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'm working on an iPhone app that continuously monitors device tilt with Core Motion. When the device has been held tilted forward past a threshold angle for a sustained period, the app raises a local notification. The detection has to keep running while my app is in the background. The situation I need to detect is, by definition, one where the user is looking at some other app — if my app were in the foreground, there would be nothing to detect. So a foreground-only implementation would not implement the feature at all. While testing this I ran into a behavior I would like to understand properly before I rely on it. What I observe CMMotionManager device-motion updates to a backgrounded app stop within a few seconds of the app leaving the foreground — unless a Core Location session is running at the same time. With location updates started under When In Use authorization and allowsBackgroundLocationUpdates = true, the device-motion callbacks continue for the whole time the app is backgrounded. Stop the location session, and they stop again. I built a focused sample to measure this. It starts device-motion updates at 10 Hz on a background OperationQueue and counts every callback, records the count on didEnterBackground, and on willEnterForeground logs how many arrived during the interval against how many would be expected at 10 Hz. Measured on an iPhone running iOS 26.5.2, launched from the Home screen with no debugger attached: location ON | background 137s | received 1366 / expected ~1373 (99.5%) location OFF | background 129s | received 2 / expected ~1286 (0.16%) Both callbacks in the second run arrived immediately after the transition to the background; nothing arrived over the remaining two minutes. One thing that cost me a test cycle, in case it saves someone else one: the difference only shows up when the app is launched from the Home screen. With the Xcode debugger attached the app is not suspended, and both cases deliver callbacks for the entire interval. The location session in the sample is configured as low as I can make it, since the app never reads the coordinates: manager.desiredAccuracy = kCLLocationAccuracyThreeKilometers manager.distanceFilter = 3000 manager.activityType = .other manager.pausesLocationUpdatesAutomatically = false manager.requestWhenInUseAuthorization() // started from the foreground, once authorization is granted manager.allowsBackgroundLocationUpdates = true manager.startUpdatingLocation() func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) { // Intentionally empty. This sample does not use the location values. } My questions Is continuous CMDeviceMotion delivery to a backgrounded app dependent on an active Core Location session? Is that intended and expected behavior on current iOS versions, or an implementation detail I should not be relying on? If it is expected behavior, what configuration would you recommend for an app in this situation? Specifically, is kCLLocationAccuracyThreeKilometers with a large distanceFilter sufficient to sustain the session, or does reliable delivery require a higher accuracy or a smaller distance filter? Is there another supported API or background execution mechanism that delivers continuous device-motion or accelerometer data to a backgrounded app? I am aware of CMSensorRecorder for retrospective retrieval, but I need to react in near real time. I would like to be sure I am not overlooking a more appropriate API. Environment: iOS 18.0 and later, iPhone only, Swift / SwiftUI. I have the focused sample project available if it would be useful. Thanks very much for any help.

I’m building an app that contributes to a crowdsourced earthquake early warning network: the device reports anomalous accelerometer readings, a server correlates them across nearby devices, and users farther from the epicenter get a warning seconds ahead. Detection has to continue while the app isn’t in the foreground. I’ve ruled out the obvious paths — CMMotionManager stops on suspension, CMPedometer and CMMotionActivityManager only return historical data, BGTaskScheduler is too infrequent, and CMSensorRecorder is watchOS-only. I’ve also read thread 765258, where DTS confirmed there’s no background capability for accelerometer data and that repurposing another one risks rejection under 2.5.4, so I’m not looking for a workaround. Is there any supported way to do this on iOS, for instance restricted to when the device is stationary and charging? Or is this outside what the platform currently allows? Thanks.

