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();
}

@JayVDiyk ... Check the solution below...let me know in case of concern — Ravindra Kushwaha, Dec 22 '15 at 06:36
But System.gc(); would not guarantee garbage collection happening at the time of the request — ND27, Mar 31 '16 at 05:45

score 15 · Accepted Answer · answered Dec 22 '15 at 06:34

15

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;
            }

     }

answered Dec 22 '15 at 06:34

Ravindra Kushwaha

7,846
14
53
103

Thanks, calling recycle fixes it. – JayVDiyk Dec 22 '15 at 06:54
@JayVDiyk ...Happy to help bro :) – Ravindra Kushwaha Dec 22 '15 at 06:55
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 – JayVDiyk Dec 22 '15 at 07:01
Means ... Your problem is not short out yet?? – Ravindra Kushwaha Dec 22 '15 at 07:03
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. – JayVDiyk Dec 22 '15 at 07:05
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 – Ravindra Kushwaha Dec 22 '15 at 07:10

Amit Vaghela · Answer 2 · 2018-03-08T07:57:50.830

8

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.

edited Mar 08 '18 at 07:57

answered Dec 22 '15 at 06:37

Amit Vaghela

22,772
22
86
142

score 2 · Answer 3 · answered Dec 22 '15 at 06:19

2

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

answered Dec 22 '15 at 06:19

ajantha

1,585
16
23

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 Dec 22 '15 at 06:30

score 2 · Answer 4 · answered Dec 22 '15 at 06:28

2

add this to your code

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

answered Dec 22 '15 at 06:28

Jatin Khattar

59
9

1

finish() doesnt do it. – JayVDiyk Dec 22 '15 at 06:30

Androider · Answer 5 · 2015-12-22T06:39:32.880

2

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.

edited Dec 22 '15 at 06:39

answered Dec 22 '15 at 06:35

Androider

3,833
2
14
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1

thanks, but LargeHeap to true does not mean that the memory leak is fixed – JayVDiyk Dec 22 '15 at 06:37
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 – learner Dec 22 '15 at 06:48

score 1 · Answer 6 · answered Dec 22 '15 at 06:36

1

try to finish the activity when pressing back button

@Override
public void onBackPressed() {
    super.onBackPressed();
    finish();
}

answered Dec 22 '15 at 06:36

Anbarasu Chinna

975
9
28

score 0 · Answer 7 · edited Sep 29 '16 at 05:45

0

Finishing an Activity doesn't clear its memory. It only removes the Activity from its stack, Android will clear its memory when it needs memory (garbage collection),if you face memory issue from drawable,

Reducing the drawable size may solve your problem.
Insufficient memory in Android devices also leads to memory issues.

edited Sep 29 '16 at 05:45

S.L. Barth is on codidact.com

8,198
71
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answered Dec 22 '15 at 06:55

Anbarasu Chinna

975
9
28

Release Memory of Particular Activity when it is Destroyed

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