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Incorrect menu consistency warnings logged in Tahoe for NSStatusItem, performance issues related?
Is anyone else getting new warning about menu items with submenus when running on Tahoe? I'm getting big performance problems using my menu as well as seeing these messages and I'm wondering if there's a connection. My app is faceless with a NSStatusItem with an NSMenu. Specifically it's my own subclass of NSMenu where I have a lot of code to manage the menu's dynamic behavior. This code is directly in the menu subclass instead of in a controller because the app I forked had it this way, a little wacky but I don't see it being a problem. A nib defines the contents of the menu, and it's instantiated manually with code like: var nibObjects: NSArray? = [] guard let nib = NSNib(nibNamed: "AppMenu", bundle: nil) else { ... } guard nib.instantiate(withOwner: owner, topLevelObjects: &nibObjects) else { ... } guard let menu = nibObjects?.compactMap({ $0 as? Self }).first else { ... } Within that nib.instantiate call I see a warning logged that seems new to Tahoe, before the menu's awakeFromNib is called, that says (edited): Internal inconsistency in menus - menu <NSMenu: 0x6000034e5340> believes it has <My_StatusItem_App.AppMenu: 0x7f9570c1a440> as a supermenu, but the supermenu does not seem to have any item with that submenu My_StatusItem_App.AppMenu: 0x7f9570c1a440 is my menu belonging to the NSStatusItem, NSMenu: 0x6000034e5340 is the submenu of one of its menu items. At a breakpoint in the NSMenu subclass's awakeFromNib I print self and see clear evidence of the warning's incorrectness. Below is a snippet of the console including the full warning, only edited for clarity and brevity. It shows on line 32 menu item with placeholder title "prototype batch item" that indeed has that submenu. Internal inconsistency in menus - menu <NSMenu: 0x6000034e5340> Title: Supermenu: 0x7f9570c1a440 (My StatusItem App), autoenable: YES Previous menu: 0x0 (None) Next menu: 0x0 (None) Items: ( "<NSMenuItem: 0x6000010e4fa0 Do The Thing Again, ke mask='<none>'>", "<NSMenuItem: 0x6000010e5040 Customize\U2026, ke mask='<none>'>", "<NSMenuItem: 0x6000010e50e0, ke mask='<none>'>" ) believes it has <My_StatusItem_App.AppMenu: 0x7f9570c1a440> Title: My StatusItem App Supermenu: 0x0 (None), autoenable: YES Previous menu: 0x0 (None) Next menu: 0x0 (None) Items: ( ) as a supermenu, but the supermenu does not seem to have any item with that submenu (lldb) po self <My_StatusItem_App.AppMenu: 0x7f9570c1a440> Title: My StatusItem App Supermenu: 0x0 (None), autoenable: YES Previous menu: 0x0 (None) Next menu: 0x0 (None) Items: ( "<NSMenuItem: 0x6000010fd7c0 About My StatusItem App\U2026, ke mask='<none>', action: showAbout:, action image: info.circle>", "<NSMenuItem: 0x6000010fd860 Show Onboarding Window\U2026, ke mask='Shift', action: showIntro:>", "<NSMenuItem: 0x6000010fd900 Update Available\U2026, ke mask='<none>', action: installUpdate:, standard image: icloud.and.arrow.down, hidden>", "<NSMenuItem: 0x6000010e46e0, ke mask='<none>'>", "<NSMenuItem: 0x6000010e4780 Start The Thing, ke mask='<none>', action: startTheThing:>", "<NSMenuItem: 0x6000010e4dc0 \U2318-\U232b key detector item, ke mask='<none>', view: <My_StatusItem_App.KeyDetectorView: 0x7f9570c1a010>>", "<NSMenuItem: 0x6000010e4e60, ke mask='<none>'>", "<NSMenuItem: 0x6000010e4f00 saved batches heading item, ke mask='<none>', view: <NSView: 0x7f9570b4be10>, hidden>", "<My_StatusItem_App.BatchMenuItem: 0x6000016e02c0 prototype batch item, ke mask='<none>', action: replaySavedBatch:, submenu: 0x6000034e5340 ()>", "<NSMenuItem: 0x6000010f7d40, ke mask='<none>'>", "<My_StatusItem_App.ClipMenuItem: 0x7f956ef14fd0 prototype copy clip item, ke mask='<none>', action: copyClip:>", "<NSMenuItem: 0x6000010fa620 Settings\U2026, ke='Command-,', action: showSettings:>", "<NSMenuItem: 0x6000010fa6c0, ke mask='<none>'>", "<NSMenuItem: 0x6000010fa760 Quit My StatusItem App, ke='Command-Q', action: quit:>" ) Is this seemingly incorrect inconsistency message harmless? Am I only grasping at straws to think it has some connection to the performance issues with this menu?
