Why does instruments using the leaks tool show so many leaks and then crash after about three leak detection cycles?
That cannot be normal ?
The app I am testing on has one index window with one label in it which, on click opens another window which on click closes itself again.
No big deal yet it seems to have leaks ?
the first detection says 72 new leaks
the second then 8 new leaks ... ?
Does anyone know why this might be ?
Thanks for your help trying to get my head around this
Having developed apps with Titanium for 8 years now this doesn't look anything like it should. Whenever leaks are found by the community it usually is quickly fixed by the dev team. That said, it is very rare leaks are found.
Most memmory leaks are developer generated. For example if you create references to UI elements outside the controller it is in you will have to clean up the reference to that UI element to let garbage collection handle it. Garbage collection cannot trigger if you didn't free the components up.
I will not be able to help you further besides the above as you have not provided any relevant information like SDK version, code that causes it etc. You might've stumbled upon a real memory leak but chances are you're not freeing up resources.
Related
I am new to Xcode and the profiling tool, instruments. I tried to find leaks of my c program. Everything is fine. It shows no leaks, but I don’t understand some terms used in the program. Does mean I still have memory leaks somewhere else in the program?
Applications like the debugger and Instruments may hook into your program after the OS has already started it running. What the message is saying is that it doesn't know how a given piece of memory was allocated because it was allocated before Instruments hooked into your program. So it has no way to track where it came from. It may or may not mean that there are more actual leaks in your program.
I believe that you can start your program from Instruments in most cases, which I think would eliminate the issue. Once you've run it once, you should be able to press the Record button (the red circle) again and it should run the app once more. I think in that situation, it should have access to all of the allocations your app makes.
For what it's worth, I have seen this message before and had it go away during the same run. It was as if it suddenly found the data that explained where the leak came from. I've also seen it happen on one run and be gone on a subsequent run with the same data. In that case it seemed like a timing issue of Instruments and not a legitimate leak.
I have an MFC application developed with VS2003
It is working fine in XP vista etc.
But when i have executed it in windows 8, and we use it for some time,
then no window is displayed. Instead of that the a MessageBox with a message 'Out of Memory' is displayed. And the Message box is Having the caption of my application.
This issue is rarely occurred in windows 7 too.
I have tried watching the handles using tools like processexplorer and it is not increasing.
Also many forums says that it is because of increase in unclosed handles or resources.
Can any one suggest how can i find where the issue is. Or any one provide possible reason for this.
I cant setup the devenv in the machine causing the issue. I am confused how to diagnose by executing a test build in that.
Please provide your findings.
Thanks in advance.
You clearly have a memory leak somewhere. It's hard to be any more specific without seeing the code.
A debugger is really the best way to solve this problem. If you can reproduce the problem on your development machine, that would be the easiest case. If not, you can attach a debugger to the running process on another machine, either locally or remotely.
The MFC libraries also support some basic memory leak detection, turned on by default for Debug builds and controllable for other builds using the AfxEnableMemoryTracking function. You can use this feature to obtain information about which blocks of memory were allocated but not properly deallocated (i.e. were leaked).
Like you mentioned, Process Explorer is another good way to track down resource leaks. Are you sure that the handle counts are remaining constant rather than trending upwards over time? If the values in the columns are never changing like the question suggests, then you are surely doing something wrong. Your application has to be creating objects in order to do its job. The point is to make sure that it disposes of them when it is finished.
If you can't reproduce the problem with the running application and have only the source code available, you'll need to go through the code and make sure that every use of new has a corresponding use of delete (and that new[] matches up with delete[]). And in general in C++, you should avoid explicit dynamic memory allocation wherever possible. Instead, use the container classes that are provided either by MFC or the standard library. For example, don't allocate arrays manually, use std::vector to do it for you. These container classes ensure that the memory is automatically deallocated in the destructor when the object goes out of scope.
I am creating one game in Windows phone using c# and silver light platform. I am new in this technology and currently facing memory leak issue.
As per research and study I have done, I have tried to do all the things including events, string and usage of garbage collector.
Can any one please give common tips to best utilize garbage collector and memory management since it seems issue right now. When my garbage collector reaches 5 lac size, it stop collecting new things and application is getting crash.
I also tried empty the garbage collectore passing parameter 0 in gc collect but it is crashing the app.
Can you please guide and help for basic things to take care, process to follow to avoid such issues and best use of GC collect?
Thanks in advance,
Jacob
In general, you should never have to call GC.Collect yourself as unused objects will be automatically collected every few seconds.
As for what can prevent objects from being collected, it comes down to them being "rooted". Roots include:
Any static references
Any references held by the run loop (your Application is the closest thing here)
Anything being displayed on the current page or any page behind it
Anything referenced by any of the above (including UI events), or referenced by anything that is referenced by any of the above (etc).
In the above scenarios, those objects and any objects they hold a reference to cannot be GC'd. So as for advice:
Avoid defining anything as static
Be careful how many objects are held by Application
Avoid a navigation model that allows your back stack to grow to ulimited levels
Potentially look at setting references to large data sets to null in your page/viewmodel's OnNavigatedFrom method and re-initialise them in OnNavigatedTo
I'd recommend using the Windows Phone Profiler, which comes with the 7.1 SDK. It will tell you what objects are in memory and why.
Without seeing any of your code, it is difficult to give specific advice.
However, I strongly suggest you run a memory profiling tool like ANTS Memory Profiler or .Net Memory Profiler. These tools will show you what portions of your code are never released and are very helpful in making the adjustments that you need.
My ipad app is receiving the Level 1 memory warning, so I ran the memory leak Profiler in Xcode 4. Sure enough, when I move one particular slider, it is causing a leak. Move it again, another leak and the leaked bytes escalate.
I am wondering if Xcode 4 provides an easy way to find out specifically which object is getting leaked. I have looked through the method from the slider movement; every time I use alloc/init, i then release it. It would be good know where Xcode is finding the leak since I cannot find it myself.
The Xcode 4 documentation references quite a number of tools. However I wonder if this documentation was not updated from Xcode 3 because those tools are not in the menus mentioned by the docs.
the slider action is:
-(IBAction) sensitivity:(UISlider *)slider{
self.grid.sensitivity=slider.value;
[self.grid setNeedsDisplay];
}
this by itself doesn't suggest a memory leak. However, the "setNeedsDisplay" method, which is quite a lengthy one, does not create a leak when it first runs, so why would it create a leak the second time it runs? All the inits/alloc in that code are released (there are only 3 objects created and released).
I find it useful to run Build/Build and Analyze from the Menu. It doesn't catch everything and it flags a few false alarms, but it's a good (and easy) place to start for automated leak detection.
1.X-Code -> Run -> Run with Performance Tool -> Leaks i am getting a memory leak like Responsible Library :UIKit Responsible Frame:UIKeyBoardInputManagerClassForIn.When i traced it does not point to my code instead it points to some frame works.Is this issue of my code? or any chance of leak from apple's frame work?
In X-Code 3.2 I connected iPhone device and the clicked Build & Analyze the right clicked on product/press cmnd+shift+(A/B) you can see many potential leaks this is static analysis but it is showing potential leaks caused only by my code.Hope this would be helpful for some one.
This issue related to the frameworks.Not in your code.So it can't so in your code.So asper my knowledge no need to worry.