Memory leak in PreferenceFragmentCompat adapter handling [121006469]

Fixed

Bug

Status Update

No update yet.

Description

js...@gmail.com

created issue #1

Dec 14, 2018 07:54PM

RecyclerView registers an observer (

https://android.googlesource.com/platform/frameworks/support/+/androidx-master-dev/recyclerview/recyclerview/src/main/java/androidx/recyclerview/widget/RecyclerView.java#1201) that is only unregistered manually, by either setting the adapter again, or calling unregisterAdapterDataObserver externally.

PreferenceFragmentCompat sets this adapter (PreferenceGroupAdapter), which implicitly registers an observer. PreferenceFragmentCompat never sets the adapter to null when the view is destroyed, so the observer keeps references to the RecyclerView and doesn't get gc'ed.

I've worked around this by explicitly setting the adapter to null in an override of onDestroyView, but since my component doesn't explicitly have ownership of the list handling, I'd argue that PreferenceFragmentCompat should do this cleanup.

It would be solved by setting the RecyclerView adapter to null in the fragment's onDestroyView.

Here's a memory dump.

2018-12-14_10-38-54_921.hprof

23 MB

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Comments

lp...@google.com <lp...@google.com> #2Jan 10, 2019 11:35PM

What are you trying to do? Can you include a sample project that reproduces your issue?

lp...@google.com <lp...@google.com> #3Jan 14, 2019 08:41PM

Marked as fixed.

I use a custom Dialog navigator that doesn't allow 2 dialogs open at the same time. I'll create a sample project in the next few days

ma...@gmail.com <ma...@gmail.com> #4Feb 28, 2020 01:26PM

Sample project here:

https://github.com/rubensousa/CustomNavigatorSample

Crash on 2.3.2:
Caused by: java.lang.ClassCastException: com.navigation.sample.SingleDialogNavigator cannot be cast to androidx.navigation.fragment.DialogFragmentNavigator
at androidx.navigation.fragment.NavHostFragment.onAttachFragment(NavHostFragment.java:293)

Expected behavior: no crash as in 2.3.1

jb...@google.com <jb...@google.com> #5Feb 28, 2020 05:57PM

Any update on this? This is preventing us from updating to newer releases

ma...@gmail.com <ma...@gmail.com> #6Feb 29, 2020 09:16PM

Project: platform/frameworks/support
Branch: androidx-main

commit ffe68e0a3be1da83217fadd4e40c5abad4f72b82
Author: Ian Lake <ilake@google.com>
Date: Tue Apr 06 12:40:35 2021

Use FragmentOnAttachListener in DialogFragmentNavigator

Rather than having the NavHostFragment
explicitly look for the DialogFragmentNavigator
to forward the fragment attach callback,
have DialogFragmentNavigator use the
Fragment 1.3 FragmentOnAttachListener API
to fully contain that logic within the
DialogFragmentNavigator.

Relnote: "`NavHostFragment` now supports custom
Navigators that use the same `@Navigator.Name(\"dialog\")`
as the default `DialogFragmentNavigator`."
Test: existing tests still pass
BUG: 175979140

Change-Id: Ib1c2cc38e7a621d133be1f4c3692e62913450dda

M navigation/navigation-fragment/api/public_plus_experimental_current.txt
M navigation/navigation-fragment/src/main/java/androidx/navigation/fragment/DialogFragmentNavigator.kt
M navigation/navigation-fragment/src/main/java/androidx/navigation/fragment/NavHostFragment.kt

https://android-review.googlesource.com/1665820

Issue 121006469