There is one xpc server and two xpc clients (clientA and clientB). When clientB sends a message to the xpc server, xpc server fills a value for dummyString in it's memory and I want clientA to know that dummyString got updated and also the new value for this dummyString. The updation of dummyString is not something that happens often. Two options we tried: Have a timer for 5 seconds in clientA and keep polling and request for the value of this dummyString. Setup a darwin notification in server that gets posted whenever dummyString is being updated. clientA receives requests for dummyString value only when it observes a notification being posted. Which of these two approaches causes the least delay for clientA to know the updated value of dummyString?

I have 2 XPC clients and an XPC server. One of the XPC clients is a binary-helper that serves as a native messaging host for the browserExtension. The other XPC client sends a specific event to the XPC server, which then triggers a Darwin notification. The binary-helper observes this Darwin notification and sends a response to the browserExtension. Currently, we're considering two options to communicate the response from binary-helper to browserExtension: Polling: Every 5 seconds, the browserExtension checks for a response. Darwin Notifications: The binary-helper sends a message to the browserExtension as soon as it observes the Darwin notification. I'm wondering if Darwin notifications are fast enough to reliably deliver this response to the browserExtension in real time, or if polling would be a more reliable approach. Any insights or experiences with using Darwin notifications in a similar scenario would be greatly appreciated.

Hi, I'm facing an issue with Darwin notifications between two applications that share the same App Group. Issue Description: When the app is in the foreground (active state), the notifications are received and handled correctly. However, when the app is in the background, notifications are not received. What I've Tried: Verified the App Group is correctly configured and accessible between the two applications. Confirmed Darwin notifications are triggered and received successfully in the foreground. Checked notification permissions and ensured all required capabilities are enabled. Setup Details: iOS version: iOS 11 Xcode version: 16.0 Notifications: Darwin notifications sent between apps using App Groups. **Code Snippet : ** func startListening(name: String, callback: @escaping () -> Void) { CFNotificationCenterAddObserver(notificationCenter, Unmanaged.passUnretained(self).toOpaque(), NotificationManager.notificationCallback, name as CFString, nil, .deliverImmediately) } func sendNotification(name: String) { CFNotificationCenterPostNotification(notificationCenter, CFNotificationName(name as CFString), nil, nil, true) } private static let notificationCallback: CFNotificationCallback = { center, observer, name, _, _ in guard let observer = observer else { return } let manager = Unmanaged.fromOpaque(observer).takeUnretainedValue() if let name = name?.rawValue as String { // Code added } } Is there any additional configuration or specific behavior of Darwin notifications in the background that could be causing this issue? I would greatly appreciate any insights, guidance, or references to relevant documentation. Thank you!

I would really like to know if it is possible to get a state for the ringer on iOS. In my application I want to repeat the logic of audio rules from Instagram during watching a video. The video plays with sound. When the ringer switches to mute status the video's audio should be muted too. When you press the volume up or down button the audio should be unmuted. I found how to catch volume up/down buttons with AVAudioSession.sharedInstance().observe(\.outputVolume) but I couldn't find anything that could help me with the ringer state. AVAudioSession.Category can't achieve this effect. Also there is a possibility to check ringer state with Darwin notify lib like var token = NOTIFY_TOKEN_INVALID notify_register_dispatch( "com.apple.springboard.ringerstate", &token, .main ) { token in var state: UInt64 = 0 notify_get_state(token, &state) print("Changed to", state == 1 ? "ON" : "OFF") } but I'm not sure that this won't lead to the application being rejected. I don't know is it a private API usage or not. I will be glad to any advice and suggestions. Thanks