General:
TN3151 Choosing the right networking API
Networking Overview document — Despite the fact that this is in the archive, this is still really useful.
TLS for App Developers DevForums post
Choosing a Network Debugging Tool documentation
WWDC 2019 Session 712 Advances in Networking, Part 1 — This explains the concept of constrained networking, which is Apple’s preferred solution to questions like How do I check whether I’m on Wi-Fi?
TN3135 Low-level networking on watchOS
Adapt to changing network conditions tech talk
Foundation networking:
DevForums tags: Foundation, CFNetwork
URL Loading System documentation — NSURLSession, or URLSession in Swift, is the recommended API for HTTP[S] on Apple platforms.
Network framework:
DevForums tag: Network
Network framework documentation — Network framework is the recommended API for TCP, UDP, and QUIC on Apple platforms.
Network Extension (including Wi-Fi on iOS):
See Network Extension Resources
Wi-Fi Fundamentals
Wi-Fi on macOS:
DevForums tag: Core WLAN
Core WLAN framework documentation
Wi-Fi Fundamentals
Secure networking:
DevForums tags: Security
Apple Platform Security support document
Preventing Insecure Network Connections documentation — This is all about App Transport Security (ATS).
Available trusted root certificates for Apple operating systems support article
Requirements for trusted certificates in iOS 13 and macOS 10.15 support article
About upcoming limits on trusted certificates support article
Apple’s Certificate Transparency policy support article
Technote 2232 HTTPS Server Trust Evaluation
Technote 2326 Creating Certificates for TLS Testing
QA1948 HTTPS and Test Servers
Miscellaneous:
More network-related DevForums tags: 5G, QUIC, Bonjour
On FTP DevForums post
Using the Multicast Networking Additional Capability DevForums post
Investigating Network Latency Problems DevForums post
Local Network Privacy FAQ DevForums post
Extra-ordinary Networking DevForums post
Share and Enjoy
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Foundation
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Hi everyone,
I'm experiencing crashes that consistently occur on iOS 18 devices, which seem to share a common root cause. I'm hoping for some guidance. Here are the details of the crashes as received from Xcode Organizer:
Crash Trace 1:
0 CoreFoundation 0x0000000192c50e54 CF_IS_OBJC + 76 (CFRuntime.c:461)
1 CoreFoundation 0x0000000192c4dd3c CFRelease + 60 (CFRuntime.c:1202)
2 CoreFoundation 0x0000000192d015e0 _signalEventSync + 252 (CFStream.c:636)
3 CoreFoundation 0x0000000192d53050 ___signalEventQueue_block_invoke + 28 (CFStream.c:646)
4 libdispatch.dylib 0x000000019a93c370 _dispatch_call_block_and_release + 32 (init.c:1549)
5 libdispatch.dylib 0x000000019a93e0d0 _dispatch_client_callout + 20 (object.m:576)
6 libdispatch.dylib 0x000000019a9456d8 _dispatch_lane_serial_drain + 744 (queue.c:3934)
7 libdispatch.dylib 0x000000019a9461e0 _dispatch_lane_invoke + 380 (queue.c:4025)
8 libdispatch.dylib 0x000000019a951258 _dispatch_root_queue_drain_deferred_wlh + 288 (queue.c:7193)
9 libdispatch.dylib 0x000000019a950aa4 _dispatch_workloop_worker_thread + 540 (queue.c:6787)
10 libsystem_pthread.dylib 0x000000021a00fc7c _pthread_wqthread + 288 (pthread.c:2696)
11 libsystem_pthread.dylib 0x000000021a00c488 start_wqthread + 8 (:-1)
Crash Trace 2:
0 libobjc.A.dylib 0x0000000186f33c20 objc_msgSend + 32
