Hi, I'm trying to modify the ScreenCaptureKit Sample code by implementing an actor for Metal rendering, but I'm experiencing issues with frame rendering sequence.
My app workflow is:
ScreenCapture -> createFrame -> setRenderData
Metal draw callback -> renderAsync (getData from renderData)
I've added timestamps to verify frame ordering, I also using binarySearch to insert the frame with timestamp, and while the timestamps appear to be in sequence, the actual rendering output seems out of order.
// ScreenCaptureKit sample
func createFrame(for sampleBuffer: CMSampleBuffer) async {
if let surface: IOSurface = getIOSurface(for: sampleBuffer) {
await renderer.setRenderData(surface, timeStamp: sampleBuffer.presentationTimeStamp.seconds)
}
}
class Renderer {
...
func setRenderData(surface: IOSurface, timeStamp: Double) async {
_ = await renderSemaphore.getSetBuffers(
isGet: false,
surface: surface,
timeStamp: timeStamp
)
}
func draw(in view: MTKView) {
Task {
await renderAsync(view)
}
}
func renderAsync(_ view: MTKView) async {
guard await renderSemaphore.beginRender() else { return }
guard let frame = await renderSemaphore.getSetBuffers(
isGet: true, surface: nil, timeStamp: nil
) else {
await renderSemaphore.endRender()
return }
guard let texture = await renderSemaphore.getRenderData(
device: self.device,
surface: frame.surface) else {
await renderSemaphore.endRender()
return
}
guard let commandBuffer = _commandQueue.makeCommandBuffer(),
let renderPassDescriptor = await view.currentRenderPassDescriptor,
let renderEncoder = commandBuffer.makeRenderCommandEncoder(descriptor: renderPassDescriptor) else {
await renderSemaphore.endRender()
return
}
// Shaders ..
renderEncoder.endEncoding()
commandBuffer.addCompletedHandler() { @Sendable (_ commandBuffer)-> Swift.Void in
updateFPS()
}
// commit frame in actor
let success = await renderSemaphore.commitFrame(
timeStamp: frame.timeStamp,
commandBuffer: commandBuffer,
drawable: view.currentDrawable!
)
if !success {
print("Frame dropped due to out-of-order timestamp")
}
await renderSemaphore.endRender()
}
}
actor RenderSemaphore {
private var frameBuffers: [FrameData] = []
private var lastReadTimeStamp: Double = 0.0
private var lastCommittedTimeStamp: Double = 0
private var activeTaskCount = 0
private var activeRenderCount = 0
private let maxTasks = 3
private var textureCache: CVMetalTextureCache?
init() {
}
func initTextureCache(device: MTLDevice) {
CVMetalTextureCacheCreate(kCFAllocatorDefault, nil, device, nil, &self.textureCache)
}
func beginRender() -> Bool {
guard activeRenderCount < maxTasks else { return false }
activeRenderCount += 1
return true
}
func endRender() {
if activeRenderCount > 0 {
activeRenderCount -= 1
}
}
func setTextureLoaded(_ loaded: Bool) {
isTextureLoaded = loaded
}
func getSetBuffers(isGet: Bool, surface: IOSurface?, timeStamp: Double?) -> FrameData? {
if isGet {
if !frameBuffers.isEmpty {
let frame = frameBuffers.removeFirst()
if frame.timeStamp > lastReadTimeStamp {
lastReadTimeStamp = frame.timeStamp
print(frame.timeStamp)
return frame
}
}
return nil
} else {
// Set
let frameData = FrameData(
surface: surface!,
timeStamp: timeStamp!
)
// insert to the right position
let insertIndex = binarySearch(for: timeStamp!)
frameBuffers.insert(frameData, at: insertIndex)
return frameData
}
}
private func binarySearch(for timeStamp: Double) -> Int {
var left = 0
var right = frameBuffers.count
while left < right {
let mid = (left + right) / 2
if frameBuffers[mid].timeStamp > timeStamp {
right = mid
} else {
left = mid + 1
}
}
return left
}
// for setRenderDataNormalized
func tryEnterTask() -> Bool {
guard activeTaskCount < maxTasks else { return false }
activeTaskCount += 1
return true
}
func exitTask() {
activeTaskCount -= 1
}
func commitFrame(timeStamp: Double,
commandBuffer: MTLCommandBuffer,
drawable: MTLDrawable) async -> Bool {
guard timeStamp > lastCommittedTimeStamp else {
print("Drop frame at commit: \(timeStamp) <= \(lastCommittedTimeStamp)")
return false
}
commandBuffer.present(drawable)
commandBuffer.commit()
lastCommittedTimeStamp = timeStamp
return true
}
func getRenderData(
device: MTLDevice,
surface: IOSurface,
depthData: [Float]
) -> (MTLTexture, MTLBuffer)? {
let _textureName = "RenderData"
var px: Unmanaged<CVPixelBuffer>?
