What may cause heavy memory leak in short time - actionscript-3

when our flash game is in scene A, the memory is stable about 800M(it loads almost all the role animations and role skill animations). But when toggle to scene B, the memory keep increasing to 1400M in one minute. I have watched the explorer and make sure it doesn't load any resource when the memory is increasing. And when I repeat it, the memory increase to 2000M and the explorer freeze, the page crashed.
So what may cause such heary memory leak in short time? I haven't met such problem before, any help will be appreciated.

The question is not giving enough concrete information on what you're doing and thus it's hard to precisely what you' doing wrong.
But there are ways to deal with these situations:
Install Adobe Scout (http://gaming.adobe.com/technologies/scout/). This is a really good profiling tool to help you see what's going on in your app.
Enable telemetry data in your app. There are settings for that in both Flash Professional and Flash Builder. If you don't know how to enable it, please search the web since it's very well explained.
Run your app and look at Scout's panels to see what is happening and how the much memory, at what time you're allocating.
Other than that there are hundreds of reasons why the memory leaks. Just look at your code and understand when you call what and use profiling tools to know where to look.

If using FlashBuilder you can run the profiler to try and track down memory leaks and watch how many instances are being created. There are other profiling tools out there if you are using another type of IDE.
If using flash professional you can check out this link Profiling tools in flash builder to improve the performance of flash professional projects

After some days's work, we finally find out the problem.
Before I ask the question, I have tried Scout and Profile but not work(because the problem not occurs). I guess only bitmapdata draw or copypixels functon was called in an infinite loop or in a enterframe event handler could such quick and big memory leak.
Then we found out how to repeat the problem in luck, it really makes it much easier to solve the problem.
So here is the procedure we solve the problem after we could repeat the problem.
run the game in profile, and take a memory snapshot.
repeat the problem, after the memory increase a lot, take a memory snapshot.
find the loitering objects between the memory snapshot.
At last, the problem is an function was called in each frame when one skill appers. And in the function a bitmapdata was used to draw the role animation

Related

why game is running slow in libgdx?

I am making racing game in Libgdx.My game apk size is 9.92 mb and I am using four texture packer of total size is 9.92 Mb. My game is running on desktop but its run on android device very slow. What is reason behind it?
There are few loopholes which we neglect while programming.
Desktop processors are way more powerful so the game may run smoothly on Desktop but may slow on mobile Device.
Here are some key notes which you should follow for optimum game flow:
No I/O operations in render method.
Avoid creating Objects in Render Method.
Objects must be reused (for instance if your game have 1000 platforms but on current screen you can display only 3, than instead of making 1000 objects make 5 or 6 and reuse them). You can use Pool class provided by LibGdx for object pooling.
Try to load only those assets which are necessary to show on current screen.
Try to check your logcat if the Garbage collector is called. If so than try to use finalize method of object class to find which class object are collected as garbage and try to improve on it.
Good luck.
I've got some additional tips for improving performance:
Try to minimize texture bindings (or generally bindings when you're making a 3D game for example) in you render loop. Use texture atlases and try to use one texture after binding as often as possible, before binding another texture unit.
Don't display things that are not in the frustum/viewport. Calculate first if the drawn object can even be seen by the active camera or not. If it's not seen, just don't load it onto your GPU when rendering!
Don't use spritebatch.begin() or spritebatch.end() too often in the render loop, because every time you begin/end it, it's flushed and loaded onto the GPU for rendering its stuff.
Do NOT load assets while rendering, except you're doing it once in another thread.
The latest versions of libgdx also provide a GLProfiler where you can measure how many draw calls, texture bindings, vertices, etc. you have per frame. I'd strongly recommend this since there always can be situations where you would not expect an overhead of memory/computational usage.
Use libgdx Poolable (interface) objects and Pool for pooling objects and minimizing the time for object creation, since the creation of objects might cause tiny but noticable stutterings in your game-render loop
By the way, without any additional information, no one's going to give you a good or precise answer. If you think it's not worth it to write enough text or information for your question, why should it be worth it to answer it?
To really understand why your game is running slow you need to profile your application.
There are free tools avaiable for this.
On Desktop you can use VisualVM.
On Android you can use Android Monitor.
With profiling you will find excatly which methods are taking up the most time.
A likely cause of slowdowns is texture binding. Do you switch between different pages of packed textures often? Try to draw everything from one page before switching to another page.
The answer is likely a little more that just "Computer fast; phone slow". Rather, it's important to note that your computer Java VM is likely Oracles very nicely optimized JVM while your phone's Java VM is likely Dalvik, which, to say nothing else of its performance, does not have the same optimizations for object creation and management.
As others have said, libGDX provides a Pool class for just this reason. Take a look here: https://github.com/libgdx/libgdx/wiki/Memory-management
One very important thing in LibGDX is that you should make sure that sometimes loading assets from the memory cannot go in the render() method. Make sure that you are loading the assets in the right times and they are not coming in the render method.
Another very important thing is that try to calculate your math and make it independent of the render in the sense that your next frame should not wait for calculations to happen...!
These are the major 2 things i encountered when I was making the Snake game Tutorial.
Thanks,
Abhijeet.
One thing I have found, is that drawing is laggy. This means that if you are drawing offscreen items, then it uses a lot of useless resources. If you just check if they are onscreen before drawing, then your performance improves by a lot surprisingly.
Points to ponder (From personal experience)
DO NOT keep calling a function,in render method, that updates something like time,score on HUD (Make these updates only when required eg when score increases ONLY then update score etc)
Make calls IF specific (Make updations on certain condition, not all the time)
eg. Calling/updating in render method at 60FPS - means you update time 60 times a sec when it just needs to be updated once per sec )
These points will effect hugely on performance (thumbs up)
You need to check the your Image size of the game.If your image size are more than decrease the size of images by using the following link "http://tinypng.org/".
It will be help you.

