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I am using Zombies to try and get rid of an EXC_BAD_ACCESS error.

In Zombies, I got this message when the app crashes -

An Objective-C message was sent to a deallocated object (zombie) at address: 0x8955310.

My question is what do I do next to solve the problem ?

James Raitsev
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Ashish Agarwal
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  • possible duplicate of [How to enable NSZombie in Xcode?](http://stackoverflow.com/questions/5386160/how-to-enable-nszombie-in-xcode) – 一二三 Nov 26 '11 at 04:44
  • The question is not clear. `what do I do next to solve the problem` can be interpreted in a variety of ways. Please rephrase. – James Raitsev Nov 26 '11 at 05:35

2 Answers2

4

Turn on malloc stack logging and zombies for your scheme in Xcode, and run the app in the simulator. Xcode should enter the debugger when the message is sent to the zombie. Run this command at the debugger prompt:

info malloc 0x8955310

(Substitute the actual address of the zombie!) You'll get stack traces from when that address was allocated and freed.

rob mayoff
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Most likely you have created an object, released it and later sent it a message.

To make sure this won't happen, a safe practice would be to set your object to nil once you are done using it

Consider:

NSMutableArray *a = [NSmutableArray array];
[a dealloc];
[a do_something_weird];

Your app is likely crash (won't always crash) in response to this message, as after release, you don't own this memory, and it may be used by some other object.

If you change this sequence to

NSMutableArray *a = [NSmutableArray array];
[a dealloc];
a=nil;
[a do_something_weird];

Exactly nothing will happen. This is a safe practice to follow when you are sure you're done using the object.

You also may want to consider using the Automatic Reference Counting feature, which helps a lot with memory management.

James Raitsev
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