being monitored , it’s not hidden or running in the background silently. We want to sign and notarize the app to make sure it runs on macOS without warning users. However, we’re concerned that since the app accesses system process information, it might be flagged as malicious. Before we pay for the Apple Developer Program, we wanted to ask: Will an app like this (which only reads running processes and does not exfiltrate or hide activity) be eligible for notarization? Thanks in advance for any insights. We'd appreciate any clarity before moving forward. Best, Jaswanth

Hi, I have some questions regarding the Background Assets Extension and DeviceCheck framework. Goal: Ensure that only users who have purchased the app can access the server's API without any user authentication using for example DeviceCheck framework and within a Background Assets Extension. My app relies on external assets, which I'm loading using the Background Assets Extension. I'm trying to determine if it's possible to obtain a challenge from the server and send a DeviceCheck assertion during this process within the Background Assets Extension. So far, I only receive session-wide authentication challenges—specifically NSURLAuthenticationMethodServerTrust in the Background Assets Extensio. I’ve tested with Basic Auth (NSURLAuthenticationMethodHTTPBasic) just for experimentation, but the delegate func backgroundDownload( _ download: BADownload, didReceive challenge: URLAuthenticationChallenge ) async -> (URLSession.AuthChallengeDisposition, URLCredential?) is never called with that authentication method. It seems task-specific challenges aren't coming through at all. Also, while the DCAppAttestService API appears to be available on macOS, DCAppAttestService.isSupported always returns false (in my testing), which suggests it's not actually supported on macOS. Can anyone confirm if that’s expected behavior?

I'm trying to launch a command line app from my objective C application (sandboxed) using NSTask and I keep getting "launch path not accessible" Here is the path: [task setLaunchPath:@"/usr/local/bin/codeview"]; I have set the appropriate attributes for codeview and it is working perfectly when I use it from the command line and /usr/local/bin IS in the $PATH I know I have NSTask configured correctly because this WILL work: [task setLaunchPath:@"/usr/bin/hexdump"]; With the exception being that I'm using a command already in /usr/bin. But I can't copy codeview into /usr/bin due to SIPS. I've tried moving codeview to various other non-SIPS protected locations all to no avail. Must all NSTask commands come from /usr/bin? Where might I put codeview so that it can be launched. Today I'm going to use an older computer and disable SIPS to put my command in /usr/bin and see if that works. If it does. I will do it on my main machine.

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)") } } }

I can see a number of events in our error logging service where we track expired BGAppRefreshTask. We use BGAppRefreshTask to update metadata. By looking into those events I can see most of reported expired tasks expired around 2-5 seconds after the app was launched. The documentations says: The system decides the best time to launch your background task, and provides your app up to 30 seconds of background runtime. I expected "up to 30 seconds" to be 10-30 seconds range, not that extremely short. Is there any heuristic that affects how much time the app gets? Is there a way to tell if the app was launched due to the background refresh task? If we have this information we can optimize what the app does during those 5 seconds. Thank you!.

I'm developing a medication scheduling app similar to Apple Health's Medications feature, and I'd like some input on my current approach to background tasks. In my app, when a user creates a medication, I generate ScheduledDose objects (with corresponding local notifications) for the next 2 weeks and save them to SwiftData. To ensure this 2-week window stays current, I've implemented a BGAppRefreshTask that runs daily to generate new doses as needed. My concern is whether BGAppRefreshTask is the appropriate mechanism for this purpose. Since I'm not making any network requests but rather generating and storing local data, I'm questioning if this is the right approach. I'm also wondering how Apple Health's Medications feature handles this kind of scheduling. Their app seems to maintain future doses regardless of app usage patterns. Has anyone implemented something similar or can suggest the best background execution API for this type of scenario? Thanks for any guidance you can provide.

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.

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 have an app that uses background audio recording. From what others say, I have enabled the audio background mode to keep the audio session active, and this worked. But when submitting the app to the app store, the app was rejected because the audio background mode is only supposed to be used for audio playback. How do I create this background mode while following Apple's guidelines?

We've seen a recent increase in background terminations: blue - System Pressure orange - Task Timeout I'm trying to understand the increase in system-pressure terminations, since there's no corresponding increase in memory at suspension. Are there other system resources for which iOS will terminate an app?

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

My load average on a largely idle system is around 22, going up to 70 or so periodically; SSMenuAgent seems to be consuming lots of CPU (and, looking at spindump, it certainly seems busy), but... it's not happening on any other system whose screens I am observing. (Er, I know about load average limitations, the process is also consuming 70-98% CPU according to both top and Activity Monitor.) Since this machine (although idle) has our network extension, I'm trying to figure out if this is due to that, or of this is generally expected. Anyone?

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 &amp; 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 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?