[Room KMP] Can't receive invalidation callback when writing data inside transactor.immediateTransaction block [340606803]

Fixed

Bug

Status Update

No update yet.

Description

b9...@gmail.com

created issue #1

May 15, 2024 04:46AM

In this block:

// before
suspend fun refreshData(){
    val response = api.getData()
    database.fruittieDao().insert(response.feed)
}

// after
suspend fun refreshData(){
    val response = api.getData()
    with(database) {
        useWriterConnection {
            it.immediateTransaction {
                fruittieDao().insert(response.feed)
            }
        }
    }
}

After wrapped in immediateTransaction, which mentioned here, data flow couldn't receive any change, neither any invalidation observer.

In pure Room without KMP, multiple DAO operations normally wrapped in database.withTransaction block. How to do in KMP?

Comments

da...@google.com <da...@google.com> #2May 15, 2024 12:38PM

For one of observables (single, maybe) we don't specify a subscvription thread so that developer can control where the action happens.
For flowables / observables; we always use the Room IO thread fo rthe actual query since we may repeat the work.

For LiveData, ti si always the Room IO Thread.

Until we can extend Room Query methods to receive non-query parameter (e.g. a Scheduler) we cannot do this.
At least room catches this instantly since it will crash w/ db access on main thread exception.

ae...@gmail.com <ae...@gmail.com> #3Dec 4, 2024 04:23PM

Hello Yigit, nice to meet you here! :)
Probably I should have described the problem more clearly.

I'm using Flowable, and hopefully it executes queries in background thread (at least, app does not crash with IllegalStateException, as with Single).

But nevertheless subscribing and disposing(!) does cause StrictMode violations. Stack trace examples:

D/StrictMode: StrictMode policy violation; ~duration=17 ms: android.os.StrictMode$StrictModeDiskWriteViolation: policy=31 violation=1
at android.os.StrictMode$AndroidBlockGuardPolicy.onWriteToDisk(StrictMode.java:1111)
at android.database.sqlite.SQLiteConnection.applyBlockGuardPolicy(SQLiteConnection.java:1043)
at android.database.sqlite.SQLiteConnection.execute(SQLiteConnection.java:552)
at android.database.sqlite.SQLiteSession.beginTransactionUnchecked(SQLiteSession.java:323)
at android.database.sqlite.SQLiteSession.beginTransaction(SQLiteSession.java:298)
at android.database.sqlite.SQLiteDatabase.beginTransaction(SQLiteDatabase.java:505)
at android.database.sqlite.SQLiteDatabase.beginTransaction(SQLiteDatabase.java:416)
at androidx.sqlite.db.framework.FrameworkSQLiteDatabase.beginTransaction(FrameworkSQLiteDatabase.java:69)
at androidx.room.InvalidationTracker.syncTriggers(InvalidationTracker.java:426)
at androidx.room.InvalidationTracker.syncTriggers(InvalidationTracker.java:465)
at androidx.room.InvalidationTracker.addObserver(InvalidationTracker.java:249)
at androidx.room.RxRoom$1.subscribe(RxRoom.java:79)
at io.reactivex.internal.operators.flowable.FlowableCreate.subscribeActual(FlowableCreate.java:71)
at io.reactivex.Flowable.subscribe(Flowable.java:14479)
at io.reactivex.internal.operators.flowable.FlowableObserveOn.subscribeActual(FlowableObserveOn.java:56)
at io.reactivex.Flowable.subscribe(Flowable.java:14479)
at io.reactivex.internal.operators.flowable.FlowableFlatMapMaybe.subscribeActual(FlowableFlatMapMaybe.java:54)
at io.reactivex.Flowable.subscribe(Flowable.java:14479)
at io.reactivex.Flowable.subscribe(Flowable.java:14416)
at io.reactivex.Flowable.subscribe(Flowable.java:14306)
at gmk57.strictroom.MainActivity.onCreate(MainActivity.java:30)

StrictMode policy violation; ~duration=108 ms: android.os.StrictMode$StrictModeDiskWriteViolation: policy=31 violation=1
at android.os.StrictMode$AndroidBlockGuardPolicy.onWriteToDisk(StrictMode.java:1111)
at android.database.sqlite.SQLiteConnection.applyBlockGuardPolicy(SQLiteConnection.java:1043)
at android.database.sqlite.SQLiteConnection.execute(SQLiteConnection.java:552)
at android.database.sqlite.SQLiteSession.beginTransactionUnchecked(SQLiteSession.java:323)
at android.database.sqlite.SQLiteSession.beginTransaction(SQLiteSession.java:298)
at android.database.sqlite.SQLiteDatabase.beginTransaction(SQLiteDatabase.java:505)
at android.database.sqlite.SQLiteDatabase.beginTransaction(SQLiteDatabase.java:416)
at androidx.sqlite.db.framework.FrameworkSQLiteDatabase.beginTransaction(FrameworkSQLiteDatabase.java:69)
at androidx.room.InvalidationTracker.syncTriggers(InvalidationTracker.java:426)
at androidx.room.InvalidationTracker.syncTriggers(InvalidationTracker.java:465)
at androidx.room.InvalidationTracker.removeObserver(InvalidationTracker.java:281)
at androidx.room.RxRoom$1$2.run(RxRoom.java:83)
at io.reactivex.disposables.ActionDisposable.onDisposed(ActionDisposable.java:30)
at io.reactivex.disposables.ActionDisposable.onDisposed(ActionDisposable.java:19)
at io.reactivex.disposables.ReferenceDisposable.dispose(ReferenceDisposable.java:43)
at io.reactivex.internal.disposables.DisposableHelper.dispose(DisposableHelper.java:124)
at io.reactivex.internal.disposables.SequentialDisposable.dispose(SequentialDisposable.java:72)
at io.reactivex.internal.operators.flowable.FlowableCreate$BaseEmitter.cancel(FlowableCreate.java:301)
at io.reactivex.internal.operators.flowable.FlowableObserveOn$BaseObserveOnSubscriber.cancel(FlowableObserveOn.java:154)
at io.reactivex.internal.operators.flowable.FlowableFlatMapMaybe$FlatMapMaybeSubscriber.cancel(FlowableFlatMapMaybe.java:158)
at io.reactivex.internal.subscriptions.SubscriptionHelper.cancel(SubscriptionHelper.java:189)
at io.reactivex.internal.subscribers.LambdaSubscriber.cancel(LambdaSubscriber.java:119)
at io.reactivex.internal.subscribers.LambdaSubscriber.dispose(LambdaSubscriber.java:104)
at gmk57.strictroom.MainActivity.onDestroy(MainActivity.java:37)

da...@google.com <da...@google.com> Jan 23, 2025 06:28PM

Reassigned to da...@google.com.

da...@google.com <da...@google.com> Mar 3, 2025 08:21PM

Marked as fixed.

ap...@google.com <ap...@google.com> #4Mar 3, 2025 08:23PM

oh this is bad :/ we should fix it, thanks!

na...@google.com <na...@google.com> #5Mar 12, 2025 06:13PM

Looks like it is broken for both add observer and remove observer since both are sync.
We need to investigate this better because these methods were not @WorkerThread before and we had to change them to fix some invalidation problems (see internal bug

b/73592149

).
Luckily this is not an issue for LiveData since it uses ComputableLiveData and always calls observe on a background thread.

Issue 340606803