From time to time, different Apps I am developing close itself, I'm assuming it is because of memory usage that the IOS kills once it is to high.
Even if it is not because of memory I will like to find out how much memory my app is consuming every step of the way.
Update:
Thanks guys, I understand Instruments purpose, but my Idea was to monitor memory while I am using the app not connected to the computer. For instance, something like placing a UILabel Text content with the current memory consumption.
Any directions?
Apple Instruments User Guide is a good way to start. There is a chapter devoted to locating memory issues. To monitor memory consumption, Allocations, Leaks and Activity Monitor instruments will be most helpful.
Let's using instrument to profile your application. Using Allocation mode, you can find out :
- how much memory your app using.
- how many objects of your app are allocated in memory.
- Which objects (GUI, NSOBjects, bla bla bla) are allocated in memory.
- Your app using more or less memory after you do somethings in your app.
More detail:
https://developer.apple.com/library/mac/#documentation/DeveloperTools/Conceptual/InstrumentsUserGuide/Introduction/Introduction.html
Use 'instruments'. Run -> Profile
Related
I am implementing an iPhone application and when I ran this app initially it was showing memory size was 5.3MB
and after 10 min it was showing memory size was 185.3 MB.
I'm releasing objects manually and also analyzed my app, I have only one memory leak(that to return object in class method). What was the problem? is it harm to app while apple approve it?. Please help me. Thanks in advance.
No, you really shouldn't release it with this kind of a leak (or memory accretion). It will lead to crashes and that will cause data loss and upset users.
Heapshot analysis is designed to track down these kinds of problems. That is, use the Allocations Instrument to track memory growth over time iteratively and then eliminate the large memory consumers.
Apple will probably approve it as long as it is not crashing within the review time.
But no you should not release the app if you have a memory leak like this. Your app will have poor user experience and might crash if the users device memory runs full. You will get a low app store rating.
I would suggest you find out which object is taking up so much memory and fix it. If at all possible switch to ARC, this will take away some leaks.
I have same problem too. NSZombieEnabled flag work for me. I think this might be helpful to cope up with ARC. I have followed this link: How do I set up NSZombieEnabled in Xcode 4?
how do i increase the available memory (more concrete: the part of the RAM) that can be used by my app?
i am not referring to the space available on the harddisk of an iphone, but to the RAM.
does anyone know if there's a way to use the whole free part of the RAM for my app only?
i have to clear this up a bit, sorry if it was too vague:
i had to think of the java heap size, which can be increased by adding a parameter to the startup command of the java programming.
as i don't know, but at the moment suppose on the iphone something similar happens (every app has just xxMB RAM for execution) this value might be adjustable, so that i can use the whole remaining RAM for my app.
which pretty much is what i need for this special app (non-app-store-publication; file-sizes between 50MB and several 100MB)
How do i increase the available memory?
Short answer: you don't.
Memory is managed by the kernel.
Your application process can't control this.
You can't explicitly control this - this is managed by iOS.
You can't do that. Try reducing your memory usage instead of looking for ways to remove well needed limits.
Store your data instead and read from it when needed.
I don't know for sure if you can configure RAM allocated for your app. I think that is taken care of by the iOS kernel
It's unlikely (read: not going to work) that you will be able to allocate anything more than a few Mb in your application at once.
Not planning on publishing your app to the App Store won't change this. Apple don't officially acknowledge the amount of memory in iOS devices. But its known that devices have between 128Mb and 512Mb of physical RAM.
With the kernel, essential applications (Phone app, etc), background processes, etc, you won't have anything like that available to your application. Careful analysis in instruments would suggest that you'll generally start getting memory warnings when you've allocated around 22Mb of RAM in your application.
A change made in iOS 5 makes the watchdog process much more aggressive with killing applications after you get a memory warning. If you get a memory warning on iOS5 you have to reduce your memory usage or you will get jettisoned by the OS.
If you want to proceed, you will have to figure out how to reduce the amount of memory your datasets require. Its unlikely that all of the 100Mb file needs to be in memory at once. iOS devices have "relatively" fast CPU's and storage, you'll have to architect your application to read and write to storage in chunks and work on smaller subsets of your data.
