ANR in FirebaseApp$GlobalBackgroundStateListener.onBackgroundStateChanged

[sergeys-opera]

Describe your environment

• Android Studio version: Android Studio Narwhal Feature Drop | 2025.1.2 Patch 1
  Build #AI-251.26094.121.2512.13930704, built on August 14, 2025
• Firebase Component: analytics, auth, common, config, crashlytics, messaging
• Component version: com.google.firebase:firebase-bom:34.3.0

Describe the problem

We see an influx of ANRs in crashlytics. The cashlytics console marks them as "Insight: Lock contention".
The stack traces:

main (blocked)
tid=1 systid=5830 | waiting to lock <0x0bdf9721> (java.lang.Object) held by thread 26
Triggered ANR
Deadlocked
com.google.firebase.FirebaseApp$GlobalBackgroundStateListener.onBackgroundStateChanged (FirebaseApp.java:708)

androidx.fragment.app.FragmentActivity.onCreate (FragmentActivity.java:216)
com.opera.celopay.ui.MainActivity.onCreate (MainActivity.kt:49)
android.app.Activity.performCreate (Activity.java:9064)

com.android.internal.os.ZygoteInit.main (ZygoteInit.java:902)

And from the background thread:

pool-3-thread-1 (blocked)
tid=26 systid=5876 | waiting to lock <0x02c59746> (com.google.android.gms.common.api.internal.c) held by thread 1
Deadlocked
com.google.android.gms.common.api.internal.BackgroundDetector.initialize (com.google.android.gms:play-services-basement@@18.5.0:1)

com.google.firebase.FirebaseApp.initializeApp (FirebaseApp.java:249)
com.opera.celopay.StandaloneCeloPayDependencies.getFirebaseApp (StandaloneCeloPayDependencies.java:44)
com.opera.celopay.AppModuleKt.buildAppModule$lambda$0$7$0 (AppModule.kt:91)
kotlin.SynchronizedLazyImpl.getValue (LazyJVM.kt:86)
com.opera.celopay.model.firebase.base.LazyEmbeddedFirebaseApp.getValue (LazyEmbeddedFirebaseApp.java:96)
com.opera.celopay.StandaloneCeloPayDependencies.getFirebaseMessaging (StandaloneCeloPayDependencies.java:48)
com.opera.celopay.AppModuleKt.buildAppModule$lambda$0$8 (AppModule.kt:95)
org.koin.core.instance.InstanceFactory.create (InstanceFactory.kt:50)

org.koin.core.scope.Scope.get (Scope.kt:212)
com.opera.celopay.model.firebase.notification.FcmModule_androidKt$buildPlatformFirebaseNotificationModule$lambda$0$0$$inlined$inject$default$1.invoke (FcmModule_android.kt:407)
kotlin.SynchronizedLazyImpl.getValue (LazyJVM.kt:86)
com.opera.celopay.model.firebase.notification.FcmTokenUpdater$fetchFirebaseToken$1.invokeSuspend (FcmTokenUpdater.java:30)
kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith (ContinuationImpl.kt:34)

java.lang.Thread.run (Thread.java:1119)

The background thread is used to fetch and update the FCM token at startup.

Steps to reproduce:

Access the Firebase instance from a background thread and start an activity in the app.

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[lehcar09]

Hi @sergeys-opera, thank you for reaching out. I tried reproducing the issue, however, I did not encounter an ANR issue.

Here the steps I did:

Create a worker and triggered from Alarm Receiver. The worker calls;

Firebase.messaging.token.addOnCompleteListener(
      OnCompleteListener { task ->
        if (!task.isSuccessful) {
          Log.w(TAG, "Fetching FCM registration token failed", task.exception)
          return@OnCompleteListener
        }

        // Get new FCM registration token
        val token = task.result
        Log.d("Worker FCM Token", token)
      },
    )

Am I missing something? Were you able to reproduce the issue? By any chance, can you share a code snippet/ MCVE to help us investigate the issue?

[sergeys-opera]

Am I missing something? Were you able to reproduce the issue?

Do you start an activity in parallel to the alarm receiver? The ANR comes from the activity that initializes the Firebase SDK.

As usual in such issues, the timing and the environment matters. The app where we encounter this issue is used primarily in Africa on crappy devices with bad network connectivity.
In the last 7 days this ANR has been reported 2k times affecting 1k users according to Crashlytics.

[lehcar09]

I’ve updated my MCVE and made a parallel call to retrieve the FCM, however, I still did not encounter the ANR.

This could be caused by a race condition and/ or Android system due to device poor performance, and I can’t say anything for sure. Usually it is very difficult to look at ANRs in isolation and figure out what's wrong.

What I can suggest is to do an asynchronous call (addOnCompleteListener) to manage the fetch of the token in parallel. That said, I’ll close this issue for now. If you can see any commonalities between these ANRs, or even better, code snippets or minimal reproducible examples, please share it with us. It'll really help us move this investigation forward. Thanks!