Kiwix-android: Memory leak in KiwixReaderFragment

[Frans-Lukas]

Describe the bug

KiwixReaderFragment is leaking

Expected behavior

No memory leaks should be present.

Steps to reproduce the behavior:

1. Open the history fragment.
2. Click a history item.
3. Open the history fragment again.
4. Close the history fragment.
5. Minimize the app (go to the android home screen).
   

Screenshots

┬───
│ GC Root: System class
│
├─ android.view.inputmethod.InputMethodManager class
│    Leaking: NO (InputMethodManager↓ is not leaking and a class is never leaking)
│    ↓ static InputMethodManager.sInstance
├─ android.view.inputmethod.InputMethodManager instance
│    Leaking: NO (DecorView↓ is not leaking and InputMethodManager is a singleton)
│    ↓ InputMethodManager.mNextServedView
├─ com.android.internal.policy.DecorView instance
│    Leaking: NO (RecyclerView↓ is not leaking and View attached)
│    mContext instance of com.android.internal.policy.DecorContext, wrapping activity org.kiwix.kiwixmobile.main.KiwixMainActivity with mDestroyed = false
│    Parent android.view.ViewRootImpl not a android.view.View
│    View#mParent is set
│    View#mAttachInfo is not null (view attached)
│    View.mWindowAttachCount = 1
│    ↓ DecorView.mAttachInfo
├─ android.view.View$AttachInfo instance
│    Leaking: NO (RecyclerView↓ is not leaking)
│    ↓ View$AttachInfo.mScrollContainers
├─ java.util.ArrayList instance
│    Leaking: NO (RecyclerView↓ is not leaking)
│    ↓ ArrayList.elementData
├─ java.lang.Object[] array
│    Leaking: NO (RecyclerView↓ is not leaking)
│    ↓ Object[].[2]
├─ androidx.recyclerview.widget.RecyclerView instance
│    Leaking: NO (View attached)
│    mContext instance of org.kiwix.kiwixmobile.main.KiwixMainActivity with mDestroyed = false
│    View.parent android.widget.LinearLayout attached as well
│    View#mParent is set
│    View#mAttachInfo is not null (view attached)
│    View.mID = R.id.right_drawer_list
│    View.mWindowAttachCount = 1
│    ↓ RecyclerView.mAdapter
│                   ~~~~~~
├─ org.kiwix.kiwixmobile.core.main.TableDrawerAdapter instance
│    Leaking: UNKNOWN
│    ↓ TableDrawerAdapter.listener
│                         ~~~~~~
├─ org.kiwix.kiwixmobile.core.main.CoreReaderFragment$7 instance
│    Leaking: UNKNOWN
│    Anonymous class implementing org.kiwix.kiwixmobile.core.main.TableDrawerAdapter$TableClickListener
│    ↓ CoreReaderFragment$7.this$0
│                           ~~~~
╰→ org.kiwix.kiwixmobile.nav.destination.reader.KiwixReaderFragment instance
​     Leaking: YES (ObjectWatcher was watching this because org.kiwix.kiwixmobile.nav.destination.reader.KiwixReaderFragment received Fragment#onDestroy() callback and Fragment#mFragmentManager is null)
​     key = b9dd5d25-5ae3-4c56-83d1-f3e2fdae4252
​     watchDurationMillis = 8963
​     retainedDurationMillis = 3963

METADATA

Build.VERSION.SDK_INT: 29
Build.MANUFACTURER: OnePlus
LeakCanary version: 2.4
App process name: org.kiwix.kiwixmobile
Analysis duration: 10339 ms

[Frans-Lukas]

Setting the tableDrawerAdapters listener to null semms to fix this leak, but another shows up:

