CODEWITHSUNDEEP
iphoneobjective-ccocoa-touch
Myron Slaw
Myron Slaw

Reputation: 886

If I release, I get bad access, if I retain, I leak

I have a view controller that i'm trying to push onto the navigation stack. I create the controller with a local variable, set it up, then assign it to a property. Then if I release the variable, I get EXE_BAD_ACCESS. if I retain (or auto release) it leaks.

CustomTVC* controller = [[CustomTVC alloc]initWithStyle:UITableViewStyleGrouped];
controller.managedObjectContext = self.managedObjectContext;

self.tableViewControllerIvar = controller;

[self.navigationController pushViewController:self.tableViewControllerIvar animated:YES];
 //[controller autorelease]; or [controller release]; or nothing

Here is exactly what happens if I release

  1. The above code is fired from pushing an add button in the nav bar.
  2. the view is pushed and everything is fine. In the new view I can push more views in over and over with no problem...unless
  3. I go back to the root view of the navigation stack. (Which is where the above code is from).
  4. Now if I drill down again to the second view, then try to push another it crashes.

Edit: I have a feeling that something is going wrong when I push the third controller onto the stack. With the push, it's inserting a new object into the managed object context which is causing the fetchedresultscontroller to update the tableview. There may be a broken pointer in there somewhere. I'll play with it and post the results. –

Edit: 5/16

Getting this error message in the log

* -[CustomTVC controllerWillChangeContent:]: message sent to deallocated instance 0x187270

This only happens after I pop the CustomTVC off the stack (go back to the navigation root view controller) I can push and save all I want as long as I don't pop the CustomTVC.

Upvotes: 4

Views: 1145

Answers (3)

Myron Slaw
Myron Slaw

Reputation: 886

Fixed it. Had to set the fetched results controllers delegate to nil in viewDidLoad. 

- (void)dealloc
{
    self.fetchedResultsController.delegate = nil;
    [_fetchedResultsController release];
    [_managedObjectContext release];
    [super dealloc];
}

seems the culprit was(according to the zombie instruments):

[NSFetchedResultsController(private methods) _managedObjectContextDidChange:]

Edit(s): Finally took the time to figure out how to put code in here correctly (I'm lazy)

Upvotes: 2

iOSDeveloperz
iOSDeveloperz

Reputation: 7

you are assigning controller to tableViewControllerIvar 

 self.tableViewControllerIvar = controller;

and you are releasing controller, so you need to retain it in the above line

 self.tableViewControllerIvar = [controller retain];

and when you are done with your "tableViewControllerIvar" then just release it, you shall not get any leaks after that

Upvotes: -1

Ryan Wersal
Ryan Wersal

Reputation: 3228

autorelease should get the job done. When you assign tableViewControllerIvar, you can just call [controller autorelease]. This should take care of that.

CustomTVC* controller = [[CustomTVC alloc]initWithStyle:UITableViewStyleGrouped];
controller.managedObjectContext = self.managedObjectContext;

self.tableViewControllerIvar = [controller autorelease];

[self.navigationController pushViewController:self.VCTVC animated:YES];

If you are still getting EXE_BAD_ACCESS, then something else must be going on. Have you absolutely confirmed that this code, when run more than once, is causing the bad access?

Upvotes: 0

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