Finding iOS Memory Leaks with Xcode's Instruments

https://spin.atomicobject.com/2016/01/25/ios-memory-leak-xcode/#.VqaGcF_w1AE.hackernews

by philk10 • 10 years ago

96 15 10 years ago

spin.atomicobject.com

gregdoesit4• 10 years ago

This article does a great job explaining the several not really documented steps of finding memory leaks using XCode.

I do wish the XCode developers would have implemented a more intuitive UI to do the same - e.g. taking inspiration from Chrome Developer Tools, or Visual Studio.

<rant> Actually, I would just be happy if XCode had the debugging features that Visual Studio 2005 (10 years ago) had. Like inspecting variables values with mouse over on breakpoints. Or when right clicking "refactor" in XCode on a method name, being able to refactor Swift code. 1 year after the release of Swift the error dialog "XCode can only refactor Objective C code" appears - so much for supporting the Apple's own language. </rant>

Anyway, article bookmarked - because even after reading this, there's no way I would remember all the steps needed to debug those memory leaks!

coralreef• 10 years ago

Like inspecting variables values with mouse over on breakpoints

Pretty sure you can do this already

gregdoesit4• 10 years ago

You would hope so. Unfortunately not if you are running swift as of XCode 7.2, the latest public release. For Objective C it works.

derwildemomo• 10 years ago

7 simple and not really documented steps of finding memory leaks using XCode

There's actually event a "Leaks" template in the instruments app, I wondered why the author didn't use that. And that tool is even documented by apple, see

https://developer.apple.com/library/ios/documentation/Develo...

cmsj• 10 years ago

The author states their reason

bestows• 10 years ago

It’s worth noting that the Leaks instrument can also be useful, but it is primarily used to detect memory that is never freed, not memory leaks from retain cycles.

The author does mention it.

For what it's worth, I can't see what gregdoesit quoted in the article.

thearn4• 10 years ago

I had pretty good luck using Instruments -> Leaks to find a leak in an OS X spritekit app (swift) I was making a few months ago.

I just wish I didn't have to hack and guess my way around spritekit to fix it...

seivan• 10 years ago

What part of SpriteKit was leaking?

makecheck• 10 years ago

Apparently 'valgrind' is also ported to OS X, I wonder how it compares. (I haven't been able to use it yet because I'm working on a 32-bit project for an older SDK and it seems that 'valgrind' is 64-bit and using the latest system.)

Arcanum-XIII• 10 years ago

But it's mostly experimental and not as easy to use as dtrace/lldb. What's more, you can't attach to the device, although there's a way to attach to the simulator — not for the faint of the heart.

ronnyf• 10 years ago

Good article. One thing to make clear here is a memory leak is not occurring on a retain cycle. The correct terminology is abandoned memory. When memory actually isn't freed and no longer usable as there are potentially no references anymore. It has been discussed on occasion at WWDC. I believe it was in 2011, around the time they introduced ARC.

Finding iOS Memory Leaks with Xcode's Instruments

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