let status = CVPixelBufferCreateWithIOSurface(kCFAllocatorDefault, surface, nil, &px)
guard status == kCVReturnSuccess, let screenImage = px?.takeRetainedValue() else {
return nil
}
CVMetalTextureCacheFlush(textureCache!, 0)
var texture: CVMetalTexture? = nil
let width = CVPixelBufferGetWidthOfPlane(screenImage, 0)
let height = CVPixelBufferGetHeightOfPlane(screenImage, 0)
let result2 = CVMetalTextureCacheCreateTextureFromImage(
kCFAllocatorDefault,
self.textureCache!,
screenImage,
nil,
MTLPixelFormat.bgra8Unorm,
width,
height,
0, &texture)
guard result2 == kCVReturnSuccess,
let cvTexture = texture,
let mtlTexture = CVMetalTextureGetTexture(cvTexture) else {
return nil
}
mtlTexture.label = _textureName
let depthBuffer = device.makeBuffer(bytes: depthData, length: depthData.count * MemoryLayout<Float>.stride)!
return (mtlTexture, depthBuffer)
}
}
Above's my code - could someone point out what might be wrong?
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I have an app whose logic is in C++ and rest of the parts (UI) are in Swift and SwiftUI.
Exceptions can occur in C++ and Swift. I've got the C++ part covered by using the Linux's signal handler mechanism to trap signals which get raised due to exceptions.
But how should I capture exceptions in Swift? When I say exceptions in Swift, I mean, divide by zero, force unwrapping of an optional containing nil, out of index access in an array, etc. Basically, anything that can go wrong, I don't want my app to abruptly crash... I need a chance to finalise my stuff, alert the user, prepare diagnostic reports and terminate. I'm looking for a 'catch-all' exception handler. As an example, let's take Android. In Android, there is the setDefaultUncaughtExceptionHandler method to register for all kinds of exceptions in any thread in Kotlin. I'm looking for something similar in Swift that should work for macOS, iOS & iPadOS, tvOS and watchOS.
I first came across the NSSetUncaughtExceptionHandler method. My understanding is, this only works when I explicitly raise NSExceptions. When I tested it, observed that the exception handler didn't get invoked for either case - divide by zero or invoking raise.
class AppDelegate: NSObject, NSApplicationDelegate {
func applicationDidFinishLaunching(_ aNotification: Notification) {
Log("AppDelegate.applicationDidFinishLaunching(_:)")
// Set the 'catch-all' exception handler for Swift exceptions.
Log("Registering exception handler using NSSetUncaughtExceptionHandler()...")
NSSetUncaughtExceptionHandler { (exception: NSException) in
Log("AppDelegate.NSUncaughtExceptionHandler()")
Log("Exception: \(exception)")
}
Log("Registering exception handler using NSSetUncaughtExceptionHandler() succeeded!")
// For C++, use the Linux's signal mechanism.
ExceptionHandlingCpp.RegisterSignals()
//ExceptionHandlingCpp.TestExceptionHandler()
AppDelegate.TestExceptionHandlerSwift()
}
static func TestExceptionHandlerSwift() {
Log("AppDelegate.TestExceptionHandlerSwift()")
DivisionByZero(0)
}
private static func DivisionByZero(_ divisor: Int) {
Log("AppDelegate.DivisionByZero()")
let num1: Int = 2
Log("Raising Exception...")
//let result: Int = num1/divisor
let exception: NSException = NSException(name: NSExceptionName(rawValue: "arbitrary"), reason: "arbitrary reason", userInfo: nil)
exception.raise()
Log("Returning from DivisionByZero()")
}
}
In the above code, dividing by zero, nor raising a NSException invokes the closure passed to NSSetUncaughtExceptionHandler, evident from the following output logs
AppDelegate.applicationWillFinishLaunching(_:)
AppDelegate.applicationDidFinishLaunching(_:)
Registering exception handler using NSSetUncaughtExceptionHandler()...
