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?
Processes & Concurrency
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I have BGProcessingTask & BGAppRefreshTask working fine. The main purpose of my use of BGProcessingTask is to upload a file to AWS S3 using multipart/form-data. I have found that any file above about 2.5MB times out after running almost four minutes. If I run the same RESTful api using curl or Postman, I can upload a 25MB file in 3 seconds or less.
I have tried to deliberately set .earliestBeginDate to 01:00 or 02:00 local time on the iPhone, but that does not seem to help.
I use the delegate (yes, I am writing in Objective C) - URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend: and find that the iOS system uploads about 140kB every 15 seconds or so.
I am looking for recommendations or insight into how I might enable uploads of 25MB files. I would be happy it I could do just one a day for my use case.
I provide code on how I set up the NSURLSession and NSURLSessionDownloadTask, as it is my guess that if there is something that needs to be modified it is there.
I have to believe there is a solution for this since I read in many posts here and in StackOverflow how developers are using this functionality for uploading many, many files.
NSURLSessionConfiguration *sConf = [NSURLSessionConfiguration backgroundSessionConfigurationWithIdentifier:bkto.taskIdentifier];
sConf.URLCache = [NSURLCache sharedURLCache];
sConf.waitsForConnectivity = YES;
sConf.allowsCellularAccess = NO;
sConf.networkServiceType = NSURLNetworkServiceTypeVideot;
sConf.multipathServiceType = NSURLSessionMultipathServiceTypeNone;
sConf.discretionary = YES;
sConf.timeoutIntervalForResource = kONEHOURINTERVAL;
sConf.timeoutIntervalForRequest = kONEMINUTEINTERVAL;
sConf.allowsExpensiveNetworkAccess = NO ;
sConf.allowsConstrainedNetworkAccess = NO;
sConf.sessionSendsLaunchEvents = YES;
myURLSession = [NSURLSession sessionWithConfiguration:sConf delegate:self delegateQueue:nil];
And then later in the code...
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:pth]];
request.HTTPMethod = kHTTPPOST;
request.HTTPBody = [NSData my body data];
request.timeoutInterval = 60;
[request setValue:@"*/*" forHTTPHeaderField:@"Accept"];
[request setValue:@"en-us,en" forHTTPHeaderField:@"Accept-Language"];
[request setValue:@"gzip, deflate, br" forHTTPHeaderField:@"Accept-Encoding"];
[request setValue:@"ISO-8859-1,utf-8" forHTTPHeaderField:@"Accept-Charset"];
[request setValue:@"600" forHTTPHeaderField:@"Keep-Alive"];
[request setValue:@"keep-alive" forHTTPHeaderField:@"Connection"];
NSString *contType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",bnd];
[request setValue:contType forHTTPHeaderField:@"Content-Type"];
[request addValue:[NSString stringWithFormat:@"%lu",(unsigned long)myData.length] forHTTPHeaderField:@"Content-Length"];
and here are a few lines from my logs to show the infrequent multi-part uploads of only small chunks of data by the iOS system:
-[BKSessionManager URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:]: bytesSent = 393,216
-[BKSessionManager URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:]: totalBytesSent = 393,216
-[BKSessionManager URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:]: task = BackgroundDownloadTask <76A81A80-4703-4686-8742-A0048EB65108>.<2>, time Fri Mar 7 16:25:27 2025
-[BKSessionManager URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:]: bytesSent = 131,072
-[BKSessionManager URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:]: totalBytesSent = 524,288
-[BKSessionManager URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:]: task = BackgroundDownloadTask <76A81A80-4703-4686-8742-A0048EB65108>.<2>, time Fri Mar 7 16:25:42 2025
-[BKSessionManager URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:]: bytesSent = 131,072
-[BKSessionManager URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:]: totalBytesSent = 655,360
-[BKSessionManager URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:]: task = BackgroundDownloadTask <76A81A80-4703-4686-8742-A0048EB65108>.<2>, time Fri Mar 7 16:25:56 2025
-[BKSessionManager URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:]: bytesSent = 131,072
-[BKSessionManager URLSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:]: totalBytesSent = 786,432
I'm a developer using Lazarus Pascal, so converting ObjC and Swift comes with its challenges.
I'm trying to figure how to properly use SMAppService to add my application as a login item for the App Store.
