Created
March 26, 2012 19:42
-
-
Save mikeabdullah/2209110 to your computer and use it in GitHub Desktop.
Safe cross-thread passing of an error
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| - (BOOL)saveAndReturnError:(NSError **)error | |
| { | |
| NSManagedObjectContext *context = [self managedObjectContext]; | |
| __block BOOL result; | |
| [context performBlockAndWait:^{ | |
| result = [context save:error]; | |
| if (!result && error) [*error retain]; | |
| }]; | |
| if (!result && error) [*error autorelease]; | |
| return result; | |
| } |
I think it is fine because (NSError *_) implies (_autoreleasing NSError) under ARC. And the block should capture the pointer to the actual NSError object that has a strong reference as a local variable to the caller. (and it seems to work fine in my tests :)
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
I'll investigate, but I it should be safe, as you have a strong reference to the NSError back in the caller, which should keep it around until that reference goes away... although ARC is pretty aggressive about releasing local variables that you are no longer using...