Registering exception handler using NSSetUncaughtExceptionHandler() succeeded!
ExceptionHandlingCpp::RegisterSignals()
....
AppDelegate.TestExceptionHandlerSwift()
AppDelegate.DivisionByZero()
Raising Exception...
Currently, I'm reading about ExceptionHandling framework, but this is valid only for macOS.
What is the recommended way to capture runtime issues in Swift?
I use AppIntent to trigger a widget refresh, Appint is used on Button or Toggle,as follows
var isAudibleArming = false
struct SoundAlarmIntent: AppIntent {
static var title: LocalizedStringResource = "SoundAlarmIntent"
func perform() async throws -> some IntentResult {
isAudibleArming = true
return .result()
}
}
func timeline( for configuration: DynamicIntentWidgetPersonIntent, in context: Context ) async -> Timeline {
var entries: [Entry] = []
let currentDate = Date()
let entry = Entry(person: person(for: configuration))
entries.append(entry)
if isAudibleArming {
let entry2 = Entry(person: Person(name: "Friend4", dateOfBirth: currentDate.adding(.second, value: 6)))
entries.append(entry2)
}
return .init(entries: entries, policy: .never)
}
The timeline function fires, with entry corresponding to view1 and entry2 corresponding to view2. I expect to show view1 immediately and view2 6 seconds later. You get the correct response on iOS17. But the 6 second delay function on the discovery code in iOS18.2 takes effect immediately, view1 flashes, view2 appears immediately instead of waiting 6 seconds to appear.
Hi
In C#, one can define associated functions by the following.
Notice that "Declarations DE" is a reference to a function in another C# project file. This lets the compiler know that there are other references in the project.
Likewise, "Form_Load" is the entry point of the code, similar to "main" in C. Any calls to related functions can be made in this section, to the functions that have been previously defined above.
So I set out trying to find similar information about SwiftUI, and found several, but only offer partial answers to my questions.
The YouTube video...
Extracting functions and subviews in SwiftUI | Bootcamp #20 - YouTube
... goes into some of the details, but still leaves me hanging.
Likewise...
SOLVED: Swift Functions In Swift UI – SwiftUI – Hacking with Swift forums
... has further information, but nothing concrete that I am looking for.
Now in the SwiftUI project, I tried this...
The most confusing thing for me, is where is "main"?
I found several examples that call functions from the structure shown above, BUT I have no reason as to why.
So one web example on StackOverFlow called the function from position 1. That did not work.
Position 2 worked to call the function at position 3, but really, why?
All this activity brings up a lot of questions for me, such as:
Does SwiftUI need function callouts similar to C#, and they are called out even before running "main". I seem to recall Borland Delphi being this way as well.
How does SwiftUI make references to other classes (places where other functions are stored in separate files)?
Does SwiftUI actually make use of "main" in the normal sense, i.e. similar to C, C#, Rust and so on?
I did notice that once a SwiftUI function is called, it makes reference to data being passed very similar to other languages, at least for the examples I found.
Note that I looked at official SwiftUI documentation, but did not come across information that answers the above.
Topic:
Programming Languages
SubTopic:
Swift
As a fun project, I'm wanting to model an electronic circuit.
Components inherit from a superclass (ElectronicComponent). Each subclass (e.g. Resistor) has certain methods to return properties (e.g. resistance), but may vary by the number of outlets (leads) they have, and what they are named.
Each outlet connects to a Junction.
In my code to assemble a circuit, while I'm able to manually hook up the outlets to the junctions, I'd like to be able to use code similar to the following…
class Lead: Hashable // implementation omitted
{
let id = UUID()
unowned let component: ElectronicComponent
weak var connection: Junction?
init(component: ElectronicComponent, to connection: Junction? = nil)
{
self.component = component
self.connection = connection
}
}
@dynamicMemberLookup
class ElectronicComponent
{
let id = UUID()
var connections: Set<Lead> = []
let label: String?
init(label: String)
{
self.label = label
}
subscript<T>(dynamicMember keyPath: KeyPath<ElectronicComponent, T>) -> T
{
self[keyPath: keyPath]
}
func connect(lead: KeyPath<ElectronicComponent, Lead>, to junction: Junction)
{
let lead = self[keyPath: lead]
lead.connection = junction
connections.insert(lead)
}
}
class Resistor: ElectronicComponent
{
var input, output: Lead?