1 CoreFoundation 0x0000000189cb14b8 _inputStreamCallbackFunc + 36 (CFObject.m:1952)
2 CoreFoundation 0x0000000189cb0aa8 _signalEventSync + 216 (CFStream.c:626)
3 CoreFoundation 0x0000000189d01e30 ___signalEventQueue_block_invoke + 28 (CFStream.c:646)
4 libdispatch.dylib 0x0000000191948370 _dispatch_call_block_and_release + 32 (init.c:1549)
5 libdispatch.dylib 0x000000019194a0d0 _dispatch_client_callout + 20 (object.m:576)
6 libdispatch.dylib 0x00000001919516d8 _dispatch_lane_serial_drain + 744 (queue.c:3934)
7 libdispatch.dylib 0x00000001919521e0 _dispatch_lane_invoke + 380 (queue.c:4025)
8 libdispatch.dylib 0x000000019195d258 _dispatch_root_queue_drain_deferred_wlh + 288 (queue.c:7193)
9 libdispatch.dylib 0x000000019195caa4 _dispatch_workloop_worker_thread + 540 (queue.c:6787)
10 libsystem_pthread.dylib 0x000000021214bc7c _pthread_wqthread + 288 (pthread.c:2696)
11 libsystem_pthread.dylib 0x0000000212148488 start_wqthread + 8
Crash Trace 3:
0 libobjc.A.dylib 0x00000001941d9ce8 objc_loadWeakRetained + 156 (NSObject.mm:525)
1 CoreFoundation 0x0000000196d0a0f4 _outputStreamCallbackFunc + 36 (CFObject.m:1960)
2 CoreFoundation 0x0000000196d09724 _signalEventSync + 216 (CFStream.c:626)
3 CoreFoundation 0x0000000196d07948 ___signalEventQueue_block_invoke + 28 (CFStream.c:646)
4 libdispatch.dylib 0x000000019e9de248 _dispatch_call_block_and_release + 32 (init.c:1549)
5 libdispatch.dylib 0x000000019e9dffa8 _dispatch_client_callout + 20 (object.m:576)
6 libdispatch.dylib 0x000000019e9e75cc _dispatch_lane_serial_drain + 768 (queue.c:3934)
7 libdispatch.dylib 0x000000019e9e8124 _dispatch_lane_invoke + 380 (queue.c:4025)
8 libdispatch.dylib 0x000000019e9f338c _dispatch_root_queue_drain_deferred_wlh + 288 (queue.c:7193)
9 libdispatch.dylib 0x000000019e9f2bd8 _dispatch_workloop_worker_thread + 540 (queue.c:6787)
10 libsystem_pthread.dylib 0x00000002220f3680 _pthread_wqthread + 288 (pthread.c:2696)
11 libsystem_pthread.dylib 0x00000002220f1474 start_wqthread + 8
Notable Points:
All crashes occur only on iOS 18 and newer versions.
The crashes are independent of the Xcode version used to build the app (tested with both Xcode 15.4 and 16).
All crash traces occur in CoreFoundation and seem to have nothing related to our app codebase.
I've attempted to profile the app using Instruments to identify any zombie objects, but the crashes do not manifest on my own devices.
I've referred to discussions, including this forum thread, but have not yet found a solution.
Questions:
Has anyone else encountered similar issues on iOS 18?
Are there specific aspects of iOS 18 that might contribute to these CoreFoundation and libobjc-related crashes?
Would appreciate any suggestions for further diagnostics or potential workarounds.
Thank you for your help!
Hi everyone,
Our app helps users block adult websites to promote focus and digital wellness. During the App Store review, it was flagged under Guideline 2.5.1 for using a VPN profile to block content, with Apple advising us to remove this feature.
Since blocking adult content is core to our app, we’re looking for compliant alternatives:
Can Network Extensions Framework (e.g., NEDNSProxyProvider) be used for on-device filtering?
Would pre-configured safe DNS (e.g., CleanBrowsing) be acceptable?
Are there compliant examples of similar apps?
Any advice on achieving this functionality within Apple’s guidelines would be greatly appreciated.