I have learned that the old method (< macOS 13) uses a helper tool, included in the app bundle, which calls the now deprecated SMLoginItemSetEnabled. Now this is already quite a pain to deal with if you're not using XCode, not to mention converting the headers being rather complicated when you're not experienced with doing this.
The "new" method (as of macOS 13) is using SMAppService.
Can anyone explain how to use this? The documentation (for me anyway) is a not very clear about that and neither are examples that can be found all over the Internet.
My main question is:
Can I now use the SMAppService functions to add/remove a login item straight in my application, or is a helper tool still required?
This week I’m handling a DTS incident from a developer who wants to escalate privileges in their app. This is a tricky problem. Over the years I’ve explained aspects of this both here on DevForums and in numerous DTS incidents. Rather than do that again, I figured I’d collect my thoughts into one place and share them here.
If you have questions or comments, please start a new thread with an appropriate tag (Service Management or XPC are the most likely candidates here) in the App & System Services > Core OS topic area.
Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"
BSD Privilege Escalation on macOS
macOS has multiple privilege models. Some of these were inherited from its ancestor platforms. For example, Mach messages has a capability-based privilege model. Others were introduced by Apple to address specific user scenarios. For example, macOS 10.14 and later have mandatory access control (MAC), as discussed in On File System Permissions.
One of the most important privilege models is the one inherited from BSD. This is the classic users and groups model. Many subsystems within macOS, especially those with a BSD heritage, use this model. For example, a packet tracing tool must open a BPF device, /dev/bpf*, and that requires root privileges. Specifically, the process that calls open must have an effective user ID of 0, that is, the root user. That process is said to be running as root, and escalating BSD privileges is the act of getting code to run as root.
IMPORTANT Escalating privileges does not bypass all privilege restrictions. For example, MAC applies to all processes, including those running as root. Indeed, running as root can make things harder because TCC will not display UI when a launchd daemon trips over a MAC restriction.
Escalating privileges on macOS is not straightforward. There are many different ways to do this, each with its own pros and cons. The best approach depends on your specific circumstances.
Note If you find operations where a root privilege restriction doesn’t make sense, feel free to file a bug requesting that it be lifted. This is not without precedent. For example, in macOS 10.2 (yes, back in 2002!) we made it possible to implement ICMP (ping) without root privileges. And in macOS 10.14 we removed the restriction on binding to low-number ports (r. 17427890). Nice!
Decide on One-Shot vs Ongoing Privileges
To start, decide whether you want one-shot or ongoing privileges. For one-shot privileges, the user authorises the operation, you perform it, and that’s that. For example, if you’re creating an un-installer for your product, one-shot privileges make sense because, once it’s done, your code is no longer present on the user’s system.
In contrast, for ongoing privileges the user authorises the installation of a launchd daemon. This code always runs as root and thus can perform privileged operations at any time.
Folks often ask for one-shot privileges but really need ongoing privileges. A classic example of this is a custom installer. In many cases installation isn’t a one-shot operation. Rather, the installer includes a software update mechanism that needs ongoing privileges. If that’s the case, there’s no point dealing with one-shot privileges at all. Just get ongoing privileges and treat your initial operation as a special case within that.
Keep in mind that you can convert one-shot privileges to ongoing privileges by installing a launchd daemon.
Just Because You Can, Doesn’t Mean You Should
Ongoing privileges represent an obvious security risk. Your daemon can perform an operation, but how does it know whether it should perform that operation?
There are two common ways to authorise operations:
Authorise the user
Authorise the client
To authorise the user, use Authorization Services. For a specific example of this, look at the EvenBetterAuthorizationSample sample code.
Note This sample hasn’t been updated in a while (sorry!) and it’s ironic that one of the things it demonstrates, opening a low-number port, no longer requires root privileges. However, the core concepts demonstrated by the sample are still valid.
The packet trace example from above is a situation where authorising the user with Authorization Services makes perfect sense. By default you might want your privileged helper tool to allow any user to run a packet trace. However, your code might be running on a Mac in a managed environment, where the site admin wants to restrict this to just admin users, or just a specific group of users. A custom authorisation right gives the site admin the flexibility to configure authorisation exactly as they want.
Authorising the client is a relatively new idea. It assumes that some process is using XPC to request that the daemon perform a privileged operation. In that case, the daemon can use XPC facilities to ensure that only certain processes can make such a request.
Doing this securely is a challenge. For specific API advice, see this post.
WARNING This authorisation is based on the code signature of the process’s main executable. If the process loads plug-ins [1], the daemon can’t tell the difference between a request coming from the main executable and a request coming from a plug-in.
