[log4perl-devel] potential bug in

[Viner, D. <dv...@ya...>]

Hi,

I've been toying with the Log::Log4perl::Appender::Synchronized in version
0.40.  I think I've discovered a bug with the shared memory handling.  I've
attached the script and the config file that always causes a core dump on my
machine.  I strongly suspect that my problem is some weird state that the
shared memory on my machine has gotten itself into.  But, I'd like to figure
out how to improve the Synchronized module to defend against whatever causes
the core dump.

I'm sure that it's the Synchronized module because using this line from the
config file
	log4perl.logger.dispatcher = DEBUG, DebugScreen, FileAppndr1
works fine, where as 
	log4perl.logger.dispatcher = DEBUG, DebugScreen, Syncer
causes a core dump.

I can't make much sense of the backtrace from GDB ... but here it is:
(gdb) bt
#0  0x280f9043 in Perl_pp_untie () at pp_sys.c:796
#1  0x280c9814 in Perl_runops_standard () at run.c:25
#2  0x28080e81 in S_call_body (myop=0x9fbff530, is_eval=0) at perl.c:1824
#3  0x28080bfe in perl_call_sv (sv=0x81b0b6c, flags=22) at perl.c:1742
#4  0x280d6b3c in Perl_sv_clear (sv=0x81b71f8) at sv.c:3742
#5  0x280d712e in Perl_sv_free (sv=0x81b71f8) at sv.c:3950
#6  0x280d6e54 in Perl_sv_clear (sv=0x80646e8) at sv.c:3824
#7  0x280d712e in Perl_sv_free (sv=0x80646e8) at sv.c:3950
#8  0x280c6bc9 in Perl_hv_free_ent (hv=0x8064640, entry=0x81b89b0) at
hv.c:1068
#9  0x280c6dae in S_hfreeentries (hv=0x8064640) at hv.c:1146
#10 0x280c6dfe in Perl_hv_undef (hv=0x8064640) at hv.c:1172
#11 0x280d6dad in Perl_sv_clear (sv=0x8064640) at sv.c:3795
#12 0x280d712e in Perl_sv_free (sv=0x8064640) at sv.c:3950
#13 0x280db8f0 in do_clean_objs (sv=0x8064580) at sv.c:8381
#14 0x280d09c8 in S_visit (f=0x280db884 <do_clean_objs>) at sv.c:162
#15 0x280d0a47 in Perl_sv_clean_objs () at sv.c:180
#16 0x2807e5f3 in perl_destruct (my_perl=0x804d030) at perl.c:417
#17 0x8049249 in main (argc=3, argv=0x9fbff914, env=0x9fbff924) at
perlmain.c:55


My machine appears to have several shared memory segments allocated... ipcs
reports:
Message Queues:
T     ID     KEY        MODE       OWNER    GROUP

Shared Memory:
T     ID     KEY        MODE       OWNER    GROUP
m 196608          0 --rw-------   dviner    users
m 3735553          0 --rw-------   dviner    users
m 393218          0 --rw-------   dviner    users
m 1048579          0 --rw-------   dviner    users
m 851974          0 --rw-------   dviner    users
m 262153          0 --rw-------   dviner    users

Semaphores:
T     ID     KEY        MODE       OWNER    GROUP

I'm using Perl v5.6.1 on FreeBSD 4.x.

Has anyone seen this error? or have a suggestion on how to debug it?

thanks
dave