Question

I have the following function

- (NSArray *) getUsers : (days) aDay {

    NSArray *arr = [[[NSArray alloc] init] autorelease];

    for (User *e in [week objectAtIndex:aDay]) {
        //Get distance to user
        e.place.distance = [[LocationManager sharedLocationManager] getDistanceWithLat:e.place.latitude Lon:e.place.longitude];
    }

    //Sort the array
    arr = [ [week objectAtIndex:aDay] sortedArrayUsingComparator:^(id obj1, id obj2){
            User *e1 = (User *)obj1;
            User *e2 = (User *)obj2;

            if (e1.place.distance <= e2.place.distance) {
                return (NSComparisonResult)NSOrderedAscending;
            } else {
                return (NSComparisonResult)NSOrderedDescending;
            }
        return (NSComparisonResult)NSOrderedSame;
    }];

    [arr retain];

    return arr;
}

It leaks and I can’t figure out how to fix it. If I remove [arr retian] then the application crash.

When I preform action profile the instruments display a leak of 100% on this line:

   arr = [ [week objectAtIndex:aDay] sortedArrayUsingComparator:^(id obj1, id obj2){

How could I fix this leak?

Answer 1

Remove NSArray *arr = [[[NSArray alloc] init] autorelease]; and [arr retain]; at all. In first line you allocated memory, but when sorting you refer to new array and got leak.

NSArray *arr = [ [week objectAtIndex:aDay] sortedArrayUsingComparator:^(id obj1, id obj2){
            User *e1 = (User *)obj1;
            User *e2 = (User *)obj2;

            if (e1.place.distance <= e2.place.distance) {
                return (NSComparisonResult)NSOrderedAscending;
            } else {
                return (NSComparisonResult)NSOrderedDescending;
            }
        return (NSComparisonResult)NSOrderedSame;
    }];

return arr;