let resistance: Measurement<UnitElectricResistance>
init(_ label: String, resistance: Measurement<UnitElectricResistance>)
{
self.resistance = resistance
super.init(label: label)
}
}
let resistorA = Resistor("R1", resistance: .init(value: 100, unit: .ohms))
let junctionA = Junction(name: "A")
resistorA.connect(lead: \.outlet2, to: junctionA)
While I'm able to do this by implementing @dynamicMemberLookup in each subclass, I'd like to be able to do this in the superclass to save repeating the code.
subscript<T>(dynamicMember keyPath: KeyPath<ElectronicComponent, T>) -> T
{
self[keyPath: keyPath]
}
Unfortunately, the compiler is not allowing me to do this as the superclass doesn't know about the subclass properties, and at the call site, the subclass isn't seen as ElectronicComponent.
I've been doing trial and error with protocol conformance and other things, but hitting walls each time.
One possibility is replacing the set of outlets with a dictionary, and using Strings instead of key paths, but would prefer not to.
Another thing I haven't tried is creating and adopting a protocol with the method implemented in there. Another considered approach is using macros in the subclasses, but I'd like to see if there is a possibility of achieving the goal using my current approach, for learning as much as anything.
Hey all!
in my personal quest to make future proof apps moving to Swift 6, one of my app has a problem when setting an artwork image in MPNowPlayingInfoCenter
Here's what I'm using to set the metadata
func setMetadata(title: String? = nil, artist: String? = nil, artwork: String? = nil) async throws {
let defaultArtwork = UIImage(named: "logo")!
var nowPlayingInfo = [
MPMediaItemPropertyTitle: title ?? "***",
MPMediaItemPropertyArtist: artist ?? "***",
MPMediaItemPropertyArtwork: MPMediaItemArtwork(boundsSize: defaultArtwork.size) { _ in
defaultArtwork
}
] as [String: Any]
if let artwork = artwork {
guard let url = URL(string: artwork) else { return }
let (data, response) = try await URLSession.shared.data(from: url)
guard (response as? HTTPURLResponse)?.statusCode == 200 else { return }
guard let image = UIImage(data: data) else { return }
nowPlayingInfo[MPMediaItemPropertyArtwork] = MPMediaItemArtwork(boundsSize: image.size) { _ in
image
}
}
MPNowPlayingInfoCenter.default().nowPlayingInfo = nowPlayingInfo
}
the app crashes when hitting
MPMediaItemPropertyArtwork: MPMediaItemArtwork(boundsSize: defaultArtwork.size) { _ in
defaultArtwork
}
or
nowPlayingInfo[MPMediaItemPropertyArtwork] = MPMediaItemArtwork(boundsSize: image.size) { _ in
image
}
commenting out these two make the app work again.
Again, no clue on why.
Thanks in advance
Crashed: com.apple.root.user-initiated-qos.cooperative
0 libswift_Concurrency.dylib 0x67f40 swift_task_create_commonImpl(unsigned long, swift::TaskOptionRecord*, swift::TargetMetadataswift::InProcess const*, void (swift::AsyncContext* swift_async_context) swiftasynccall*, void*, unsigned long) + 528
1 libswift_Concurrency.dylib 0x64d78 swift_asyncLet_begin + 40
2 AAAA 0x47aef28 (1) suspend resume partial function for ActivityContextModule.fetchRecord(startDate:endDate:) + 50786796
3 libswift_Concurrency.dylib 0x60f5c swift::runJobInEstablishedExecutorContext(swift::Job*) + 252
4 libswift_Concurrency.dylib 0x62514 swift_job_runImpl(swift::Job*, swift::SerialExecutorRef) + 144
5 libdispatch.dylib 0x15ec0 _dispatch_root_queue_drain + 392
6 libdispatch.dylib 0x166c4 _dispatch_worker_thread2 + 156
7 libsystem_pthread.dylib 0x3644 _pthread_wqthread + 228
8 libsystem_pthread.dylib 0x1474 start_wqthread + 8
Hello,
I am developing a private internal Flutter app for our customer, which will not be published on the Apple Store. One of the key features of this app is to collect RF strength metrics to share user experience with the network.
