Fix threading issues on ios

[adamivancza]

Summary

• Serialize iOS HybridMapView state access and provider adapter mutations onto the main thread.
• Keep provider adapters synchronous and unchanged, with the thread boundary at the RN/Nitro entry point.
• Resolve Promise-returning reads (fetchCamera, getVisibleRegion) asynchronously on main to avoid blocking worklet/background callers.

Why

Nitro hybrid objects can be accessed from worklet/background runtimes, but UIKit/MapKit access must happen on the main thread. This prevents off-main map mutations and cached-state races.

Observed warning before this fix:

[UIKitCore] +[UIView setAnimationsEnabled:] being called from a background thread.
Performing any operation from a background thread on UIView or a subclass is not supported

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: c9ad4d0d-d60a-4b37-870e-3e4e7775761f

📥 Commits

Reviewing files that changed from the base of the PR and between 64c2acd and 94a73a1.

📒 Files selected for processing (1)

• package/ios/HybridMapView.swift

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📝 Walkthrough

Summary by CodeRabbit

• Bug Fixes
  • Improved map stability when views are mounted, recycled, or updated quickly.
  • Fixed cases where camera actions or map interactions could fail after the view changed state.
  • Ensured map updates and callbacks are applied on the main thread for more reliable behavior.
  • Reduced issues with stale map state by resetting and re-syncing map features more safely during lifecycle changes.

Walkthrough

HybridMapView.swift now tracks mount state with a generation-checked lifecycle, routes adapter access through main-thread helpers, and rejects stale async camera work after recycle. Property, callback, camera, and teardown paths now use backing fields plus explicit main-thread propagation.

Changes

Main-thread lifecycle and adapter routing

Layer / File(s)	Summary
Lifecycle tracking fields and helpers package/ios/HybridMapView.swift	Adds lifecycleLock, lifecycleGeneration, adapter storage, and recycled-state tracking used to invalidate stale async work.
Lifecycle validation and adapter install package/ios/HybridMapView.swift	Introduces lifecycle snapshot, activation, recycle, and validation helpers, and enforces main-thread adapter installation.
Main-thread execution utilities package/ios/HybridMapView.swift	Adds onMain and promiseOnMain helpers that run work on the main thread and reject with MapView is not mounted when lifecycle validation fails.
Property, callback, camera, and recycle routing package/ios/HybridMapView.swift	Moves map properties, callback wiring, camera methods, and prepareForRecycle onto the new main-thread and lifecycle-checked adapter flow.

Estimated code review effort: 4 (Complex) | ~60 minutes

Sequence Diagram(s)

sequenceDiagram
  participant JS as JS caller
  participant View as HybridMapView
  participant Main as Main thread
  participant Adapter as Map adapter

  JS->>View: fetchCamera()
  View->>Main: promiseOnMain(snapshot)
  Main->>Main: validateActiveLifecycle(snapshot)
  alt lifecycle mismatch
    Main-->>JS: reject "MapView is not mounted"
  else lifecycle matches
    Main->>Adapter: currentAdapter(matching: snapshot)
    Adapter-->>Main: camera data
    Main-->>JS: resolve camera data
  end

Loading

🚥 Pre-merge checks | ✅ 6

✅ Passed checks (6 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title matches the main change: fixing iOS threading issues in HybridMapView.
Description check	✅ Passed	The description clearly describes the iOS main-thread serialization and async camera reads in this PR.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Security Check	✅ Passed	No security-relevant behavior changed; diff only swaps public getters for private backing fields in main-thread syncState.

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@package/ios/HybridMapView.swift`:
- Around line 400-428: The synchronous camera methods in HybridMapView are
bypassing the recycle safety check and can recreate a new adapter after
prepareForRecycle(). Update applyCamera, animateCamera, and fitToCoordinates to
enforce the same recycle-generation guard used by fetchCamera and
getVisibleRegion, either by making currentAdapter() reject access once recycled
or by checking the generation before calling it so stale calls fail instead of
reattaching the map.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: e45387cd-d86c-46cd-bd02-1400a5075cc8

📥 Commits

Reviewing files that changed from the base of the PR and between c4278b9 and 64c2acd.

📒 Files selected for processing (1)

• package/ios/HybridMapView.swift

[jkasprzyk17]

Great work on this PR 👏

The main-thread confinement and lifecycle guard look solid, and the fix for the CodeRabbit feedback in the third commit makes sense.

One small follow-up before merge: in syncState, please use the backing _ fields directly instead of the public getters. Since syncState is already called from installAdapter on the main thread, lines like:

adapter.onRegionChange = onRegionChange
adapter.markers = markers

add unnecessary onMain hops. It would be cleaner and more consistent with prepareForRecycle to do:

adapter.onRegionChange = _onRegionChange
adapter.markers = _markers
// ... same for the other callback/overlay fields

Once that’s in, I’m happy to approve. Thanks!

[adamivancza]

Great work on this PR 👏

The main-thread confinement and lifecycle guard look solid, and the fix for the CodeRabbit feedback in the third commit makes sense.

One small follow-up before merge: in syncState, please use the backing _ fields directly instead of the public getters. Since syncState is already called from installAdapter on the main thread, lines like:

adapter.onRegionChange = onRegionChange
adapter.markers = markers

add unnecessary onMain hops. It would be cleaner and more consistent with prepareForRecycle to do:

adapter.onRegionChange = _onRegionChange
adapter.markers = _markers
// ... same for the other callback/overlay fields

Once that’s in, I’m happy to approve. Thanks!

oh indeed - totally missed that! fixed!

[jkasprzyk17]

Looks good with the syncState fix. Thanks!

Happy to approve.