NSUserDefaults crash when read and write happen on 2 threads

Originator:nobrien
Number:rdar://21463254 Date Originated:19-Jun-2015 10:53 AM
Status:Open Resolved:
Product:iOS SDK Product Version:iOS 8.3.0
Classification:Crash/Hang/Data Loss Reproducible:Rarely
 
Summary:
Main thread reads one value from NSUserDefaults while a background thread writes to NSUserDefaults (with a different key)

Repro:
Can’t really repro, but have crashlytics logs

Note:
thread was writing 20 values to NSUserDefaults while main thread just read one value

Attached:
I’ve attached the 2 conflicting thread stacks of the crash that resulted in a EXC_BAD_ACCESS KERN_INVALID_ADDRESS at 0x0000001161555dd0

Comments


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