On Thu, Oct 09, 2008 at 11:25:24PM -0700, chromatic wrote:
> While tracking down another bug in Rakudo, I saw this backtrace. Note that
> the "Class already registered!" exception gets thrown multiple times. I've
> seen this before several times in other Rakudo backtraces since the
> exceptions/concurrency merge.
This seems to be a generic problem with exception handling in
Parrot itself. Here's a short PIR program that mimics what is
happening in PGE:
$ cat x.pir
.sub 'main' :main
'foo'(1)
'foo'(2)
'foo'(3)
'foo'(4)
'foo'(5)
debug 1
.end
.sub 'foo'
.param int count
say count
push_eh end
$P0 = newclass 'Foo::Bar'
say "Foo::Bar created"
pop_eh
end:
.return (0)
.end
The first call to 'foo' creates the class, the remainder should
trap "Class Foo::Bar already register" exceptions that are
caught by the push_eh. However, those exceptions never disappear
from the backtrace, as illustrated through gdb (using the
C<debug> opcode here as a breakpoint):
$ gdb parrot
GNU gdb 6.8-debian
Copyright (C) 2008 Free Software Foundation, Inc.
(gdb) b Parrot_debug_ic
Function "Parrot_debug_ic" not defined.
Make breakpoint pending on future shared library load? (y or [n]) y
Breakpoint 1 (Parrot_debug_ic) pending.
(gdb) run x.pir
Starting program: /home/pmichaud/parrot/trunk/parrot x.pir
[Thread debugging using libthread_db enabled]
1
Foo::Bar created
2
3
4
5
[New Thread 0xb766b6c0 (LWP 25876)]
[Switching to Thread 0xb766b6c0 (LWP 25876)]
Breakpoint 1, Parrot_debug_ic (cur_opcode=0x811cc70, interp=0x804f040)
at src/ops/core.ops:932
932 if ($1 != 0) { Interp_debug_SET(interp, $1); }
(gdb) bt
#0 Parrot_debug_ic (cur_opcode=0x811cc70, interp=0x804f040)
at src/ops/core.ops:932
#1 0xb7ba755c in runops_slow_core (interp=0x804f040, pc=0x811cc70)
at src/runops_cores.c:222
#2 0xb7b78fa9 in runops_int (interp=0x804f040, offset=66)
at src/interpreter.c:937
#3 0xb7b79883 in runops (interp=0x804f040, offs=66) at src/inter_run.c:101
#4 0xb7b79b4f in runops_args (interp=0x804f040, sub=0x80e86e4, obj=0x80b1058,
meth_unused=0x0, sig=0xb7e47cb8 "vP",
ap=0xbffd264c "\224\205\016\bp���\224�\020\b\210&��([EMAIL PROTECTED]") at
src/inter_run.c:236
#5 0xb7b79c9c in Parrot_runops_fromc_args (interp=0x804f040, sub=0x80e86e4,
sig=0xb7e47cb8 "vP") at src/inter_run.c:300
#6 0xb7b622c7 in Parrot_ex_throw_from_c (interp=0x804f040,
exception=0x80e8594) at src/exceptions.c:291
#7 0xb7b6239e in Parrot_ex_throw_from_c_args (interp=0x804f040, ret_addr=0x0,
exitcode=20, format=0xb7e4afa0 "Class %Ss already registered!\n")
at src/exceptions.c:338
#8 0xb7b9b13a in fail_if_type_exists (interp=0x804f040, name=0x80e86ac)
at src/oo.c:556
#9 0xb7b9b1a4 in Parrot_oo_register_type (interp=0x804f040, name=0x80e86ac)
at src/oo.c:587
#10 0xb7d7d8aa in init_class_from_hash (interp=0x804f040, self=0x80e8690,
info=0x80e85b0) at ./src/pmc/class.pmc:222
#11 0xb7d7f338 in Parrot_Class_init_pmc (interp=0x804f040, pmc=0x80e8690,
init_data=0x80e86ac) at ./src/pmc/class.pmc:512
#12 0xb7ba6b41 in pmc_new_init (interp=0x804f040, base_type=50, init=0x80e86ac)
