Re: [Pyobjc-dev] crasher demo app

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

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

-bob