Thanks!
Hi,
I'm new here. I have an app that I want to refresh a few variables at midnight. What ways can i go about doing this?
I have an AppDelegate started, but I'm not sure how to make it work, yet.
Is there an easy way to make it update?
I have a dedicated render thread with a run loop that has a CADisplayLink added to it (that's the only input source attached). The render thread has this loop in it:
while (_continueRunLoop)
{
[runLoop runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
}
I have some code to stop the render thread that sets _continueRunLoop to false in a block, and then does a pthread_join on the render thread:
[_renderThreadRunLoop performBlock:^{
self->_continueRunLoop = NO;
}];
pthread_join(_renderThread, NULL);
I have noticed recently (iOS 18?) that if the Display Link is paused or invalidated before trying to stop the loop then the pthread_join blocks forever and the render thread is still sitting in the runMode:beforeDate: method. If the display link is still active then it does exit the loop, but only after one more turn of the display link callback.
The most likely explanation I can think of is there has been a behaviour change to performBlock - I believe this used to "consume" a turn of the run loop, and exit the runMode:beforeDate call but now it happens without leaving that function.
I can't find specific mention in the docs of the expected behaviour for performBlock - just that other RunLoop input sources cause the run method to exit, and timer sources do not. Is it possible that the behaviour has changed here?
We run simple iOS Swift code triggered by a remote notification:
UserDefaults.standard.set("key", forKey: "value")
It runs fine when the app is active or inactive, but when the device is closed/locked and the code is triggered, we see a warning in Xcode:
Couldn't write values for keys (
key
) in CFPrefsPlistSource<0x3018802d0> (Domain: com.example, User: kCFPreferencesCurrentUser, ByHost: No, Container: (null), Contents Need Refresh: No): Path not accessible
Not updating lastKnownShmemState in CFPrefsPlistSource<0x3018802d0> (Domain: com.example, User: kCFPreferencesCurrentUser, ByHost: No, Container: (null), Contents Need Refresh: No): 767 -> 767
The issue is that there seems to be no way to catch that warning. The value is set, when it's re-read the value is correct. But the value is never written to disk, so after an app restart/update the value is gone, potentially has an old wrong value.
This code runs without any interruption, it's just showing the warning on iOS 17.7.1 on iPad:
UserDefaults.standard.set("key", forKey: "value")
UserDefaults.standard.synchronize()
print("value: \(UserDefaults.standard.string(forKey: "key"))")
Should there not be a way to catch this, so the code can act accordingly to the circumstances? It would be good to know inside the code that the value is not persisted. I would expect that an exception is generated somewhere which can be caught.
It seems .completeFileProtectionUntilFirstUserAuthentication enables files to be written to disk while the device is closed/locked, can something similar be used for UserDefaults.standard?
I can't seem to find much documentation on the observe(_:options:changeHandler:) method itself. There is this page which has some example use, but there is no link to a 'real' documentation page for the method. Additionally the 'quick help' has a little bit of info, but no parameter definitions or explanation of if/how the return value or changeHandler closure are retained.
We are developing remote desktop app on macOS and recently got user's report about unexpected app crash on macOS 15.2 beta.
On macOS 15.2, there's strange app crash on NSDictionary extension method.
We have narrowed down the steps and create the sample code to duplicate this issue.
Create a cocoa app project in objective-c
Try to access [NSNull null] value in NSDictionary
Use specific method name for NSDictionary extension - (long long)longLongValueForKey:(NSString*)key withDefault:(long long)defaultValue;
The console output for the example app is like below, the method pointer seems to be wrong when trying to get value with longLongValueForKey:withDefault: method to a [NSNull null] object.
