I recently profiled my app using Xcode VM tracker instrument.I found that app has lot of dirty memory especially performance tool data. So i want to know what are the reasons of the huge dirty memory and performance tool data.
Any help would be appreciated.
Your app takes 51MB to store, when it is suspended. The performance tool itself adds an overhead of 30MB. Which leaves 20MB for your app.
From the listed items, it looks like your app is graphics heavy. In fact, it looks very similar to this post. Which makes me wonder if these objects are still processing or waiting to be released, when the app is suspended.
Alternatively, I wonder if you could free a lot of those animations and images when entering background, and reconstruct them when entering foreground.
Finally, note that Apple recommends removing strong references to images, data from disk and media to reduce dirty memory.
Since I just had the same problem, here is what I found:
The "Performance tool data" entries were from libBacktraceRecording.dylib.
You can disable backtrace recording in the scheme editor.
See the related question Memory leak with “libBacktraceRecording.dylib” in React Native ios application.
Related
I am currently struggling with memory management inside a webgl application on the web, on iOS only.
I keep getting the following error message :
Application 'UIKitApplication:com.apple.Preferences[0xa7c1]' was killed by jetsam.
I understand that Jetsam is the system process responsible for memory management, but the crash occurs while the browser uses around 25% of the device's RAM, which is not that high. I don't have any other open application while running my webGL content. What I don't understand is what Taun Chapman said :
Jetsam monitors memory use and kills applications which are not good memory citizens. A good memory citizen is an application which is willing to give back memory when asked and does not keep asking for more memory.
Well, the app needs more memory in a short time (when unzipping 3D models using workers), I can't continue my app without it! And it crashed at these particular times.
Moreover, I think I have some memory leaks in my app, according to Chrome DevTools I am currently trying to fix. But the browser itself seems to have some leaks too. Thus, fixing mine will just delay the inevitable.
I know the following question is odd, or inappropriate, but do you know if the jetsam "limit" can be increased ? Or if you can add an exception on the currently running WebGL app ?
For your information, I use the Three.js WebGL library and the zip.js library to compress my 3D models.
Yes, I've already read the following question : Why does simple website crash on mobile (iOS Safari and Chrome, at least)?, but the problem does not come from my CSS.
The 10.3.2 version of iOS (released the 15th of May) made Jetsam less aggressive, or at least, the memory is better handled.
https://support.apple.com/en-gb/HT207798
I am working on an iOS app in Xcode. Earlier I got it to start and run, up to a limited level of functionality. Then there were compilation failures claiming untouched boilerplate generated code had syntax errors. Copying the source code into a new project gets a different problem.
Right now, I can compile and start running, but it states before even the launch image shows up that the application was closed due to memory pressure. The total visual assets is around 272M, which could be optimized some without hurting graphical richness, and is so far the only area of the program expected to be large. (The assets may or may not be kept in memory; for instance every current loading image is populated and my code never accesses any loading image programmatically.) And it crashes before the loading image has itself loaded.
How can I address this memory issue? I may be able to slim down the way images are handled, but I suspect there is another root cause. Or is this excessive memory consumption?
Thanks,
Review the Performance Tuning section of Apple's iOS Programming documentation. Use Apple's Instruments application to determine how, when, and how much memory your app is using.
One approach you should consider is to disconnect the graphics resources from your application, and add them back one-by-one once you feel they meet the requirements and limitations of iOS.
Now, this part of my answer is opinion: it sounds like your app is a high risk for being rejected from the App Store, in case that is your intended destination for this app.
I am working on an iOS app in Xcode. Earlier I got it to start and run, up to a limited level of functionality. Then there were compilation failures claiming untouched boilerplate generated code had syntax errors. Copying the source code into a new project gets a different problem.
Right now, I can compile and start running, but it states before even the launch image shows up that the application was closed due to memory pressure. The total visual assets is around 272M, which could be optimized some without hurting graphical richness, and is so far the only area of the program expected to be large. (The assets may or may not be kept in memory; for instance every current loading image is populated and my code never accesses any loading image programmatically.) And it crashes before the loading image has itself loaded.
How can I address this memory issue? I may be able to slim down the way images are handled, but I suspect there is another root cause. Or is this excessive memory consumption?
Thanks,
Review the Performance Tuning section of Apple's iOS Programming documentation. Use Apple's Instruments application to determine how, when, and how much memory your app is using.
One approach you should consider is to disconnect the graphics resources from your application, and add them back one-by-one once you feel they meet the requirements and limitations of iOS.
Now, this part of my answer is opinion: it sounds like your app is a high risk for being rejected from the App Store, in case that is your intended destination for this app.
I am particularly new to iOS & still quite distant from the basic Concepts.
I read in iOS books & forums that the application crashes due to low memory but why does it crash?
It would be helpful if someone could throw some light.
iOS Devices Use virtual memory with Paging . As it is a Mobile device and there is no Extensible memory or pretty
large Memory available (Like Hard drives) , so the availability of the pages is limited by various factors such as the number of applications open , Allocations by different applications , etc. Moreover , some on-board applications will always keep using some pages even when they are in dormant state such as safari , i-tunes , messaging etc.
So , essentially with number of application active , the number of pages your application can use gets diminished further.
So , your application will crash in cases when the rate of allocation by your application is exceeding the rate at which pages are being freed by other Applications.
OS only frees up read-only data from the memory while writable data is not freed-up .When the writable data crosses a certain threshold , the OS asks the application to free memory.Unable to free the memory leads to the crash.
Memory Allocations Apple
It does not really crash. Apps get terminated by the kernel if they do not free enough memory after a notification.
To make this transparent a crash report is written which contains the specifics about the current situation. To the user it looks like the application crashed, as it just suddenly disappears.
The devices don’t have much memory and if you are piggy with memory, you are looking for trouble
iOS have good memory tool called ARC. Please read the full documentation here
I've been burned before in my own apps when loading table views consisting of nothing but UIImages, which might look like tiny thumbnails in the table but end up being full resolution (and lots of memory) objects behind the scenes.
You need to be careful when working with objects that can be potential memory hogs.
But take heart, Apple provides tools like Xcode Instruments you can use to profile your app's memory performance.
I’m helping out a company with a project for iOS, which is using Core Text. Some users of the app have reported that text is occasionally missing from within the app. It seems™ that this is somewhat memory related, because it’s solvable by shutting down the app along with background apps.
I made a few lines of code which simulates the use of the app – so the app “runs itself”, navigating between view controllers randomly, scrolling in text fields etc – to track if this issue occurs by normal use.
I’ve found some memory leaks related to the use of Core Text, but according to instruments the amount of memory lost is quite low. However, when the simulation has been running for about 20 minutes or so, the app is shut down by the os because of memory warnings.
I’m intending to fix this memory leaks, but my problem is that I will not be able to ensure that this fixes the main bug (missing text), since I cannot reproduce it myself.
So my final question is: have anyone experienced issues with missing text on iOS while using Core Text, which are due to leaked memory? Does it sound plausible? If so, is this related to only specific versions of iOS?
I appreciate any answers that can help me out!
UIViewControllers may implement didReceiveMemoryWarning that the system calls when your app is on low memory. Framework classes, as core text, are most likely do implement this and act accordingly to save memory. So it is possible that your core text object aims to help your app resolving the low-mem situation with freeing some of its resources that can even cause it to blank its contents. Fix first all memory leaks in your app.
On the other hand, all bugs are very difficult to correct if you can't reproduce them. If you suspect that the issue is due to low memory, try to simulate this yourself by allocating huge amount of memory in your application and hope that you can reproduce the erroneous behavior that way.