Xcode 7.2: Scrolling gets choppy over time

Originator:igeek1
Number:rdar://24016734 Date Originated:28-Dec-2015 04:27 PM
Status:3rd party to Resolve Resolved:20-Jun-2016 05:14 PM
Product:Developer Tools Product Version:Xcode 7.2 (7C68)
Classification:UI/Usability Reproducible:Sometimes
 
Summary:
The longer Xcode has been open, the choppier scrolling in the source code editor gets.

Steps to Reproduce:
1. Open a project in Xcode.
2. Work on the project for, say, 5 hours over the course of a day.
3. Scroll in the source editor (no fancy panels or assistants open - just the project navigator next to the code editor, with the Variables View and Debugger visible at the bottom).

Expected Results:
Scrolling is as smooth as it was when Xcode is first launched.

Actual Results:
Scrolling is choppy. I forgot to check it with the Quartz Debug frame meter, but it looks like it’s around 15 fps. Relaunching Xcode always restores scrolling performance.

Regression:
Unknown, but it feels like this is new as of Xcode 6 or 7. It’s hard to test because it takes so long to reproduce.

Notes:
I’ve attached two Activity Monitor samples of Xcode. One is of scrolling in the editor when the issue was reproducing. Immediately after recording that sample, I relaunched Xcode, confirmed that scrolling was smooth again, and recorded another sample.

I have several plugins installed via Alcatraz. They should be visible in the attached samples. I haven’t tested whether any of them is causing this issue, since it would likely take days of careful testing to do a binary search to see if one of them is causing the issue, and I’d rather not disable them all at once because they help me work faster.

Scrolling samples also posted to http://cl.ly/eB3F

Comments

I've been trying to reproduce this, with no luck. I'm going to assume that either I stopped using the plugin that was causing the problem, or I'm still using it but it was updated.

By igeek1 at June 20, 2016, 9:14 p.m. (reply...)

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