I'm struggling with memory leak in my Android application. I read milion articles, but still memory is leaking and finally ending. To be more detailed: I have 3 activities which contain grid of image views. All image view contains bitmap from file. Of course I load those bitmaps in small size (using options.inSampleSize). In addition I use kind o cache (class with static map contains bitmaps and its filenames to avoid necessity of loading the same bitmaps from files more than one time) :
public class PhotoCache {
private static Map<String, Bitmap> photos = new HashMap<String, Bitmap>();
public static void addPhoto(String key, Bitmap val) {
photos.put(key, val);
}
public static Bitmap getPhoto(String key) {
return photos.get(key);
}
public static boolean containsPhoto(String key) {
return photos.containsKey(key);
}
}
Unfortunately when I move from one activity to another and load more bitmaps from device the memory use is growing very fast, and after about 30 steps (move from one activity to another) there is outOfMemory exception raised.
-> I think that the best thing I can do is recycling bitmaps in onPause methods of my activities and fragments, but then application crashes when I click on back button, because bitmaps which were in use by earlier activity are recycled. I'm looking for some solution for that. Maybe I should load bitmaps in onResume method? Or block clicking the back button more than x (3-5) times? [I don't want to use some ready bitmap solutions and frameworks like Glide or similar.]
I've researched at least 10 similar topics on SO, however, none have reached a definitive answer for me allowing me to avoid the Out of Memory error Bitmaps are known for.
Taking into consideration the advice from these previous questions, I constructed the following method setBipmapFromPath to produce an optimally sized (both in dimensions and kilobytes) wallpaper image from a file path. This method works fine on a large RAM device like my G2, however, it crashes in an emulator with 1.5GB of RAM using a 256kb picture.
I welcome any criticism that will help me prevent the Out of Memory error. My hope is to also ensure the image can still act as a proper background image, as in, fill the screen of the device reasonably without insane stretch marks.
My methods:
public void recycleWallpaperBitmap() {
if (mBitmap != null) {
mBitmap.recycle();
mBitmap = null;
}
}
private void setBitmapFromPath() {
// Recycle the bitmap just in case.
recycleWallpaperBitmap();
String path = mProfileManager.getWallpaperPath();
if (path != null) {
WindowManager wm = (WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
int displayWidth = display.getWidth(); // deprecated
int displayHeight = display.getHeight(); // deprecated
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = false;
mBitmap = ThumbnailUtils.extractThumbnail(BitmapFactory.decodeFile(path, options),
displayWidth, displayHeight);
}
}
This method works fine on a large RAM device like my G2, however, it crashes in an emulator with 1.5GB of RAM using a 256kb picture.
It will fail on the G2 as well, depending on where and when you call this method. Your "256kb" picture will take up several MB of heap space, and there is no assurance that you have that amount of heap space available in a single contiguous block.
Also, I would not use a class and method designed for creating thumbnails will be suitable for creating wallpaper-sized images.
I welcome any criticism that will help me prevent the Out of Memory error.
Use inSampleSize on your BitmapFactory.Options to downsample the image to closer to the right size while it is being read in.
Then, dump your use of ThumbnailUtils and allow your ImageView to scale it the rest of the way, to avoid making yet another copy of the image.
Bonus points for using inBitmap instead of junking and re-allocating your Bitmap every time, since the screen size is not changing, and therefore your wallpaper dimensions are not changing.
These techniques and more are covered in the developer documentation.
I am using android google maps v2 and I am creating map markers and assigning a bitmap. I am getting the bitmap from my assets directory. The reason I get them from assets is that the path I am using to find the 'right' icon is dynamic.
My question is should I be saving the underlying bitmap so that I can reuse it again and again. I read:
http://developer.android.com/training/displaying-bitmaps/manage-memory.html
but frankly a lot of there really big sample project was over my head.
Should I be recreating the bitmap each time I need to pass that to a marker for creation, or should I read each bitmap( up to a limit) into memory and save them for reuse.
Each will be drawn on the map regardless so I am not sure I can reuse anyway.
Example: I have 300 markers on the map, with 20 different possible bitmaps. I.E. about 15% are the same marker icon.
Since bitmap decoding is quite expensive operation I would definitely recommend to go with bitmap caching. Especially in your case when the number of unique bitmaps is much smaller than number of markers on a map. Simple [LruCache][1] - based in-memory cache would work just fine. You just need to be careful about how much memory do you use for your cache.