********* longLongValueForKey: a: 0
********* longLongValueForKey: b: 100
********* longLongValueForKey: c: 0
********* longLongValueForKey:withDefault: a: -1
********* longLongValueForKey:withDefault: b: 100
********* exception: -[NSNull longLongValue]: unrecognized selector sent to instance 0x7ff8528d9760
********* longLongValueForKey:withDefault1: a: -1
********* longLongValueForKey:withDefault1: b: 100
********* longLongValueForKey:withDefault1: c: -1
Please create an objective-c app project and add below code to reproduce this issue.
//
// AppDelegate.m
// DictionaryTest
//
// Created by splashtop on 2024/11/13.
//
#import "AppDelegate.h"
#define IsNullObject(id) ((!id) || [id isKindOfClass:[NSNull class]])
@interface NSDictionary (extension)
(long long)longLongValueForKey:(NSString*)key;
(long long)longLongValueForKey:(NSString*)key withDefault:(long long)defaultValue;
(long long)longLongValueForKey:(NSString*)key withDefault1:(long long)defaultValue;
@end
@interface AppDelegate ()
@property (strong) IBOutlet NSWindow *window;
@end
@implementation AppDelegate
(void)applicationDidFinishLaunching:(NSNotification *)aNotification {
// Insert code here to initialize your application
NSDictionary* dict = @{
@"b" : @(100),
@"c" : [NSNull null],
};
@try {
long long a = [dict longLongValueForKey:@"a"];
NSLog(@"********* longLongValueForKey: a: %lld", a);
long long b = [dict longLongValueForKey:@"b"];
NSLog(@"********* longLongValueForKey: b: %lld", b);
long long c = [dict longLongValueForKey:@"c"];
NSLog(@"********* longLongValueForKey: c: %lld", c);
}
@catch(NSException* e) {
NSLog(@"********* exception: %@", e);
}
@try {
long long a = [dict longLongValueForKey:@"a" withDefault:-1];
NSLog(@"********* longLongValueForKey:withDefault: a: %lld", a);
long long b = [dict longLongValueForKey:@"b" withDefault:-1];
NSLog(@"********* longLongValueForKey:withDefault: b: %lld", b);
long long c = [dict longLongValueForKey:@"c" withDefault:-1];
NSLog(@"********* longLongValueForKey:withDefault: c: %lld", c);
}
@catch(NSException* e) {
NSLog(@"********* exception: %@", e);
}
@try {
long long a = [dict longLongValueForKey:@"a" withDefault1:-1];
NSLog(@"********* longLongValueForKey:withDefault1: a: %lld", a);
long long b = [dict longLongValueForKey:@"b" withDefault1:-1];
NSLog(@"********* longLongValueForKey:withDefault1: b: %lld", b);
long long c = [dict longLongValueForKey:@"c" withDefault1:-1];
NSLog(@"********* longLongValueForKey:withDefault1: c: %lld", c);
}
@catch(NSException* e) {
NSLog(@"********* exception: %@", e);
}
}
@end
@implementation NSDictionary (extension)
(long long)longLongValueForKey:(NSString*)key {
long long defaultValue = 0;
id value = [self objectForKey:key];
if (IsNullObject(value) || value == [NSNull null]) {
return defaultValue;
}
if ([value isKindOfClass:[NSNumber class]] || [value isKindOfClass:[NSString class]]) {
return [value longLongValue];
}
return defaultValue;
}
(long long)longLongValueForKey:(NSString*)key withDefault:(long long)defaultValue {
id value = [self objectForKey:key];
if (IsNullObject(value) || value == [NSNull null]) {
return defaultValue;
}
if ([value isKindOfClass:[NSNumber class]] || [value isKindOfClass:[NSString class]]) {
return [value longLongValue];
}
return defaultValue;
}
(long long)longLongValueForKey:(NSString*)key withDefault1:(long long)defaultValue {
id value = [self objectForKey:key];
if (IsNullObject(value) || value == [NSNull null]) {
return defaultValue;
}
if ([value isKindOfClass:[NSNumber class]] || [value isKindOfClass:[NSString class]]) {
return [value longLongValue];
}
return defaultValue;
}
@end
error: Error Domain=NSCocoaErrorDomain Code=256 "The application “Google Chrome” could not be launched because a miscellaneous error occurred." UserInfo={NSURL=file:///Applications/Google%20Chrome.app/, NSLocalizedDescription=The application “Google Chrome” could not be launched because a miscellaneous error occurred., NSUnderlyingError=0x6000038376c0 {Error Domain=RBSRequestErrorDomain Code=5 "Launch failed." UserInfo={NSLocalizedFailureReason=Launch failed., NSUnderlyingError=0x6000038349f0 {Error Domain=OSLaunchdErrorDomain Code=112 "Could not find specified domain" UserInfo={NSLocalizedFailureReason=Could not find specified domain}}}}}
I'll describe my crash with an example, looking for some insights into the reason why this is happening.
