Re: trying to debug problems with NSAutoreleasepool

[Sebastian Reitenbach]

Hi,
Richard Frith-Macdonald <richard@tiptree.demon.co.uk> wrote: 
> On 2007-11-27 14:01:43 +0000 "Sebastian Reitenbach" 
> <sebastia@l00-bugdead-prods.de> wrote:
> 
> > Hi,
> > 
> > I try to figure out how that NSAutoreleasepool is working, because I 
> > want to 
> > debug
> > some problems I have there while trying to get opengroupware to run 
> > on 
> > gnustep-base. The webui application breaks in a lot of places in 
> > NSAutoreleasepool.m:405
> > here the backtrace:
> 
> <snipped reasonable looking trace (though line numbers make it look 
> like it's not a  current version of gnustep)>
The version installed is a 1.15.1, I'm pretty sure about that,
maybe the line number offsets differ
by one or two, because I tried to add NSLog statements,
that I commented out instead of removing again.
That backtrace was from a segmentation fault, I was wrong saying
it was an exception.

> 
> > I added a NSLog statement before that in the while loop in 
> > -emptyPool, but 
> > that ended up in an endless loop, eating up all my stack frames.
> 
> Sure ... NSLog autoreleases things ... likely to cause difficulties in 
> the middle of emptying the current pool.
yes, now I know that too.

> 
> > in LSLoginAccountCommand.m, and in the other places where it runs 
> > into that 
> > exception, the NSAutoreleasepool seems to be handled like in other 
> > applications that work well.
> 
> What exception?
Sorry, exception was wrong, it just segfaults, without exception. 
I ran it in gdb, and above backtrace was from that segfault.

> 
> > Any idea what could be my problem or how I could try to figure out?
> 
> You didn't say what your problem was ... the stacktrace looked like a 
> normal emptying of a pool.
> Perhaps you have objects in the poolthat are crashing when they are 
> released?
I think, that seems to be the case. but how do I find out what kind of 
objects 
that are? The webui segfaults with the backtrace above, when I think it is 
emptying the last object from the pool, not sure about that. I do not 
fully understand what is going on there.
At least at ten places in opengroupware I commented out a 
[pool release]; or equivalent, to prevent these crashers.

As I doubt, that commenting out these lines, is the right solution,
I tried to investigate the issue, to maybe find sth. better, but for now
I got a bit stuck.

kind regards
Sebastian