[cherry-pick][4.2] Fix commits during the Android draw pass#9123
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bartlomiejbloniarz merged 2 commits intoMar 20, 2026
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## Summary Separates the synchronous UI props update logic into its own `applySynchronousUpdates` method. Adds `partitionUpdates` and `shouldUseSynchronousUpdatesInPerformOperations` helpers to support the extracted method. ## Test plan
## Summary This PR intends to solve the most annoying crash that we currently face on Android. The crash is caused by Reanimated calling `ShadowTree::commit` when handling events that were emitted while in the Android drawing pass. Performing a commit can cause other changes queued by React Native to also get applied. This can lead to the view hierarchy being modified, which is not allowed while in the draw pass. To fix this, we have a workaround where if we are in the draw pass, we instead only apply non-layout changes (that can be applied without a ShadowTree commit), and schedule the layout changes to happen when we are outside of the draw call. We want to apply the non-layout updates there to maintain things like transform driven sticky headers. closes #8422 🤞 ## Test plan I added a new Android Draw Pass example, it would also make sense to test the sticky header and other event related examples
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Pull request overview
Cherry-picks upstream fixes to prevent Reanimated from committing Fabric ShadowTree updates during the Android draw pass (a known crash scenario), by splitting “layout” vs “non-layout” updates and deferring layout-affecting commits until the next frame. It also refactors synchronous UI prop updates into a dedicated helper for better reuse.
Changes:
- Refactors
performOperationsto remove the “triggered by event” boolean and extracts synchronous-props logic intoapplySynchronousUpdates(+partitionUpdates/ feature-flag helper). - Adds Android draw-pass detection (
DrawPassDetector) and a “non-layout operations only” pathway invoked when events arrive during draw. - Adds an Android Draw Pass example screen and tweaks StickyHeaderExample to exercise layout changes during scroll.
Reviewed changes
Copilot reviewed 13 out of 14 changed files in this pull request and generated 2 comments.
Show a summary per file
| File | Description |
|---|---|
| packages/react-native-reanimated/apple/reanimated/apple/native/NativeProxy.mm | Updates call site for new performOperations() signature |
| packages/react-native-reanimated/android/src/main/java/com/swmansion/reanimated/NodesManager.java | Adds draw-pass-aware operation execution + new non-layout path |
| packages/react-native-reanimated/android/src/main/java/com/swmansion/reanimated/NativeProxy.java | Updates native method signatures + routes flush via draw-pass-aware path |
| packages/react-native-reanimated/android/src/main/java/com/swmansion/reanimated/DrawPassDetector.java | New helper to track whether UI thread is currently in a draw pass |
| packages/react-native-reanimated/android/src/main/cpp/reanimated/android/NativeProxy.h | Updates native proxy API (adds non-layout ops) |
| packages/react-native-reanimated/android/src/main/cpp/reanimated/android/NativeProxy.cpp | Implements/exports new JNI methods for non-layout ops |
| packages/react-native-reanimated/Common/cpp/reanimated/NativeModules/ReanimatedModuleProxy.h | Updates public API + adds private applySynchronousUpdates |
| packages/react-native-reanimated/Common/cpp/reanimated/NativeModules/ReanimatedModuleProxy.cpp | Extracts synchronous updates; adds non-layout-only entrypoint |
| packages/react-native-reanimated/Common/cpp/reanimated/Fabric/updates/UpdatesRegistry.h | Adds getPendingUpdates() API |
| packages/react-native-reanimated/Common/cpp/reanimated/Fabric/updates/UpdatesRegistry.cpp | Implements getPendingUpdates() |
| apps/fabric-example/ios/Podfile.lock | Updates CocoaPods checksums from cherry-pick |
| apps/common-app/src/apps/reanimated/examples/index.ts | Registers new Android Draw Pass example |
| apps/common-app/src/apps/reanimated/examples/StickyHeaderExample.tsx | Adds animated width to force layout updates during scroll |
| apps/common-app/src/apps/reanimated/examples/AndroidDrawPassExample.tsx | New example demonstrating the historical crash + fix |
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bartlomiejbloniarz
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tjzel
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Mar 19, 2026
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Cherry picks #9078 and #9072