Here is a good example of how to implement in-memory cache:
http://developer.android.com/training/displaying-bitmaps/cache-bitmap.html
Follow up
Just thought about this a bit more and you can do even better job here. Instead of caching bitmaps you can cache BitmapDescriptor for every unique bitmap you have. This way you can get some extra performance by avoiding making calls to BitmapDescriptorFactory every time you need to create a marker
UPDATE
Here is what I mean:
LruCache<String, BitmapDescriptor> cache;
private void initCache()
{
//Use 1/8 of available memory
cache = new LruCache<String, BitmapDescriptor>((int)(Runtime.getRuntime().maxMemory() / 1024 / 8));
}
private void addMarker(LatLng position, String assetPath)
{
MarkerOptions opts = new MarkerOptions();
opts.icon(getBitmapDescriptor(assetPath));
opts.position(position);
mMap.addMarker(opts);
}
private BitmapDescriptor getBitmapDescriptor(String path) {
BitmapDescriptor result = cache.get(path);
if (result == null) {
result = BitmapDescriptorFactory.fromAsset(path);
cache.put(path, result);
}
return result;
}
I'm working on implementing a cache for a lot of bitmap tiles I have. What I've done so far:
Successfully implemented a LRU Cache system, but the tiles still load slowly when they must be loaded from the app's resources. The cache currently has about an 85% hit rate.
Whenever I must load the bitmap from resources, it is still slow like I said. With this in mind, I am now loading the Bitmaps from an Async task. Before this, everything would load without error, but it was fairly slow. Now, it's faster since it's not working on the main thread, but I inevitably run into an OOM error. Here's the code for my Async task:
public class loadBitmap extends AsyncTask<Void,Void,Void>
{
Bitmap bit;
#Override
protected Void doInBackground(Void... params)
{
Options opts = new Options();
bit = BitmapFactory.decodeResource(reso, drawable, opts);
return null;
}
#Override
protected void onPostExecute(Void result)
{
// TODO Auto-generated method stub
drawLoadedBit(bit);
super.onPostExecute(result);
}
}
Any ideas on how I can implement this so I don't get the Out of Memory error? Since this is called in the draw method, I'm thinking that the multiple calls to it are causing it. Thanks for any advice.
Refer to this link
He gives a good tutorial on using regenative bitmaps. Further, to decouple the bitmap from the view [once the view is disposed], you can #Override View#onRemovedFromWindow() to recycle the bitmap. Going even further, if you still have this issue, you can create a BitmapPool in which you allocate your bitmaps. You can implement an algorithm go calculate the sizes of the bitmaps and release older bitmaps that would push you over an arbitrary memory amount (bitamp memory is about width*height*4 + object size which should be nominal)
When the Bitmap is loaded, keep it around in a class variable. Then next time a draw is requested, check to see if the class variable is non-null before loading it from resources again.
I developed an application that uses lots of images on Android.
The app runs once, fills the information on the screen (Layouts, Listviews, Textviews, ImageViews, etc) and user reads the information.
There is no animation, no special effects or anything that can fill the memory.
Sometimes the drawables can change. Some are android resources and some are files saved in a folder in the SDCARD.
Then the user quits (the onDestroy method is executed and app stays in memory by the VM ) and then at some point the user enters again.
Each time the user enters to the app, I can see the memory growing more and more until user gets the java.lang.OutOfMemoryError.
So what is the best/correct way to handle many images?
Should I put them in static methods so they are not loaded all the time?
Do I have to clean the layout or the images used in the layout in a special way?
One of the most common errors that I found developing Android Apps is the “java.lang.OutOfMemoryError: Bitmap Size Exceeds VM Budget” error. I found this error frequently on activities using lots of bitmaps after changing orientation: the Activity is destroyed, created again and the layouts are “inflated” from the XML consuming the VM memory available for bitmaps.
Bitmaps on the previous activity layout are not properly de-allocated by the garbage collector because they have crossed references to their activity. After many experiments I found a quite good solution for this problem.
First, set the “id” attribute on the parent view of your XML layout:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/RootView"
>
...
Then, on the onDestroy() method of your Activity, call the unbindDrawables() method passing a reference to the parent View and then do a System.gc().
#Override
protected void onDestroy() {
super.onDestroy();
unbindDrawables(findViewById(R.id.RootView));
System.gc();
}
private void unbindDrawables(View view) {
if (view.getBackground() != null) {
view.getBackground().setCallback(null);
}
if (view instanceof ViewGroup) {
for (int i = 0; i < ((ViewGroup) view).getChildCount(); i++) {
unbindDrawables(((ViewGroup) view).getChildAt(i));
}
((ViewGroup) view).removeAllViews();
}
}
This unbindDrawables() method explores the view tree recursively and:
Removes callbacks on all the background drawables
Removes children on every viewgroup
It sounds like you have a memory leak. The problem isn't handling many images, it's that your images aren't getting deallocated when your activity is destroyed.