@objc public protocol LauncherContainer {
var launcher: Launcher { get }
}
@objc public protocol Launcher: UIViewControllerTransitioningDelegate {
func initiateLaunch(url: URL, launchingHotInstance: Bool)
}
@objc final class LauncherContainer: NSObject, LauncherContainer, TabsContentCellTapHandler {
...
init(
...
) {
...
super.init()
}
...
//
// ContentCellTapHandler
//
public func tabContentCellItemDidTap(
tabId: String
) {
...
launcher.initiateNewTabNavigation(
tabId: tabId // Crash happens here
)
}
public class Launcher: NSObject, Launcher, FooterPillTapHandler {
public func initiateNewTabNavigation(tabId: String) {
...
}
}
public protocol TabsContentCellTapHandler: NSObject {
func tabContentCellItemDidTap(
tabId: String,
}
I'll describe my crash with an example, looking for some insights into the reason why this is happening.
@objc public protocol LauncherContainer {
var launcher: Launcher { get }
}
@objc public protocol Launcher: UIViewControllerTransitioningDelegate {
func initiateLaunch(url: URL, launchingHotInstance: Bool)
}
@objc final class LauncherContainer: NSObject, LauncherContainer, TabsContentCellTapHandler {
...
init(
...
) {
...
super.init()
}
...
//
// ContentCellTapHandler
//
public func tabContentCellItemDidTap(
tabId: String
) {
...
launcher.initiateNewTabNavigation(
tabId: tabId // Crash happens here
)
}
public class Launcher: NSObject, Launcher, FooterPillTapHandler {
public func initiateNewTabNavigation(tabId: String) {
...
}
}
public protocol TabsContentCellTapHandler: NSObject {
func tabContentCellItemDidTap(
tabId: String,
}
Crash stack last 2 lines are- libswiftCore.dylib swift_unknownObjectRetain libswiftCore.dylib String._bridgeToObjectiveCImpl()
String._bridgeToObjectiveCImpl() gets called when the caller and implementation is in Swift file
I believe due to @objc class LauncherContainer there'd be bridging header generated. Does that mean tabId passed to tabContentCellItemDidTap is a String but the one passed to initiateNewTabNavigation is NSString?
TabId is UUID().uuidString if that helps. Wondering if UUID().uuidString has something to do with this.
Thanks a ton for helping. Please find attached screenshot of the stack trace.
In my project, i have a Swift class with a class level property of type string. Like this :
class TWSwiftString {
var pString:String!
init(_ pString: String) {
self.pString = pString
}
}
I am creating intance of this class and then creating a opaque pointer to this intance. Like this :
let str = TWSwiftString("World")
// Increasing RC by 1
strptr = Unmanaged.passRetained(str).toOpaque()
Now using this opaque pointer i want to modify the value of pString by directly operating on memory. Like this:
withUnsafeMutablePointer(to: &strptr.pString) { strPointer in
strPointer.pointee = "World"
}
Although i am able to modify pString like this and print. Lets assume i have a approach to make sure memory remains valid when it is operated on and freeing of memory is also handled somehow .
