Performance Checker Xcode 14

[daniapopov]

Expected Behavior

DispatchSemaphore seems like it isn't working as intended here

Current Behavior

It seems like there is a queue prioritization bug
Console output is:

Performance Checker: Thread running at QOS_CLASS_USER_INITIATED waiting on a lower QoS thread running at QOS_CLASS_UTILITY. Investigate ways to avoid priority inversions

Steps to Reproduce

Run in Xcode 14

Environment

• SDK Version: v.8.13.0
• OS Version: MacOS 10.12.6 Monterey

[bohan-amplitude]

Hi @daniapopov , Thank you for your feedback. I'll look into this and get back to you.

[qingzhuozhen]

Hi @daniapopov, thanks for raising this up. This may be for the recent change in Xcode 14. Found a related article. I tested with Xcode 14.0.1 and v8.14 and wasn't able to reproduce the warning. Would you mind sharing a bit more on the steps to reproduce? Is this still constantly happening for you now?
cc @bgiori @liuyang1520 @yuhao900914

[liuyang1520]

Thank you for the feedback! I cannot reproduce in my local with:

• Xcode Version 14.1 (14B47b)
• Thread Performance Checker enabled
• Amplitude v8.14.0
  Close this due to inactivity.

[daniapopov]

Still seeing this with the latest Amplitude SDK:

I am running this w/ Performance Checker enabled in the Scheme Editor:

You don't need to do this. But it might help to have this break point enabled as well:

[daniapopov]

@qingzhuozhen @liuyang1520 I missed that this issue was closed. Can we reopen this?

[qingzhuozhen]

cc @justin-fiedler

[justin-fiedler]

Hi @daniapopov thanks for using Amplitude!

We are in process of making the iOS Swift SDK our recommended latest SDK.

• https://www.docs.developers.amplitude.com/data/sdks/ios-swift/
• https://www.docs.developers.amplitude.com/data/sdks/ios-swift/migration/

The older iOS SDK is being transitioned to maintenance mode and will not receive as frequent of updates.

We will try to address this issue but it may take a while. In the meantime we recommend updating to the Swift SDK for the latest features and bug fixes.

Thank you!

[daniapopov]

@justin-fiedler
Excited that you guys are migration to the new SDK, and we are going to upgrade. But in my first quick test it looks like this issue comes from the shared package that both the new and old sdk depend on.
This stack trace clearly shows the issue is inside Analytics Connector.... and the new SDK has the same issue

[daniapopov]

With the new SDK it looks like the issue happens during Identity:

[daniapopov]

Created new issue in Swift SDK:
amplitude/Amplitude-Swift#90