[1] I’m talking in-process plug-ins here. Plug-ins that run in their own process, such as those managed by ExtensionKit, aren’t a concern.
Choose an Approach
There are (at least) seven different ways to run with root privileges on macOS:
A setuid-root executable
The sudo command-line tool
The authopen command-line tool
AppleScript’s do shell script command, passing true to the administrator privileges parameter
The osascript command-line tool to run an AppleScript
The AuthorizationExecuteWithPrivileges routine, deprecated since macOS 10.7
The SMJobSubmit routine targeting the kSMDomainSystemLaunchd domain, deprecated since macOS 10.10
The SMJobBless routine, deprecated since macOS 13
An installer package (.pkg)
The SMAppService class, a much-needed enhancement to the Service Management framework introduced in macOS 13
Note There’s one additional approach: The privileged file operation feature in NSWorkspace. I’ve not listed it here because it doesn’t let you run arbitrary code with root privileges. It does, however, have one critical benefit: It’s supported in sandboxed apps. See this post for a bunch of hints and tips.
To choose between them:
Do not use a setuid-root executable. Ever. It’s that simple! Doing that is creating a security vulnerability looking for an attacker to exploit it.
If you’re working interactively on the command line, use sudo, authopen, and osascript as you see fit.
IMPORTANT These are not appropriate to use as API. Specifically, while it may be possible to invoke sudo programmatically under some circumstances, by the time you’re done you’ll have code that’s way more complicated than the alternatives.
If you’re building an ad hoc solution to distribute to a limited audience, and you need one-shot privileges, use either AuthorizationExecuteWithPrivileges or AppleScript.
While AuthorizationExecuteWithPrivileges still works, it’s been deprecated for many years. Do not use it in a widely distributed product.
The AppleScript approach works great from AppleScript, but you can also use it from a shell script, using osascript, and from native code, using NSAppleScript. See the code snippet later in this post.
If you need one-shot privileges in a widely distributed product, consider using SMJobSubmit. While this is officially deprecated, it’s used by the very popular Sparkle update framework, and thus it’s unlikely to break without warning.
If you only need escalated privileges to install your product, consider using an installer package. That’s by far the easiest solution to this problem.
Keep in mind that an installer package can install a launchd daemon and thereby gain ongoing privileges.
If you need ongoing privileges but don’t want to ship an installer package, use SMAppService. If you need to deploy to older systems, use SMJobBless.
For instructions on using SMAppService, see Updating helper executables from earlier versions of macOS.
For a comprehensive example of how to use SMJobBless, see the EvenBetterAuthorizationSample sample code. For the simplest possible example, see the SMJobBless sample code. That has a Python script to help you debug your setup. Unfortunately this hasn’t been updated in a while; see this thread for more.
Hints and Tips
I’m sure I’ll think of more of these as time goes by but, for the moment, let’s start with the big one…
Do not run GUI code as root. In some cases you can make this work but it’s not supported. Moreover, it’s not safe. The GUI frameworks are huge, and thus have a huge attack surface. If you run GUI code as root, you are opening yourself up to security vulnerabilities.
Appendix: Running an AppleScript from Native Code
Below is an example of running a shell script with elevated privileges using NSAppleScript.
WARNING This is not meant to be the final word in privilege escalation. Before using this, work through the steps above to see if it’s the right option for you.
Hint It probably isn’t!
let url: URL = … file URL for the script to execute …
let script = NSAppleScript(source: """
on open (filePath)
if class of filePath is not text then
error "Expected a single file path argument."
end if
set shellScript to "exec " & quoted form of filePath
do shell script shellScript with administrator privileges
end open
""")!
// Create the Apple event.
let event = NSAppleEventDescriptor(
eventClass: AEEventClass(kCoreEventClass),
eventID: AEEventID(kAEOpenDocuments),
targetDescriptor: nil,
returnID: AEReturnID(kAutoGenerateReturnID),
transactionID: AETransactionID(kAnyTransactionID)
)
// Set up the direct object parameter to be a single string holding the
// path to our script.
let parameters = NSAppleEventDescriptor(string: url.path)
event.setDescriptor(parameters, forKeyword: AEKeyword(keyDirectObject))
// The `as NSAppleEventDescriptor?` is required due to a bug in the
// nullability annotation on this method’s result (r. 38702068).
var error: NSDictionary? = nil
guard let result = script.executeAppleEvent(event, error: &error) as NSAppleEventDescriptor? else {
let code = (error?[NSAppleScript.errorNumber] as? Int) ?? 1
let message = (error?[NSAppleScript.errorMessage] as? String) ?? "-"
throw NSError(domain: "ShellScript", code: code, userInfo: nil)
}
let scriptResult = result.stringValue ?? ""
Revision History
2025-03-24 Added info about authopen and osascript.