For Android, we successfully implemented the required functionality and are able to collect the following metrics:
Signal strength level (0-4)
Signal strength in dBm
RSSI
RSRQ
Cell ID
Location Area Code
Carrier name
Mobile country code
Mobile network code
Radio access technology
Connection status
Duplex mode
However, for iOS, we are facing challenges with CoreTelephony, which is not returning the necessary data. We are aware that CoreTelephony is deprecated and are looking for alternatives.
We noticed that a lot of the information we need is available via FTMInternal-4. Is there a way to access this data for a private app? Are there any other recommended approaches or frameworks that can be used to gather cellular network information on iOS for an app that won't be distributed via the Apple Store?
my swift code
import Foundation
import CoreTelephony
class RfSignalStrengthImpl: RfSignalStrengthApi {
func getCellularSignalStrength(completion: @escaping (Result<CellularSignalStrength, Error>) -> Void) {
let networkInfo = CTTelephonyNetworkInfo()
guard let carrier = networkInfo.serviceSubscriberCellularProviders?.values.first else {
completion(.failure(NSError(domain: "com.xxxx.yyyy", code: 0, userInfo: [NSLocalizedDescriptionKey: "Carrier not found"])))
return
}
let carrierName = carrier.carrierName ?? "Unknown"
let mobileCountryCode = carrier.mobileCountryCode ?? "Unknown"
let mobileNetworkCode = carrier.mobileNetworkCode ?? "Unknown"
let radioAccessTechnology = networkInfo.serviceCurrentRadioAccessTechnology?.values.first ?? "Unknown"
var connectionStatus = "Unknown"
...
...
}
Thank you for your assistance.
On iOS 18 some string functions return incorrect values in some cases.
Found problems on replacingOccurrences() and split() functions, but there may be others.
In the results of these functions in some cases a character is left in the result string when it shouldn't.
This did not happen on iOS17 and older versions.
I created a very simple Test Project to reproduce the problem.
If I run these tests on iOS17 or older the tests succeed.
If I run these tests on iOS18 the tests fail.
test_TestStr1() function shows a problem in replacingOccurrences() directly using strings.
test_TestStr2() function shows a problem in split() that seems to happen only when bridging from NSString to String.
import XCTest
final class TestStrings18Tests: XCTestCase {
override func setUpWithError() throws {
// Put setup code here. This method is called before the invocation of each test method in the class.
}
override func tearDownWithError() throws {
// Put teardown code here. This method is called after the invocation of each test method in the class.
}
func test_TestStr1()
{
let str1 = "_%\u{7}1\u{7}_";
let str2 = "%\u{7}1\u{7}";
let str3 = "X";
let str4 = str1.replacingOccurrences(of: str2, with: str3);
//This should be true
XCTAssertTrue(str4 == "_X_");
}
func test_TestStr2()
{
let s1 = "TVAR(6)\u{11}201\"Ã\"\u{11}201\"A\"";
let s2 = s1.components(separatedBy: "\u{11}201");
let t1 = NSString("TVAR(6)\u{11}201\"Ã\"\u{11}201\"A\"") as String;
let t2 = t1.components(separatedBy: "\u{11}201");
XCTAssertTrue(s2.count == t2.count);
let c = s2.count
//This should be True
XCTAssertTrue(s2[0] == t2[0]);
}
}
Topic:
Programming Languages
SubTopic:
Swift
I'm working on a cross-platform C# application that converts HTML content to PDF. The goal is to render dynamic HTML pages (including CSS and JavaScript) as high-quality, printable PDF files. Additionally, I need to support features like adding headers/footers, securing PDFs with passwords, and controlling user permissions. While everything works well on Windows, I need some help rendering consistency and handling permissions on MacOS.
similiar to
Error when debugging: Cannot creat… | Apple Developer Forums - https://developer.apple.com/forums/thread/651375
Xcode 12 beta 1 po command in de… | Apple Developer Forums - https://developer.apple.com/forums/thread/651157
which do not resolve this issue that I am encountering
Description of problem
I am seeing an error which prevents using lldb debugger on Swift code/projects. It is seen on any Swift or SwiftUI project that I've tried. This is the error displayed in lldb console when first breakpoint is encountered:
Cannot create Swift scratch context (couldn't create a ClangImporter)(lldb)
Xcode Version 12.3 (12C33)
macOS Big Sur Intel M1
Troubleshooting
I originally thought this was also working on an Intel Mac running Big Sur/Xcode 12.3, but was mistaken. Using my customized shell environment on the following setups, I encounter the same couldn't create a ClangImporter.
