Bitmap memory leaks

Question

So, before honeycomb, the Bitmap obeject was just a pointer for a native heap memory space( using malloc ), and i could clean that native memory calling .recycle() ; after honeycomb the memory for the Bitmap is allocated in the app heap, which gets gc calls.

My question is, my app need to support 2.2+ so what should I do? Check the version and call recyle? Dont call recycle at all? What is your advice for that. Because i have a BitmapCache which hold some Bitmap instances and i dont want them living in the memory for ever.

score 3 · Accepted Answer · answered Apr 21 '12 at 03:41

In any android version whether it is froyo,gingerbread or honeycomb. You have to check yourself for memory management. Yes, from 2.2+ you can adjust you application from sdcard, but keeping the bitmaps in heap memory, always will create problem for whether you use either version. If you want pure using of bitmaps, then why dont you follow their way, try this link. They have given you many ways to managing the bitmaps efficiently. Follow this link: Displaying bitmaps efficiently

score 0 · Answer 2 · answered Apr 21 '12 at 05:12

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first, any android platform version like: android 2.2, or android 3.0 , or higher than android 3.0, the bitmap that you dont want use, you also need invoke bitmap.recycle()

although android >=3.0 , the bitmap save in the dalvik heap, not save in native heap. so as the java heap, if you have some references to refer the object, the object cann't be gc by system, and the bitmap memory can taken many memory, if you dont ensure the object references counter is zero, it will a big problem.

the Bitmap cache you said can save bitmap, so if you use WeakReference or SoftReference to save the bitmap, and using WeakReference.get() or SoftReference.get() to return the bitmap, the bitmap reference is in right control of system. Otherwise you need manage by yourself.

answered Apr 21 '12 at 05:12

idiottiger

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so, if I have a WeakReference , gc will take care of it for me right? however my implementation has to call recycle() for the pre 3.0 versions? when should i call that recycle ? and why in this tutorial http://developer.android.com/training/displaying-bitmaps/cache-bitmap.html they said it is not recommended to use Soft and Week References? – Arthur Neves Apr 21 '12 at 16:50
You should be calling recycle() (regardless of version) whenever you are finished with a bitmap, before setting it to null. It depends on what you want to do as to when you should be calling it. I tend to reuse bitmaps rather than removing them and creating new ones. – David Scott Apr 24 '12 at 15:12

score 0 · Answer 3 · edited May 23 '17 at 11:49

As you notice on developer pages they said that weak referencies are outdated solution.. Check all bitmap referenced tutorials from link I left here and try to use scaling down (when possible), caching and AsyncTask, as well as lazy bitmap loading from this example..

These things combined will be solution I am pretty sure..

btw.. I am currently on this topics too, cause just weak references are ok, but not perfect solution and I want to make my app lag-proof for future versions of AndroidOS..

Hope it's not too much links but when we get it, it will work like a charm ;)

Cheers

Bitmap memory leaks

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