I'm working on an XPC server and need to determine the owner of the client process that connects to it. Specifically, I'd like to retrieve details such as the fully qualified user name or other identifying information from the XPC client connection.I'm considering using xpc_connection_get_pid() to get the client’s process ID, but I’m unsure of the best way to map this to the user who owns the process.
Is there a recommended API or approach to capture this information securely?
Processes & Concurrency
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As far as I understand, the main thread has a run loop.
When an iOS app launches, the process must keep the run loop running to stay alive.
Does that mean the main thread is the very first thread created when the process starts?
Hi! I've been developing iOS and macOS apps for many years, but now I am looking to dive into smth i have never touched before, namely privileged helpers, and i am struggling hard trying to find my footing.
Here’s my use case: I have a CLI tool that requires elevated privileges. I want to create a menu bar app that can interact with this tool, but I’m struggling to find solid documentation or examples of how to accomplish this using SMAppService. I might just be missing something obvious.
If anyone could point me toward relevant documentation, examples, articles, tutorials, or even a WWDC session that covers running privileged helpers with SMAppService, I would greatly appreciate it.
Thanks in advance!
After logging in to the main App, turn on screen recording, then switch to the interface of another App to perform operations. After about ten-odd minutes, when returning to the main App, it was found that the app was forcefully quit by the system, and subsequent operations could not be carried out.
Hi All,
In continuation of this thread https://developer.apple.com/forums/thread/804439
I want to perform data upload after getting it from the BLE device. As state restoration wake should not deal with data upload i though of using a processing task to perform the data upload.
So the flow will be something like:
Connect to device -> listen to notification -> go to background -> wake from notification -> handle data download from ble device -> register processing task for data upload -> hopefully get the data uploaded
From reading about processing task i understand that the task execution is completely handled by the OS and depends on user behaviour and app usage. I even saw that if the user is not using the app for a while, the OS might not even perfoirm the task. So my quesiton is: does state restoration wakeup and perfroming data dowloads in the backgound considered app usage that will increase the likeluhood the task will get execution time?
Can we rely on this for a scenario that the user opens the app for the first time, register, onboard for ble, connect to devie and then put it in the background for days or weeks and only relying on state restoration and processing tasks to do their thing?
Sorry for the long read and appreciate your support!
Shimon
Topic:
App & System Services
SubTopic:
Processes & Concurrency
Tags:
Background Tasks
Core Bluetooth
Im using the low-level C xpc api <xpc/xpc.h> and i get this error when I run it: Underlying connection interrupted. I know this error stems from the call to xpc_session_send_message_with_reply_sync(session, message, &reply_err);. I have no previous experience with xpc or dispatch and I find the xpc docs very limited and I also found next to no code examples online. Can somebody take a look at my code and tell me what I did wrong and how to fix it? Thank you in advance.
Main code:
#include <stdio.h>
#include <xpc/xpc.h>
#include <dispatch/dispatch.h>
// the context passed to mainf()
struct context {
char* text;
xpc_session_t sess;
};
// This is for later implementation and the name is also rudimentary
void mainf(void* c) {
//char * text = ((struct context*)c)->text;
xpc_session_t session = ((struct context*)c)->sess;
dispatch_queue_t messageq = dispatch_queue_create("y.ddd.main",
DISPATCH_QUEUE_SERIAL);
xpc_object_t message = xpc_dictionary_create(NULL, NULL, 0);
xpc_dictionary_set_string(message, "test", "eeeee");
if (session == NULL) {
printf("Session is NULL\n");
exit(1);
}
__block xpc_rich_error_t reply_err = NULL;
__block xpc_object_t reply;
dispatch_sync(messageq, ^{
reply = xpc_session_send_message_with_reply_sync(session,
message,
&reply_err);
if (reply_err != NULL) printf("Reply Error: %s\n",
xpc_rich_error_copy_description(reply_err));
});
if (reply != NULL)
printf("Reply: %s\n", xpc_dictionary_get_string(reply, "test"));
else printf("Reply is NULL\n");
}
int main(int argc, char* argv[]) {
// Create seperate queue for mainf()
dispatch_queue_t mainq = dispatch_queue_create("y.ddd.main",
