Detect Zombie at runtime

Question

Is there a way to find a Zombie at runtime in objective-c?
I'm looking for a way to prevent an object to call a method on a zombie, is there any way to detect one without making the app crash?
I do know about weak reference under ARC iOS5 and common sense programming practice.
I was thinking that a way could be asking the object size (I know that maybe "inside" there are just reference) but if the object still exist it should give a value, if it doesn't probably just the single pointer size.
Using malloc_size(pointerToObject)
Could it work?

UPDATE: I do know how to run Instruments for Zombies detection

Answer 1

I don't think Andrea is asking how to run instruments to detect zombies, I think she wants to guard against calling a dealloced instance at runtime. I'm not sure what malloc size will return in this case. I think anything you come up with short of what they've done with NSZombies (which is to never truly free instances) will be gimicky and only work part of the time. I think your best best is the boring old diligent programming and profiling with instruments to guard against making these calls rather than trying to catch the error at runtime.

Answer 2

Try running the application with Instruments, and select the "Zombies" template.

Answer 3

On the scheme menu (upper left, next to run/stop). Select "Edit Scheme...". A sheet will appear. Select the Run/Debug scheme there. Select the "Diagnostics" tab on the center pane. Check Zombies.