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SwifUI Performance With Rapid UI Updates
The code below is a test to trigger UI updates every 30 seconds. I'm trying to keep most work off main and only push to main once I have the string (which is cached). Why is updating SwiftUI 30 times per second so expensive? This code causes 10% CPU on my M4 Mac, but comment out the following line: Text(model.timeString) and it's 0% CPU. The reason why I think I have too much work on main is because of this from instruments. But I'm no instruments expert. import SwiftUI import UniformTypeIdentifiers @main struct RapidUIUpdateTestApp: App { var body: some Scene { DocumentGroup(newDocument: RapidUIUpdateTestDocument()) { file in ContentView(document: file.$document) } } } struct ContentView: View { @Binding var document: RapidUIUpdateTestDocument @State private var model = PlayerModel() var body: some View { VStack(spacing: 16) { Text(model.timeString) // only this changes .font(.system(size: 44, weight: .semibold, design: .monospaced)) .transaction { $0.animation = nil } // no implicit animations HStack { Button(model.running ? "Pause" : "Play") { model.running ? model.pause() : model.start() } Button("Reset") { model.seek(0) } Stepper("FPS: \(Int(model.fps))", value: $model.fps, in: 10...120, step: 1) .onChange(of: model.fps) { _, _ in model.applyFPS() } } } .padding() .onAppear { model.start() } .onDisappear { model.stop() } } } @Observable final class PlayerModel { // Publish ONE value to minimize invalidations var timeString: String = "0.000 s" var fps: Double = 30 var running = false private var formatter: NumberFormatter = { let f = NumberFormatter() f.minimumFractionDigits = 3 f.maximumFractionDigits = 3 return f }() @ObservationIgnored private let q = DispatchQueue(label: "tc.timer", qos: .userInteractive) @ObservationIgnored private var timer: DispatchSourceTimer? @ObservationIgnored private var startHost: UInt64 = 0 @ObservationIgnored private var pausedAt: Double = 0 @ObservationIgnored private var lastFrame: Int = -1 // cache timebase once private static let secsPerTick: Double = { var info = mach_timebase_info_data_t() mach_timebase_info(&info) return Double(info.numer) / Double(info.denom) / 1_000_000_000.0 }() func start() { guard timer == nil else { running = true; return } let desiredUIFPS: Double = 30 // or 60, 24, etc. let periodNs = UInt64(1_000_000_000 / desiredUIFPS) running = true startHost = mach_absolute_time() let t = DispatchSource.makeTimerSource(queue: q) // ~30 fps, with leeway to let the kernel coalesce wakeups t.schedule( deadline: .now(), repeating: .nanoseconds(Int(periodNs)), // 33_333_333 ns ≈ 30 fps leeway: .milliseconds(30) // allow coalescing ) t.setEventHandler { [weak self] in self?.tick() } timer = t t.resume() } func pause() { guard running else { return } pausedAt = now() running = false } func stop() { timer?.cancel() timer = nil running = false pausedAt = 0 lastFrame = -1 } func seek(_ seconds: Double) { pausedAt = max(0, seconds) startHost = mach_absolute_time() lastFrame = -1 // force next UI update } func applyFPS() { lastFrame = -1 } // next tick will refresh string // MARK: - Tick on background queue private func tick() { let s = now() let str = formatter.string(from: s as NSNumber) ?? String(format: "%.3f", s) let display = "\(str) s" DispatchQueue.main.async { [weak self] in self?.timeString = display } } private func now() -> Double { guard running else { return pausedAt } let delta = mach_absolute_time() &- startHost return pausedAt + Double(delta) * Self.secsPerTick } } nonisolated struct RapidUIUpdateTestDocument: FileDocument { var text: String init(text: String = "Hello, world!") { self.text = text } static let readableContentTypes = [ UTType(importedAs: "com.example.plain-text") ] init(configuration: ReadConfiguration) throws { guard let data = configuration.file.regularFileContents, let string = String(data: data, encoding: .utf8) else { throw CocoaError(.fileReadCorruptFile) } text = string } func fileWrapper(configuration: WriteConfiguration) throws -> FileWrapper { let data = text.data(using: .utf8)! return .init(regularFileWithContents: data) } }
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Clarification on SwiftUI Environment Write Performance