DISPATCH_QUEUE_CONCURRENT);
dispatch_queue_t xpcq = dispatch_queue_create("y.ddd.xpc",
NULL);
// Create the context being sent to mainf
struct context* c = malloc(sizeof(struct context));
c->text = malloc(sizeof("Hello"));
strcpy(c->text, "Hello");
xpc_rich_error_t sess_err = NULL;
xpc_session_t session = xpc_session_create_xpc_service("y.getFilec",
xpcq,
XPC_SESSION_CREATE_INACTIVE,
&sess_err);
if (sess_err != NULL) {
printf("Session Create Error: %s\n",
xpc_rich_error_copy_description(sess_err));
xpc_release(sess_err);
exit(1);
}
xpc_release(sess_err);
xpc_session_set_incoming_message_handler(session, ^(xpc_object_t message) {
printf("message recieved\n");
});
c->sess = session;
xpc_rich_error_t sess_ac_err = NULL;
xpc_session_activate(session, &sess_ac_err);
if (sess_err != NULL) {
printf("Session Activate Error: %s\n",
xpc_rich_error_copy_description(sess_ac_err));
xpc_release(sess_ac_err);
exit(1);
}
xpc_release(sess_ac_err);
xpc_retain(session);
dispatch_async_f(mainq, (void*)c, mainf);
xpc_release(session);
dispatch_main();
}
XPC Service code:
#include <stdio.h>
#include <xpc/xpc.h>
#include <dispatch/dispatch.h>
int main(void) {
xpc_rich_error_t lis_err = NULL;
xpc_listener_t listener = xpc_listener_create("y.getFilec",
NULL,
XPC_LISTENER_CREATE_INACTIVE,
^(xpc_session_t sess){
printf("Incoming Session: %s\n", xpc_session_copy_description(sess));
xpc_session_set_incoming_message_handler(sess,
^(xpc_object_t mess) {
xpc_object_t repl = xpc_dictionary_create_empty();
xpc_dictionary_set_string(repl, "test", "test");
xpc_rich_error_t send_repl_err = xpc_session_send_message(sess, repl);
if (send_repl_err != NULL) printf("Send Reply Error: %s\n",
xpc_rich_error_copy_description(send_repl_err));
});
xpc_rich_error_t sess_ac_err = NULL;
xpc_session_activate(sess, &sess_ac_err);
if (sess_ac_err != NULL) printf("Session Activate: %s\n",
xpc_rich_error_copy_description(sess_ac_err));
},
&lis_err);
if (lis_err != NULL) {
printf("Listener Error: %s\n", xpc_rich_error_copy_description(lis_err));
xpc_release(lis_err);
}
xpc_rich_error_t lis_ac_err = NULL;
xpc_listener_activate(listener, &lis_ac_err);
if (lis_ac_err != NULL) {
printf("Listener Activate Error: %s\n", xpc_rich_error_copy_description(lis_ac_err));
xpc_release(lis_ac_err);
}
dispatch_main();
}
Regarding the Background Assets capability on iOS:
In the install scenario, resources defined as the "install" type are incorporated into the App Store download progress. Do resources of the "update" type in the update scenario also get incorporated into the App Store download progress in the same way?
If an exception occurs during the download of install-type resources and the download cannot proceed further, will the system no longer actively block users from launching the app and instead enable the launch button?
Currently, if a user has enabled automatic updates on their device, after the app is updated and released on the App Store, will the Background Assets download start immediately once the automatic update completes? Or does Background Assets have its own built-in scheduling logic that prevents it from running concurrently with the automatic update?
I'm developing a macOS application that tracks the duration of a user's session using a timer, which is displayed both in the main window and in an menu bar extra view. I have a couple of questions regarding the timer's behavior:
What happens to the timer if the user closes the application's window (causing the app to become inactive) but does not fully quit it? Does the timer continue to run, pause, or behave in some other way?
Will the app nap feature stop the timer when app is in-active state?
When the application is inactive and the system is either in sleep mode or locked, does the timer’s tolerance get affected? In other words, will the timer fire with any additional delay compared to its scheduled time under these conditions?
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.
I'm developing a macOS application that tracks the duration of a user's session using a timer, which is displayed both in the main window and in an menu bar extra view. I have a couple of questions regarding the timer's behavior:
What happens to the timer if the user closes the application's window (causing the app to become inactive) but does not fully quit it? Does the timer continue to run, pause, or behave in some other way?
Will the app nap feature stop the timer when app is in-active state?
Issue:
Background downloads using the flutter_downloader package work perfectly in debug mode and release mode when run directly from Xcode (plugged in).
However, when I create an archive build and install the app separately (via TestFlight or direct IPA install), the background download stops working as soon as the app is minimized.