Will this approach work if i have 100s of intance of this string which are being operated in this manner ? What if the size of new value is greater than existing string value ? For this i am thinking of chunk of memory initially and then keep on increasing size of it as bigger string then this chunk comes. Does this approach seems feasible ? Any other problems i can encounter by using this approach ?
Chatgpt gave this answer :
To directly update the memory of a Swift class’s property, particularly to alter a String property, is generally discouraged due to Swift's memory safety model. However, if we want to access and modify a class property directly, the best practice is to use a property accessor, as manually altering memory could lead to undefined behavior or even crashes. Why Direct Memory Manipulation Is Risky When you attempt to manipulate memory directly, especially with Swift’s memory model, you might alter not only the value but also the memory layout of Swift’s String type, which could break things internally. The Swift compiler may store String differently based on the internal structure, so even if we manage to locate the correct memory address, directly modifying it is unreliable.
do you have any opinion around chatgpt resoponse ?
Hello,
My code calls a macOS system library which returns Foundation Date properties. I have a program that will run every night, and output the data via the Swift JSONEncoder and uses DateEncodingStrategy.iso8601. As you likely know, a DST shift happened over the weekend here in the US. In my output, every single Date changed by 1 hour, despite the fact that nothing in the underlying data changed overnight. Here is an example diff in the output. I see the "Z", which I think should not be affected by DST changes.
- "dateAdded" : "2003-12-15T17:02:56Z",
- "dateModified" : "2007-03-07T04:31:16Z",
+ "dateAdded" : "2003-12-15T18:02:56Z",
+ "dateModified" : "2007-03-07T05:31:16Z",
Here is a sample of the data:
public struct Track: Codable, Hashable {
var dateAdded: Date?
var dateModified: Date?
}
And the encoding is here:
extension Array where Element == Track {
public func jsonData() throws -> Data {
let encoder = JSONEncoder()
encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
encoder.dateEncodingStrategy = .iso8601
return try encoder.encode(self)
}
}
Pretty basic stuff overall. So my questions are:
Am I correct in my assumption that .iso8601 is UTC, and that UTC is daylight savings shift agnostic?
Is this the right way to ensure the my JSON is encoded in UTC?
If the library I am calling is building its Date incorrectly, how may I work around the problem?
I'm not reporting the library name right now, in order to ensure that my code is doing the right thing without assumptions.
Thanks for any tips!
Hi, I would like to know if it is safe to call the uploadTask from URLSession from the main thread ?
We've a user who is reporting repeated crashes at startup, here is the stack we see:
Exception Type: EXC_CRASH (SIGKILL)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Termination Reason: FRONTBOARD 2343432205
<RBSTerminateContext| domain:10 code:0x8BADF00D explanation:scene-update watchdog transgression: app<com.appspot.myApp(E7590BB1-722C-491D-9199-F867DE4B880A)>:2212 exhausted real (wall clock) time allowance of 10.00 seconds
ProcessVisibility: Background
ProcessState: Running
WatchdogEvent: scene-update
WatchdogVisibility: Background
WatchdogCPUStatistics: (
"Elapsed total CPU time (seconds): 21.260 (user 10.230, system 11.030), 35% CPU",
"Elapsed application CPU time (seconds): 0.006, 0% CPU"
) reportType:CrashLog maxTerminationResistance:Interactive>
Triggered by Thread: 0
Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0 libsystem_kernel.dylib 0x1def7a688 mach_msg2_trap + 8
1 libsystem_kernel.dylib 0x1def7dd98 mach_msg2_internal + 80