I'm looking for clarification on a SwiftUI performance point mentioned in the recent Optimize your app's speed and efficiency | Meet with Apple video. (YouTube link not allowed, but the video is available on the Apple Developer channel.) At the 1:48:50 mark, the presenter says: Writing a value to the Environment doesn't only affect the views that read the key you're updating. It updates any view that reads from any Environment key. [abbreviated quote] That statement seems like a big deal if your app relies heavily on Environment values. Context I'm building a macOS application with a traditional three-panel layout. At any given time, there are many views on screen, plus others that exist in the hierarchy but are currently hidden (for example, views inside tab views or collapsed splitters). Nearly every major view reads something from the environment—often an @Observable object that acts as a service or provider. However, there are a few relatively small values that are written to the environment frequently, such as: The selected tab index The currently selected object on a canvas The Question Based on the presenter's statement, I’m wondering: Does writing any value to the environment really cause all views in the entire SwiftUI view hierarchy that read any environment key to have their body re-evaluated? Do environment writes only affect child views, or do they propagate through the entire SwiftUI hierarchy? Example: View A └─ View B ├─ View C └─ View D If View B updates an environment value, does that affect only C and D, or does it also trigger updates in A and B (assuming each view has at least one @Environment property)? Possible Alternative If all views are indeed invalidated by environment writes, would it be more efficient to “wrap” frequently-changing values inside an @Observable object instead of updating the environment directly? // Pseudocode @Observable final class SelectedTab { var index: Int } ContentView() .environment(\.selectedTab, selectedTab) struct TabView: View { @Environment(\.selectedTab) private var selectedTab var body: some View { Button("Action") { // Would this avoid invalidating all views using the environment? selectedTab.index = 1 } } } Summary From what I understand, it sounds like the environment should primarily be used for stable, long-lived objects—not for rapidly changing values—since writes might cause far more view invalidations than most developers realize. Is that an accurate interpretation? Follow-Up In Xcode 26 / Instruments, is there a way to monitor writes to @Environment?
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Inconsistent subviews redrawing in LazyVStack
Hello Apple forum ! I spotted a weird behaviour with LazyVStack in a ScrollView. I understand that it loads its views only once upon appearance unlinke VStack that loads everything in one shot. What I noticed also, it seems to reload its views sometimes when scrolling back up to earlier loaded views. The thing is, it isn't always the case. struct LazyVStackTest: View { var body: some View { ScrollView { LazyVStack { ForEach(0..<1000, id: \.self) { _ in // if true { MyText() // } } } } } struct MyText: View { var body: some View { let _ = Self._printChanges() HStack { Text("hello") } } } } If we consider the code above on XCode 26 beta 7 on an iOS 26 or iOS 18.2 simulator. Scroll to the bottom : you'll see one "LazyVStackTest.MyText: @self changed" for each row. Then scroll back up to the top, we'll see again the same message printed multiple times. --> So I gather from this that LazyVStack not only loads lazily but also removes old rows from memory & recreates them upon reappearance. What I don't get however is that if you uncomment the "if true" statement, you won't see the reloading happening. And I have absolutely no clue as to why 😅 If someone could help shed some light on this weird behaviour, it would be greatly appreciated ^^ PS : the issue is also present with XCode 16.2 but at a deeper lever (ex: if we embed another custom View "MyText2" inside "MyText", the reloading is in "MyText2" & not "MyText")
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176
Aug ’25
Why does CADisplayLink of an external UIScreen drift in time?