┬───
│ GC Root: System class
│
├─ android.view.inputmethod.InputMethodManager class
│    Leaking: NO (InputMethodManager↓ is not leaking and a class is never leaking)
│    ↓ static InputMethodManager.sInstance
├─ android.view.inputmethod.InputMethodManager instance
│    Leaking: NO (DecorView↓ is not leaking and InputMethodManager is a singleton)
│    ↓ InputMethodManager.mNextServedView
├─ com.android.internal.policy.DecorView instance
│    Leaking: NO (RecyclerView↓ is not leaking and View attached)
│    mContext instance of com.android.internal.policy.DecorContext, wrapping activity org.kiwix.kiwixmobile.main.KiwixMainActivity with mDestroyed = false
│    Parent android.view.ViewRootImpl not a android.view.View
│    View#mParent is set
│    View#mAttachInfo is not null (view attached)
│    View.mWindowAttachCount = 1
│    ↓ DecorView.mAttachInfo
├─ android.view.View$AttachInfo instance
│    Leaking: NO (RecyclerView↓ is not leaking)
│    ↓ View$AttachInfo.mScrollContainers
├─ java.util.ArrayList instance
│    Leaking: NO (RecyclerView↓ is not leaking)
│    ↓ ArrayList.elementData
├─ java.lang.Object[] array
│    Leaking: NO (RecyclerView↓ is not leaking)
│    ↓ Object[].[2]
├─ androidx.recyclerview.widget.RecyclerView instance
│    Leaking: NO (RelativeLayout↓ is not leaking and View attached)
│    mContext instance of org.kiwix.kiwixmobile.main.KiwixMainActivity with mDestroyed = false
│    View.parent android.widget.LinearLayout attached as well
│    View#mParent is set
│    View#mAttachInfo is not null (view attached)
│    View.mID = R.id.right_drawer_list
│    View.mWindowAttachCount = 1
│    ↓ RecyclerView.mChildren
├─ android.view.View[] array
│    Leaking: NO (RelativeLayout↓ is not leaking)
│    ↓ View[].[0]
├─ android.widget.RelativeLayout instance
│    Leaking: NO (View attached)
│    mContext instance of org.kiwix.kiwixmobile.main.KiwixMainActivity with mDestroyed = false
│    View.parent androidx.recyclerview.widget.RecyclerView attached as well
│    View#mParent is set
│    View#mAttachInfo is not null (view attached)
│    View.mWindowAttachCount = 3
│    ↓ RelativeLayout.mListenerInfo
│                     ~~~~~~~~~~~
├─ android.view.View$ListenerInfo instance
│    Leaking: UNKNOWN
│    ↓ View$ListenerInfo.mOnClickListener
│                        ~~~~~~~~~~~~~~
├─ org.kiwix.kiwixmobile.core.main.TableDrawerAdapter$sam$android_view_View_OnClickListener$0 instance
│    Leaking: UNKNOWN
│    Anonymous class implementing android.view.View$OnClickListener
│    ↓ TableDrawerAdapter$sam$android_view_View_OnClickListener$0.function
│                                                                 ~~~~~~
├─ org.kiwix.kiwixmobile.core.main.TableDrawerAdapter$onBindViewHolder$1 instance
│    Leaking: UNKNOWN
│    Anonymous subclass of kotlin.jvm.internal.FunctionReference
│    ↓ TableDrawerAdapter$onBindViewHolder$1.receiver
│                                            ~~~~~~
├─ org.kiwix.kiwixmobile.core.main.CoreReaderFragment$7 instance
│    Leaking: UNKNOWN
│    Anonymous class implementing org.kiwix.kiwixmobile.core.main.TableDrawerAdapter$TableClickListener
│    ↓ CoreReaderFragment$7.this$0
│                           ~~~~
╰→ org.kiwix.kiwixmobile.nav.destination.reader.KiwixReaderFragment instance
​     Leaking: YES (ObjectWatcher was watching this because org.kiwix.kiwixmobile.nav.destination.reader.KiwixReaderFragment received Fragment#onDestroy() callback and Fragment#mFragmentManager is null)
​     key = 5c2f320e-626c-420a-9d2f-22a8b2603781
​     watchDurationMillis = 15543
​     retainedDurationMillis = 10509

METADATA

Build.VERSION.SDK_INT: 29
Build.MANUFACTURER: OnePlus
LeakCanary version: 2.4
App process name: org.kiwix.kiwixmobile
Analysis duration: 16812 ms

[gouri-panda]

@Frans-Lukas Do you wanna work on this issue?