It's difficult to say why this is without looking at your code. However, this article has some tips that might help:
http://android-developers.blogspot.de/2009/01/avoiding-memory-leaks.html
In particular, using static variables is likely to make things worse, not better. You might need to add code that removes callbacks when your application redraws -- but again, there's not enough information here to say for sure.
To avoid this problem you can use native method Bitmap.recycle() before null-ing Bitmap object (or setting another value). Example:
public final void setMyBitmap(Bitmap bitmap) {
if (this.myBitmap != null) {
this.myBitmap.recycle();
}
this.myBitmap = bitmap;
}
And next you can change myBitmap w/o calling System.gc() like:
setMyBitmap(null);
setMyBitmap(anotherBitmap);
I've ran into this exact problem. The heap is pretty small so these images can get out of control rather quickly in regards to memory. One way is to give the garbage collector a hint to collect memory on a bitmap by calling its recycle method.
Also, the onDestroy method is not guaranteed to get called. You may want to move this logic/clean up into the onPause activity. Check out the Activity Lifecycle diagram/table on this page for more info.
This explanation might help:
http://code.google.com/p/android/issues/detail?id=8488#c80
"Fast Tips:
1) NEVER call System.gc() yourself. This has been propagated as a fix here, and it doesn't work. Do not do it. If you noticed in my explanation, before getting an OutOfMemoryError, the JVM already runs a garbage collection so there is no reason to do one again (its slowing your program down). Doing one at the end of your activity is just covering up the problem. It may causes the bitmap to be put on the finalizer queue faster, but there is no reason you couldn't have simply called recycle on each bitmap instead.
2) Always call recycle() on bitmaps you don't need anymore. At the very least, in the onDestroy of your activity go through and recycle all the bitmaps you were using. Also, if you want the bitmap instances to be collected from the dalvik heap faster, it doesn't hurt to clear any references to the bitmap.
3) Calling recycle() and then System.gc() still might not remove the bitmap from the Dalvik heap. DO NOT BE CONCERNED about this. recycle() did its job and freed the native memory, it will just take some time to go through the steps I outlined earlier to actually remove the bitmap from the Dalvik heap. This is NOT a big deal because the large chunk of native memory is already free!
4) Always assume there is a bug in the framework last. Dalvik is doing exactly what its supposed to do. It may not be what you expect or what you want, but its how it works. "
I had the exact same problem. After a few testing I found that this error is appearing for large image scaling. I reduced the image scaling and the problem disappeared.
P.S. At first I tried to reduce the image size without scaling the image down. That did not stop the error.
Following points really helped me a lot. There might be other points too, but these are very crucial:
Use application context(instead of activity.this) where ever possible.
Stop and release your threads in onPause() method of activity
Release your views / callbacks in onDestroy() method of activity
I suggest a convenient way to solve this problem.
Just assign the attribute "android:configChanges" value as followed in the Mainfest.xml for your errored activity.
like this:
<activity android:name=".main.MainActivity"
android:label="mainActivity"
android:configChanges="orientation|keyboardHidden|navigation">
</activity>
the first solution I gave out had really reduced the frequency of OOM error to a low level. But, it did not solve the problem totally. And then I will give out the 2nd solution:
As the OOM detailed, I have used too much runtime memory. So, I reduce the picture size in ~/res/drawable of my project. Such as an overqualified picture which has a resolution of 128X128, could be resized to 64x64 which would also be suitable for my application. And after I did so with a pile of pictures, the OOM error doesn't occur again.
I too am frustrated by the outofmemory bug. And yes, I too found that this error pops up a lot when scaling images. At first I tried creating image sizes for all densities, but I found this substantially increased the size of my app. So I'm now just using one image for all densities and scaling my images.
My application would throw an outofmemory error whenever the user went from one activity to another. Setting my drawables to null and calling System.gc() didn't work, neither did recycling my bitmapDrawables with getBitMap().recycle(). Android would continue to throw the outofmemory error with the first approach, and it would throw a canvas error message whenever it tried using a recycled bitmap with the second approach.
I took an even third approach. I set all views to null and the background to black. I do this cleanup in my onStop() method. This is the method that gets called as soon as the activity is no longer visible. If you do it in the onPause() method, users will see a black background. Not ideal. As for doing it in the onDestroy() method, there is no guarantee that it will get called.
