I created a simple animation of a circle that changes sizes. The circle pulses like a heartbeat in the center of the screen. My expectation was for the CPU use to be very low, but that is not the case. In addition, even if the CPU use isn't as low as I would expect, I did not expect the CPU use to increase over time because nothing else is happening in the app. Here is the code: import SwiftUI @main struct TestApp: App { var body: some Scene { WindowGroup { SplashScreenView() } } } import SwiftUI struct SplashScreenView: View { var body: some View { ZStack { SplashNucleusView(minSize: 50, maxSize: 100) } } } import SwiftUI struct SplashNucleusView: View { let minSize: Double let maxSize: Double @State private var nucleusColor: Color = .primary @State private var nucleusRadius: Double = 10 @State private var nucleusOpacity: Double = 1.0 private var nucleusAnimation: Animation { .easeInOut(duration: 0.25) .repeatForever(autoreverses: true) } let timer = Timer.publish(every: 0.5, on: .main, in: .common).autoconnect() var body: some View { Circle() .fill(nucleusColor) .frame(width: nucleusRadius) .opacity(nucleusOpacity) .onReceive(timer) { _ in withAnimation(nucleusAnimation) { nucleusRadius = Double.random(in: minSize...maxSize) } } } } This is how the animation looks: The animation is snappy until the CPU use reaches 95%, at which point there is visible stuttering. Here is how the CPU looks when the animation duration value is 0.5 seconds and the timer publishing interval is 3 seconds: Changing the animation duration value to 0.25 seconds and the timer publishing interval to 0.5 seconds changes the CPU use as follows: The complete view has many other moving parts, which make the issue much worse. The issue is evident with only the circle view. I spent hours working with the debugger, reading about animations, and testing new approaches, but the result is always the same. Why is this happening?

Requirement : We wanted to run UI Automation using xcuitest in devices with MDM profiles. Steps : We have created a test target for our app and signed with MDM profile (in-house) Generated app and testbundle-Runner along with xctestrun files using “xcodebuild build-for-testing -scheme “App-TestRelease" -configuration “Release” -derivedDataPath "${CURDIR}/derivedData" -workspace "${PROJECT_NAME}.xcworkspace" -sdk iphoneos” Tried running “xcodebuild test-without-building -destination platform=iOS,id=000842883-**** -xctestrun App-TestRelease_iphoneos17.5-arm64.xctestrun -derivedDataPath /derived/“ Facing below issues xcodebuild[35481:3588352] IDELaunchReport: e2934a094f300d40:e2934a094f300d40: Finished with error: Unable to launch com.org.mdm.XCTest.xctrunner Domain: com.apple.platform.iphoneos Code: -12 User Info: { IDERunOperationFailingWorker = IDELaunchiPhoneLauncher; } -- Request to launch com.org.mdm.XCTest.xctrunner failed. Domain: com.apple.dt.deviceprocesscontrolservice Code: 2 Failure Reason: The request to open "com.org.mdm.XCTest.xctrunner" failed. : Failed to launch process with bundle identifier 'com.org.mdm.XCTest.xctrunner'. -- The request to open "com.org.mdm.XCTest.xctrunner" failed. Domain: FBSOpenApplicationServiceErrorDomain Code: 1 Failure Reason: The request was denied by service delegate (SBMainWorkspace) for reason: Security ("Unable to launch com.org.mdm.XCTest.xctrunner because it has an invalid code signature, inadequate entitlements or its profile has not been explicitly trusted by the user"). User Info: { BSErrorCodeDescription = RequestDenied; FBSOpenApplicationRequestID = 0x9f9; } -- The operation couldn’t be completed. Unable to launch com.org.mdm.XCTest.xctrunner because it has an invalid code signature, inadequate entitlements or its profile has not been explicitly trusted by the user. Domain: FBSOpenApplicationErrorDomain Code: 3 Failure Reason: Unable to launch com.org.mdm.XCTest.xctrunner because it has an invalid code signature, inadequate entitlements or its profile has not been explicitly trusted by the user. User Info: { BSErrorCodeDescription = Security; }

Do you know any software that indicates the frequency of the cores in real time? the macbook pro adapts the frequency of the cores according to the load/temperature it seems to me thank

When I was using Instruments to test the Display on my phone, I discovered a long-duration frame. Below that frame, there were some gaps in the vsync queue. As I understand it, vsync signals should appear consistently and steadily. How can this behavior be explained? My phone is iPhone 15 Plus and iOS 18.

I'm a big fan of MetricKit. I decided to see how my apps are performing with iOS 18 and well, I'm not getting any metric payloads from those devices. Metric payloads received from my test devices adopting iOS 18 has pretty much bottomed out to zero. Is anyone getting MetricKit MXMetricPayloads from iOS 18 devices? FB15461298 - MetricKit: Production issue / regression with iOS 18 - Significant dropout or metric payloads being generated since 18.0 - nearly no reports To demonstrate the issue, I decided to graph the metric payloads my infrastructure receives for all of my apps across all of my devices over the last 16 months starting with WWDC23 timeframe. This data is grouped by count per month. A trend can easily be seen starting in June 2024 where I started to adopt iOS 18 betas. Zooming in since WWDC24, grouped by week, it is much easier to see the decline. Note, the second screenshot shows data collected from Xcode builds, TestFlight, and App Store. The last data point from today was a manual creation from Xcode's Debug window, so at least that triggering mechanism works and I can confirm all of my code to upload off device works as expected. On the bright side, I guess I will ship this 'payload received over time' feature in my MetricKit payload analyzer app with a scrolling window and group by features that make up these screenshots.

