I want to build a Swift library package that uses modified build of OpenSSL and Curl.
I have already statically compiled both and verified I can use them in an Objective-C framework on my target platform (iOS & iOS Simulator). I'm using XCFramework files that contain the static library binaries and headers:
openssl.xcframework/
ios-arm64/
openssl.framework/
Headers/
[...]
openssl
ios-arm64_x86_64-simulator/
openssl.framework/
Headers/
[...]
openssl
Info.plist
I'm not sure how I'm supposed to set up my Swift package to import these libraries.
I can use .systemLibrary but that seems to use the embedded copies of libssl and libcurl on my system, and I can't figure out how to use the path: parameter to that.
I also tried using a .binaryTarget pointing to the XCFramework files, but that didn't seem to work as there is no module generated and I'm not sure how to make one myself.
At a basic high level, this is what I'm trying to accomplish:
where libcrypto & libssl come from the provided openssl.xcframework file, and libcurl from curl.xcframework
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Why doesn’t deinit support async? At the end of a test, I want to wipe data from HealthKit, and it’s delete function is asynchronous.
For some time now Xcode has been downloading crash reports from users of my app about crashes related to arrays. One of them looks like this:
...
Code Type: ARM-64
Parent Process: launchd [1]
User ID: 501
Date/Time: 2024-07-18 14:59:40.4375 +0800
OS Version: macOS 15.0 (24A5289h)
...
Crashed Thread: 0
Exception Type: EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000001, 0x00000001045048b8
Termination Reason: Namespace SIGNAL, Code 5 Trace/BPT trap: 5
Terminating Process: exc handler [1771]
Thread 0 Crashed:
0 MyApp 0x00000001045048b8 specialized Collection.map<A>(_:) + 596
1 MyApp 0x00000001045011e4 MyViewController.validateToolbarButtons() + 648 (MyViewController.swift:742)
...
The relevant code looks like this:
class MyViewController {
func validateToolbarButtons() {
let indexes = tableView.clickedRow == -1 || tableView.selectedRowIndexes.contains(tableView.clickedRow) ? tableView.selectedRowIndexes : IndexSet(integer: tableView.clickedRow)
let items = indexes.map({ myArray[$0] })
...
}
}
The second crash looks like this:
...
Code Type: X86-64 (Native)
Parent Process: launchd [1]
User ID: 502
Date/Time: 2024-07-15 15:53:35.2229 -0400
OS Version: macOS 15.0 (24A5289h)
...
Crashed Thread: 0
Exception Type: EXC_BAD_INSTRUCTION (SIGILL)
Exception Codes: 0x0000000000000001, 0x0000000000000000
Termination Reason: Namespace SIGNAL, Code 4 Illegal instruction: 4
Terminating Process: exc handler [13244]
Thread 0 Crashed:
0 libswiftCore.dylib 0x00007ff812904fc0 _assertionFailure(_:_:flags:) + 288
1 MyApp 0x0000000101a31e04 specialized _ArrayBuffer._getElementSlowPath(_:) + 516
2 MyApp 0x00000001019d04eb MyObject.myProperty.setter + 203 (MyObject.swift:706)
3 MyApp 0x000000010192f66e MyViewController.controlTextDidChange(_:) + 190 (MyViewController.swift:166)
...
And the relevant code looks like this:
class MyObject {
var myProperty: [MyObject] {
get {
...
}
set {
let items = newValue.map({ $0.id })
...
}
}
}
What could cause such crashes? Could they be caused by anything other than concurrent access from multiple threads (which I'm quite sure is not the case here, as I only access these arrays from the main thread)?
So any time I create a class that's both @Observable and Codable, e.g.
@Observable class GameLocationManager : Codable {
I get a warning in the macro expansion code:
@ObservationIgnored private let _$observationRegistrar = Observation.ObservationRegistrar()
Immutable property will not be decoded because it is declared with an initial value which cannot be overwritten.
I've been ignoring them for now, but there are at least a half a dozen of them now in my (relatively small) codebase, and I'd like to find a solution (ideally one that doesn't require me to write init(decoder:) for every @Observable class in my project...), especially since I'm not sure what the actual consequences of ignoring this might be.
