MapView.init reads CLLocationManager.accuracyAuthorization on the main thread, which can hang for seconds

Aperta
  • Qualcosa non va?
#2,447 0 commenti 0 reazioni 0 assegnatari Vedi su GitHub

Nessuno ha ancora preso questa issue.

Valutazione

Difficoltà
3/5
Tempo stimato
1-2 giorni
Idoneità per principianti
69/100
Tipo di issue
Bug
Chiarezza
Specificata chiaramente
Stato di attività
Attiva
Stack tecnologico
ios, swift
Ambito
mobile, performance

Direzione di ricerca

Start in Sources/MapboxMaps/Location/AppleLocationProvider.swift at the accuracyAuthorization read in AppleLocationProvider.init, then trace where the default location provider is created from MapView.init. Compare the two approaches described in the issue: defer provider creation until location is used, or receive authorization through locationManagerDidChangeAuthorization(_:). Done means creating a map view no longer makes this synchronous authorization read on the main thread while location is unused.

Scritto dal modello di indicizzazione a partire dal testo della issue.

Descrizione

auto-triaged bug :beetle: p2 performance :zap:

Environment

  • Xcode version: 26.6
  • iOS version: 26.6.2 (the event below); the code path is the same on every iOS version
  • Devices affected: iPhone 14 Plus (iPhone14,7) in this event; any device can hit it, because the call blocks on locationd
  • Maps SDK Version: 11.23.1, through @rnmapbox/maps 10.3.5. The same read is still on main (11.33.0).

Observed behavior and steps to reproduce

Creating a MapView reads CLLocationManager.accuracyAuthorization on the main thread. That getter is a synchronous XPC call to locationd. When locationd is slow to answer, the main thread blocks: our Sentry app-hang reports show 2.8–3.6 s with the main thread fully blocked.

The map never shows the user's location, and the app never asks for location permission. The read happens only because MapView.init builds the default location provider.

Steps: create a MapView on the main thread (any app; ours is a React Native app through @rnmapbox/maps). The read happens every time. The hang happens when locationd is slow, which we see in production a few times a month.

Main thread, from the app-hang report (innermost first):

mach_msg2_trap
xpc_connection_send_message_with_reply_sync
__NSXPCCONNECTION_IS_WAITING_FOR_A_SYNCHRONOUS_REPLY__
-[NSXPCConnection _sendInvocation:orArguments:count:methodSignature:selector:withProxy:]
CLGetUncertaintyScaleFactors
CLSetClientTransientAuthorizationInfo
CLClientGetLocation
CLLocationManager.accuracyAuthorization.getter
AppleLocationProvider.init
LocationDataModel.createDefault
MapView.setupManagers
MapView.commonInit
MapView.init
RNMBXMapView.createMapView

The read is Sources/MapboxMaps/Location/AppleLocationProvider.swift line 171 on main:

self.latestLocationAndAccuracyAuth = ([], locationManager.accuracyAuthorization)

Expected behavior

Creating a map view does not make a synchronous call to locationd on the main thread, at least while the map does not use location. Apple's documentation for CLLocationManager warns that its synchronous authorization reads can make the UI unresponsive when called on the main thread.

Notes / preliminary analysis

Two possible fixes:

  1. Create the default location provider lazily, on the first use of location (a puck, a location consumer, or mapView.location), not in MapView.init.
  2. Do not read accuracyAuthorization in AppleLocationProvider.init. Take the value from locationManagerDidChangeAuthorization(_:), which Core Location calls when the manager is created.

@rnmapbox/maps has a second copy of this read (its RNMBXLocationModule creates an AppleLocationProvider when the package loads). We have a patch for that side, and we will offer it to rnmapbox separately. That patch cannot reach the read in MapView.init.

Additional links and references

Lingua principale
Swift
Stelle
601
Fork
198
Nessuna PR unita negli ultimi 30g

Preparare l'ambiente

Come iniziare

  1. Leggi tutta la issue e poi la guida ai contributi del progetto.
  2. Commenta sulla issue per dire che te ne occupi tu — evita che due persone facciano lo stesso lavoro.
  3. Fai un fork del repository e lavora su un branch.
  4. Apri una pull request che faccia riferimento al numero della issue.

Altre issue di mapbox/mapbox-maps-ios

Tutte le issue di mapbox/mapbox-maps-ios

Issue simili

Altre issue su Swift

Ricevi le nuove issue nella tua casella

Un breve riepilogo di issue GitHub adatte ai principianti.