So recently I migrated the topshelf extension for my app from the deprecated TVServiceProvider to the new TVContentProvider in 13.0 and onwards.I finally got it working (not helped by wasting hours figuring out that the NSExtensionPrincipalClass has to be the first thing listed in the NSExtension dictionary in the Info.plist or the extension just terminates, I kid you not!) but there is one last thing that I can't figure out.What works:1. remove any instance of my application from the Apple TV2. install and launch my app from xcode on the Apple TV3. when i back out of the app, the topshelf code is working, it calls the loadTopShelfContentWithCompletionHandler function and I am able to give it what it wants and it gets displayed correctlyProblem is, if I terminate the application from Xcode, I can no longer get the topshelf to work when I try and launch it again from Xcode. It is not listed as running (as a process to attach to, for example). The app runs fine, but there is no extension process launched alongside it.I can get it working again in one of two ways; either A) reboot the Apple TV, in which case I find tvOS launches the extension a few seconds after boot without me doing anything (not even highlighting my app), or, B) following the steps above if I delete the instance from the Apple TV and install it again using Xcode.Essentially, it behaves as if the top shelf extension is launched once, and only once, on bootup of the Apple TV, or on first install. It appears to get terminated when I launch the app again using xcode (e.g. with a new build or something, or even running the same build) and only A) or B) above can get it running again.Has anyone else seen this?

I am the developer of MIDIDeviceManager, an iOS and iPadOS application used by musicians to control external MIDI hardware during live performance. Before enabling any background execution mode, I would like to ask which architecture Apple intends for this type of application. What the application does The app organises the patches of a musician's MIDI instruments into Pads, Scenes and Setlists so they can be recalled during a performance. It sends MIDI to external hardware such as guitar processors, synthesisers and vocal processors, and it also receives incoming MIDI that triggers its own Scenes — typically from a Bluetooth foot controller, a wired MIDI controller, or another app on the same device. Its purpose is to function as the software equivalent of a programmable hardware MIDI controller. It is not a lyrics app or an audio player, and it produces no audio. The problem During a performance, musicians commonly run more than one app. A typical setup is lyrics or chord charts displayed in one app while a Bluetooth foot controller recalls presets on a Line 6 Helix through MIDIDeviceManager. This requires the app to keep receiving and processing incoming CoreMIDI events while another app is frontmost. Once iOS suspends the app, those events are no longer delivered and the foot controller stops working. This affects iPhone as much as iPad. Several of my TestFlight users perform with iPhone alone, where the device sits on a stand and is not touched during a song. What I have observed I tested this directly on an iPhone 17 Pro Max. With two apps running simultaneously, an app legitimately using the audio background mode continued to receive and act on incoming CoreMIDI events from a Bluetooth foot controller while backgrounded. At the same moment, MIDIDeviceManager received nothing once iOS suspended it. This suggests that, under certain circumstances, an app executing under an appropriate background mode may continue receiving CoreMIDI while backgrounded. Background modes considered audio — appears to provide the required behaviour, but my app produces no audio output. I do not wish to declare a background capability that does not accurately describe what the app does. bluetooth-central — does not appear applicable, since Bluetooth MIDI connections are established through CoreMIDI and managed by the system MIDI server rather than by my own Core Bluetooth session. I have not been able to identify any mode intended for continuous MIDI reception, so UIBackgroundModes is currently empty. A previous rejection An earlier submission did declare audio, and was rejected under Guideline 2.5.4 on 7 July 2026 (submission ID eab58179-8177-4d05-9c37-5e1006828a96): "The app declares support for audio in the UIBackgroundModes key in the Info.plist but we are unable to locate any features that require persistent audio. Background audio is intended for use by apps that provide audible content to the user while in the background, such as music player, music creation, or streaming audio apps." That assessment is correct — the app produces no audio, and I removed the key. But the functional requirement remains: the app needs to receive MIDI while another app is frontmost. I am asking here rather than resubmitting, because I would rather understand the intended architecture than guess again. My questions Which background mode, if any, is appropriate for an app whose purpose is to continue receiving and processing incoming CoreMIDI events while another app is frontmost? If background MIDI reception is supported, is CoreMIDI expected to continue delivering incoming MIDI to a backgrounded app, or is there a different recommended architecture for apps of this type? If the answer is that no background mode applies and this capability is not available to apps of this kind, I would very much appreciate knowing that clearly. I can then document the limitation for my users and design accordingly rather than pursue an unsupported approach. My objective is not to find a workaround, but to implement this the way Apple intends professional MIDI applications to work. Thank you.

