react / react/react-native

[Android] Timers do not run when using HeadlessJsTaskService

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Needs: Triage :mag: Platform: Android
Dominant language
C++
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Description

Description

Hello!

I noticed that when using HeadlessJsTaskService, the timers do not run as expected. I did some investigations and I found out that React Native uses Android's Choreographer to schedule the timers.
I am testing the app on a real device: Samsung Galaxy S22 Ultra.
Apparently, Samsung's OneUI pauses the Choreographer when the app goes into background.
In order to fix this, React Native should use another technique to get "ticks", like a Handler or something, at least for the timers (I saw UI events are also processed using Choreographer).

Steps to reproduce
  1. Install the application using "yarn android"
  2. Open up Android Studio with Logcat open
  3. Wait for the background service to start
  4. Put the app in foreground by going on the home screen
  5. Look in the logs and wait for the line with "CoreRune.SYSPERF_ACTIVE_APP_BBA_ENABLE : stop animation in background states"
React Native Version

0.84.1

Affected Platforms

Runtime - Android

Output of npx @react-native-community/cli info
System:
  OS: macOS 26.3.1
  CPU: (14) arm64 Apple M3 Max
  Memory: 160.17 MB / 36.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 22.13.1
    path: /Users/george/.nvm/versions/node/v22.13.1/bin/node
  Yarn:
    version: 3.6.4
    path: /Users/george/.nvm/versions/node/v22.13.1/bin/yarn
  npm:
    version: 10.9.2
    path: /Users/george/.nvm/versions/node/v22.13.1/bin/npm
  Watchman:
    version: 2025.05.26.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.16.2
    path: /Users/george/.rvm/gems/ruby-3.0.0/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 25.0
      - iOS 26.0
      - macOS 26.0
      - tvOS 26.0
      - visionOS 26.0
      - watchOS 26.0
  Android SDK:
    API Levels:
      - "30"
      - "31"
      - "33"
      - "34"
      - "35"
      - "36"
      - "36"
    Build Tools:
      - 30.0.2
      - 30.0.3
      - 33.0.0
      - 34.0.0
      - 35.0.0
      - 36.0.0
      - 36.0.0
    System Images:
      - android-34 | Android TV ARM 64 v8a
      - android-35 | ARM 64 v8a
      - android-35 | Google Play ARM 64 v8a
      - android-35 | Google Play Tablet ARM 64 v8a
      - android-36 | Google Play ARM 64 v8a
      - android-36 | Pre-Release 16 KB Page Size Google Play ARM 64 v8a
    Android NDK: Not Found
IDEs:
  Android Studio: 2025.3 AI-253.30387.90.2532.14935130
  Xcode:
    version: 26.0.1/17A400
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.13
    path: /usr/bin/javac
  Ruby:
    version: 3.0.0
    path: /Users/george/.rvm/rubies/ruby-3.0.0/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 20.1.0
    wanted: 20.1.0
  react:
    installed: 19.2.3
    wanted: 19.2.3
  react-native:
    installed: 0.84.1
    wanted: 0.84.1
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: Not found
  newArchEnabled: false
Stacktrace or Logs
2026-04-04 17:31:59.258 11074-11128 ReactNativeJS           com.choreographerissue               I  Hello from service!
2026-04-04 17:32:00.260 11074-11128 ReactNativeJS           com.choreographerissue               I  Hello from service!
2026-04-04 17:32:01.264 11074-11128 ReactNativeJS           com.choreographerissue               I  Hello from service!
2026-04-04 17:32:02.267 11074-11128 ReactNativeJS           com.choreographerissue               I  Hello from service!
2026-04-04 17:32:02.526 11074-11074 Choreographer           com.choreographerissue               D  CoreRune.SYSPERF_ACTIVE_APP_BBA_ENABLE : stop animation in background states
MANDATORY Reproducer

https://github.com/gmanole01/react-native-choreographer-issue

Screenshots and Videos

No response

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the HeadlessJsTaskService entry point and the Android timer scheduling path that uses Choreographer. Reproduce the issue with the mandatory reproducer while watching Logcat, then verify that timers continue running in the background without disrupting the existing foreground behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
android, react-native
Domain
mobile-dev
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
45/100

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