Re: abnormal thread termination

[Riccardo Mottola]

Hi,

Richard Frith-Macdonald wrote:
> This message indicates a bug in the program as far as I can tell from looking 
> at the source;
>
> It’s generated by the handler set by pthread_key_create() and should only be 
> called if the thread exits while the thread-specific data associate with the 
> key (ie the NSThread object) is non-null.
>
> When a thread is detached by NSThread, it runs a method and calls +exit when 
> the method completes, and +exit destroys the NSThread object and sets the 
> thread-specific data to null.
> When a non-gnustep thread is used for gnustep code, there are two functions 
> provided to register/deregister it (and the latter similarly destroys the 
> NSThread instance and nulls-out the thread-specific variable).
>
> So seeing the message means that a thread has somehow exited without cleaning 
> up its gnustep related thread-specific data (thus leaking an NSThread instance 
> and a presumably other related objects).
>
> I don’t see how that can happen other than by an application level bug (ie some 
> code in that thread calls pthread_exit() or something similar).
>
> Of course, I may have missed spotting some race condition or logic error in the 
> code

I don't guarantee that my code is correct, I haven't yet tested it on 
the Mac.
The code worked "fine" before I started detaching the method in a 
separate thread by use of detachNewThreadSelector. The detached method 
allocates its own autorelease pool.
It actually still appears to work and do everything - except the message.

I really do not do anything at the thread exit and do not manipulate the 
thread otherwise in the code: I do not hold a reference for it.

I tried running the code in a debugger and set a breakpoint in 
NSException and don't get any, so the exception is happening in the 
thread clenanup perhaps? Perhaps a memory problem that is now evident?

The gdb looks like:

[New Thread 2bc0a600 (LWP 100913/GDFCompanion)]
2015-07-13 17:56:43.232 GDFCompanion[2746:100913] name: Aborted, 66
2015-07-13 17:56:43.232 GDFCompanion[2746:100913] name: Failed, 4
WARNING thread 0x2d441e78 terminated without calling +exit!

The two messages between are logs, don't get fooled by the menacious 
sounding Aborted and Failed names.

I wonder that GDB reports the thread to have a certain ID, the warning 
message though another! Yet there are no other threads spawned: the main 
thread and the worker thread.

What could I try to watch besides an exception?

Riccardo