Hello, I have a problem with the .onMove function. I believe I have set everything up properly. However, the moving does not seem to be working correctly. When I try to move the item, it is highlighted first, as it is supposed to be. Then, while I am moving it through the list, it disappears for some reason, and at the end of the move, it comes back to its initial place. (I use iOS 16.0 minimum, so I don't have to include the EditButton(). It works the same in the edit mode tho)
import SwiftUI
struct Animal: Identifiable {
var id = UUID()
var name: String
}
struct ListMove: View {
@State var animals = [Animal(name: "Dog"), Animal(name: "Cat"), Animal(name: "Cow"), Animal(name: "Goat"), Animal(name: "Chicken")]
var body: some View {
List {
ForEach(animals) { animal in
Text(animal.name)
}
.onMove(perform: move)
}
}
func move(from source: IndexSet, to destination: Int) {
animals.move(fromOffsets: source, toOffset: destination)
}
}
#Preview {
ListMove()
}
Hey all!
During the migration of a production app to swift 6, I've encountered a problem: when hitting the UNUserNotificationCenter.current().requestAuthorization the app crashes.
If I switch back to Language Version 5 the app works as expected.
The offending code is defined here
class AppDelegate: NSObject, UIApplicationDelegate {
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
FirebaseApp.configure()
FirebaseConfiguration.shared.setLoggerLevel(.min)
UNUserNotificationCenter.current().delegate = self
let authOptions: UNAuthorizationOptions = [.alert, .badge, .sound]
UNUserNotificationCenter.current().requestAuthorization(options: authOptions) { _, _ in }
application.registerForRemoteNotifications()
Messaging.messaging().delegate = self
return true
}
}
The error is depicted here:
I have no idea how to fix this.
Any help will be really appreciated
thanks in advance
Topic:
Programming Languages
SubTopic:
Swift
Tags:
User Notifications
Notification Center
Concurrency
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
Hello Everyone,
I have a use case where I wanted to interpret the "Data" object received as a part of my NWConnection's recv call. I have my interpretation logic in cpp so in swift I extract the pointer to the raw bytes from Data and pass it to cpp as a UnsafeMutableRawPointer.
In cpp it is received as a void * where I typecast it to char * to read data byte by byte before framing a response.
I am able to get the pointer of the bytes by using
// Swift Code
// pContent is the received Data
if let content = pContent, !content.isEmpty {
bytes = content.withUnsafeBytes { rawBufferPointer in
guard let buffer = rawBufferPointer.baseAddress else {
// return with null data.
}
// invoke cpp method to interpret data and trigger response.
}
// Cpp Code
void InterpretResponse (void * pDataPointer, int pDataLength) {
char * data = (char *) pDataPointer;
for (int iterator = 0; iterator < pDataLength; ++iterator )
{
std::cout << data<< std::endl;
data++;
}
}
When I pass this buffer to cpp, I am unable to interpret it properly.
Can someone help me out here?
Thanks :)
Harshal
We are getting a crash _dispatch_assert_queue_fail when the cancellationHandler on NSProgress is called.
We do not see this with iOS 17.x, only on iOS 18. We are building in Swift 6 language mode and do not have any compiler warnings.
We have a type whose init looks something like this:
init(
request: URLRequest,
destinationURL: URL,
session: URLSession
) {
progress = Progress()
progress.kind = .file
progress.fileOperationKind = .downloading
progress.fileURL = destinationURL
progress.pausingHandler = { [weak self] in
self?.setIsPaused(true)
}
progress.resumingHandler = { [weak self] in
self?.setIsPaused(false)
}
progress.cancellationHandler = { [weak self] in
self?.cancel()
}
When the progress is cancelled, and the cancellation handler is invoked. We get the crash. The crash is not reproducible 100% of the time, but it happens significantly often. Especially after cleaning and rebuilding and running our tests.
* thread #4, queue = 'com.apple.root.default-qos', stop reason = EXC_BREAKPOINT (code=1, subcode=0x18017b0e8)
* frame #0: 0x000000018017b0e8 libdispatch.dylib`_dispatch_assert_queue_fail + 116
frame #1: 0x000000018017b074 libdispatch.dylib`dispatch_assert_queue + 188
frame #2: 0x00000002444c63e0 libswift_Concurrency.dylib`swift_task_isCurrentExecutorImpl(swift::SerialExecutorRef) + 284
frame #3: 0x000000010b80bd84 MyTests`closure #3 in MyController.init() at MyController.swift:0
frame #4: 0x000000010b80bb04 MyTests`thunk for @escaping @callee_guaranteed @Sendable () -> () at <compiler-generated>:0
frame #5: 0x00000001810276b0 Foundation`__20-[NSProgress cancel]_block_invoke_3 + 28
frame #6: 0x00000001801774ec libdispatch.dylib`_dispatch_call_block_and_release + 24
frame #7: 0x0000000180178de0 libdispatch.dylib`_dispatch_client_callout + 16
frame #8: 0x000000018018b7dc libdispatch.dylib`_dispatch_root_queue_drain + 1072
frame #9: 0x000000018018bf60 libdispatch.dylib`_dispatch_worker_thread2 + 232
frame #10: 0x00000001012a77d8 libsystem_pthread.dylib`_pthread_wqthread + 224
Any thoughts on why this is crashing and what we can do to work-around it? I have not been able to extract our code into a simple reproducible case yet. And I mostly see it when running our code in a testing environment (XCTest). Although I have been able to reproduce it running an app a few times, it's just less common.