Why does Flash Builder 4.6 Profiler seem to leak Strings, whereas Debug mode GC's as expected

While unit profiling my classes I noticed that the String class endlessly accumulates (eating up over 90% of the memory in my sizable app). Luckily this is only while running in Profiler mode of Flash Builder 4.6. In debug or deployment (as AIR) memory usage levels off as expected using embedded on-screen memory profilier (Mr Doobs Stats).
To verify I made a test app that was simply a URLLoader continuously loading a text file. When running in Profilier mode using URLLoaderDataFormat.String the String data is never GC'd and grows continuously whereas using URLLoaderDataFormat.BINARY the data is nearly immediately GC'd and stays level.
I hesitate to call this a bug, because possibly it's necessary part of the way the Profilier works… but perhaps this is abnormal for the Profiler? This is the essence of my StackOverflow inquiry.
At any rate, this burned up a couple work-days for me, so if you're Googling wondering why the String class is growing like crazy and never getting GC'd consider measuring your apps memory usage outside the Profilier to verify. In my case I was mislead into thinking I had run into some problem with Master Strings — though it's good understand Master Strings and their impact on memory (see:) don't get mislead like I did.

Way to Log Function Calls in SWF at Runtime?

Is there any way (tool, library, etc.) to log all the actionscript function calls at runtime in a SWF created from Flash Professional? I often inherit projects, and want to more easily analyze and understand their operation. Profiling be nice too.
Logging all calls will probably not help much, because if there are many "small" items involved (i.e. cells in a list, nodes in a tree, particles in a particle engine, enemies in a game, etc. etc.) the log files will clutter up with repetition and soon grow to a size where the sheer amount of information will make learning about the functionality a slow, tedious and painful task.
It is more useful to use a profiler to manage dependencies, memory etc., and use a debugger to step through the code, and/or set breakpoints at interesting points and navigate deeper into the architecture from there.
FDT has a great profiler and debugger. And as a free tool, Monster Debugger is quite good.
You can try Show method entry and Show method exit in SWFWire Debugger. It also offers some profiling. You can also track object creation and destruction, and memory usage.
Disclaimer: I wrote this app

Memory Problems with ActionScript

I am having trouble with memory allocation during a stress/performance testing of a program. In the test, I tried to do loading/unloading same set of resources again and again. The error I got was "Error, #1000, out of memory". The stack trace was about URLLoader/onComplete and URLStream/readBytes. I checked the memory being used at the time of failure, it was less than the maximum amount that the program has used before. I don't think it's caused by memory leak because the memory used through time is pretty consistent (allocate when loading resources, deallocate, allocate, ...) Also, this problem happens kinda randomly. I am kind of stuck. Any suggestions?
If you are using Flex Builder, use the flex profiler to get a better idea of memory being used by various objects.
You can also monitor memory consumption with something as simple as ProcessExplore for Windows or Activity Monitor for Mac. If all you're doing is loading/unloading resources, and you are managing the life of these resources correctly (i.e. removing listeners, making available for garbage collection, etc), then you should see a very consistent peak/valley memory graph. If the memory continues to rise, you've got a leak. Be especially careful if the resources you are loading/unloading are bitmaps as bitmapdata tends to be a prime culprit in flash memory leaks. Good luck!

Can I detect when the Garbage collector works?

Am working on a swing app.
I will experiance slowness after continuous half an hour of use.
can it because of GC running?
How can i find when the garbage collector runs through any jdk 1.5 commandline option?
Thanks
When you start Java with -XX:+PrintGC, it will print messages whenever it garbage-collects.
You can use jconsole.exe, which can be found in the bin directory of your jdk. It shows you a lot of details about your running JVM.
It's highly unlikely that the GC is causing observable problems. Once upon a time Java had a horribly slow GC that gave it a near-permanent bad reputation. That time is past.
What exactly is the slowness? A GC should really never take more than a fraction of a second, even for the rare full collection pass.
Edit: Even if the GC is running a measurable amount, it's likely only a symptom of the problem. Whatever code is placing that much demand on the GC would internally cause more slowness than the GC will.
The simplest way to investigate this if you use recent JDK is jvisualvm which allow you to attach to a running process. You can then see garbage collections, memory usage and profile if needed. (It is essentially the corresponding NetBeans functionality available as a standalone applciation in the JDK).
It complements and enhances jconsole!
(But what you describe may be excessive GC's caused by a memory leak in your program. Use jvisualvm to figure out)
I strongly doubt it's the GC you are seeing. As 280Z28 points out, the GC runs pretty fast usually (though can still kill performance if you're doing something wrong). Are you using the program in that time? If not, maybe you're a little low on memory and it got paged out? (leaving Eclipse running for longer than maybe half a day without using it results in a state I can't work anymore with it. On systems with little memory it might happen sooner).
GC itself probably is not the problem. However, if you have a memory leak, it might result in GC using all CPU trying to clear memory.
As everyone has mentioned previously, GC is almost certainly not the problem.
I'd try something like YJP (Your Java Profiler, free for 30 days) to profile your application and find out what is slowing down. A memory leak is a very possible cause.