2 libsystem_kernel.dylib 0x1def7dcb0 mach_msg_overwrite + 424
3 libsystem_kernel.dylib 0x1def7dafc mach_msg + 24
4 libdispatch.dylib 0x1968d8f14 _dispatch_mach_send_and_wait_for_reply + 544
5 libdispatch.dylib 0x1968d92b4 dispatch_mach_send_with_result_and_wait_for_reply + 60
6 libxpc.dylib 0x21714a930 xpc_connection_send_message_with_reply_sync + 256
7 Foundation 0x18d80a3ac __NSXPCCONNECTION_IS_WAITING_FOR_A_SYNCHRONOUS_REPLY__ + 16
8 Foundation 0x18d806b14 -[NSXPCConnection _sendInvocation:orArguments:count:methodSignature:selector:withProxy:] + 2160
9 CoreFoundation 0x18eb868dc ___forwarding___ + 1004
10 CoreFoundation 0x18eb86430 _CF_forwarding_prep_0 + 96
11 CFNetwork 0x1900c71e0 -[__NSURLBackgroundSession setupBackgroundSession] + 800
12 CFNetwork 0x1900b3e80 -[__NSURLBackgroundSession initWithConfiguration:delegate:delegateQueue:delegateDispatchQueue:] + 552
13 CFNetwork 0x1900b4784 +[NSURLSession _sessionWithConfiguration:delegate:delegateQueue:delegateDispatchQueue:] + 1496
14 MyApp 0x1054210b4 CombineBgXferRepository.session.getter (in MyApp) (CombineBgXferRepository.swift:62) + 7966900
15 MyApp 0x105422fa4 CombineBgXferRepository.startUploadTask(fileURL:request:) (in MyApp) (CombineBgXferRepository.swift:310) + 7974820
If it is ok to call this uploadTask from the main thread, does this crash indicate a problem with the operating system? Are there scenarios where the background upload service does not respond to requests?
Hi,
I'm trying to set up FIRDebugEnabled as launch arguments in app delegate based on user choice using ProcessInfo.processInfo.arguments. Which is working fine in iOS 17 and below devices and stoped working in iOS 18
Here is my sample,
if condition {
var arguments = ProcessInfo.processInfo.arguments
arguments.append("-FIRDebugEnabled")
ProcessInfo.processInfo.setValue(arguments, forKey: "arguments")
}
Hi, I encounter unexpected behavior from the FileWrapper updates that occurs when I remove file using FileManager.removeItem
If I first remove a file from the directory, then create NSFileWrapper instance, I get unexpected values from calls to matchesContents(of:)
import Foundation
let copyURL = URL(filePath: "/Users/marcinkrzyzanowski/Downloads/filewrappertest.test/COPY.png")
// THIS OPERATION BREAKS IT. REMOVE IT TO WORK AS EXPECTED
try! FileManager().removeItem(at: copyURL)
let dirURL = URL(filePath: "/Users/marcinkrzyzanowski/Downloads/filewrappertest.test")
let fw = try FileWrapper(url: dirURL)
fw.fileWrappers // ["IMG_0736.png"]
try FileManager.default.copyItem(at: URL(filePath: "/Users/marcinkrzyzanowski/Downloads/filewrappertest.test/IMG_0736.png"), to: copyURL)
fw.fileWrappers // ["IMG_0736.png"]
fw.matchesContents(of: dirURL) // true (expected: false)
try fw.read(from: dirURL)
fw.fileWrappers! // ["COPY.png", "IMG_0736.png"]
fw.matchesContents(of: dirURL) // true
I don't understand why the "FileManager.removeItem" affects the NSFileWrapper behavior in such a way. It does not change even when I add a delay after removeItem. Any idea?
Hi,
I have a question regarding reading the configuration of a managed app deployed via an MDM system. The application has an Action Extension and can receive shared files via this extension.
The problem I am facing is that I can read the managed configuration in the host app by accessing the UserDefaults.standard.object(forKey: "com.apple.configuration.managed") dictionary. With this, I can configure the host app. However, I am unable to read this configuration key in the Action Extension part of the application.
My question is whether there is any possibility to read the managed configuration even in the extension. So far, I have been unable to figure out how to read it.
I found the sample code, but it was not very helpful since it is very basic and does not deal with extensions at all.
Any hints are appreciated.
