NSThread and problem posting notification

[Lucas Schnorr]

Hi,

Everything below use the latest base, gui and the gnustep runtime, from 
the subversion repository at gna. All compiled with clang in an ubuntu 
system, 64 bits.

I have a program that launches a thread to do some background work. 
After the thread finishes, I get an exception:

2012-03-05 10:08:26.409 tobjc[6709] Problem posting notification: 
<NSException: 0x7f22d8005658> NAME:NSRangeException REASON:Index -1 is 
out of range 1 (in 'objectAtIndex:') INFO:{Array = ("<NSRunLoop: 
0x1cfe998>"); Count = 1; Index = 4294967295; }

When this exception appears, I need to kill the program by hand.

Here's the backtrace:

#0  -[NSException raise] (self=0xabd048, _cmd=0x7ffff6ebc8b0)
    at /home/schnorr/misc/gnustep/core/base/Source/NSException.m:956
#1  0x00007ffff684418c in -[GSArray _raiseRangeExceptionWithIndex:from:] 
(self=0xb08398,
    _cmd=0x7ffff6ebc9f0, index=4294967295, sel=0x7ffff6ee93c0)
    at /home/schnorr/misc/gnustep/core/base/Source/GSArray.m:97
#2  0x00007ffff684500e in -[GSArray objectAtIndex:] (self=0xb08398, 
_cmd=0x7ffff6ee93c0,
    index=4294967295) at 
/home/schnorr/misc/gnustep/core/base/Source/GSArray.m:331
#3  0x00007ffff6900df9 in -[NSConnection removeRunLoop:] (self=0xb5ee18, 
_cmd=0x7ffff6ee8a90,
    loop=0xe469c8) at 
/home/schnorr/misc/gnustep/core/base/Source/NSConnection.m:1596
#4  0x00007ffff6914bd7 in +[NSConnection(Private) _threadWillExit:] 
(self=0x7ffff6ee8a00,
    _cmd=0x7ffff6ee91a0, notification=0xb5ef48)
    at /home/schnorr/misc/gnustep/core/base/Source/NSConnection.m:4020
#5  0x00007ffff69c29ef in -[NSNotificationCenter _postAndRelease:] 
(self=0x7472d8, _cmd=0x7ffff6f12f20,
    notification=0xb5ef48) at 
/home/schnorr/misc/gnustep/core/base/Source/NSNotificationCenter.m:1223
#6  0x00007ffff69c33b5 in -[NSNotificationCenter 
postNotificationName:object:userInfo:] (self=0x7472d8,
    _cmd=0x7ffff6f3fd90, name=0x79e578, object=0xacd628, info=0x0)
    at 
/home/schnorr/misc/gnustep/core/base/Source/NSNotificationCenter.m:1282
#7  0x00007ffff6a80d91 in unregisterActiveThread (thread=0xacd628)
    at /home/schnorr/misc/gnustep/core/base/Source/NSThread.m:459
#8  0x00007ffff6a80bf6 in +[NSThread exit] (self=0x7ffff6f3fa80, 
_cmd=0x7ffff6f3fe00)
    at /home/schnorr/misc/gnustep/core/base/Source/NSThread.m:523
#9  0x00007ffff6a82445 in nsthreadLauncher (thread=0xacd628)
    at /home/schnorr/misc/gnustep/core/base/Source/NSThread.m:809
#10 0x00007ffff5f48efc in start_thread (arg=0x7fffeb72d700) at 
pthread_create.c:304
#11 0x00007ffff5c8389d in clone () at 
../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#12 0x0000000000000000 in ?? ()

I have made a small example so that you can try to reproduce the problem:

git clone git://github.com/schnorr/tobjc.git
cd tobjc
make
./tobjc.app/tobjc

Click on "Start/Stop Thread" (or Alt+t), see that the thread was created 
in the terminal, then click again in the same button to stop the thread 
(with [thread cancel], the thread checks at each loop if it was 
canceled). When the thread stops, the exception above appears. The code 
for all this is on tobjc.m source file.

Am I doing something wrong when starting/canceling the thread, or it is 
a bug in NSThread, NSNotificationCenter or NSConnection?

Thanks
Lucas