This is not a question but more of a hint where I was having trouble with. In my SwiftData App I wanted to move from Swift 5 to Swift 6, for that, as recommended, I stayed in Swift 5 language mode and set 'Strict Concurrency Checking' to 'Complete' within my build settings.
It marked all the places where I was using predicates with the following warning:
Type '' does not conform to the 'Sendable' protocol; this is an error in the Swift 6 language mode
I had the same warnings for SortDescriptors.
I spend quite some time searching the web and wrapping my head around how to solve that issue to be able to move to Swift 6. In the end I found this existing issue in the repository of the Swift Language https://github.com/swiftlang/swift/issues/68943. It says that this is not a warning that should be seen by the developer and in fact when turning Swift 6 language mode on those issues are not marked as errors.
So if anyone is encountering this when trying to fix all issues while staying in Swift 5 language mode, ignore those, fix the other issues and turn on Swift 6 language mode and hopefully they are gone.
When swizzling NSURLRequest initialiser and returning a mutable copy, the original instance does not get deallocated and eventually gets leaked and a crash follows after that.
Here's the swizzling setup:
static func swizzleInit() {
let initSel = NSSelectorFromString("initWithURL:cachePolicy:timeoutInterval:")
guard let initMethod = class_getInstanceMethod(NSClassFromString("NSURLRequest"), initSel) else {
return
}
let origInitImp = method_getImplementation(initMethod)
let block: @convention(block) (AnyObject, Any, NSURLRequest.CachePolicy, TimeInterval) -> NSURLRequest = { _self, url, policy, interval in
typealias OrigInit = @convention(c) (AnyObject, Selector, Any, NSURLRequest.CachePolicy, TimeInterval) -> NSURLRequest
let origFunc = unsafeBitCast(origInitImp, to: OrigInit.self)
let request = origFunc(_self, initSel, url, policy, interval)
return request.tagged()
}
let newImplementation = imp_implementationWithBlock(block as Any)
method_setImplementation(initMethod, newImplementation)
}
// create a mutable copy if needed and add a header
private func tagged() -> NSURLRequest {
guard let mutableRequest = self as? NSMutableURLRequest ?? self.mutableCopy() as? NSMutableURLRequest else {
return self
}
mutableRequest.setValue("test", forHTTPHeaderField: "test")
return mutableRequest
}
Then, we have a few test cases:
// memory leak and crash
func testSwizzleNSURLRequestInit() {
let request = NSURLRequest(url: URL(string: "https://example.com")!)
XCTAssertEqual(request.value(forHTTPHeaderField: "test"), "test")
}
// no crash, as the request is mutable, so no copy is created
func testSwizzleNSURLRequestInit2() {
let request = URLRequest(url: URL(string: "https://example.com")!)
XCTAssertEqual(request.value(forHTTPHeaderField: "test"), "test")
}
// no crash, as the request is mutable, so no copy is created
func testSwizzleNSURLRequestInit3() {
let request = NSMutableURLRequest(url: URL(string: "https://example.com")!)
XCTAssertEqual(request.value(forHTTPHeaderField: "test"), "test")
}
// no crash, as the new instance does not get deallocated
// when the test method completes (?)
var request: NSURLRequest?
func testSwizzleNSURLRequestInit4() {
request = NSURLRequest(url: URL(string: "https://example.com")!)
XCTAssertEqual(request?.value(forHTTPHeaderField: "test"), "test")
}
It appears a memory leak occurs only when any other instance except for the original one is being returned from the initialiser.
Is there a workaround to prevent the leak, while allowing for modifications of all requests?
Hi, I have issue on build my react native project and got this error "Undefined symbol: _swift_willThrowTypedImpl" how can I fix it?