I am using Apple's original Lightning Digital AV-adapter (Lightning-to-HDMI dongle) to connect my iPhone to an external display via a HDMI cable. I need to synchronize rendering with the external display's refresh rate, so I create a new CADisplayLink tied to the external display's UIScreen: UIScreen.screens[externalDisplayIdx].displayLink(withTarget:, selector:). The callback is being called regularly, but with increasing delay relative to the CADisplayLink.timestamp, so the next time the callback is called, I have less and less time to draw the next frame (see the snippet below). Assuming 60 FPS, the value of secondsTillDeadline starts at an arbitrary value in the range of approx -0.0001 to 0.0166667, and then it slowly decreases towards zero (and for a brief period it goes into small negative numbers). Once it reaches zero, it flips back to 0.0166667 and continues to decrease again. This cycle repeats indefinitely. Changing the external display's resolution (UIScreen's mode) or the CADisplayLink's preferredFrameRateRange to a lower FPS does not seem to have any effect on the temporal drifting (even the rate of change seem to be the same). When I create a new CADisplayLink for the iPhone's main screen, the value of secondsTillDeadline is stable, it does not drift and it is very close to 0.0166667, as expected. Is this drift caused by the external monitor or by Apple's Lightning-to-HDMI dongle ...or is the problem somewhere else? Can the drifting be stopped? func onDisplayLinkUpdate(displayLink: CADisplayLink) { // Gradually decreases from 0.01667 to -0.0001, then flips back to 0.01667 and continues to decrease let secondsTillDeadline = displayLink.targetTimestamp - CACurrentMediaTime() }
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249
Aug ’25
JAX Metal: Random Number Generation Performance Issue on M1 Max
JAX Metal shows 55x slower random number generation compared to NVIDIA CUDA on equivalent workloads. This makes Monte Carlo simulations and scientific computing impractical on Apple Silicon. Performance Comparison NVIDIA GPU: 0.475s for 12.6M random elements M1 Max Metal: 26.3s for same workload Performance gap: 55x slower Environment Apple M1 Max, 64GB RAM, macOS Sequoia Version 15.6.1 JAX 0.4.34, jax-metal latest Backend: Metal Reproduction Code import time import jax import jax.numpy as jnp from jax import random key = random.PRNGKey(42) start_time = time.time() random_array = random.normal(key, (50000, 252)) duration = time.time() - start_time print(f"Duration: {duration:.3f}s")
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319
Aug ’25
Request for Device Temperature Monitoring and Thermal Attribution Analysis APIs
Background: During daily usage of iOS devices, devices experience noticeable thermal issues. This heating not only affects user experience, but may also lead to device performance throttling, shortened battery life, and other problems. We need better understanding and monitoring of device thermal states to optimize application performance and user experience. Issues Encountered: Insufficient thermal monitoring capabilities: Unable to obtain real-time accurate temperature data from devices Difficult power consumption analysis: Hard to determine which specific modules or threads cause high power consumption and heating Requested Solutions: Temperature Monitoring API: Provide accessible device temperature reading interfaces Thermal Attribution Analysis Capability: During heating events, we expect to receive more detailed power consumption monitoring data, such as CPU, GPU, network, location services, display, high power consumption thread stacks and other information to help developers identify high energy consumption operations
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Aug ’25
How to get UITextView to fit inside container, AND auto wrap