✅ What I’ve already done
Info.plist
<key>UIBackgroundModes</key>
<array>
<string>remote-notification</string>
<string>fetch</string>
<string>processing</string>
<string>audio</string>
<string>push-to-talk</string>
</array>
AppDelegate.swift
import UIKit
import Flutter
import Firebase
import flutter_downloader
import BackgroundTasks
@main
@objc class AppDelegate: FlutterAppDelegate {
static let backgroundChannel = "com.example.app/background_service"
private var backgroundCompletionHandler: (() -> Void)?
override func application(
_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
) -> Bool {
FirebaseApp.configure()
GeneratedPluginRegistrant.register(with: self)
FlutterDownloaderPlugin.setPluginRegistrantCallback(registerPlugins)
if #available(iOS 10.0, *) {
UNUserNotificationCenter.current().delegate = self
}
if #available(iOS 13.0, *) {
registerBackgroundTask()
}
return super.application(application, didFinishLaunchingWithOptions: launchOptions)
}
@available(iOS 13.0, *)
private func registerBackgroundTask() {
BGTaskScheduler.shared.register(
forTaskWithIdentifier: "com.example.app.process_download_queue",
using: nil
) { [weak self] task in
guard let self = self else { return }
self.handleDownloadQueueTask(task: task as! BGProcessingTask)
}
}
@available(iOS 13.0, *)
private func handleDownloadQueueTask(task: BGProcessingTask) {
scheduleNextDownloadTask()
let headlessEngine = FlutterEngine(name: "BackgroundTaskEngine", project: nil, allowHeadlessExecution: true)
headlessEngine.run()
let channel = FlutterMethodChannel(
name: AppDelegate.backgroundChannel,
binaryMessenger: headlessEngine.binaryMessenger
)
task.expirationHandler = {
channel.invokeMethod("backgroundTaskExpired", arguments: nil)
}
channel.invokeMethod("processNextInBackground", arguments: nil) { result in
task.setTaskCompleted(success: (result as? Bool) ?? false)
}
}
override func application(
_ application: UIApplication,
handleEventsForBackgroundURLSession identifier: String,
completionHandler: @escaping () -> Void
) {
self.backgroundCompletionHandler = completionHandler
super.application(application, handleEventsForBackgroundURLSession: identifier, completionHandler: completionHandler)
}
override func applicationDidEnterBackground(_ application: UIApplication) {
if #available(iOS 13.0, *) {
scheduleNextDownloadTask()
}
}
@available(iOS 10.0, *)
override func userNotificationCenter(
_ center: UNUserNotificationCenter,
willPresent notification: UNNotification,
withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void
) {
if #available(iOS 14.0, *) {
completionHandler([.list, .banner, .badge, .sound])
} else {
completionHandler([.alert, .badge, .sound])
}
}
@available(iOS 10.0, *)
override func userNotificationCenter(
_ center: UNUserNotificationCenter,
didReceive response: UNNotificationResponse,
withCompletionHandler completionHandler: @escaping () -> Void
) {
completionHandler()
}
}
// MARK: - Helper
@available(iOS 13.0, *)
func scheduleNextDownloadTask() {
let request = BGProcessingTaskRequest(identifier: "com.example.app.process_download_queue")
request.requiresNetworkConnectivity = true
request.requiresExternalPower = false
request.earliestBeginDate = Date(timeIntervalSinceNow: 60)
do {
try BGTaskScheduler.shared.submit(request)
print("BGTask: Download queue processing task scheduled successfully.")
} catch {
print("BGTask: Could not schedule download queue task: \(error)")
}
}
private func registerPlugins(registry: FlutterPluginRegistry) {
if !registry.hasPlugin("FlutterDownloaderPlugin") {
FlutterDownloaderPlugin.register(with: registry.registrar(forPlugin: "FlutterDownloaderPlugin")!)
}
}
🧩 Observations
Background download works correctly when:
The app is plugged in and run via Xcode (release/debug)
It stops working when:
The app is installed from an archived build (IPA/TestFlight) and minimized
All entitlements and background modes are properly added.
Provisioning profile includes required background modes.
❓Question
Is there any known limitation or signing difference between Xcode run and archived release builds that could cause URLSession background tasks not to trigger?
Has anyone faced a similar issue when using flutter_downloader on iOS 13+ with BGTaskScheduler or URLSession background configuration?
Any help or working setup example for production/TestFlight would be appreciated.
I'm using libxpc in a C server and Swift client. I set up a code-signing requirement in the server using xpc_connection_set_peer_code_signing_requirement(). However, when the client doesn't meet the requirement, the server just closes the connection, and I get XPC_ERROR_CONNECTION_INTERRUPTED on the client side instead of XPC_ERROR_PEER_CODE_SIGNING_REQUIREMENT, making debugging harder.
What I want:
To receive XPC_ERROR_PEER_CODE_SIGNING_REQUIREMENT on the client when code-signing fails, for better debugging.
