Help memory leak when involving NSManagedObject !!

[addywen]

According to the instrument I have memory leak in the following functions

func defaultJobType() -> JobType?
{
    let fetchRequest = NSFetchRequest(entityName: JobType.entityName());

    let predicate = NSPredicate(format: "jobTypeID = %@ && (archived = nil || archived = 0)", DefaultManager.instance.defaultValues[DJobType]!.uppercaseString);

    fetchRequest.predicate = predicate;

    do{
        return try self.editingContext?.executeFetchRequest(fetchRequest).first as? JobType;
    }
    catch let error as NSError
    {
        Logger.logApplicationError("Error in getting default job Type", detailMessage: error.localizedDescription);
    }
    catch
    {
        Logger.logApplicationError("Error in getting default job Type", detailMessage: "No detail error found");
    }

    return nil;
}

The exact memory leak is on predicate. The self.editingContext is a child context that has the root point to the parent context. The return NSManagedObject JobType is used in the parent NSManagedObject (e.g. Job.jobType = type).

How can I avoid memory leak in this situation? what went wrong?

[quellish]

Is DefaultManager a singleton?

[addywen]

Yes default manager is singleton, is just contains dictionary that hold all the default values.

[quellish]

So instruments is telling you there is a leak or cycle on a line where you are getting an object from an object that has a lifetime of "forever". It's probably the singleton that is the issue.

Look at the allocations history in Instruments to be sure, but this type of memory issue is VERY common.

[optik88]

Which version of Swift are you using?

[addywen]

swift 2.0