To prevent a black screen from occurring if the user presses the back button on the device, I reload the activity in the onRestart() method by calling the startActivity(getIntent()) and then finish() methods.
Note: it's not really necessary to change the background to black.
The BitmapFactory.decode* methods, discussed in the Load Large Bitmaps Efficiently lesson, should not be executed on the main UI thread if the source data is read from disk or a network location (or really any source other than memory). The time this data takes to load is unpredictable and depends on a variety of factors (speed of reading from disk or network, size of image, power of CPU, etc.). If one of these tasks blocks the UI thread, the system flags your application as non-responsive and the user has the option of closing it (see Designing for Responsiveness for more information).
Well I've tried everything I found on the internet and none of them worked. Calling System.gc() only drags down the speed of app. Recycling bitmaps in onDestroy didn't work for me too.
The only thing that works now is to have a static list of all the bitmap so that the bitmaps survive after a restart. And just use the saved bitmaps instead of creating new ones every time the activity if restarted.
In my case the code looks like this:
private static BitmapDrawable currentBGDrawable;
if (new File(uriString).exists()) {
if (!uriString.equals(currentBGUri)) {
freeBackground();
bg = BitmapFactory.decodeFile(uriString);
currentBGUri = uriString;
bgDrawable = new BitmapDrawable(bg);
currentBGDrawable = bgDrawable;
} else {
bgDrawable = currentBGDrawable;
}
}
I had the same problem just with switching the background images with reasonable sizes. I got better results with setting the ImageView to null before putting in a new picture.
ImageView ivBg = (ImageView) findViewById(R.id.main_backgroundImage);
ivBg.setImageDrawable(null);
ivBg.setImageDrawable(getResources().getDrawable(R.drawable.new_picture));
FWIW, here's a lightweight bitmap-cache I coded and have used for a few months. It's not all-the-bells-and-whistles, so read the code before you use it.
/**
* Lightweight cache for Bitmap objects.
*
* There is no thread-safety built into this class.
*
* Note: you may wish to create bitmaps using the application-context, rather than the activity-context.
* I believe the activity-context has a reference to the Activity object.
* So for as long as the bitmap exists, it will have an indirect link to the activity,
* and prevent the garbaage collector from disposing the activity object, leading to memory leaks.
*/
public class BitmapCache {
private Hashtable<String,ArrayList<Bitmap>> hashtable = new Hashtable<String, ArrayList<Bitmap>>();
private StringBuilder sb = new StringBuilder();
public BitmapCache() {
}
/**
* A Bitmap with the given width and height will be returned.
* It is removed from the cache.
*
* An attempt is made to return the correct config, but for unusual configs (as at 30may13) this might not happen.
*
* Note that thread-safety is the caller's responsibility.
*/
public Bitmap get(int width, int height, Bitmap.Config config) {
String key = getKey(width, height, config);
ArrayList<Bitmap> list = getList(key);
int listSize = list.size();
if (listSize>0) {
return list.remove(listSize-1);
} else {
try {
return Bitmap.createBitmap(width, height, config);
} catch (RuntimeException e) {
// TODO: Test appendHockeyApp() works.
App.appendHockeyApp("BitmapCache has "+hashtable.size()+":"+listSize+" request "+width+"x"+height);
throw e ;
}
}
}
/**
* Puts a Bitmap object into the cache.
*
* Note that thread-safety is the caller's responsibility.
*/
public void put(Bitmap bitmap) {
if (bitmap==null) return ;
String key = getKey(bitmap);
ArrayList<Bitmap> list = getList(key);
list.add(bitmap);
}
private ArrayList<Bitmap> getList(String key) {
ArrayList<Bitmap> list = hashtable.get(key);
if (list==null) {
list = new ArrayList<Bitmap>();
hashtable.put(key, list);
}
return list;
}
private String getKey(Bitmap bitmap) {
int width = bitmap.getWidth();
int height = bitmap.getHeight();
Config config = bitmap.getConfig();
return getKey(width, height, config);
}
private String getKey(int width, int height, Config config) {
sb.setLength(0);
sb.append(width);
sb.append("x");
sb.append(height);
sb.append(" ");
switch (config) {
case ALPHA_8:
sb.append("ALPHA_8");
break;
case ARGB_4444:
sb.append("ARGB_4444");
break;
case ARGB_8888:
sb.append("ARGB_8888");
break;
case RGB_565:
sb.append("RGB_565");
break;
default:
sb.append("unknown");
break;
}
return sb.toString();
}
}