iOS Memory Issue With No Leaks - ios

Question

I have a problem with my app, where it consumes a lot of memory and crashes after about 40 minutes. I have run instruments to see if there were any leaks, but none appeared. Inside the app, I am using Mapbox to display maps and drawing a line annotation wherever the user has travelled. I am storing these locations in an array, removing the current annotation and presenting a new one whenever the user has moved.
In my MapViewController.m
- (void)drawCurrentPolyline
{
[self removePolylineForTrip:locationServices.trip forClass:nil];
[self addPolylineForTrip:locationServices.trip forClass:nil];
globalData.locationData = [[NSMutableArray alloc] init];
colour = [globalData convertColourFromString:[globalData.currentTrip objectForKey:#"colour"]];
[colourArray addObject:colour];
if ([currentLocations count] >= 2)
{
for (int i = [currentLocations count] - 2; i <= [currentLocations count] - 1; i++)
{
CLLocation *locationCoordinate = [[CLLocation alloc] initWithLatitude:[[currentLocations[i] objectForKey:#"latitude"] doubleValue] longitude:[[currentLocations[i] objectForKey:#"longitude"] doubleValue]];
[globalData.locationData addObject:locationCoordinate];
}
}
else
{
for (NSDictionary *location in currentLocations)
{
CLLocation *locationCoordinate = [[CLLocation alloc] initWithLatitude:[[location objectForKey:#"latitude"] doubleValue] longitude:[[location objectForKey:#"longitude"] doubleValue]];
[globalData.locationData addObject:locationCoordinate];
}
}
}
- (void)removePolylineForTrip:(int)trip forClass:(MapPreferencesTableViewController *)mapPreferencesTableViewController
{
NSMutableDictionary *dictionary = [tripAnnotions objectForKey:[NSString stringWithFormat:#"trip%d", trip]];
NSMutableArray *annotationArray = [dictionary objectForKey:#"annotions"];
for (RMAnnotation *annotation in annotationArray)
{
if ([[annotation.userInfo objectForKey:#"type"] isEqualToString:#"line"])
{
[mapView removeAnnotation:annotation];
}
}
}
- (void)addPolylineForTrip:(int)trip forClass:(MapPreferencesTableViewController *)mapPreferencesTableViewController
{
globalData.locationData = [[NSMutableArray alloc] init];
globalData.tripData = [globalData.trips objectForKey:[NSString stringWithFormat:#"trip%d", trip]];
NSMutableArray *locationArray = [globalData.tripData objectForKey:#"locationData"];
colour = [globalData convertColourFromString:[globalData.tripData objectForKey:#"colour"]];
[colourArray addObject:colour];
double lineWidth = 5.0;
NSString *type = #"line";
for (NSDictionary *location in locationArray)
{
CLLocation *locationCoordinate = [[CLLocation alloc] initWithLatitude:[[location objectForKey:#"latitude"] doubleValue] longitude:[[location objectForKey:#"longitude"] doubleValue]];
[globalData.locationData addObject:locationCoordinate];
}
if ([locationArray count] > 1)
{
RMAnnotation *annotation = [[RMAnnotation alloc] initWithMapView:mapView
coordinate:((CLLocation *)[globalData.locationData objectAtIndex:0]).coordinate
andTitle:[NSString stringWithFormat:#"Trip %d", trip]];
NSMutableDictionary *annotationData = [[NSMutableDictionary alloc] init];
[annotationData setObject:globalData.locationData forKey:#"locations"];
[annotationData setObject:colour forKey:#"colour"];
[annotationData setObject:[NSString stringWithFormat:#"%f", lineWidth] forKey:#"width"];
[annotationData setObject:type forKey:#"type"];
[annotationData setObject:[NSString stringWithFormat:#"%d", trip] forKey:#"trip"];
annotation.userInfo = annotationData;
// NSLog(#"User Info For Annotation:\n%#", annotation.userInfo);
//annotation.layer = [NSString stringWithFormat:#"%d", trip];
[annotation setBoundingBoxFromLocations:globalData.locationData];
// Add annotation for tracking
[self addAnnotationToTripArray:annotation forTrip:trip];
[mapView addAnnotation:annotation];
}
}
I think the problem might be the fact that I am storing each of the user locations in a mutable array. Hence, I told the app to remove everything in the array once a memory warning has appeared. However, the app still crashes. I cannot seem to find the source of the memory consumption. There are no leaks (except for some small core graphics ones).
Could someone please guide me from where to go from here, or help me find the source of this issue? The simulator used over 1GB of data, and the app became very slow.

Answer 1

Remember, it's not a leak if it's not memory that's been orphaned somehow. Pay attention to your memory usage over time. Instruments will tell you the number of objects living and what kind they are. Things to look out for are things like large arrays of things growing over time and UIView's not getting removed from the superViews.
I had a similar issue and it was because I had MBProgressHUD instances that were hidden, but never removed from their superView.

Answer 2

As #InkGolem states, increasing memory is not necessarily a leak.
Use instruments to check for leaks and memory loss due to retained but not leaked memory. The latter is unused memory that is still pointed to. Use Mark Generation (Heapshot) in the Allocations instrument on Instruments.
For HowTo use Heapshot to find memory creap, see: bbum blog
Basically there method is to run Instruments allocate tool, take a heapshot, run an intuition of your code and another heapshot repeating 3 or 4 times. This will indicate memory that is allocated and not released during the iterations.
To figure out the results disclose to see the individual allocations.
If you need to see where retains, releases and autoreleases occur for an object use instruments:
Run in instruments, in Allocations set "Record reference counts" on on (you have to stop recording to set the option). Cause the picker to run, stop recording, search for there ivar (datePickerView), drill down and you will be able to see where all retains, releases and autoreleases occurred.