Crashes related to KVO and UserDefaults
Since using this library, we are seeing some crash reports which look related to KVO and UserDefaults. We haven't been able to reproduce them but are seeing crash reports on all iOS versions (although more on iOS 15).
Has anyone seen something similar or any pointers on how to fix this (happy to submit a PR)?
Here are some ideas/observations/infos:
- All crashes happen on a background queue, which might suggest it is some concurrency issue. UserDefaults is thread safe, but maybe KVO isn't?
- We are also using Zephry and previously a lot of the crashes originated in that library, but after dispatching all access to UserDefaults to the main thread the crashes stopped.
- We are using the observation feature from Defaults in a few places.
OS Version: iOS 17.2.1 (21C66)
Report Version: 104
Exception Type: EXC_BREAKPOINT (SIGTRAP)
Crashed Thread: 13
Application Specific Information:
_replaceRangeInArrayAtIndex:withRange:
Thread 13 Crashed:
0 libobjc.A.dylib 0x31c20a838 object_getClass
1 Foundation 0x329a60850 _NSKeyValueObservationInfoGetObservances
2 Foundation 0x329a605b0 NSKeyValueWillChange
3 Foundation 0x329adda48 -[NSObject(NSKeyValueObservingPrivate) _changeValueForKeys:count:maybeOldValuesDict:maybeNewValuesDict:usingBlock:]
4 Foundation 0x329b39a20 -[NSObject(NSKeyValueObservingPrivate) _notifyObserversOfChangeFromValuesForKeys:toValuesForKeys:]
5 CoreFoundation 0x32bbcebe4 -[CFPrefsSource forEachObserver:]
6 CoreFoundation 0x32bbbe898 -[CFPrefsSource _notifyObserversOfChangeFromValuesForKeys:toValuesForKeys:]
7 CoreFoundation 0x32bbbe794 ___CFPrefsDeliverPendingKVONotificationsGuts_block_invoke
8 CoreFoundation 0x32bb46858 __CFDictionaryApplyFunction_block_invoke
9 CoreFoundation 0x32bb44dec CFBasicHashApply
10 CoreFoundation 0x32bb35bc8 CFDictionaryApplyFunction
11 CoreFoundation 0x32bb6a3c0 _CFPrefsDeliverPendingKVONotificationsGuts
12 CoreFoundation 0x32bb68a60 -[_CFXPreferences _deliverPendingKVONotifications]
13 CoreFoundation 0x32bb68954 __108-[_CFXPreferences withSearchListForIdentifier:container:cloudConfigurationURL:perform:]_block_invoke
14 CoreFoundation 0x32bb68748 normalizeQuintuplet
15 CoreFoundation 0x32bb685bc -[_CFXPreferences withSearchListForIdentifier:container:cloudConfigurationURL:perform:]
16 CoreFoundation 0x32bbc92a4 -[_CFXPreferences setValue:forKey:appIdentifier:container:configurationURL:]
17 CoreFoundation 0x32bbc91e4 _CFPreferencesSetAppValueWithContainerAndConfiguration
18 Foundation 0x329b0a8f0 -[NSUserDefaults(NSUserDefaults) setObject:forKey:]
19 Structured 0x2053b982c NSUserDefaults._set<T> (UserDefaults.swift:18)
20 Structured 0x2053b9ae8 NSUserDefaults.subscript.setter (UserDefaults.swift:24)
21 Structured 0x2053b93f4 NSUserDefaults.subscript.setter
22 Structured 0x2054365a0 [inlined] Defaults.subscript.setter
23 Structured 0x2054365a0 BackupManager.createBackup (Backup.swift:378)
OS Version: iOS 15.6.1 (19G82)
Report Version: 104
Exception Type: EXC_BREAKPOINT (SIGTRAP)
Crashed Thread: 24
Application Specific Information:
_replaceRangeInArrayAtIndex:withRange: > removeIndex:
Thread 24 Crashed:
0 libobjc.A.dylib 0x38c072028 object_getClass
1 Foundation 0x35d53a86c _NSKeyValueObservationInfoGetObservances
2 Foundation 0x35d53bf38 NSKeyValueWillChange
3 Foundation 0x35d5248a4 -[NSObject(NSKeyValueObservingPrivate) _changeValueForKeys:count:maybeOldValuesDict:maybeNewValuesDict:usingBlock:]
4 Foundation 0x35d543604 -[NSObject(NSKeyValueObservingPrivate) _notifyObserversOfChangeFromValuesForKeys:toValuesForKeys:]
5 CoreFoundation 0x35a568004 -[CFPrefsSource forEachObserver:]
6 CoreFoundation 0x35a603148 -[CFPrefsSource _notifyObserversOfChangeFromValuesForKeys:toValuesForKeys:]
7 CoreFoundation 0x35a5de1b8 ___CFPrefsDeliverPendingKVONotificationsGuts_block_invoke
8 CoreFoundation 0x35a5337d8 __CFDictionaryApplyFunction_block_invoke
9 CoreFoundation 0x35a531090 CFBasicHashApply
10 CoreFoundation 0x35a532fb0 CFDictionaryApplyFunction
11 CoreFoundation 0x35a5c9558 _CFPrefsDeliverPendingKVONotificationsGuts
12 CoreFoundation 0x35a52ffec -[_CFXPreferences _deliverPendingKVONotifications]
13 CoreFoundation 0x35a55ed3c __108-[_CFXPreferences withSearchListForIdentifier:container:cloudConfigurationURL:perform:]_block_invoke
14 CoreFoundation 0x35a536bd0 normalizeQuintuplet
15 CoreFoundation 0x35a52fcc4 -[_CFXPreferences withSearchListForIdentifier:container:cloudConfigurationURL:perform:]
16 CoreFoundation 0x35a5e1338 -[_CFXPreferences setValue:forKey:appIdentifier:container:configurationURL:]
17 CoreFoundation 0x35a5642a4 _CFPreferencesSetAppValueWithContainerAndConfiguration
18 Foundation 0x35d5337c8 -[NSUserDefaults(NSUserDefaults) setObject:forKey:]
19 Structured 0x20126887c NSUserDefaults._set<T> (UserDefaults.swift:18)
20 Structured 0x201268b38 NSUserDefaults.subscript.setter (UserDefaults.swift:24)
21 Structured 0x201268444 NSUserDefaults.subscript.setter
22 Structured 0x200c4e018 [inlined] Defaults.subscript.setter
23 Structured 0x200c4e018 AppState.activate (AppState.swift:182)
24 WidgetKit 0x369c6ff3c objectdestroy.36Tm
sindresorhus / Defaults
💾 Swifty and modern UserDefaults
2.1k
How does funding with Polar work?
1
Pay now to fund the work behind this issue.
2
Get updates on progress being made.
3
Maintainer is rewarded once the issue is completed.
FAQ
Backer
You're funding impactful open source efforts
Contributor
You want to contribute to this effort
Maintainer
You want to get funding like this too