Blockly Sample Application Memory Leaks

[hatem93]

Blockly Sample Application Memory Leaks

[vicng]

Thanks for bringing up this issue.

Running it on my machine, I see leaks (filtered by "Blockly") and allocations that aren't being deallocated (filtered by "BKY").

It's something that I was planning on looking at in the very near future, along with performance optimization (I've been putting it on hold while building out a features over the last few months). So please hold tight -- they will be fixed shortly!

[hatem93]

thanks for the fast response looking forward to the fixes

[hatem93]

any updates?

[vicng]

Sorry, I have been busy/sidetracked for the last couple of weeks -- I will try to get a fix in this week.

[vicng]

FYI, pull request #388 now fixes the sources of major memory leakage.

However, there's still one source of minor leakage that I can't seem to solve, which is from "ContiguousArrayStorage" (ie. arrays being created for Field objects). I suspect that it's a bug in the iOS SDK or even in Instruments, as it only shows up for iOS 10 and not 8/9.

The good news is that these remaining leaks only seem to occur when first loading a workbench with new blocks and that the leaks are small in memory.

I'll keep my eye on this issue though, I'm hoping WWDC 17/iOS 11 may provide more insight into the problem. If you continue running into large memory issues, let us know.

[hatem93]

thanks alot will let you know

[hatem93]

Sorry for the late response i have tried the new update, I am still having some leaks from blockly in my application and in the blockly sample application provided, I am not sure wether i am doing something wrong or not.

here is an image from the instruments from blocksample application

still using the same configuration as before

i am now in the process of releasing my application on apple store do you know wether the memory leaks issue will lead to a rejection from apple.

[vicng]

I don't think minor leaks will get you rejected by Apple (some of the iOS SDK leaks), but obviously it isn't a good sign if your app is leaking terribly.

When looking for leaks, it's more important to check for severity than existence. I usually check two things:

1. Cyclical references - Does memory not get de-allocated (eg. after say popping a view controller)? This is the most severe type of leak and you shouldn't submit if you have any of them. None of these exist in the Blockly library, so if this is happening, it's most likely part of your codebase.
2. Leaks due to bad reference counting (the Memory Leaks Instrument) - I've found that these happen just from using certain parts of the iOS SDK. It's hard to generate your own now with ARC so it's mostly making sure that you aren't calling those leaky parts too often (eg. you can see there's something leaky with NSNumberFormatter, which Blockly uses).

Lastly, make sure you're enabling "whole-module-optimization" when building for release. This will improve performance of your app and it may eliminate some of these leaks you have been seeing.

Hopefully this answers your questions.

If you have 5 minutes, please fill out our dev questionnaire too -- it really helps us out figure out how to cater to our devs.

Good luck on your submission!

[hatem93]

Thanks alot for the advices and the continous support