I'm coding resumable uploads using iOS 17's URLSession's uploadTask(withResumeData:. This function returns a non-Optional URLSessionUploadTask and does not throw. In cases where the system determines the resumeData is no longer valid, how do I detect that (so I can create a new URLSessionUploadTask from scratch)?
I'm doing this for background uploads, so it's all URLSessionDelegate apis, but what are the failure modes, and what Error types and Codes would we get specially?
Obviously, I expect the resume data is no longer usable or necessary when get a server success i.e. in the 2xx range. Does the resume data also become invalid for other server responses, like 4xx's? or 5xx's?.
I expect the resume data usually shouldn't become invalid when getting URLError's like .networkConnectionLost, since that's like half the point of having the feature in the first place, to resume after the a broken network connection. But I do expect that if the resumeData is invalid, then I should be able to reach the server and get a server response, so in that case what Code would we get?
I'm assuming the system is caching our upload file somewhere, and the resume data somehow makes a reference to it, so does that file get optimized away at some point in time when left untouched, and need us to start a fresh upload? We are also saving the file for potential future re-uploads, until we get certain assurances of completion from our backend, but I am just wondering on which logic branches I need to determine that the resumeData I thought I could use is no longer usable.
The expected number of months for the below code should be -48 months. It used to work like this Until iOS17. Now when building with iOS 18 it gives -47 months.
Changing the two dates with one day back works as expected
import Foundation
var calendar = Calendar(identifier: .gregorian)
calendar.timeZone = .gmt
let components1 = DateComponents(
calendar: calendar,
year: 2004,
month: 2,
day: 29 //28 in case of changing day to 28 it works as expected
)
guard let date1 = components1.date else {
exit(1)
}
let components2 = DateComponents(
calendar: calendar,
year: 2008,
month: 2,
day: 29 //28 in case of changing day to 28 it works as expected
)
guard let date2 = components2.date else {
exit(1)
}
print(date1)
print(date2)
let months = calendar.dateComponents([.month, .isLeapMonth], from: date2, to: date1)
print(months)
Consider this very trivial code which accesses the operatingSystemVersion property of NSProcessInfo as documented at https://developer.apple.com/documentation/foundation/nsprocessinfo/1410906-operatingsystemversion
osversion.c:
#include <Foundation/Foundation.h>
int main(int argc, char *argv[]) {
NSOperatingSystemVersion osVersion = [[NSProcessInfo processInfo] operatingSystemVersion];
fprintf(stderr, "OS version: %ld.%ld.%ld\n", osVersion.majorVersion, osVersion.minorVersion, osVersion.patchVersion);
}
Compile it:
/usr/bin/clang -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX13.1.sdk -iframework /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX13.1.sdk/System/Library/Frameworks -x objective-c -o a.out -framework Foundation osversion.c
Then run it:
./a.out
It works fine and prints the OS version:
OS version: 14.6.1
Run it again and pass it some arbitrary program arguments:
./a.out foo bar
Still continues to work fine and prints the output:
OS version: 14.6.1
Now run it again and this time pass it two program arguments, the first one being - and the second one being something of the form {x=y}
./a.out - {x=y}
This time notice how it prints a couple of warning logs from CFPropertyListCreateFromXMLData before printing the output:
2024-10-11 11:18:03.584 a.out[61327:32412190] CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 1. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.
2024-10-11 11:18:03.585 a.out[61327:32412190] CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 1. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.
OS version: 14.6.1
As far as I can see there's nothing wrong in the code nor the user inputs to the program. Is this some issue in the internal implementation of NSProcessInfo? Should this be reported as an issue through feedback assistant (which category)?
Although this example was run on 14.6.1 of macos, the issue is reproducible on older versions too.
I want to download some large files on watchOS and I found Apple Music app is able to download songs in background and pause downloading depending on battery life. Does there any way to do the same thing in my own app? After users choose to download, keep the downloading task in background and pause/resume on demand.