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Re: How EXC_BAD_ACCESS in objc_msgSend if receiver, parms OK?
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Re: How EXC_BAD_ACCESS in objc_msgSend if receiver, parms OK?


  • Subject: Re: How EXC_BAD_ACCESS in objc_msgSend if receiver, parms OK?
  • From: Matt Neuburg <email@hidden>
  • Date: Mon, 20 Feb 2012 10:16:22 -0800

On Fri, 17 Feb 2012 16:06:01 -0800, Greg Parker <email@hidden> said:
>No. objc_msgSend() also reads from the class's method cache and method list. It's possible for the receiver object to be valid, but still crash because of a memory smasher that hit the method cache or method list

It's also possible for the receiver object to be valid but the wrong object. I remember in my early Cocoa programming days I mismanaged the memory for an NSString object and was mystified when *another NSString object took its place*. I believe NSZombie would have tracked that down by occupying the slot pointed to by the variable and not letting some other string slip into it. In other words, believe in zombies, not in your intuitions about how everything looks okay. :) m.

--
matt neuburg, phd = email@hidden, <http://www.apeth.net/matt/>
A fool + a tool + an autorelease pool = cool!
Programming iOS 5! http://shop.oreilly.com/product/0636920023562.do
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