2024-11-15 Added info about SMJobSubmit. Made other minor editorial changes.
2024-07-29 Added a reference to the NSWorkspace privileged file operation feature. Made other minor editorial changes.
2022-06-22 First posted.
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?
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?
I have used C APIs to create a XPC server(mach service) as a launch daemon. I use dispatch_source_create () followed by dispatch_resume() to start the listener. I dont have any code for cleaning up memory.
I want to make sure that the XPC server is shutdown gracefully, without any memory leaks.
I know that launchd handles the cycle and the XPC framework takes care of XPC objects.
But do I need to do additional cleanup when the XPC listener is shutdown ?
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();
}
Hi. I'm trying to learn macOS app development. i'm trying to run unix commands:
func execute(_ command: String) throws -> String {
let process = Process()
let pipe = Pipe()
process.executableURL = URL(fileURLWithPath: "/bin/bash")
process.arguments = ["-c", command]
process.standardOutput = pipe
// process.standardError
try process.run()
process.waitUntilExit()
guard let data = try pipe.fileHandleForReading.readToEnd() else {
throw CommandError.readError
}
guard let output = String(data: data, encoding: .utf8) else {
throw CommandError.invalidData
}
process.waitUntilExit()
guard process.terminationStatus == 0 else {
throw CommandError.commandFailed(output)
}
return output
}
when try to run "pgrep" in sandbox mode ON, i get:
sysmon request failed with error: sysmond service not found error. if i turn it off it works. i don't know what to do. anyone can help me out?
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?
I'm using Swift 6 and tasks to concurrently process multiple PDF files for rendering, and it's working well.
But currently I'm manually limiting the number of simultaneous tasks to 2 out of fear that the system might run many tasks concurrently without having enough RAM to do the PDF processing.
Testing on a variety of devices, I've tried increasing the task limit and haven't seen any crashes, but I'm quite concerned about the possibility. Any given device might be using a lot of RAM at any moment, and any given PDF might strain resources more than the average PDF.
Is there a recommended technique for handling this kind of scenario?
Should I not worry about it and just go ahead and start a high number of tasks, trusting that the system won't run too many concurrently and therefore won't run out of RAM?
Topic:
App & System Services
SubTopic:
Processes & Concurrency
Desired Behavior
I want the app to be able to handle multiple Push-to-Start notifications even when it is completely terminated. Each Live Activity should:
Be successfully displayed upon receiving a Push-to-Start notification.
Trigger background tasks to send its update token to the server, regardless of the time interval between notifications.
Problem
I am facing an issue with iOS Live Activities when using Push-to-Start notifications to trigger Live Activities in an app that has been completely terminated. Here’s the detailed scenario:
When the app is completely terminated and I send the first Push-to-Start notification:
The Live Activity is successfully displayed.
didFinishLaunchingWithOptions` is triggered, and background tasks execute correctly, including sending the update token to the server.
When I send consecutive Push-to-Start notifications in quick succession (e.g., within a few seconds or minutes):
Both notifications successfully display their respective Live Activities.
Background tasks are executed correctly for both notifications.
However, when there is a longer interval (e.g., 10 minutes) between two Push-to-Start notifications:
The first notification works perfectly—it displays the Live Activity, triggers didFinishLaunchingWithOptions, and executes background tasks.
The second notification successfully displays the Live Activity but fails to execute any background tasks, such as sending the update token to the server.
My HypothesisI
suspect that iOS might impose a restriction where background runtime for Push-to-Start notifications can only be granted once within a certain time frame after the app has been terminated.
Any insights into why this issue might be occurring or how to ensure consistent background task execution for multiple Push-to-Start notifications would be greatly appreciated!
We are building a 'server' application that can either run as a daemon or can run in background without showing any GUI. Basically, the end user can either configure this to run as a daemon so that it can be tied to the user's session or will launch the process which user will start and quit as needed.