I’m looking at the new BGTaskScheduler.submitTaskRequest(_:completionHandler:) API on iOS 27 that replaces the now deprecated submit(_:).* The documentation says: This method asynchronously submits the task request and invokes the completion handler with any errors that occur during submission. It also says: The completion handler may be invoked on a arbitrary queue after an arbitrary amount of delay. Do not call this method from the main thread or performance-critical contexts. I’m confused when it says “Do not call this method from the main thread.” Since the method asynchronously submits the request and reports errors later through the completion handler, I initially read this as a warning not to wait for the completion handler to be called assuming it returns quickly. But it specifically says not to call the method from the main thread, which suggests the initial call itself may perform blocking expensive work before returning (although this is confusingly stated in the same block describing the completion handler behavior). Is the intended usage to create/configure the request on the main thread, then dispatch only submitTaskRequest to a background queue, or is calling that on the main thread actually okay just like the submit(_:) API it replaced? My current code in a synchronous function running on the main thread: BGTaskScheduler.shared.register(forTaskWithIdentifier: id, using: .main) { @Sendable registeredTask in // The background continued processing task has started, use it to update progress... } let request = BGContinuedProcessingTaskRequest(identifier: id, title: title, subtitle: subtitle) request.strategy = .fail // Start the task immediately and fail if it cannot if BGTaskScheduler.supportedResources.contains(.gpu) { request.requiredResources = .gpu } do { try BGTaskScheduler.shared.submit(request) // FIXME: How to migrate to the new API? } catch { // No worries, user will just have to keep the app open until the task completes print("BGTaskScheduler request failed: \(error.localizedDescription)") } *I assume this change was made to address issues like FB21052216 (https://developer.apple.com/forums/thread/807370)

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 have an issue spawning continued background processing tasks: they are never started, even after restarting the device, regardless of which app spawns a task. deleting and reinstalling an app, or installing a new app that didn't exist before also does not work. it can be reproduced by setting your device local time to one year in advance and then trying to spawn the task. the task will not start and even after returning to the proper date, all apps on the device are still unable to spawn any. i also believe there are other things that trigger this issue (or something related), as many of my users have complained about tasks not starting. prior to my changing the date of my device, they worked perfectly for me. one user changed their date to test at the same time as me and the only fix they found was erasing their device and restoring a backup. on ios 26 tasks fail silently, but on ios 27 with the new api to submit a task, an error is caught: Error Domain=BGTaskSchedulerErrorDomain Code=1 "connection to service with pid 94 named com.apple.duetactivityscheduler" UserInfo={NSDebugDescription=connection to service with pid 94 named com.apple.duetactivityscheduler} in addition, a more detailed error with a stack trace is logged at the same time: <NSXPCConnection: 0x10c60c0a0> connection to service with pid 94 named com.apple.duetactivityscheduler: Exception caught during decoding of reply to message 'submitTaskRequest:withHandler:', dropping incoming message and calling failure block. Ignored Exception: Exception while decoding argument 0 (#1 of invocation): <NSInvocation: 0x10c6d72c0> return value: {v} void target: {@?} 0x0 (block) argument 1: {@} 0x0 Exception: value for key 'NS.objects' was of unexpected class 'NSSet' (0x20620c358) [/System/Library/Frameworks/CoreFoundation.framework]. Allowed classes are: {( "'NSDate' (0x20620c268) [/System/Library/Frameworks/CoreFoundation.framework]", "'NSError' (0x2061fd3b0) [/System/Library/Frameworks/Foundation.framework]", "'NSNumber' (0x2061fd478) [/System/Library/Frameworks/Foundation.framework]", "'NSData' (0x20620c650) [/System/Library/Frameworks/CoreFoundation.framework]", "'NSArray' (0x20620c6c8) [/System/Library/Frameworks/CoreFoundation.framework]", "'NSString' (0x2061fd428) [/System/Library/Frameworks/Foundation.framework]", "'NSDictionary' (0x20620c538) [/System/Library/Frameworks/CoreFoundation.framework]", "'NSURL' (0x20620c678) [/System/Library/Frameworks/CoreFoundation.framework]" )} ( 0 CoreFoundation 0x000000019fbc2e0c 43092235-E272-3CAF-B9AE-76669EC5AE46 + 622092 1 libobjc.A.dylib 0x000000019f940298 objc_exception_throw + 88 2 Foundation 0x00000001a002beac E642F95D-61DA-3E8C-A2D2-CFEB7F7B688B + 126636 3 Foundation 0x00000001a0035090 E642F95D-61DA-3E8C-A2D2-CFEB7F7B688B + 163984 ...