I am currently having an issue in where whenever I place a UITextView with text that's long, it simply pushes past the width of the container it is in, and when I do try and set a width, it does auto wrap and ignores that. I do not come from UIKit and come from SwiftUI, through a mix of ChatGPT and Stack overflow, I have come up with this solution, however, are there any better/simpler ones, I dont want to have to use expensive GeoReaders just to get a width. struct AutoDetectedPhoneNumberView: UIViewRepresentable { let text: String var width: CGFloat func makeUIView(context: Context) -> UITextView { let textView = UITextView() textView.dataDetectorTypes = [.phoneNumber] textView.isEditable = false textView.isScrollEnabled = false textView.backgroundColor = .clear textView.font = UIFont.systemFont(ofSize: 16) textView.textContainer.lineBreakMode = .byWordWrapping textView.translatesAutoresizingMaskIntoConstraints = false print(width) NSLayoutConstraint.activate([ textView.widthAnchor.constraint(equalToConstant: width) ]) return textView } func updateUIView(_ uiView: UITextView, context: Context) { uiView.text = text } } GeometryReader { geo in AutoDetectedPhoneNumberView(text: phone, width: geo.size.width) }
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111
Jul ’25
SwiftUI Table performance issue
I found the Table with Toggle will have performance issue when the data is large. I can reproduce it in Apple demo: https://developer.apple.com/documentation/swiftui/building_a_great_mac_app_with_swiftui Replace with a large mock data, for example database.json Try to scroll the table, it's not smooth. I found if I delete the Toggle, the performance be good. TableColumn("Favorite", value: \.favorite, comparator: BoolComparator()) { plant in Toggle("Favorite", isOn: $garden[plant.id].favorite) .labelsHidden() } Is this bug in SwiftUI? Any workaround? My Mac is Intel, not sure it can repro on Apple Silicon
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315
Jul ’25
How to Enable Game Mode
What is Game Mode? Game Mode optimizes your gaming experience by giving your game the highest priority access to your CPU and GPU, lowering usage for background tasks. And it doubles the Bluetooth sampling rate, which reduces input latency and audio latency for wireless accessories like game controllers and AirPods. See Use Game Mode on Mac See Port advanced games to Apple platforms How can I enable Game Mode in my game? Add the Supports Game Mode property (GCSupportsGameMode) to your game’s Info.plist and set to true Correctly identify your game’s Application Category with LSApplicationCategoryType (also Info.plist) Note: Enabling Game Mode makes your game eligible but is not a guarantee; the OS decides if it is ok to enable Game Mode at runtime An app that enables Game Mode but isn’t a game will be rejected by App Review. How can I disable Game Mode? Set GCSupportsGameMode to false. Note: On Mac Game Mode is automatically disabled if the game isn’t running full screen.
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Jul ’25
Can Game Mode be activated when a child (Java) process's window is fullscreened?
Imagine a native macOS app that acts as a "launcher" for a Java game.** For example, the "launcher" app might use the Swift Process API or a similar method to run the java command line tool (lets assume the user has installed Java themselves) to run the game. I have seen How to Enable Game Mode. If the native launcher app's Info.plist has the following keys set: LSApplicationCategoryType set to public.app-category.games LSSupportsGameMode set to true (for macOS 26+) GCSupportsGameMode set to true The launcher itself can cause Game Mode to activate if the launcher is fullscreened. However, if the launcher opens a Java process that opens a window, then the Java window is fullscreened, Game Mode doesn't seem to activate. In this case activating Game Mode for the launcher itself is unnecessary, but you'd expect Game Mode to activate when the actual game in the Java window is fullscreened. Is there a way to get Game Mode to activate in the latter case? ** The concrete case I'm thinking of is a third-party Minecraft Java Edition launcher, but the issue can also be demonstrated in a sample project (FB13786152). It seems like the official Minecraft launcher is able to do this, though it's not clear how. (Is its bundle identifier hardcoded in the OS to allow for this? Changing a sample app's bundle identifier to be the same as the official Minecraft launcher gets the behavior I want, but obviously this is not a practical solution.)
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Jun ’25
Can child processes inherit Info.plist properties of a parent app (such as LSSupportsGameMode)?