What I’ve tried:
Using xpc_connection_set_peer_code_signing_requirement(), but it causes the connection to be dropped immediately.
Questions:
Why does the server close the connection without sending the expected error?
How can I receive the correct error on the client side?
Are there any other methods for debugging code-signing failures with libxpc?
Thanks for any insights!
Topic:
App & System Services
SubTopic:
Processes & Concurrency
Tags:
XPC
Signing Certificates
Code Signing
An XPC service’s process has a system-managed lifecycle: the process is launched on-demand when another process tries to connect to it, and the system can decide to kill it when system resources are low. XPC services can tell the system when they shouldn’t be killed using xpc_transaction_begin/end.
Do extensions created with ExtensionFoundation and/or ExtensionKit have the same behavior?
I'm try to monitor all processes by ES client. But I found the process name is different from the Activity Monitor displayed. As shown in the picture below, there are ShareSheetUI(Pages) and ShareSheetUI(Finder) processes in Activity Monitor, but I can only get the same name ShareSheetUI, I thought of many ways to display the name in parentheses, but nothing worked, so there is a way to display the process name like Activity Monitor?
I am developing the application in Mac. My requirement is to start the application automatically when user login.
I have tried adding the plist file in launch agents, But it doesn't achieve my requirement.
Please find the code added in the launch agents
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>com.sftk.secure</string>
<key>ProgramArguments</key>
<array>
<string>/Applications/Testing.app/Contents/MacOS/Testing</string>
</array>
<key>RunAtLoad</key>
<true/>
<key>KeepAlive</key>
<false/>
</dict>
</plist>
I have tried by adding manually in the setting, but it was opened sometimes and closed suddenly. On open manually it works.
Please provide a solution to start the application automatically on system starts
Hi everyone,
We’re developing a macOS SwiftUI app that uses a local Swift Package (CasSherpaCore) to invoke an external compiled binary (sherpa-onnx-offline-tts) for text-to-speech synthesis using system calls. The package works flawlessly when tested from terminal or via a lightweight test C program.
However, when we invoke it from a SwiftUI app (even with Full Disk Access granted to Xcode and Terminal), we consistently get the error:
sh: /Users/xxxxxxxxxxx/SherpaONNX/sherpa-onnx/build/bin/sherpa-onnx-offline-tts: Operation not permitted
We’ve tried:
Granting Full Disk Access to Xcode and Terminal.
Removing the quarantine flag with xattr -d com.apple.quarantine.
Setting executable permission via chmod +x.
Using both system() and Process in C and Swift contexts.
Testing within a Swift Package that’s integrated into the app as a local dependency.
Running the command manually from terminal (works perfectly).
It appears that macOS (or Xcode’s runtime sandbox) is restricting execution of binaries from certain locations or contexts when launched via system() inside the app.
Questions:
Is there a specific entitlement or configuration that allows execution of local binaries from a SwiftUI macOS app?
Is this related to System Integrity Protection (SIP) or a hardened runtime limitation?
Are there best practices or alternative approaches to safely execute local TTS binaries from within a Swift app?
Any help would be deeply appreciated. This is a core feature in our project and we’re stuck at this point. Thank you so much in advance!
Hello, aspiring programmer here.
I am developing a StepCounter APP, which keeps track of how many steps I have taken and sends to an MQTT server. I am trying to make this happen even while the app is not in focus, but so far I have not been able to get this working.
First tried with silent background music, which seemed pretty inconsistent and inpractical, since I usually play youtube videoes while walking, making the app stop with its silent audio. Then tried GPS, which didnt really do anything (could be implementation problem).
Has anyone made background processing work for their apps?
My app is for personal use currently, so distribution won't be a problem. It registers a privileged helper using SMAppService, and I was wondering whether there is a way to customize the authorization dialog that the system presents to the user.
Hello, aspiring programmer here.
I am developing a StepCounter APP, which keeps track of how many steps I have taken and sends to an MQTT server. I am trying to make this happen even while the app is not in focus, but so far I have not been able to get this working.
First tried with silent background music, which seemed pretty inconsistent and inpractical, since I usually play youtube videoes while walking, making the app stop with its silent audio. Then tried GPS, which didnt really do anything (could be implementation problem).
Has anyone made background processing work for their apps?
My app uses SMAppService to register a privileged helper, the helper registers without errors, and can be seen in System Settings. I can get a connection to the service and a remote object proxy, but the helper process cannot be found in Activity Monitor and the calls to the proxy functions seem to always fail without showing any specific errors. What could be causing this situation?