Question

I am using Instrument leaks tools to check leaks in the code.

//MyClass.h
@property (nonatomic, retain) NSMutableArray *marrProperty;

//MyClass.m
NSSortDescriptor *createdTime = [[NSSortDescriptor alloc] initWithKey:@"createdTime" ascending:NO selector:@selector(compare:)];             
NSArray *sortedArray = [self.anManagedObj.aRelationships sortedArrayUsingDescriptors:[NSArray arrayWithObject:createdTime]];
[createdTime release];
NSMutableArray *marr = [[NSMutableArray alloc] initWithArray:sortedArray];
self.marrProperty = marr;
[marr release];

After checking with the leaks tool in Instrument, I was told the leaks happened in the following code:

NSMutableArray *marr = [[NSMutableArray alloc] initWithArray:sortedArray];
self.marrProperty = marr;

I don’t know why, because I just alloc and release well.

Answer 1

Instruments is showing you were the leaked object was allocated, not where it was leaked.

You need to find the extra retain. You can use Instruments to do that; the Allocations instrument can be configured to track retain/release events.

This will likely be helpful.