Some related Stackoverflow questions and links:
Monitor memory usage in an iphone app?
How much memory can an iPhone app use?
10 iPhone Memory Management Tips
I'm reading some people stating that if another (3rd party) app on someone's iPhone has been leaking memory, that this may reduce the (mystery) amount of RAM your app would otherwise have available.
This confuses me -- does not all app memory get released when the app is closed by the user? And only one app is open at a time on iPhone?
Normally, any memory that your application allocates will be freed when it exits. However, many of Apple's applications continue running after they're "closed", so memory leaks in Mail, for instance, can affect available memory.
In addition, there are apps out there that claim to free up allocated memory. They really don't do anything other than force some dirty pages out of the buffer cache, but they appear to do something, so people believe they must be doing something useful.
On a jailbroken phone - yes, third party apps can be running at the same time as yours. Running out of memory is common with people who like to have many apps running at once hence the need for task managers, killing tasks etc.
On an unhacked phone - no. Yours is the only non-apple app that is running, no others can run at the same time.
So what can you do? All you can do is try to use the minimum memory possible which you're probably already doing. Realistically you can only test with a factory, unhacked phone, unless you are going to spend hours trying to please everyone. If you think you are maybe using too much you could identify the larger allocations using the instruments tools ("Run with performance tool >" from within Xcode) and then post that chunk of code here to get ideas of how to reduce it.
You should run Instruments and then add the instrument "Memory Monitor" to see the memory use of all of the other processes on your phone. (Add with Window -> Library , then drag the Memory Monitor instrument to the instrument panel.
What I'm still trying to determine is why is iOS releasing memory from MY app, and not all of the other memory pig apps that are not currently running.
If an application produces a lot of memory leaks, are they "just" an in-app problem or are they also in RAM after the termination of the application? So does the iPhone OS release the memory allocated for the sandboxed application?
Thank you
Memory leaks are blocks of memory allocated by the OS for your program to use while it is running, but not correctly returned as not in use when the program has finished with them. So this memory is 'lost'. Your program isn't using it, but the system doesn't yet know that it is free for other use.
When your application finishes running, all of the memory allocated to it by the OS, will be returned for re-use. Which answers your question.
However, memory leaks are a significant bug. On a low-memory device, like an iPhone, the less memory you consume the better, you don't want to be leaking memory as you run. If the device runs low on memory, your application may be terminated or crash, unexpectedly.
Memory leaks occur when you allocate any object and miss out to release that objects while running application , so do analyse in xcode which will help in checking memory leaks, and run profile mode in xcode will help to check leaks possible in application.
and use NSAutoReleasePool to release the autorelease objects which will be created when you just assign objects wothout allocating
hope it helps .
Memory leaks are an in-app problem, but can have side effects on the total available RAM.
They are blocks of memory that are marked in use when they actually are no more used. So they are lost to the app. If you have leaks, this will increase memory consuption. And bad memory usage will be noted by the system and the app might be jettisoned (killed) by the watchdog, jetsam.
So keep your memory leaks to a minimum ;-)
It has an effect on the overall OS, but negligible in consequences. Because your app is not killed when you tap the hole button, but rather "backgrounded", all the memory that's used by your app is still live and unavalaible to the system. Jetsam will first tell you that the memory is low and ask you to get rid of stuff you don't need. Of course you cannot free your leaks.
If you still use too much memory for the system, and it needs to allocate more memory for another process, your app will get killed. All the memory it used will be freed, leaks included.
Leaks are bad, use the static CLang analyzer in Build and analyze.
Now, I know my app uses a lot of graphics, but not 60mb of graphics. However, Instruments shows me that the app is using 60+mb of virtual memory just after startup. The compiled app is 24mb big, and we're talking about the idle welcome screen after startup; any idea why the VM size might be this huge?
The virtual memory is the address space allocated by your app from calls like malloc. This does not mean that it uses this much physical memory. For example, all libraries (libSystem, ...) that your app links to are allocated in shared memory, which is part of your virtual memory.
A good explanation of memory types can be found in the help of the "Activity Monitor" application. There's also a great blog post from Mike Ash.
How/when are you loading your image?
I'll take a guess and say that 60MB is the size of your app with uncompressed images.