This is similar to this post https://developer.apple.com/forums/thread/700770 on using objc_copyClassList to obtain the available classes. When iterating the list, I try casting the result to an instance of a protocol and that works fine:
protocol DynamicCounter {
init(controlledByPlayer: Bool, game: Game)
}
class BaseCounter: NSObject, DynamicCounter {
}
static func withAllClasses<R>(
_ body: (UnsafeBufferPointer<AnyClass>) throws -> R
) rethrows -> R {
var count: UInt32 = 0
let classListPtr = objc_copyClassList(&count)
defer {
free(UnsafeMutableRawPointer(classListPtr))
}
let classListBuffer = UnsafeBufferPointer(
start: classListPtr, count: Int(count)
)
return try body(classListBuffer)
}
static func initialize() {
let monoClasses = withAllClasses { $0.compactMap { $0 as? DynamicCounter.Type } }
for cl in monoClasses {
cl.initialize()
}
}
The above code works fine if I use DynamicCounter.Type on the cast but crashes if try casting to BaseCounter.Type instead.
Is there a way to avoid the weird and non Swift classes?
I have a relatively unique project layered with file types (top to bottom) SwiftUI, Swift, Objective C, and C. The purpose of this layering is that I have a C language firmware application framework for development of firmware on custom electronic boards.
Specifically, I use the standard C preprocessor in specific ways to make data driven structures, not code. There are header files shared between the firmware project and the Xcode iPhone app to set things like the BLE protocol and communication command/reply protocols, etc. The app is forced to adhere to that defined by the firmware, rather than rely a design to get it right.
The Objective C code is mainly to utilize the Bluetooth stack provided by iOS. I specifically use this approach to allow C files to be compiled. Normally, everything has worked perfectly, but a serious and obtuse problem just surfaced a couple days ago.
My important project was created long ago. More recently, I started a new project using most of the same technology, but its project is newer. Ironically, it continues to work perfectly, but ironically the older project stopped working. (Talking about the Xcode iOS side.)
Essentially, the Objective C handling of the C preprocessor is not fully adhering to the standard C preprocessing in one project. It's very confusing because there is no code change. It seems Xcode was updated, but looks like the project was not updated, accordingly? I'm guessing there is some setting that forces Objective C to adhere to the standard C preprocessor rules.
I did see a gnu compiler version that did not get updated compared to the newer project, but updating that in the Build Settings did not fix the problem.
The error is in the title:
Token is not a valid binary operator in a preprocessor subexpression.
The offending macro appears in a header file, included in several implementation files. Compiling a single implementation files isolates the issue somewhat. An implementation with no Objective C objects compiles just fine. If there are Objective C objects then I get the errors. Both cases include the same header.
It seems like the Objective C compiler, being invoked, uses a different C preprocessor parser, rather than the standard. I guess I should mention the bridging header file where these headers exist, as well. The offending header with the problem macro appears as an error in the bridging header if a full build is initiated.
Is there an option somewhere, that forces the Objective C compiler to honor the standard C processor? Note, one project seems to.
#define BLE_SERVICE_BLANK( enumTag, uuid, serviceType )
#define BLE_CHARACTERISTIC_BLANK( enumTag, uuid, properties, readPerm, writePerm, value)
#define BLE_SERVICE_ENUM_COUNTER( enumTag, uuid, serviceType) +1
#define BLE_CHARACTERISTIC_ENUM_COUNTER( enumTag, uuid, properties, readPerm, writePerm, value) +1
#if 0 BLE_SERVICE_LIST(BLE_SERVICE_ENUM_COUNTER, BLE_CHARACTERISTIC_BLANK) > 0
#define USING_BLE_SERVICE
...
#if 0 BLE_SERVICE_LIST(BLE_SERVICE_BLANK, BLE_CHARACTERISTIC_ENUM_COUNTER) > 0
#define USING_BLE_CHARACTERISTIC
...
token is not a valid binary operator in a preprocessor subexpression
refers to the comparison. BLE_SERVICE_LIST() does a +1 for each item in the list. There is no further expansion. One counts services. The other counts characteristics. The errors are associated with the comparisons.
In below Swift code , is there any possiblities of failure of Unmanaged.passRetain and Unmanaged.takeRetain calls ?
// can below call fail (constructor returns nil due to OS or language error) and do i need to do explicit error handling here?
let str = TWSwiftString(pnew)
// Increasing RC by 1
// can below call fail (assuming str is valid) and do i need to do explicit error handling for the same ?
let ptr:UnsafeMutableRawPointer? = Unmanaged.passRetained(str).toOpaque()
// decrease RC by 1
// can below call fail (assuming ptr is valid) ? and do i need to do explicit error handling
Unmanaged<TWSwiftString>.fromOpaque(pStringptr).release()
I make some small program to make dots. Many of them.
