Re: Segfault when NSTextView is released

[Fred Kiefer]

Looks like this is rather a question for David. It is more about the
semantic of ARC for different sorts of ivars, than about NSTextView itself.
In the code you did send the tvIvar ivar was not defined as a property.
In this case I would expect that the compiler wont do anything special.

To get me to long into a potential NSTextView issue you will have to
provide an ARC free example that crashes :-(
I am still using gcc for GNUstep development. So I tried to rewrite your
code to the old gcc supported form of properties and it did not crash in
that form.

Automatic reference counting is great, but you really need to know what
you are doing.

Fred


On 13.02.2014 11:41, Lundberg, Johannes wrote:
> I solved the problem temporary by changing properties for NSTextView from
> strong to assign.
> 
> 
> --
> Johannes Lundberg
> BRILLIANTSERVICE CO., LTD.
> 
> 
> On Thu, Feb 13, 2014 at 7:14 PM, Lundberg, Johannes <
> johannes@brilliantservice.co.jp> wrote:
> 
>> Thanks Fred.
>>
>> I put together a small program for you.
>>
>> The problem seems to be when the text view is assigned to an ivar.
>> Removing from superview and setting ivar = nil maybe over releases it or
>> something?
>>
>>
>>
>>
>> --
>> Johannes Lundberg
>> BRILLIANTSERVICE CO., LTD.
>>
>>
>> On Thu, Feb 13, 2014 at 5:50 PM, Fred Kiefer <fredkiefer@gmx.de> wrote:
>>
>>> I hope to be able to look into this tomorrow. It would help if you could
>>> send a piece of example code showing the issue.
>>>
>>> Fred
>>>
>>> On the road
>>>
>>> Am 13.02.2014 um 09:16 schrieb "Lundberg, Johannes" <
>>> johannes@brilliantservice.co.jp>:
>>>
>>> Nope I was wrong..
>>> Using the designated initializer (with textContainer nil or set to
>>> created text container object) fixes the release bug but whenever I try to
>>> change a property I get crash. Stuck between rock and hard place...
>>>
>>> #0  0x0000000800d9e191 in -[NSTextView setTextColor:] (self=<value
>>> optimized out>, _cmd=<value optimized out>, color=<value optimized out>) at
>>> NSTextView.m:2407
>>> #1  0x000000000041d74f in -[PhotoViewController loadView]
>>> (self=0x81df558d0, _cmd=0x8011e7770) at PhotoViewController.m:81
>>> #2  0x0000000800dc5122 in -[NSViewController view] (self=0x81df558d0,
>>> _cmd=<value optimized out>) at NSViewController.m:94
>>> #3  0x000000000042b255 in -[AppDelegate applicationDidFinishLaunching:]
>>> (self=0x81b091510, _cmd=0x8010fe2a0, notification=0x81d1f1c50) at
>>> AppDelegate.m:171
>>> #4  0x00000008015dec4c in -[NSNotificationCenter _postAndRelease:]
>>> (self=0x81b2b96b0, _cmd=<value optimized out>, notification=0x81d1f1c50) at
>>> NSNotificationCenter.m:1191
>>> #5  0x0000000800c9884e in -[NSApplication _didFinishLaunching]
>>> (self=0x81b0a9490, _cmd=<value optimized out>) at NSApplication.m:1186
>>> #6  0x0000000800c995ce in -[NSApplication run] (self=0x81b0a9490,
>>> _cmd=<value optimized out>) at NSApplication.m:1539
>>> #7  0x0000000000426935 in main (argc=2, argv=0x7fffffffc798) at main.m:20
>>>
>>>
>>>
>>> --
>>> Johannes Lundberg
>>> BRILLIANTSERVICE CO., LTD.
>>>
>>>
>>> On Thu, Feb 13, 2014 at 3:14 PM, Lundberg, Johannes <
>>> johannes@brilliantservice.co.jp> wrote:
>>>
>>>> Ok it seems like using the
>>>>
>>>> -(id) initWithFrame: (NSRect)frameRect
>>>>       textContainer: (NSTextContainer *)container;
>>>>
>>>> initializer is the way to go. No segfault with this initializer.
>>>>
>>>> However as it says in the header:
>>>> /* This variant will create the text network (NSTextStorage,
>>>> NSLayoutManager,
>>>> and a NSTextContainer). The network will be owned by the NSTextView;
>>>> releasing it will release all parts of the network. */
>>>> -(id) initWithFrame: (NSRect)frameRect;
>>>>
>>>> initWithFrame should work and not cause segfault so something seems to
>>>> be wrong..
>>>>
>>>> (I know I wrote alloc] init] in the previous mail but I was actually
>>>> using initWithFrame and it caused segfault for me)
>>>>
>>>>
>>>> --
>>>> Johannes Lundberg
>>>> BRILLIANTSERVICE CO., LTD.
>>>>
>>>>
>>>> On Thu, Feb 13, 2014 at 1:58 PM, Lundberg, Johannes <
>>>> johannes@brilliantservice.co.jp> wrote:
>>>>
>>>>> Hi
>>>>>
>>>>> I'm using latest version of GNUstep on FreeBSD 10 64bit with ARC.
>>>>> When my NSTextView is freed I get segfault. I haven't seen this
>>>>> behavior for any other UI element.
>>>>>
>>>>> Example: Put this code in loadview
>>>>>     NSTextView *tv = [[NSTextView alloc] init];
>>>>>
>>>>> and it segfaults when object is released.
>>>>>
>>>>> I haven't really done any debugging yet except finding where this
>>>>> happens. Thought I send this mail first before I dive into the gui source
>>>>> code.
>>>>>
>>>>> #0  0x0000000802d9aa74 in objc_msgSend_fpret () from
>>>>> /usr/local/lib/libobjc.so.4.6
>>>>> #1  0x0000000800db5379 in -[NSView dealloc] (self=0x81aee9b90,
>>>>> _cmd=<value optimized out>) at NSView.m:651
>>>>> #2  0x0000000800d9951a in -[NSTextView dealloc] (self=<value optimized
>>>>> out>, _cmd=<value optimized out>) at NSTextView.m:1141
>>>>> #3  0x0000000800d9121b in -[NSTextContainer dealloc] (self=0x81ddd1f30,
>>>>> _cmd=0x8011e3b60) at NSTextContainer.m:134
>>>>> #4  0x00000008014fe67a in -[GSArray dealloc] (self=0x81e411290,
>>>>> _cmd=<value optimized out>) at GSArray.m:137
>>>>> #5  0x0000000802d9b5c9 in objc_autoreleasePoolPop () from
>>>>> /usr/local/lib/libobjc.so.4.6
>>>>> #6  0x000000080154a400 in -[NSAutoreleasePool dealloc]
>>>>> (self=0x81af462f0, _cmd=<value optimized out>) at NSAutoreleasePool.m:729
>>>>> #7  0x0000000800c975d4 in -[NSApplication run] (self=0x81aca9490,
>>>>> _cmd=0x8011e3b60) at NSApplication.m:1543
>>>>> #8  0x0000000000425965 in main (argc=2, argv=0x7fffffffc798) at
>>>>> main.m:20