M1 Mac mini, main account (an "Admin" account)
same M1 Mac mini, new "dev" account (an "Admin" account)
Intel MBP, main account
They are all using an Intel Homebrew install, and my customized shell environment if that provides a clue?
I captured some lldb debugging info by putting expr types in ~/.lldbinit but the outputs were basically identical (when discounting scratch file paaths and memory addresses) compared to the "working clean" account log (described below)
log enable -f /tmp/lldb-log.txt lldb expr types
works in a "clean" user account
I created a new, uncustomized "Standard" testuser account on the M1 Mac mini, and launched the same system Xcode.app. There was no longer this error message, and was able to inspect variables at a swift program breakpoint in Swift context, including po symbol.
Impact
Effectively this makes the debugger in Swift on Xcode projects on my systems essentially unable to inspect Swift contexts' state.
func oneStepForward(_ input: Int) -> Int {
return input + 1
}
func oneStepBackward(_ input: Int) -> Int {
return input - 1
}
func chooseStepFunction(backward: Bool) -> (Int) -> Int {
return backward ? oneStepBackward : oneStepForward
//Error. type of expression is ambiguous without a type annotation
}
Why am I getting this error ?
If I change this function to the following it works and will compile.
func chooseStepFunction(backward: Bool) -> (Int) -> Int {
if backward {
return oneStepBackward
} else {
return oneStepForward
}
}
// Why am I getting the error in the previous version while it works in the second version ?
Thx in advance.
Is this possible while inserting a String into Set
Crashed: com.apple.root.user-initiated-qos.cooperative
0 libswiftCore.dylib 0xf4c0 _assertionFailure(_:_:flags:) + 136
1 libswiftCore.dylib 0x17f484 ELEMENT_TYPE_OF_SET_VIOLATES_HASHABLE_REQUIREMENTS(_:) + 3792
2 MyEatApp 0x44f6e8 specialized _NativeSet.insertNew(_:at:isUnique:) + 4333926120 (<compiler-generated>:4333926120)
3 MyEatApp 0x44eaec specialized Set._Variant.insert(_:) + 4333923052 (<compiler-generated>:4333923052)
4 MyEatApp 0x479f7c HomeViewModel.hanldeAnnouncementCard(from:) + 293 (HomeViewModel+PersonalizedOffer.swift:293)
5 libswift_Concurrency.dylib 0x5c134 swift::runJobInEstablishedExecutorContext(swift::Job*) + 292
6 libswift_Concurrency.dylib 0x5d5c8 swift_job_runImpl(swift::Job*, swift::SerialExecutorRef) + 156
7 libdispatch.dylib 0x13db0 _dispatch_root_queue_drain + 364
8 libdispatch.dylib 0x1454c _dispatch_worker_thread2 + 156
9 libsystem_pthread.dylib 0x9d0 _pthread_wqthread + 232
10 libsystem_pthread.dylib 0xaac start_wqthread + 8
I've just upgraded to Xcode 16 and my app now fails when attempting to read a text file from the main bundle. It finds the path but can't open the file so this snippet prints: "File read error for path: /private/var/containers/Bundle/Application/AABAD428-96BC-4B34-80B4-97FA80B77E58/Test.app/csvfile.csv"
This worked fine up to 15.4. Has something changed? Thanks.
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let bundle = Bundle.main
let path = bundle.path(forResource: "csvfile", ofType: "csv")!
do {
let content = try String(contentsOfFile: path, encoding: String.Encoding.ascii)
} catch {
print("File read error for path: \(String(describing: path))")
}
}
}
We started building our project in XCode 16 only to find a super weird crash that was 100% reproducible.
I couldn't really understand why it was crashing, so I tried to trim down the problematic piece of code to something that I could provide in a side project. The actual piece of code crashing for us is significantly different, but this small example showcases the crash as well.
https://github.com/Elih96/XCode16CrashReproducer
our observation is, that this combination of async let usage + struct structure leads to a SIGABRT crash in the concurrency library.
In both the main project and the example project, moving away from async let and using any other concurrency mechanism fixes the crash.
This was reproducible only on Xcode 16 with iOS 15 set as minimum deployment for the target. It works fine on Xcode 15, and if we bump the min deployment to 16 on Xcode 16, it also runs fine. I've attached a small project that reproduces the error.
