Re: [Pyobjc-dev] crasher demo app

[Bob I. <bo...@re...>]

On Mar 25, 2004, at 1:33 PM, Bob Ippolito wrote:

>
> On Mar 25, 2004, at 12:09 PM, Bob Ippolito wrote:
>
>> On Mar 25, 2004, at 1:18 AM, Burris T. Ewell wrote:
>>
>>> Okay, here is a bare bones implementation of what I was describing.
>>>
>>> http://www.gigagig.org/BT/mcfoo.tgz
>>>
>>> Start this up.  It helps to click on the cells, try to drag them.  
>>> Sometimes it will hang.  Sometimes it will crash like this:
>>>
>>> *** malloc[1540]: Deallocation of a pointer not malloced: 0x726df0; 
>>> This could be a double free(), or free() called with the middle of 
>>> an allocated block; Try setting environment variable MallocHelp to 
>>> see tools to help debug
>>> *** malloc_zone_malloc[1540]: argument too large: 4294967292
>>>
>>> mcfoo has exited due to signal 10 (SIGBUS).
>>
>> Bill brought this to my attention off-list.  I haven't looked at your 
>> problem, however it's relatively safe to say that it's one of two 
>> things:
>>
>> (1) Reference counting.  Some of Cocoa doesn't retain things (like 
>> the table data source, I think).  So you will have to keep a 
>> reference to things like this somewhere on your own.  This sucks, 
>> most of us think it's a bug in Cocoa, and we have filed reports in 
>> radar.  If this does turn out to be your problem, I suggest filing a 
>> duplicate bug.
>
> Try retaining the cell, I did this, and it doesn't crash for me:
>
> class mcfooAppDelegate(NibClassBuilder.AutoBaseClass):
>     def init(self):
>         self.workers = []
>         self.cells = []
>         return self
>
>     def awakeFromNib(self):
>         cols = self.table.tableColumns()
>         cell = MyCell.alloc().init()
>         self.cells.append(cell)
>         cols[0].setDataCell_(cell)
>
> In any case, YMMV with Python threads.  Have fun debugging them :P

Never mind, it did crash.. eventually.

-bob