[Frans-Lukas]

@gouri-panda I won't until next weekend so if you feel like doing it before then, go ahead.

[kelson42]

@gouri-panda If you can fix it quickly this would be much appreciated, I believe nobody is comfortable with the idea of shipping 3.4.1 with known memoery leaks.

[macgills]

@gouri-panda I will be taking over this ticket in the interest of expediting it

[macgills]

@Frans-Lukas I cannot reproduce this issue using the repro steps. Can you reverify this leak on latest develop?

[Frans-Lukas]

Still reproducible, could it be book specific?

┬───
│ GC Root: System class
│
├─ android.view.inputmethod.InputMethodManager class
│    Leaking: NO (InputMethodManager↓ is not leaking and a class is never leaking)
│    ↓ static InputMethodManager.sInstance
├─ android.view.inputmethod.InputMethodManager instance
│    Leaking: NO (DecorView↓ is not leaking and InputMethodManager is a singleton)
│    ↓ InputMethodManager.mNextServedView
├─ com.android.internal.policy.DecorView instance
│    Leaking: NO (RecyclerView↓ is not leaking and View attached)
│    mContext instance of com.android.internal.policy.DecorContext, wrapping activity org.kiwix.kiwixmobile.main.KiwixMainActivity with mDestroyed = false
│    Parent android.view.ViewRootImpl not a android.view.View
│    View#mParent is set
│    View#mAttachInfo is not null (view attached)
│    View.mWindowAttachCount = 1
│    ↓ DecorView.mAttachInfo
├─ android.view.View$AttachInfo instance
│    Leaking: NO (RecyclerView↓ is not leaking)
│    ↓ View$AttachInfo.mScrollContainers
├─ java.util.ArrayList instance
│    Leaking: NO (RecyclerView↓ is not leaking)
│    ↓ ArrayList.elementData
├─ java.lang.Object[] array
│    Leaking: NO (RecyclerView↓ is not leaking)
│    ↓ Object[].[2]
├─ androidx.recyclerview.widget.RecyclerView instance
│    Leaking: NO (View attached)
│    mContext instance of org.kiwix.kiwixmobile.main.KiwixMainActivity with mDestroyed = false
│    View.parent android.widget.LinearLayout attached as well
│    View#mParent is set
│    View#mAttachInfo is not null (view attached)
│    View.mID = R.id.right_drawer_list
│    View.mWindowAttachCount = 1
│    ↓ RecyclerView.mAdapter
│                   ~~~~~~
├─ org.kiwix.kiwixmobile.core.main.TableDrawerAdapter instance
│    Leaking: UNKNOWN
│    ↓ TableDrawerAdapter.listener
│                         ~~~~~~
├─ org.kiwix.kiwixmobile.core.main.CoreReaderFragment$7 instance
│    Leaking: UNKNOWN
│    Anonymous class implementing org.kiwix.kiwixmobile.core.main.TableDrawerAdapter$TableClickListener
│    ↓ CoreReaderFragment$7.this$0
│                           ~~~~
╰→ org.kiwix.kiwixmobile.nav.destination.reader.KiwixReaderFragment instance
​     Leaking: YES (ObjectWatcher was watching this because org.kiwix.kiwixmobile.nav.destination.reader.KiwixReaderFragment received Fragment#onDestroy() callback and Fragment#mFragmentManager is null)
​     key = e2d4fa0d-7fad-4970-9cb9-09cd05c6c623
​     watchDurationMillis = 6936
​     retainedDurationMillis = 1915

METADATA

Build.VERSION.SDK_INT: 29
Build.MANUFACTURER: OnePlus
LeakCanary version: 2.4
App process name: org.kiwix.kiwixmobile
Analysis duration: 10368 ms