I have a Generator which generates dots in a loop:
//reprat until all dots in frame
while !newDots.isEmpty {
virginDots = []
for newDot in newDots {
autoreleasepool{
virginDots.append(
contentsOf: newDot.addDots(in: size, allDots: &result, inSomeWay))
}
newDots = virginDots
}
counter += 1
print ("\(result.count) dots in \(counter) grnerations")
}
Sometimes this loop needs hours/days to finish (depend of inSomeWay settings), so it would be very nice to send partial result to a View, and/or if result is not satisfying — break this loop and start over.
My understanding of Tasks and Concurrency became worse each time I try to understand it, maybe it's my age, maybe language barier. For now, Button with {Task {...}} action doesn't removed Rainbow Wheel from my screen. Killing an app is wrong because killing is wrong.
How to deal with it?
import Foundation
import FirebaseAuth
import GoogleSignIn
import FBSDKLoginKit
class AuthController {
// Assuming these variables exist in your class
var showCustomAlertLoading = false
var signUpResultText = ""
var isSignUpSucces = false
var navigateHome = false
// Google Sign-In
func googleSign() {
guard let presentingVC = (UIApplication.shared.connectedScenes.first as? UIWindowScene)?.windows.first?.rootViewController else {
print("No root view controller found.")
return
}
GIDSignIn.sharedInstance.signIn(withPresenting: presentingVC) { authentication, error in
if let error = error {
print("Error: \(error.localizedDescription)")
return
}
guard let authentication = authentication else {
print("Authentication is nil")
return
}
guard let idToken = authentication.idToken else {
print("ID Token is missing")
return
}
guard let accessToken = authentication.accessToken else {
print("Access Token is missing")
return
}
let credential = GoogleAuthProvider.credential(withIDToken: idToken.tokenString, accessToken: accessToken.tokenString)
self.showCustomAlertLoading = true
Auth.auth().signIn(with: credential) { authResult, error in
guard let user = authResult?.user, error == nil else {
self.signUpResultText = error?.localizedDescription ?? "Error occurred"
DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
self.showCustomAlertLoading = false
}
return
}
self.signUpResultText = "\(user.email ?? "No email")\nSigned in successfully"
self.isSignUpSucces = true
DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
self.showCustomAlertLoading = false
DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
self.navigateHome = true
}
}
print("\(user.email ?? "No email") signed in successfully")
}
}
}
// Facebook Sign-In
func signInWithFacebook(presentingViewController: UIViewController, completion: @escaping (Bool, Error?) -> Void) {
let manager = LoginManager()
manager.logIn(permissions: ["public_profile", "email"], from: presentingViewController) { result, error in
if let error = error {
completion(false, error)
return
}
guard let result = result, !result.isCancelled else {
completion(false, NSError(domain: "Facebook Login Error", code: 400, userInfo: nil))
return
}
if let token = result.token {
let credential = FacebookAuthProvider.credential(withAccessToken: token.tokenString)
Auth.auth().signIn(with: credential) { (authResult, error) in
if let error = error {
completion(false, error)
return
}
completion(true, nil)
}
}
}
}
// Email Sign-In
func signInWithEmail(email: String, password: String, completion: @escaping (Bool, Error?) -> Void) {
Auth.auth().signIn(withEmail: email, password: password) { (authResult, error) in
if let error = error {
completion(false, error)
return
}
completion(true, nil)
}
}
}
Topic:
Programming Languages
SubTopic:
Swift
https://developer.apple.com/forums/thread/768776
Swift concurrency is an important part of my day-to-day job. I created the following document for an internal presentation, and I figured that it might be helpful for others.
If you have questions or comments, put them in a new thread here on DevForums. Use the App & System Services > Processes & Concurrency topic area and tag it with both Swift and Concurrency.
Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"
Swift Concurrency Proposal Index
This post summarises the Swift Evolution proposals that went into the Swift concurrency design. It covers the proposal that are implemented in Swift 6.2, plus a few additional ones that aren’t currently available.
The focus is here is the Swift Evolution proposals. For general information about Swift concurrency, see the documentation referenced by Concurrency Resources.
Swift 6.0
The following Swift Evolution proposals form the basis of the Swift 6.0 concurrency design.
SE-0176 Enforce Exclusive Access to Memory
link: SE-0176
notes: This defines the “Law of Exclusivity”, a critical foundation for both serial and concurrent code.