My high-level goal is to add support for Game Mode in a Java game, which launches via a macOS "launcher" app that runs the actual java game as a separate process (e.g. using the java command line tool). I asked this over in the Graphics & Games section and was told this, which is why I'm reposting this here. I'm uncertain how to speak to CLI tools and Java games launched from a macOS app. These sound like security and sandboxing questions which we recommend you ask about in those sections of the forums. The system seems to decide whether to enable Game Mode based on values in the Info.plist (e.g. for LSApplicationCategoryType and GCSupportsGameMode). However, the child process can't seem to see these values. Is there a way to change that? (The rest of this post is copied from my other forums post to provide additional context.) Imagine a native macOS app that acts as a "launcher" for a Java game.** For example, the "launcher" app might use the Swift Process API or a similar method to run the java command line tool (lets assume the user has installed Java themselves) to run the game. I have seen How to Enable Game Mode. If the native launcher app's Info.plist has the following keys set: LSApplicationCategoryType set to public.app-category.games LSSupportsGameMode set to true (for macOS 26+) GCSupportsGameMode set to true The launcher itself can cause Game Mode to activate if the launcher is fullscreened. However, if the launcher opens a Java process that opens a window, then the Java window is fullscreened, Game Mode doesn't seem to activate. In this case activating Game Mode for the launcher itself is unnecessary, but you'd expect Game Mode to activate when the actual game in the Java window is fullscreened. Is there a way to get Game Mode to activate in the latter case? ** The concrete case I'm thinking of is a third-party Minecraft Java Edition launcher, but the issue can also be demonstrated in a sample project (FB13786152). It seems like the official Minecraft launcher is able to do this, though it's not clear how. (Is its bundle identifier hardcoded in the OS to allow for this? Changing a sample app's bundle identifier to be the same as the official Minecraft launcher gets the behavior I want, but obviously this is not a practical solution.)
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223
Jun ’25
Swift Charts - weak scrolling performance
Hello there! I wanted to give a native scrolling mechanism for the Swift Charts Graph a try and experiment a bit if the scenario that we try to achieve might be possible, but it seems that the Swift Charts scrolling performance is very poor. The graph was created as follows: X-axis is created based on a date range, Y-axis is created based on an integer values between moreless 0-320 value. the graph is scrollable horizontally only (x-axis), The time range (x-axis) for the scrolling content was set to one year from now date (so the user can scroll one year into the past as a minimum visible date (.chartXScale). The X-axis shows 3 hours of data per screen width (.chartXVisibleDomain). The data points for the graph are generated once when screen is about to appear so that the Charts engine can use it (no lazy loading implemented yet). The line data points (LineMark views) consist of 2880 data points distributed every 5 minutes which simulates - two days of continuous data stream that we want to present. The rest of the graph displays no data at all. The performance result: The graph on the initial loading phase is frozen for about 10-15 seconds until the data appears on the graph. Scrolling is very laggy - the CPU usage is 100% and is unacceptable for the end users. If we show no data at all on the graph (so no LineMark views are created at all) - the result is similar - the empty graph scrolling is also very laggy. Below I am sharing a test code: @main struct ChartsTestApp: App { var body: some Scene { WindowGroup { ContentView() Spacer() } } } struct LineDataPoint: Identifiable, Equatable { var id: Int let date: Date let value: Int } actor TestData { func generate(startDate: Date) async -> [LineDataPoint] { var values: [LineDataPoint] = [] for i in 0..<(1440 * 2) { values.append( LineDataPoint( id: i, date: startDate.addingTimeInterval( TimeInterval(60 * 5 * i) // Every 5 minutes ), value: Int.random(in: 1...100) ) ) } return values } } struct ContentView: View { var startDate: Date { return endDate.addingTimeInterval(-3600*24*30*12) // one year into the past from now } let endDate = Date() @State var dataPoints: [LineDataPoint] = [] var body: some View { Chart { ForEach(dataPoints) { item in LineMark( x: .value("Date", item.date), y: .value("Value", item.value), series: .value("Series", "Test") ) } } .frame(height: 200) .chartScrollableAxes(.horizontal) .chartYAxis(.hidden) .chartXScale(domain: startDate...endDate) // one year possibility to scroll back .chartXVisibleDomain(length: 3600 * 3) // 3 hours visible on screen .onAppear { Task { dataPoints = await TestData().generate(startDate: startDate) } } } } I would be grateful for any insights or suggestions on how to improve it or if it's planned to be improved in the future. Currently, I use UIKit CollectionView where we split the graph into smaller chunks of the graph and we present the SwiftUI Chart content in the cells, so we use the scrolling offered there. I wonder if it's possible to use native SwiftUI for such a scenario so that later on we could also implement some kind of lazy loading of the data as the user scrolls into the past.