We're working on an Endpoint Security extension and using Swift 6 with Concurrency. I've heard there are some subtleties to getting the threading right across those two domains and am hoping that someone can help shed light on it. In particular, ES events can be delivered on a high priority thread and I'd like to be sure that any work done in the Concurrency domain retains that priority to minimize latency between event delivery and response.

We are developing a system consisting of two iOS apps from the same developer (same Team ID): ・App A acquires data from an external accessory. For regulatory/compliance reasons that we cannot detail here, App A must have no networking capability at all. ・App B is intended to receive data from App A and upload it to a server. Two important environmental constraints: ・The deployment environment is a closed local network. The server App B talks to is on the local network, and Internet access is not guaranteed. Therefore, any APNs-dependent approach (silent push, etc.) is not viable. ・Latency requirement: near-real-time is ideal, but a delay of up to a few minutes is acceptable. What we have considered: 1.App Groups shared container — App A can write data, but there is no way to wake App B in the background when new data is written. 2.URL schemes — can launch App B reliably, but bring it to the foreground, which disrupts the user's workflow. 3.BGTaskScheduler — rejected; execution timing is entirely at the system's discretion. 4.Silent push — rejected; requires APNs / Internet connectivity, which we cannot assume (see above). Our current leading candidate is a combination of (1) and (2): App A writes data to the App Groups container, then opens App B via a URL scheme; App B reads the container and uploads. This works, but the foreground app switch on every hand-off is far from ideal. We are aware that some apps abuse background modes (e.g., playing silent audio) to stay resident. We assume this violates App Review Guideline 2.5.4 and is not an option for us — please correct us if there is any legitimate variant of this approach. Questions: 1.Is there any supported mechanism to keep App B running (or reliably woken) in the background, so that it can receive data from App A and upload it — without user interaction and without Internet access? 2.If not, is there any way to mitigate the foreground switch in our current App Groups + URL scheme approach (e.g., returning to App A automatically after the hand-off)? Or would that ping-pong pattern itself be an App Review concern? Any guidance would be appreciated.

Short version, in case it saves someone the trip I just took: if your app plays audio AND uses a background URLSession with sessionSendsLaunchEvents = true, playback can be killed mid-episode the moment you call the handleEventsForBackgroundURLSession completion handler, but only in a process that was launched into the background and never went foreground. There is no crash log and no jetsam event: applicationWillTerminate simply fires. To users it looks exactly like the app crashed while playing, which is how it was reported to me, and why I wasted a while looking for a crash that did not exist. My setup: podcast app, audio background mode a background URLSession (sessionSendsLaunchEvents = true, isDiscretionary = false) used only to refresh RSS feeds those feed downloads are started from a BGAppRefreshTask What happens: iOS launches the app into the background to run a BGAppRefreshTask. The scene connects unattached; the process never becomes foreground. The task starts a batch of feed downloads on the background session. They outlive the ~10 s refresh window and finish about two minutes later. Meanwhile the user presses Play on their AirPods. Playback starts, inside that same never-foreground process. The downloads finish. iOS calls handleEventsForBackgroundURLSession. I store the handler and invoke it on the main thread from urlSessionDidFinishEvents, as documented. ~1 ms later applicationWillTerminate fires and the audio stops. At that moment the app is playing audio: AVAudioSession active, category .playback, and -[UIApplication backgroundTimeRemaining] returning greatestFiniteMagnitude. A sysdiagnose shows audiomxd holding a MediaPlayback isPlayingProcessAssertion for the process, taken 27 s earlier, invalidated only as part of the teardown, and CMSessionMgr logging "pid ... is now Terminated. Background entitlement: YES" while IsPlayingOutput:YES. The tell, and the thing that took me longest to spot: if the process HAS been foreground at some point in its life, calling the identical completion handler on the identical session does not kill it, and playback carries on. Across a full day of logs, "has this process ever been foreground" is the only variable that predicts the kill. The audio background mode is not the problem, the app happily played for ~6 minutes as a never-foreground process on another occasion, and died only at the completion-handler call. Half of this is documented behaviour: the system takes a power assertion when it resumes you for the session, and calling the completion handler releases it. What I did not expect is that the audio assertion does not take over at that point. My workaround so far is sessionSendsLaunchEvents = false on the feed session. RSS refreshes are not urgent: the transfers still run in the background, and the system hands the results to me at the next launch, where my refresh task parses them. I'm still verifying if this works as expected. So, questions for anyone who has been here: Has anyone else with an audio app hit this? I have a hunch it shows up in the wild as unexplained "the app crashed while playing" reports, particularly for podcast and audiobook apps that refresh content in the background, because there is no crash log to point at. If you combine background audio with a background URLSession, how do you handle it? Do you avoid launch events entirely, or split urgent from non-urgent transfers across separate sessions? Is there a better pattern than turning launch events off for transfers that genuinely are not urgent? Filed as FB23789310 with a sysdiagnose and a timestamped log excerpt. If you have seen this too, a dupe would help.