SE-0282 Clarify the Swift memory consistency model ⚛︎
link: SE-0282
notes: This defines Swift’s memory model, that is, the rules about what is and isn’t allowed when it comes to concurrent memory access.
SE-0296 Async/await
link: SE-0296
introduces: async functions, async, await
SE-0297 Concurrency Interoperability with Objective-C
link: SE-0297
notes: Specifies how Swift imports an Objective-C method with a completion handler as an async method. Explicitly allows @objc actors.
SE-0298 Async/Await: Sequences
link: SE-0298
introduces: AsyncSequence, for await syntax
notes: This just defines the AsyncSequence protocol. For one concrete implementation of that protocol, see SE-0314.
SE-0300 Continuations for interfacing async tasks with synchronous code
link: SE-0300
introduces: CheckedContinuation, UnsafeContinuation
notes: Use these to create an async function that wraps a legacy request-reply concurrency construct.
SE-0302 Sendable and @Sendable closures
link: SE-0302
introduces: Sendable, @Sendable closures, marker protocols
SE-0304 Structured concurrency
link: SE-0304
introduces: unstructured and structured concurrency, Task, cancellation, CancellationError, withTaskCancellationHandler(…), sleep(…), withTaskGroup(…), withThrowingTaskGroup(…)
notes: For the async let syntax, see SE-0317. For more ways to sleep, see SE-0329 and SE-0374. For discarding task groups, see SE-0381.
SE-0306 Actors
link: SE-0306
introduces: actor syntax
notes: For actor-isolated parameters and the nonisolated keyword, see SE-0313. For global actors, see SE-0316. For custom executors and the Actor protocol, see SE-0392.
SE-0311 Task Local Values
link: SE-0311
introduces: TaskLocal
SE-0313 Improved control over actor isolation
link: SE-0313
introduces: isolated parameters, nonisolated
SE-0314 AsyncStream and AsyncThrowingStream
link: SE-0314
introduces: AsyncStream, AsyncThrowingStream, onTermination
notes: These are super helpful when you need to publish a legacy notification construct as an async stream. For a simpler API to create a stream, see SE-0388.
SE-0316 Global actors
link: SE-0316
introduces: GlobalActor, MainActor
notes: This includes the @MainActor syntax for closures.
SE-0317 async let bindings
link: SE-0317
introduces: async let syntax
SE-0323 Asynchronous Main Semantics
link: SE-0323
SE-0327 On Actors and Initialization
link: SE-0327
notes: For a proposal to allow access to non-sendable isolated state in a deinitialiser, see SE-0371.
SE-0329 Clock, Instant, and Duration
link: SE-0329
introduces: Clock, InstantProtocol, DurationProtocol, Duration, ContinuousClock, SuspendingClock
notes: For another way to sleep, see SE-0374.
SE-0331 Remove Sendable conformance from unsafe pointer types
link: SE-0331
SE-0337 Incremental migration to concurrency checking
link: SE-0337
introduces: @preconcurrency, explicit unavailability of Sendable
notes: This introduces @preconcurrency on declarations, on imports, and on Sendable protocols. For @preconcurrency conformances, see SE-0423.
SE-0338 Clarify the Execution of Non-Actor-Isolated Async Functions
link: SE-0338
note: This change has caught a bunch of folks by surprise and there’s a discussion underway as to whether to adjust it.
SE-0340 Unavailable From Async Attribute
link: SE-0340
introduces: noasync availability kind
SE-0343 Concurrency in Top-level Code
link: SE-0343
notes: For how strict concurrency applies to global variables, see SE-0412.
SE-0374 Add sleep(for:) to Clock
link: SE-0374
notes: This builds on SE-0329.
SE-0381 DiscardingTaskGroups
link: SE-0381
introduces: DiscardingTaskGroup, ThrowingDiscardingTaskGroup
notes: Use this for task groups that can run indefinitely, for example, a network server.
SE-0388 Convenience Async[Throwing]Stream.makeStream methods
link: SE-0388
notes: This builds on SE-0314.
SE-0392 Custom Actor Executors
link: SE-0392
introduces: Actor protocol, Executor, SerialExecutor, ExecutorJob, assumeIsolated(…)
notes: For task executors, a closely related concept, see SE-0417. For custom isolation checking, see SE-0424.
SE-0395 Observation
link: SE-0395
introduces: Observation module, Observable
notes: While this isn’t directly related to concurrency, it’s relationship to Combine, which is an important exising concurrency construct, means I’ve included it in this list.
