CODEWITHSUNDEEP
objective-cmemoryuiviewnsmutablearraymemory-leaks
DKV
DKV

Reputation: 25

EXC_BAD_ACCESS for NSMutableArray

I have a NSMutableArray with a few view elements.

I remove the view from the view hierarchy and then check the retain count of the array, it returns 1. I then send [array release] but the code dumps with EXC_BAD_ACCESS.

I see that there are elements in the array but still the code dumps.

Here is what I found during debugging. The array has all the 100 objects present (count on the array returns 100) and the contents when seen on a debugger returns "Out of Scope" for the elements. Also, since the array is in the view hierarchy, the following code reduces the retain count by two:

for (Liv *view1 in viewArray){
    NSLog(@"view count = %d", [view1 retainCount]);
    [view1 removeFromSuperview];

    NSLog(@"view count = %d", [view1 retainCount]); 
}

Upvotes: 0

Views: 268

Answers (2)

bbum
bbum

Reputation: 162722

Do not use retainCount

It is useless for this kind of debugging; you are working with views in the framework's view hierarchy. There could be any number of reasons why the retain count goes up or down by 2, 10, or 42.

From the roundabout evidence posted so far, this appears to be a very straightforward memory management issue.

First, use "build and analyze" to have the llvm static analyzer check your code. Fix any problems it identifies.

Next, how is the array allocated? Where do you store it? Post all of the lines of code that declare or manipulate the array.

Finally, as Paul said, turn on zombies and see what happens.

There is an off chance that this isn't a retain/release issue, but there isn't any evidence to indicate that yet.

Upvotes: 3

paulbailey
paulbailey

Reputation: 5346

Did you retain or alloc the array? If not, you shouldn't be sending it a release.

EXC_BAD_ACCESS means you're sending a message to a object that's already been released. You (or some code somewhere) is releasing it prior to the part of your code where you're sending release (or removeAllObjects).

Basically, if your retains and releases are balanced, you won't get this error. We'll need to see some code before we can offer anything more than generic advice.

Using NSLog() and retainCount isn't the easiest way to debug errors of this nature. Assuming you're on Xcode 3.2.6, then try running your code via Run > Run with Performance Tool > Zombies. That should give you a good pointer as to which part of your code is faulty.

Upvotes: 0

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