Summary: Starting from iPadOS 26.4, the maximum memory available to a single app has been reduced from approximately 6GB to 3GB on an 8GB iPad. This change persists in iPadOS 26.5 and has not been addressed. This breaks core functionality of memory-intensive applications such as 3D scanning apps that require large amounts of RAM to process models. Device: iPad with 8GB RAM Affected versions: iPadOS 26.4, iPadOS 26.5 Working version: iPadOS 26.0 / 26.1 / 26.2 / 26.3 Measured Data: iPadOS 26.0–26.3: App available memory ≈ 6GB (75% of total RAM) iPadOS 26.4–26.5: App available memory ≈ 3GB (37.5% of total RAM) Measurement method: Apple system API Impact: This is a regression, not expected behavior. The available memory per app has been cut by 50% without any official documentation or release notes mentioning this change. As a result, our 3D scanning application crashes immediately when attempting to process 3D models on iPadOS 26.4 and later. The app requires substantial RAM to load and process 3D model data. With only 3GB available, memory allocation fails during model processing, causing the app to crash (EXC_RESOURCE / OOM kill). This core functionality was working correctly on iPadOS 26.3 and earlier with the same device and same app binary. This regression makes our app's primary feature completely unusable for all users on iPadOS 26.4+. Steps to Reproduce: On an 8GB iPad, install iPadOS 26.0 Measure available app memory using Apple system API Upgrade to iPadOS 26.4 or 26.5 Measure available app memory again Observe: available memory drops from ~6GB to ~3GB Expected Result: Available memory per app should remain consistent across minor OS updates, or any changes should be documented. Actual Result: Available memory per app dropped by 50% starting in iPadOS 26.4, with no documentation of this change. Additional Notes: Disabling Apple Intelligence does not resolve the issue This issue was not fixed in iPadOS 26.5 Other developers have reported increased crash rates starting in iPadOS 26.4 (Apple Developer Forums)

In /usr/include/libproc.h, there are a few number of APIs listed as private but which are commonly used (e.g. proc_pidpath). I'm trying to figure out how the proc_listallpids API is supposed to be used. From the examples I'm seeing in open source projects, the idea is to: call proc_listallpids(NULL, 0) to get a hint about the number of pids currently existing. call proc_listallpids with an appropriate buffer and retry if needed (I guess if the number of processes grew more than expected between the 2 calls). OK. What I'm not getting is how the resulting array of pids is to be used. What I am observing is that the array of pids you get is a list of the existing of the existing pids in a descendant order. BUT after pid 0, there can be additional pids. Numerous projects are just skipping pid = 0, but are using the pids after 0 as if they were valid. From what I'm seeing these are not valid pids and the correct way to handle the array of pids is to stop at pid 0 (or 1 if you want to skip the "kernel"). [Q] Is the proc_listallpids like the proc_pidpath a Voldemort API? Everyone can see it but you are not allowed to discuss it and to get more info about it you need to contact DTS. Or is it possible to know the right way to use this API and its results?