I wanted to understand what is the recommended mechanism for such an application from Apple -
Should this application be built as a macOS Bundle ? Apple documentation also says that we should not daemonize the process by calling fork. Hence if we create a unix-style executable, will I not need to fork to make it run in a detached state when I launch the executable via double-click ? [Reference Link]
Is it fine to have an application on macOS which is a bundle but does not show any UI when launched by double click on the app-icon or via 'open'? While we have been able to achieve this by using NSApplicationMain and not showing the UI, was wondering if using CFRunLoop is best for this case as it is a non-gui application.
If we can get the right documentation link or recommendations on how we should build such an application which can run in a non-gui mode and also in a daemonized manner, it will help us.
Should the application be always built as a macos bundle or should it be a unix-style executable to support both the cases - by the same application/product and how should we look at the distribution of such applications.
I am developing a macOS non-interactive macOS application which does not show any ui.
i want to block main thread and do all the work on worker thread . Once done with work in worker thread, want to unblock main thread by exiting event loop to terminate application.
Because i dont want to show any UI or use any Foundation/Cocoa functionality, i am thinking of using CFRunLoop to block main thread from exiting until i finish my work in worker thread.
When i tried this in a project, I am able to finish work in worker thread after block main thread using CFRunLoop.
I also want this application to be a bundled application, which can be launched by double clicking on application bundle . But when i tried it in my xcode project by launching it using double clicking on application bundle, application keeps on toggling/bouncing in the dock menu with a status "Not responding". Although i am able to complete my work in worker thread.
import Foundation
let runLoop = CFRunLoopGetCurrent()
func workerTask() {
DispatchQueue.global().async {
print("do its work")
sleep(5) // do some work
print("calling exit event loop")
CFRunLoopStop(runLoop)
print ("unblocking main thread")
}
}
workerTask ()
// blocking main thread
print ("blocked main thread")
CFRunLoopRun()
print ("exit")
Why i am getting this application bouncing in doc menu behavior ? I tried by using NSApplicationMain instead of CFRunLoop in my project, in that case i didnt get this behavior .
Does NSApplicationMain does some extra work before starting NSRunLoop which i am not doing while using CFRunLoop, which is showing this toggling/Bouncing application icon in Dock menu ?
or Is this bouncing app icon issue is related to run loop i am using which is CFRunLoop ?
Note : If i dont use a bundled application and use a commandline application then i am able to do all steps in worker thread and exit main thread as i wanted after finishing my work . But i need to do all this in application which can be launched using double clicking (bundled applcation).
If not by using CFRunLoop, then how can i achive this ? - Create a application which shows no UI and do all work in worker thread while main thread is blocked. Once work is done unblock main thread and exit. And user should be able to launch application using double click the application icon.
When using the old withTaskCancellationHandler(operation:onCancel:isolation:) to run background tasks, you were notified that the background task gets cancelled via the handler being called. SwiftUI provides the backgroundTask(_:action:) modifier which looks quite handy. However how can I check if the background task will be cancelled to avoid being terminated by the system?
I have tried to check that via Task.isCancelled but this always returns false no matter what.
Is this not possible when using the modifier in which case I should file a bug report?
Thanks for your help
Topic:
App & System Services
SubTopic:
Processes & Concurrency
Tags:
SwiftUI
Background Tasks
WidgetKit
Hello Apple Developer Community,
I am developing a medical app that is classified as Class B according to FDA regulations. The app connects to a medical device using Bluetooth Low Energy (BLE) to collect critical medical data such as ECG readings. To ensure accurate data collection and maintain the quality of the medical readings, the app needs to wake up every five minutes in the background and perform tasks for approximately 30 seconds.
I understand that iOS has strict limitations on background execution to preserve battery and system performance. However, due to the medical nature of the app and the need for periodic data collection, I am seeking guidance on the following:
If I can provide documentation that the app is associated with an FDA-approved Class B medical device, would Apple allow more lenient background task execution policies?
Are there specific APIs, such as BackgroundTasks, CoreBluetooth, or other recommended strategies, that could help me achieve this behavior reliably?
Is there a process to apply for an exception or special consideration for medical apps that require periodic background activity?
Any insights or recommendations would be greatly appreciated. Thank you!
I have implemented a XPC server using C APIs. I want to write unit tests for it.