What exactly is included/calculated in the following metrics within RealityKit Trace - RealityKit Metrics - 3D render attributes: 3D Mesh Triangles Total Triangles Submitted 3D Mesh Vertices Total Vertices Submitted As the second part of the question, what differentiates between: 3D Mesh Triangles vs Total Triangles Submitted 3D Mesh Vertices vs Total Vertices Submitted

Recently, we reworked a crucial part of our app and managed to half the amount of CPU cycles our app requires (according to Xcode Instruments). Nonetheless, when using the Time Profiler component in instruments, it shows that the CPU time spent was either higher or the same (depending on execution). The main time-consuming factor here: libsystem_pthread.dylib - the amount of CPU time spent by this library has doubled from original implementation to reworked implementation. Therefore, I'm having a few questions: How should I interpret this result? How is this even possible if the CPU clock cycles halved? What is the better metric here, the CPU cycles or the time profiler? How can I reduce the impact of that said library? What does that library do and how can I influence its performance? Thanks in advance.

Hi there, In a project that I am working on, whenever I try running instruments for allocations to see the memory allocations that are happening under the hood, I see the statistics, and the traces updating, however the chart never updates. I have made new projects on the machine, and I have tried different Xcode versions, and they all show the chart just fine. I have tried running the project on other machines with no success. I have double checked the arguments and options on the active schema I am trying to profile with the schema of a new project and they are identical. Here is a picture of how it looks: My questions are as follows: What properties and settings can disable the chart from showing up? What diagnostic steps recommended that I should take? I can not share a reproducible as this is the only project I have with this problem and it is not mine, but please tell me if there is anything else I can provide in order to debug this. All the best Parsa

My website is using a lot of memory. JavaScript Allocations Timeline shows that js occupies 130MB. However, instruments show that the overall memory usage of webview reaches 480MB. I would like to know if there is any tool to analyze the distribution of this 480MB of memory usage.

Hello there, I try to add universal links to my app but get some problems. When I started researching how I can test it I found a lot of talks about App Search API Validation Tool. But this service is not open for me, I'm always redirected to the home page. Is there something wrong with me or is this service not working at all?

Hi, I want to delete an application from my device using xcrun devicectl command. I installed application using xcrun devicectl and I want to be able to delete it when I need but I cannot find proper arguments for command. Thank you!

Trying to examine performance issues in Xcode Instruments using the Animation Hitches instrument in Xcode 16.0 beta 6 (16A5230g). When connected to my iPhone 15 Pro Max and I try to start a run with my app, it has an error “Failed to split user provided arguments: working directory doesn't exist” with timestamp “(Before Run Started)”. When running the app on an iOS simulator, the instrument runs fine—but I want to profile on a real device.
 Instruments > Settings, Recording Location set to Default and that directory does exist.

When using Instruments in Xcode 15.3 on macOS Sonoma 14.3.1 symbols from system frameworks are not displaying. I've tried creating a template "App" project and running it on the iOS 17.4 simulator without any code changes and still am not seeing symbols so I can be sure it's not unique to my real-world project build settings. If I install Xcode 15.0 and run the same build in the same 17.4 simulator using Instruments 15.0 it shows thread names and symbols for UIKit and other frameworks but is still missing SwiftUI symbols. Instruments 15.3 Instruments 15.0 I've spent 2 days trying to narrow down why I couldn't debug my app and even deleted all my partitions and reinstalled macOS which didn't fix the issue.

Context I'm trying to profile a binary (a simple C++ program compiled into dummy.o) and collect CPU Counters data. I have a configuration that works fine from the Instruments Counters GUI (see Screenshots below). I've exported this configuration to a template file named prof1.tracetemplate. Problem When I try to run a recording with that same template from the command line with xctrace (I also tried with sudo): $ xctrace record --template prof1.tracetemplate --launch dummy.o I get the following errors: Starting recording with the prof1 template. Launching process: dummy.o. Ctrl-C to stop the recording Run issues were detected (trace is still ready to be viewed): [Error] Unexpected failure: Couriers have returned unexpectedly. [Error] Failed to start the recording: Failed to force all hardware CPU counters: 13. [Error] Failed to pause recording session: Cannot pause session session unless it's running. Current state: kSessionError [Error] Unexpected failure: Data source agent failed to arm. Recording failed with errors. Saving output file... Output file saved as: Launch_dummy.o_2024-01-31_14.22.32_0B6E1A78.trace System Chip: Apple M1 macOS: 14.1.1 (23B81) xctrace version: 15.2 (15C500b) xcode version: 15.2 (15C500b) Screenshots

Instruments CPU Profiler failed to start the profilable app (get-task-allow is set to true) with error "No PMI Record Found". Device is iPhone 13 Pro currently running iOS 17.0.3. Tried to profile in instruments shipped with Xcode 14.3.1, Xcode 15.0.1 and Xcode 15.1 Beta, same issue across. If it helps, I was able to successfully profile on iPhone X running iOS f16.7 using Xcode 14.2 instruments.

When trying to profile any process with the Instruments CPU Profiler I get this message: (Before run started) No allocated PMI record. Not sure what to do here. I tried other instruments like time profile and that works fine so not sure what to do here... Didn't find any people having similar issues when googling so I'm hoping someone here can help me out. Im using a m1 max 14 inch macbook pro with macOS 12.3 and instruments 13.0 (13A1030d)

Does the new HTTP Traffic instrument require iOS15 running on the device? I am attempting to profile my app and I get an error saying 'This device is lacking a required capability'?