Hi everyone, I am currently working on a specialized analytics and time-tracking application, and I am trying to find a reliable way to detect which app the user currently has open in the foreground in real-time. On Android, this is typically handled via Accessibility Services or UsageStats, but I am well aware of iOS’s strict sandboxing rules and privacy protections. So far, I have researched and tested a few workarounds, but none perfectly fit the use case: Screen Time API (FamilyControls / DeviceActivity): This is fantastic for blocking apps or getting daily aggregate usage, but it does not provide real-time callbacks or the bundle ID of the app currently on the screen. MDM (Mobile Device Management): Requires enterprise enrollment and wiping the device, which isn't feasible for a consumer-facing app. ReplayKit (Broadcast Extension): We are currently utilizing RPBroadcastSampleHandler to screen record the device and using OCR and Core ML to visually identify the app (e.g., detecting the YouTube UI). However, this is incredibly resource-intensive and pushes the 50MB Jetsam limit for extensions. My Question: Is there any official API, restricted entitlement, or system notification (like NSWorkspace.shared.frontmostApplication on macOS) that allows a background process to simply read the bundleID of the active foreground app on iOS? If not, is ReplayKit combined with OCR or Machine Learning truly the only way to detect what app a user is actively viewing on iOS without a jailbreak? Thank you in advance for any insights!

Hello everyone, We have a feature in our iOS app called "automatic background sync", which syncs data between the mobile app and our backend periodically. It is specifically designed to work when the app is in a backgrounded state. We use both silent remote notifications that are sent from our backend periodically (using Firebase Cloud Messaging), and also BGAppRefresh task. The sync process should be as reliable as possible and work continuously while the app is in the background, even if the user does not open the app for a long period of time. We enforce a 20 second deadline to call the completion handler to match the 30 second limit. We have a specific customer that has multiple where the background sync does not work properly: One of them has continuous syncs for about a week, then it stops until the user opens (moves to foreground) the app again. Another user only has a sync when they open the app, then it stops when it is backgrounded. Looking at their logs: The app remains in the background and is rarely being actively killed, and it likely is not the reason that the user stopped receiving syncs. Their background app refresh setting in iOS settings is enabled. Both user's app stopped waking up and doing the task either from silent remote notifications or background tasks. Thank you!

I have run into an interesting topic today. So far, I have been under the impression that when I am using the setCodeSigningRequirement() function on an NSXPCConnection, I am completely removing any chance of receiving AND sending messages to untrusted XPC Peers. However, I created a malicious replacement for my daemon, and I wanted to check if my application can still send and receive messages to it. I checked with codesign --verify that the replacement does NOT fulfil the code signing requirement. I put a system log instruction in the malicious tool's XPC function. When calling the XPC Peer, I expected to see: XPC connection to <redacted> failed! [Error Domain=NSCocoaErrorDomain Code=4102 "The code signature requirement failed." UserInfo={NSDebugDescription=The code signature requirement failed.}] and I did. However, I also saw the system log from the malicious tool's XPC function. Then, I checked all XPC documentation, and I found for the original C implementation - xpc_connection_set_peer_code_signing_requirement() - the following in the discussion section: All messages received on this connection will be checked to ensure they come from a peer who satisfies the code signing requirement. For a listener connection, requests that do not satisfy the requirement are dropped. When a reply is expected on the connection and the peer does not satisfy the requirement XPC_ERROR_PEER_CODE_SIGNING_REQUIREMENT will be delivered instead of the reply. (this is in xpc/connection.h) which seems to align with the observed results. However, this is (embarassingly?) new for me, I would have never expected this, given how in my head pre-checking before any connection is made seems straightforward, even with public Apple SDK APIs: Grab a SecCode (not SecStaticCode) object of the daemon (malicious or not). This is running code, so it cannot be substituted between the check and the outgoing message. Perform validations on the SecCode object in some form - on macOS 15.0+ it's pretty easy with LightweightCodeRequirement's SecCodeCheckValidityWithProcessRequirement(). Immediately drop the connection if the peer is untrusted, before any message is sent. Am I overlooking something or making wrong assumptions here? or Am I right and this is something that I have to accept that's implemented less than ideally and I can perform above steps 1-3 myself and make a difference? Thanks in advance!