I came across the following links that use Swift APIs-
Testing and Debugging XPC Code With an Anonymous Listener
TN3113
I have tried to write anonymous listener code and the client code in the same file, using C APIs-
#include <unistd.h>
#include <syslog.h>
#include <pthread.h>
#include <stdio.h>
#include <xpc/xpc.h>
#include <xpc/connection.h>
#include <CoreFoundation/CoreFoundation.h>
static void Anon_Client_Connection_Handler(xpc_connection_t connection, xpc_object_t clientMessage)
{
const char *description = xpc_copy_description(clientMessage);
printf("Event received - %s\n", description);
free((void *)description);
xpc_type_t type = xpc_get_type(clientMessage);
if (type == XPC_TYPE_ERROR)
{
if (clientMessage == XPC_ERROR_CONNECTION_INVALID)
printf("Client_Connection_Handler received invalid connection n");
else if (clientMessage == XPC_ERROR_TERMINATION_IMMINENT)
printf("Client_Connection_Handler received termination notice n");
}
else
{
const char *clientMsg = xpc_dictionary_get_string(clientMessage, "message");
printf("Received from client: %s ", clientMsg);
}
}
static void Anon_Listener_Connection_Handler(xpc_connection_t connection)
{
printf("Anon_Listener_Connection_Handler called, setting up event handler \n");
xpc_connection_set_event_handler(connection, ^(xpc_object_t clientMessage) {
printf("Processing the connection! \n");
Anon_Client_Connection_Handler(connection, clientMessage);
});
xpc_connection_resume(connection);
}
int main(int argc, const char *argv[])
{
xpc_connection_t anon_listener = xpc_connection_create(NULL, NULL);
xpc_connection_set_event_handler(anon_listener, ^(xpc_object_t clientConnection) {
printf("Client tried to connect \n");
Anon_Listener_Connection_Handler(clientConnection);
});
xpc_connection_resume(anon_listener);
printf("\nINFO Anonymous connection resumed");
xpc_object_t anon_endpoint = xpc_endpoint_create(anon_listener);
xpc_connection_t clientConnection = xpc_connection_create_from_endpoint(anon_endpoint);
xpc_object_t message = xpc_dictionary_create(NULL, NULL, 0);
xpc_dictionary_set_string(message, "message", "client's message");
xpc_connection_send_message_with_reply(clientConnection, message, dispatch_get_main_queue(), ^(xpc_object_t event) {
printf("\nINFO inside reply");
const char *description = xpc_copy_description(event);
printf("\nINFO %s",description);
free((void *)description);
});
xpc_release(message);
xpc_release(anon_listener);
printf("\nINFO Releasing listener");
xpc_release(anon_endpoint);
printf("\nINFO Releasing endpoint");
// dispatch_main();
return 0;
}
and this is the output I get
INFO Anonymous connection resumed
INFO Releasing listener
INFO Releasing endpoint
I am not able to connect to the client and exchange messages. Where am I going wrong?
I've been experimenting with the new low-level Swift API for XPC (XPCSession and XPCListener). The ability to send and receive Codable messages is an appealing alternative to making an @objc protocol in order to use NSXPCConnection from Swift — I can easily create an enum type whose cases map onto the protocol's methods.
But our current XPC code validates the incoming connection using techniques similar to those described in Quinn's "Apple Recommended" response to the "Validating Signature Of XPC Process" thread. I haven't been able to determine how to do this with XPCListener; neither the documentation nor the Swift interface have yielded any insight.
The Creating XPC Services article suggests using Xcode's XPC Service template, which contains this code:
let listener = try XPCListener(service: serviceName) { request in
request.accept { message in
performCalculation(with: message)
}
}
The apparent intent is to inspect the incoming request and decide whether to accept it or reject it, but there aren't any properties on IncomingSessionRequest that would allow the service to make that decision. Ideally, there would be a way to evaluate a code signing requirement, or at least obtain the audit token of the requesting process.
(I did notice that a function xpc_listener_set_peer_code_signing_requirement was added in macOS 14.4, but it takes an xpc_listener_t argument and I can't tell whether XPCListener is bridged to that type.)
Am I missing something obvious, or is there a gap in the functionality of XPCListener and IncomingSessionRequest?
Are there any plans to add RBI support (the sending keyword) to the OSAllocatedLock interface? So it could be used with non-sendable objects without surrendering to the unchecked API
Is the title possible ? I tried [[thread valueForKey:@"_private"] valueForKey:@"tid"] but the tid was not kvc compliant. private apis are alright because this is just for testing remote process thread creation. I already have a working method but it has hardcoded assembly so you can't do anything else.
this question is mainly for Quinn (figured he may know something about this)