I'm sure I didn't provide the ideal reproduction scenario, but that's what I managed to trim it down to. Making random changes such as removing some properties from the B struct or remove the:
let _ = A().arrayItems.map { _ in "123" }
will stop the crash from happening, so I just stopped making changes.
The stack trace from the crash:
frame #0: 0x00000001036d1008 libsystem_kernel.dylib`__pthread_kill + 8
frame #1: 0x0000000102ecf408 libsystem_pthread.dylib`pthread_kill + 256
frame #2: 0x00000001801655c0 libsystem_c.dylib`abort + 104
frame #3: 0x000000020a8b7de0 libswift_Concurrency.dylib`swift::swift_Concurrency_fatalErrorv(unsigned int, char const*, char*) + 28
frame #4: 0x000000020a8b7dfc libswift_Concurrency.dylib`swift::swift_Concurrency_fatalError(unsigned int, char const*, ...) + 28
frame #5: 0x000000020a8baf54 libswift_Concurrency.dylib`swift_task_dealloc + 124
frame #6: 0x000000020a8b72c8 libswift_Concurrency.dylib`asyncLet_finish_after_task_completion(swift::AsyncContext*, swift::AsyncLet*, void (swift::AsyncContext* swift_async_context) swiftasynccall*, swift::AsyncContext*, void*) + 72
* frame #7: 0x000000010344e6e4 CrashReproducer.debug.dylib`closure #1 in closure #1 in CrashReproducerApp.body.getter at CrashReproducerApp.swift:17:46
frame #8: 0x00000001cca0a560 SwiftUI`___lldb_unnamed_symbol158883
frame #9: 0x00000001cca09fc0 SwiftUI`___lldb_unnamed_symbol158825
frame #10: 0x00000001cca063a0 SwiftUI`___lldb_unnamed_symbol158636
frame #11: 0x00000001cca09268 SwiftUI`___lldb_unnamed_symbol158726
hi
i want create a commande line tool for arm64 et intel x86-64
Xcode 16 macbook pro M3
my setting :
and
but my application compile only for arm64
who can explain to me ?
Hello,
Im developing an app entirely with C++, and I need to call various swift functions because it requires the Swift library.
Ive seen several posts on forums about C++ callbacks and honestly I dont understand how its done exactly. I get the general idea but I am not able to understand it and make it work. I feel like people throw vague ideas and weird function names and everything gets confusing.
Could anyone give me the smallest example that works please ?
Just to make sure you know what I mean, here is an example of what I want to do, but you dont have to generate the code exactly for this, I want an example that I can understand please, but the swift code has to depend on a swift library. I dont want to simply call a swift function that returns x*2 ...
{1} notif.swift file : coded in swift language
include <UserNotifications/UserNotifications.h>
function A that show notification in swift code.
{2} mainwindow.cpp file : coded in C++ language
import notif.swift ??
button connected to slot/function mybuttonclicked.
MainWindow::mybuttonclicked(){
std::string my_result = call function A_from_swift_file(argument_1);
}
--The end ---
I wrote the notif.swift with '?' because I dont know how you include the swift file from your cpp code and I could not find that anywhere. Maybe it is obvious, but I would really appreciate getting some help on this, Thank you everyone
Topic:
Programming Languages
SubTopic:
General
i have macos 15 and xcode 16 swift 6 and want to make apps
to run on macintosh.
i know the syntax of this programming language, but i need
informations like which libraries i have to import for func's
which name i do not know, and parameters i have not found
on websites or the tutorial on swift.
i need procedures like
open window at x,y,width,height
draw rectangle at x,y,width,height,color
draw text at x,y,width,height,color,size
read keyboard-letter,up/dn,shift
read mouse x,y,buttons
Topic:
Programming Languages
SubTopic:
Swift
Hi,
After update to Xcode 16 a lot of errors happen, for example:
import Foundation
extension Collection {
func get(at i: Index) -> Element? {
return indices.contains(i) ? self[i] : nil
}
}
Errors:
Cannot find type 'Index' in scope
Cannot find 'indices' in scope
What is wrong?
Thanks.
The speaker mentions there is "less risk of creating a retain cycle in when capturing self in a closure within a value type", such as a SwiftUI view struct.
Can you elaborate on when this could actually occur?
Thanks!