Hi everyone! I'm writing a watch app using backgroud refresh. But the backround task was not triggered either on simulator or real watch device. main code

I develop a tool on macOS which is composed of an UI app to manage the main app settings, and an Agent that runs in background doing some tasks ? (Running the agent is optional, can be launched from the UI app, and can be launched by macOS at startup with SMAppService. ) Agent has the LSUIElement flag set, and only shows a Menu Extra (or whatever it now named), and sometimes some notifications. The whole App package is bundled this way MainAppUI.app/Contents/Library/LoginItems/AppAgent.app (for SMAppService to work) This has been working correctly for years Now on macOS 27 beta, once I quit the UI App, having launched the Agent, the Dock reports the UI App is still running in background (with the grey dot) . But only the Agent is running, not the UI app process. Moreover, System Settings->Background apps reports both the UI app AND the Agent as both requesting to run in background. I would have expected only the Agent being listed in System Settings, and nothing appearing in the Dock. Is this a bug in the OS beta , showing the top-level container bundle as the app running in background instead of the executable direct container ? Or maybe it's on me and I should bundle my app differently ? (I cannot "reverse" the bundle and put the Agent as the main app, with UI "inside", as double clicking the main app should launch the UI App , not the Agent. ) BTW, filed FB23203848 for the same subject. thanks for any direction

I have a weird situation arising in my app where calling BGTaskScheduler.shared.submit(request) seems to fail silently, without raising any of the BGTaskScheduler.Error's. Here's what's happening. A user registers and submits 5 BGContinuedProcessingTask's, with different ID's using the wildcard. When trying to submit the 6th task like this: try bgTask.submit() //submit task isCreatingBGTask = false // toggle ProgressView off dismiss() //Dismiss the sheet The sheet will dismiss, but the device never gives the haptic feedback, and the task is not visible in the notification centre. Having a maximum number of running tasks makes sense, but why isn't it raising the error BGTaskScheduler.Error(.immediateRunIneligible). It also doesn't seem like there's a way to query the tasks that are in progress (at least I couldn't find a way). So for now I'll just track my own tasks manually, and prevent submission at 5 tasks, but I'm wondering what would happen if another app had 2 tasks going, and then my user tries to submit 3 or something like that.

I have one report from a customer, who migrated all data from his old MacBook to a new one. His is on Tahoe 26.5.1 (25F80). Here is my relevant code: + (BOOL)enableLoginItem:(BOOL)enable { NSOperatingSystemVersion osv = NSProcessInfo.processInfo.operatingSystemVersion; if (osv.majorVersion >= 13) { NSError* error; SMAppService* service = [SMAppService loginItemServiceWithIdentifier:MY_HELPER_APP_ID]; if (![service registerAndReturnError:&error] && error) @throw error; return YES; } return SMLoginItemSetEnabled((__bridge CFStringRef)MY_HELPER_APP_ID, enable); } What should I do to re-enable the login helper?

I just noticed something on macOS 27 beta 1 and I'm not sure if it's a bug or just how the new feature works. After quitting an app with Cmd+Q, the Dock keeps showing the gray dot with the "Running in Background" message. So I checked — ps aux shows nothing running for the app at all. The only trace is its auto-updater job in launchctl list (com.anthropic.claudefordesktop.ShipIt), which is registered but has no PID, so it's not actually executing anything. Out of curiosity I tried Discord and got the exact same thing (com.discord.discord.ShipIt), so this probably happens with any Electron app that uses the Squirrel updater. Is this intended behavior? Trying to understand if the indicator reflects registered background items (and not just live processes) so I know what to expect for Electron-based apps.