SE-0401 Remove Actor Isolation Inference caused by Property Wrappers
link: SE-0401, commentary
availability: upcoming feature flag: DisableOutwardActorInference
SE-0410 Low-Level Atomic Operations ⚛︎
link: SE-0410
introduces: Synchronization module, Atomic, AtomicLazyReference, WordPair
SE-0411 Isolated default value expressions
link: SE-0411, commentary
SE-0412 Strict concurrency for global variables
link: SE-0412
introduces: nonisolated(unsafe)
notes: While this is a proposal about globals, the introduction of nonisolated(unsafe) applies to “any form of storage”.
SE-0414 Region based Isolation
link: SE-0414, commentary
notes: To send parameters and results across isolation regions, see SE-0430.
SE-0417 Task Executor Preference
link: SE-0417, commentary
introduces: withTaskExecutorPreference(…), TaskExecutor, globalConcurrentExecutor
notes: This is closely related to the custom actor executors defined in SE-0392.
SE-0418 Inferring Sendable for methods and key path literals
link: SE-0418, commentary
availability: upcoming feature flag: InferSendableFromCaptures
notes: The methods part of this is for “partial and unapplied methods”.
SE-0420 Inheritance of actor isolation
link: SE-0420, commentary
introduces: #isolation, optional isolated parameters
notes: This is what makes it possible to iterate over an async stream in an isolated async function.
SE-0421 Generalize effect polymorphism for AsyncSequence and AsyncIteratorProtocol
link: SE-0421, commentary
notes: Previously AsyncSequence used an experimental mechanism to support throwing and non-throwing sequences. This moves it off that. Instead, it uses an extra Failure generic parameter and typed throws to achieve the same result. This allows it to finally support a primary associated type. Yay!
SE-0423 Dynamic actor isolation enforcement from non-strict-concurrency contexts
link: SE-0423, commentary
introduces: @preconcurrency conformance
notes: This adds a number of dynamic actor isolation checks (think assumeIsolated(…)) to close strict concurrency holes that arise when you interact with legacy code.
SE-0424 Custom isolation checking for SerialExecutor
link: SE-0424, commentary
introduces: checkIsolation()
notes: This extends the custom actor executors introduced in SE-0392 to support isolation checking.
SE-0430 sending parameter and result values
link: SE-0430, commentary
introduces: sending
notes: Adds the ability to send parameters and results between the isolation regions introduced by SE-0414.
SE-0431 @isolated(any) Function Types
link: SE-0431, commentary, commentary
introduces: @isolated(any) attribute on function types, isolation property of functions values
notes: This is laying the groundwork for SE-NNNN Closure isolation control. That, in turn, aims to bring the currently experimental @_inheritActorContext attribute into the language officially.
SE-0433 Synchronous Mutual Exclusion Lock 🔒
link: SE-0433
introduces: Mutex
SE-0434 Usability of global-actor-isolated types
link: SE-0434, commentary
availability: upcoming feature flag: GlobalActorIsolatedTypesUsability
notes: This loosen strict concurrency checking in a number of subtle ways.
Swift 6.1
Swift 6.1 has the following additions.
Vision: Improving the approachability of data-race safety
link: vision
SE-0442 Allow TaskGroup’s ChildTaskResult Type To Be Inferred
link: SE-0442, commentary
notes: This represents a small quality of life improvement for withTaskGroup(…) and withThrowingTaskGroup(…).
SE-0449 Allow nonisolated to prevent global actor inference
link: SE-0449, commentary
notes: This is a straightforward extension to the number of places you can apply nonisolated.
Swift 6.2
Xcode 26 beta has two new build settings:
Approachable Concurrency enables the following feature flags: DisableOutwardActorInference, GlobalActorIsolatedTypesUsability, InferIsolatedConformances, InferSendableFromCaptures, and NonisolatedNonsendingByDefault.
Default Actor Isolation controls SE-0466
Swift 6.2, still in beta, has the following additions.
SE-0371 Isolated synchronous deinit
link: SE-0371, commentary
introduces: isolated deinit
notes: Allows a deinitialiser to access non-sendable isolated state, lifting a restriction imposed by SE-0327.
SE-0457 Expose attosecond representation of Duration
link: SE-0457
introduces: attoseconds, init(attoseconds:)
SE-0461 Run nonisolated async functions on the caller’s actor by default
link: SE-0461
availability: upcoming feature flag: NonisolatedNonsendingByDefault
introduces: nonisolated(nonsending), @concurrent
notes: This represents a significant change to how Swift handles actor isolation by default, and introduces syntax to override that default.
