Release Memory of Particular Activity when it is Destroyed

Question

I have a launcher Activity that load and resize big bitmap as it's background when it opens.

Whenever hit the back button, the Activity is destroyed. But I think the memory is not released yet.

When I open back the app, hit the back button and open it again (repeatedly), I will get a OutOfMemoryError.

I am sorry for this newbie question but I am wondering how do I release the memory whenever an Activity is destroyed?

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_welcome);

    //MARK - movingBackgroundImageView
    movingBackgroundImageView = (ImageView) findViewById(R.id.movingBackgroundImageView);
    movingBackgroundImageView.setColorFilter(Color.argb(255, 255, 255, 255));
    movingBackgroundImageView.setScaleType(ImageView.ScaleType.MATRIX);
    movingBackgroundImageView.setAlpha(0.28f);

    prepareBackgroundAnimation();
}

private void prepareBackgroundAnimation() {

    DisplayMetrics displaymetrics = new DisplayMetrics();
    getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);

    screenWidth = displaymetrics.widthPixels;
    screenHeight = displaymetrics.heightPixels;

    movingImageHeight = displaymetrics.heightPixels;
    movingImageWidth = 1920.0 / 1080.0 * movingImageHeight;

    bitmapImage = BitmapFactory.decodeResource(this.getResources(), R.drawable.moving_background_image);
    scaledBitmap = bitmapImage.createScaledBitmap(bitmapImage, (int) movingImageWidth, (int) movingImageHeight, false);
    movingBackgroundImageView.setImageBitmap(scaledBitmap);

    backgroundImageInBeginning = true;

    movingBackgroundImageView.post(new Runnable() {
        @Override
        public void run() {
            movingBackgroundImageView.setImageMatrix(matrix);
            moveBackground();
        }
    });
}

12-22 13:44:49.549 30885-30885/? E/AndroidRuntime: FATAL EXCEPTION: main Process: id.testingapp.android.TestingApp, PID: 30885 java.lang.OutOfMemoryError: Failed to allocate a 26211852 byte allocation with 14018312 free bytes and 13MB until OOM at dalvik.system.VMRuntime.newNonMovableArray(Native Method) at android.graphics.Bitmap.nativeCreate(Native Method) at android.graphics.Bitmap.createBitmap(Bitmap.java:939) at android.graphics.Bitmap.createBitmap(Bitmap.java:912) at android.graphics.Bitmap.createBitmap(Bitmap.java:843) at android.graphics.Bitmap.createScaledBitmap(Bitmap.java:719) at id.testingapp.android.TestingApp.WelcomeActivity.prepareBackgroundAnimation(WelcomeActivity.java:140) at id.TestingApp.android.TestingApp.WelcomeActivity.onCreate(WelcomeActivity.java:72) at android.app.Activity.performCreate(Activity.java:6283) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2758) at android.app.ActivityThread.access$900(ActivityThread.java:177) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1448) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:145) at android.app.ActivityThread.main(ActivityThread.java:5942) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)

EDIT:

I have tried to put all these in onDestroyed() but the problem persists

@Override
protected void onDestroy() {
    finish();
    bitmapImage = null;
    scaledBitmap = null;
    super.onDestroy();
    Runtime.getRuntime().gc();
    System.gc();
}

Solution 1

Add following code for it

@Override
protected void onDestroy() {
    //android.os.Process.killProcess(android.os.Process.myPid());

    super.onDestroy();
    if(scaledBitmap!=null)
            {
                scaledBitmap.recycle();
                scaledBitmap=null;
            }

     }

Solution 2

In activity if you're calling the finish() method from is destroyed and all its resources are queued for garbage collection.

So, all memory that was used by this activity will be freed during next GC cycle.

OR

you can try this to clean memory,

@Override
public void onDestroy() {
    super.onDestroy();
    Runtime.getRuntime().gc();      
}

check this details. hope that helps.

Solution 3

add this to your code

@Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
    if ((keyCode == KeyEvent.KEYCODE_BACK))
    {
        finish();
    }
    return super.onKeyDown(keyCode, event);
}

Solution 4

Try to set the bitmap to null while activity is destroyed and if desire run the garbage collector.

Solution 5

even after destroying the activity by calling finish(), it's resources are queued for garbage collection. activity will be freed during next GC cycle.

@Override
public void onDestroy() {
    super.onDestroy();
    Runtime.getRuntime().gc();      
}

You can also use android:largeHeap="true" to request a larger heap size, in your application tag in manifest.

View more solutions

Comments

[Nishant Srivastava]

Please post the complete stacktrace.

[Ravindra Kushwaha]

@JayVDiyk ... Check the solution below...let me know in case of concern

[pRaNaY]

can you try System.gc();?

[JayVDiyk]

@RavindraKushwaha Your code works! Thank you....

[ND27]

But System.gc(); would not guarantee garbage collection happening at the time of the request

[JayVDiyk]

I have updated the code with my animation which seems to be the problem. Tried to set bitmap to null in onDestroy but it doesnt seem to work. Any thoughts?

[JayVDiyk]

finish() doesnt do it.

[JayVDiyk]

thanks, but LargeHeap to true does not mean that the memory leak is fixed

[learner]

even if you call GC , JVM will not ensure that. Gc always get called at runtime when JVM looks for memory.developer cannot handle JVM

[JayVDiyk]

Thanks, calling recycle fixes it.

[Ravindra Kushwaha]

@JayVDiyk ...Happy to help bro :)

[JayVDiyk]

I've tried several times. It works, but it doesnt seem to clear all memory leak, because after 15 times of opening and closing. the OutOfMemoryError comes back

[Ravindra Kushwaha]

Means ... Your problem is not short out yet??

[JayVDiyk]

At first It thought it works. because before using the recycle method, the OutOfMemoryError will happen after 3 times opening and closing the app. Now after the recycle, the app will have the error after 15 times of opening and closing.

[Ravindra Kushwaha]

You can use the code on your onCreate method..And make check that the Bitmap is rescycled or NULL or not...before using the bitmap