Re: Breaking into debugger after program hangs....

FROM : j o a r
DATE : Thu Apr 28 22:57:10 2005

On 28 apr 2005, at 22.43, John Draper wrote:

> I never DID understand this "Toll free" concept....  can someone 
> come forward and explain
> this?    Isn't this just a kind of "wrapper" around the lower level 
> Carbon Procedural calls?


It means that at the data level, the two are one and the same (for 
example CFArray  == NSArray), and that any operation that can work on 
one, can also work on the other (possibly requiring a "cast" to help 
identify the type).

> Well - then perhaps I was wrong in how I enabled Zombies,  because 
> I just followed the
> instructions in the Tech Note....  It clearly says I just select 
> the Target (Executeable)
> and go to File --> Show Inspector --> Arguments (tab) --> and put 
> in the "NSZombieEnabled = YES"
> Is that right?  If so,  then my program is NOT reporting what 
> happened....  Do I need to
> issue some "secret" command to "gdb" to get this info?


That should be right, barring the special case that Nick mentioned.
I'm a bit concerned that you say that you enter "NSZombieEnabled = 
YES", because I think that at least in Xcode 1.5 and later, you enter 
NSZombieEnabled in one field, and YES in another. But you probably 
did the right thing - it's difficult not to.

> And as of yet - nobody came forward to tell me how I can "break" 
> out of a "Hang" and
> get back into the debugger....  isn't there ANYONE out on this 
> list that knows?
> And where are these APPLE PEOPLE I heard about who actually read 
> this list...  Can't any of you please answer this?


I would suggest that you drop that tone of voice immediately if you 
want to find help on this or any other mailing list. I don't see how 
shouting would make anyone more inclined to help you...

If your application is signaled, like you say happens in your case, 
you should break into the debugger automatically. If you want to 
break automatically on exceptions, break on "-[NSException raise]", 
using the instructions I gave you earlier (although I don't think it 
would help you right now). If you want to break manually, hit the 
"pause" button in the debugger window toolbar. Are you sure you're 
using the debugger at all? You hit Cmd+R to launch the application 
outside of the debugger, and Cmd+Y to launch it in the debugger.

j o a r