SE-0462 Task Priority Escalation APIs
link: SE-0462
introduces: withTaskPriorityEscalationHandler(…)
notes: Code that uses structured concurrency benefits from priority boosts automatically. This proposal exposes APIs so that code using unstructured concurrency can do the same.
SE-0463 Import Objective-C completion handler parameters as @Sendable
link: SE-0463
notes: This is a welcome resolution to a source of much confusion.
SE-0466 Control default actor isolation inference
link: SE-0466, commentary
availability: not officially approved, but a de facto part of Swift 6.2
introduces: -default-isolation compiler flag
notes: This is a major component of the above-mentioned vision document.
SE-0468 Hashable conformance for Async(Throwing)Stream.Continuation
link: SE-0468
notes: This is an obvious benefit when you’re juggling a bunch of different async streams.
SE-0469 Task Naming
link: SE-0469
introduces: name, init(name:…)
SE-0470 Global-actor isolated conformances
link: SE-0470
availability: upcoming feature flag: InferIsolatedConformances
introduces: @SomeActor protocol conformance
notes: This is particularly useful when you want to conform an @MainActor type to Equatable, Hashable, and so on.
SE-0471 Improved Custom SerialExecutor isolation checking for Concurrency Runtime
link: SE-0471
notes: This is a welcome extension to SE-0424.
SE-0472 Starting tasks synchronously from caller context
link: SE-0472
introduces: immediate[Detached](…), addImmediateTask[UnlessCancelled](…),
notes: This introduces the concept of an immediate task, one that initially uses the calling execution context. This is one of those things where, when you need it, you really need it. But it’s hard to summary when you might need it, so you’ll just have to read the proposal (-:
In Progress
The proposals in this section didn’t make Swift 6.2.
SE-0406 Backpressure support for AsyncStream
link: SE-0406
availability: returned for revision
notes: Currently AsyncStream has very limited buffering options. This was a proposal to improve that. This feature is still very much needed, but the outlook for this proposal is hazy. My best guess is that something like this will land first in the Swift Async Algorithms package. See this thread.
SE-NNNN Closure isolation control
link: SE-NNNN
introduces: @inheritsIsolation
availability: not yet approved
notes: This aims to bring the currently experimental @_inheritActorContext attribute into the language officially. It’s not clear how this will play out given the changes in SE-0461.
Revision History
2025-09-02 Updated for the upcoming release Swift 6.2.
2025-04-07 Updated for the release of Swift 6.1, including a number of things that are still in progress.
2024-11-09 First post.
Hi,
I have a complex structure of classes, and I'm trying to migrate to swift6
For this classes I've a facade that creates the classes for me without disclosing their internals, only conforming to a known protocol
I think I've hit a hard wall in my knowledge of how the actors can exchange data between themselves. I've created a small piece of code that can trigger the error I've hit
import SwiftUI
import Observation
@globalActor
actor MyActor {
static let shared: some Actor = MyActor()
init() {
}
}
@MyActor
protocol ProtocolMyActor {
var value: String { get }
func set(value: String)
}
@MyActor
func make(value: String) -> ProtocolMyActor {
return ImplementationMyActor(value: value)
}
class ImplementationMyActor: ProtocolMyActor {
private(set) var value: String
init(value: String) {
self.value = value
}
func set(value: String) {
self.value = value
}
}
@MainActor
@Observable
class ViewObserver {
let implementation: ProtocolMyActor
var value: String
init() async {
let implementation = await make(value: "Ciao")
self.implementation = implementation
self.value = await implementation.value
}
func set(value: String) {
Task {
await implementation.set(value: value)
self.value = value
}
}
}
struct MyObservedView: View {
@State var model: ViewObserver?
var body: some View {
if let model {
Button("Loaded \(model.value)") {
model.set(value: ["A", "B", "C"].randomElement()!)
}
} else {
Text("Loading")
.task {
self.model = await ViewObserver()
}
}
}
}
The error
Non-sendable type 'any ProtocolMyActor' passed in implicitly asynchronous call to global actor 'MyActor'-isolated property 'value' cannot cross actor boundary
Occurs in the init on the line "self.value = await implementation.value"
I don't know which concurrency error happens... Yes the init is in the MainActor , but the ProtocolMyActor data can only be accessed in a MyActor queue, so no data races can happen... and each access in my ImplementationMyActor uses await, so I'm not reading or writing the object from a different actor, I just pass sendable values as parameter to a function of the object..
can anybody help me understand better this piece of concurrency problem?
Thanks
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