Application get crashed when reached at end of List. [158892717]

Fixed

Bug

Status Update

No update yet.

Description

th...@gmail.com

created issue #1

Jun 14, 2020 08:05AM

Component used: Paging
Version used: 3.0.0-alpha01

I have followed codelabs paging 3 tutorial. I have implemented paging from network and database.
This is the repository provided by codelabs tutorial :-

https://github.com/googlecodelabs/android-paging

I have founded 2 issues in Paging 3.

1. Application get crashed when Recylerview reach at end(last page).
Inside GithubRemoteMediator.kt
I have set val endOfPaginationReached = page > 2 to allow maximum 2 pages for testing.
So, the problem is when I reach at the last page of list, application get crashed as remoteKeys.nextKey is null(as we have set nextKey=null for last page of list).

2. Offline cache broken
How to support caching when application is open without internet connection. currently it is showing retry button. How to show previously loaded data. I have tried to fix this by removing

// clear all tables in the database
if (loadType == LoadType.REFRESH) {
repoDatabase.remoteKeysDao().clearRemoteKeys()
repoDatabase.reposDao().clearRepos()
}

as this will now not gone delete data from database.
But still Pager does not load data available.

So how I can fix this problem?
Is there any way of detecting end of paging?
Why Pager is not returning data available in database.

Comments

du...@google.com <du...@google.com> #2Jun 15, 2020 04:16PM

Reassigned to du...@google.com.

A couple of questions:

1. Have you saw crash in real device or only in simulators?
2. Do you use dynamic feature for language ID?

th...@gmail.com <th...@gmail.com> #3Jun 17, 2020 09:21AM

Tested on Android 12 Emulator with custom executor, but cannot repro this issue.

ap...@google.com <ap...@google.com> #4Jun 17, 2020 08:08PM

Second crash in the description is from a real device. Experienced it myself on two different Xiaomi phones, plus lots of crashes from users in the Google Play console.
Dynamic features are not used in the application.

As a wild guess, I have downgraded build tools from 31.0.0 to 30.0.3, compileSdk from 31 to 30, and moved all work with Language ID to the service in a separate process (just to be sure that crash can kill secondary process instead of main). This combination is in beta for 2 days by now and I don't see any SIGSEGV crashes.

du...@google.com <du...@google.com> #5Jun 17, 2020 08:16PM

Marked as fixed.

Hmm, I feel the crash might be something related to separate/secondary process.

I also changed compileSdk and targetSDK to 31 but still cannot repro this issue.

du...@google.com <du...@google.com> #6Jun 17, 2020 08:18PM

On the contrary, there was no separate process before, when crashes started.

In the new build (with the aforementioned changes) I can see SIGSEGV crash, but only one instead of dozens and it has a bit different backtrace:

signal 11 (SIGSEGV), code 1 (SEGV_MAPERR)
liblanguage_id_jni.so (offset 0x11e000)

backtrace:
  #00  pc 000000000003c7c0  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 000000000003b960  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 000000000003bb48  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 000000000003bafc  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 0000000000036c98  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 0000000000032714  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 0000000000031cac  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 0000000000057438  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/oat/arm64/base.odex (offset 0x57000)

th...@gmail.com <th...@gmail.com> #7Jun 18, 2020 03:08AM

FYI, ML Kit launched a new language ID SDK in the latest release, which uses a new language ID model. https://developers.google.com/ml-kit/release-notes#august_11_2021

Could you try the new SDK version(17.0.0) to check if you can still repro this native crash? Thanks!

Issue 158892717