thread question

[David Relson]

After a 6 month break, I'm resuming work on a multithreaded, gnustep-base 
program and have encountered some new and different behaviors.

My environment is Mandrake Linux 7.2 running a 2.2.18 kernel, egcs-1.1.2, 
libobjc_d.so (built from libobjc-0.9.0 using make debug=yes), and 
libpthread.so.

The first time the program uses +[NSThread 
detachNewThreadSelector:toTarget:withObject:], I get the following:

Program received signal SIG32, Real-time event 32.
0x40418c12 in sigsuspend () from /lib/libc.so.6
(gdb) where
#0  0x40418c12 in sigsuspend () from /lib/libc.so.6
#1  0x403bb850 in pthread_setconcurrency () from /lib/libpthread.so.0
#2  0x403bae0f in pthread_create () from /lib/libpthread.so.0
#3  0x402bd117 in __objc_thread_detach (
    func=0x402bd600 <__objc_thread_detach_function>, arg=0x81d0220)
    at thr-posix.c:83
#4  0x402bd712 in objc_thread_detach (selector=0x402a1b20, object=0x81d0350,
    argument=0x0) at thr.c:153
#5  0x4020bff3 in +[NSThread detachNewThreadSelector:toTarget:withObject:] (
    self=0x402a1aa0, _cmd=0x8110568, aSelector=0x8110560, aTarget=0x8161308,
    anArgument=0x81d0158) at NSThread.m:194

what is signal 32?  I don't recall seeing seeing them 6 months ago.  There 
is a "#define __SIGRTMIN 32" in /usr/include/bits/signum.h, which seems to 
indicate that 32 is the first run-time signal.  and that means ???

Using "handle SIG32 nostop" allows the signals to happen without obvious 
interference with my program.  After a group of the "Program received 
signal SIG32, Real-time event 32." messages, I get:

Program received signal SIGTRAP, Trace/breakpoint trap.
0x40418c12 in sigsuspend () from /lib/libc.so.6
(gdb) where
#0  0x40418c12 in sigsuspend () from /lib/libc.so.6
#1  0x403bb850 in pthread_setconcurrency () from /lib/libpthread.so.0
#2  0x403bd797 in sem_destroy () from /lib/libpthread.so.0
#3  0x403b9bc5 in pthread_mutex_lock () from /lib/libpthread.so.0
#4  0x402bd3b2 in __objc_mutex_lock (mutex=0x8123fb8) at thr-posix.c:233
#5  0x402bd969 in objc_mutex_lock (mutex=0x8123fb8) at thr.c:326
#6  0x402bb5f0 in sel_get_name (selector=0x810ff30) at selector.c:293
#7  0x401ca19c in GSObjCSelectorName (this=0x810ff30)
    at ../Headers/Foundation/NSObjCRuntime.h:132
#8  0x401c9cf7 in NSStringFromSelector (aSelector=0x810ff30)
    at NSObjCRuntime.m:34

Can anyone tell me what all this stuff is, or where to find information on it?

Thanks.

David

--------------------------------------------------------
David Relson                   Osage Software Systems, Inc.
relson@osagesoftware.com       Ann Arbor, MI 48103
www.osagesoftware.com          tel:  734.821.8800