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1.1k
Jun ’25
Severe hangs with LazyHStack inside ScrollView
Hi, I got a problem with severe hangs when I use code like this on tvOS 18.2 If I try to use HStack instead of LazyHStack inside the scrollview then the problem does not occur any more but then the scroll performance is compromised and the vertical scroll is no longer that smooth. Does someone has any experience with this? Is this SwiftUI problem or am I missing something? ScrollView { LazyVStack { ForEach(0...100, id: \.self) { _ in ScrollView { LazyHStack { ForEach(0...20, id: \.self) { _ in Color.red.frame(height: 300) } } } } } }
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115
Apr ’25
XPC - performance/load testing
I have an XPC server running on macOS and want to perform comprehensive performance and load testing to evaluate its efficiency, responsiveness, and scalability. Specifically, I need to measure factors such as request latency, throughput, and how well it handles concurrent connections under different load conditions. What are the best tools, frameworks, or methodologies for testing an XPC service? Additionally, are there any best practices for simulating real-world usage scenarios and identifying potential bottlenecks?
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119
Apr ’25
Slow app launch time
Hello, We are experiencing slow launch time indicators in our performance monitoring tools(Crashlytics/DataDog/Xcode), and trying to understand what is the best approach to reduce it. Currently, cold launch takes ~900ms on iPhone 16 Pro , but ~2s on iPhone 11. Profiling app launch detected that most of the time is spend on loading the libraries. Our app is massive, we use a total of ~40 3rd parties libraries + 10 internal libraries. We enabled the "mergeable libraries" XCode new feature however the app launch is as written above. We also postponed some of the work in didFinishLaunch, which help a bit... But maybe we are trying to achieve the impossible? Could it be that large apps just can't reach the golden 500ms goal? Currently we are trying to create an "umbrella" library for all the third parties in order to force them to become part of the mergeable libraries. We would like to know if, are we on the right track?
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333
Mar ’25
How can I optimize SwiftUI CPU load on frequent updates
Dear Sirs, I'm writing an audio application that should show up to 128 horizontal peakmeters (width for each is about 150, height is 8) stacked inside a ScrollViewReader. For the actual value of the peakmeter I have a binding to a CGFloat value. The peakmeter works as expected and is refreshing correct. For testing I added a timer to my swift application that is firing every 0.05 secs, meaning I want to show 20 values per second. Inside the timer func I'm just creating random CGFloat values in range of 0...1 for the bound values. The peakmeters refresh and flicker as expected but I can see a CPU load of 40-50% in the activity monitor on my MacBook Air with Apple M2 even when compiled in release mode. I think this is quite high and I'd like to reduce this CPU load. Should this be possible? I.e. I thought about blocking the refresh until I've set all values? How could this be done and would it help? What else could I do? Thanks and best regards, JFreyberger
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1.1k
Feb ’25
Performance Implications of XPC polling
On my MAC, I have a XPC server running as a daemon. It also checks the clients for codesigning requirements. I have multiple clients(2 or more). Each of these clients periodically(say 5 seconds) poll the XPC server to ask for a particular data. I want to understand how the performance of my MAC will be affected when multiple XPC clients keep polling a XPC server.
4
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435
Feb ’25