at src/pmc.c:368
#13 0xb7b105a3 in Parrot_newclass_p_sc (cur_opcode=0x811cc98, interp=0x804f040)
at src/ops/object.ops:242
#14 0xb7ba755c in runops_slow_core (interp=0x804f040, pc=0x811cc98)
at src/runops_cores.c:222
#15 0xb7b78fa9 in runops_int (interp=0x804f040, offset=66)
at src/interpreter.c:937
#16 0xb7b79883 in runops (interp=0x804f040, offs=66) at src/inter_run.c:101
#17 0xb7b79b4f in runops_args (interp=0x804f040, sub=0x80e8a10, obj=0x80b1058,
meth_unused=0x0, sig=0xb7e47cb8 "vP",
ap=0xbffd29bc "�\210\016\bp�\021\b�)��([EMAIL PROTECTED]") at
src/inter_run.c:236
#18 0xb7b79c9c in Parrot_runops_fromc_args (interp=0x804f040, sub=0x80e8a10,
sig=0xb7e47cb8 "vP") at src/inter_run.c:300
#19 0xb7b622c7 in Parrot_ex_throw_from_c (interp=0x804f040,
exception=0x80e88c0) at src/exceptions.c:291
#20 0xb7b6239e in Parrot_ex_throw_from_c_args (interp=0x804f040, ret_addr=0x0,
exitcode=20, format=0xb7e4afa0 "Class %Ss already registered!\n")
at src/exceptions.c:338
#21 0xb7b9b13a in fail_if_type_exists (interp=0x804f040, name=0x80e89d8)
at src/oo.c:556
#22 0xb7b9b1a4 in Parrot_oo_register_type (interp=0x804f040, name=0x80e89d8)
at src/oo.c:587
#23 0xb7d7d8aa in init_class_from_hash (interp=0x804f040, self=0x80e89bc,
info=0x80e88dc) at ./src/pmc/class.pmc:222
#24 0xb7d7f338 in Parrot_Class_init_pmc (interp=0x804f040, pmc=0x80e89bc,
init_data=0x80e89d8) at ./src/pmc/class.pmc:512
#25 0xb7ba6b41 in pmc_new_init (interp=0x804f040, base_type=50, init=0x80e89d8)
at src/pmc.c:368
#26 0xb7b105a3 in Parrot_newclass_p_sc (cur_opcode=0x811cc98, interp=0x804f040)
at src/ops/object.ops:242
#27 0xb7ba755c in runops_slow_core (interp=0x804f040, pc=0x811cc98)
at src/runops_cores.c:222
#28 0xb7b78fa9 in runops_int (interp=0x804f040, offset=66)
at src/interpreter.c:937
#29 0xb7b79883 in runops (interp=0x804f040, offs=66) at src/inter_run.c:101
#30 0xb7b79b4f in runops_args (interp=0x804f040, sub=0x80e8d3c, obj=0x80b1058,
meth_unused=0x0, sig=0xb7e47cb8 "vP",
ap=0xbffd2d2c "�\213\016\bp�����\021\bh-��([EMAIL PROTECTED]") at
src/inter_run.c:236
#31 0xb7b79c9c in Parrot_runops_fromc_args (interp=0x804f040, sub=0x80e8d3c,
sig=0xb7e47cb8 "vP") at src/inter_run.c:300
#32 0xb7b622c7 in Parrot_ex_throw_from_c (interp=0x804f040,
exception=0x80e8bec) at src/exceptions.c:291
#33 0xb7b6239e in Parrot_ex_throw_from_c_args (interp=0x804f040, ret_addr=0x0,
exitcode=20, format=0xb7e4afa0 "Class %Ss already registered!\n")
at src/exceptions.c:338
#34 0xb7b9b13a in fail_if_type_exists (interp=0x804f040, name=0x80e8d04)
at src/oo.c:556
#35 0xb7b9b1a4 in Parrot_oo_register_type (interp=0x804f040, name=0x80e8d04)
at src/oo.c:587
#36 0xb7d7d8aa in init_class_from_hash (interp=0x804f040, self=0x80e8ce8,
info=0x80e8c08) at ./src/pmc/class.pmc:222
#37 0xb7d7f338 in Parrot_Class_init_pmc (interp=0x804f040, pmc=0x80e8ce8,
init_data=0x80e8d04) at ./src/pmc/class.pmc:512
#38 0xb7ba6b41 in pmc_new_init (interp=0x804f040, base_type=50, init=0x80e8d04)
at src/pmc.c:368
#39 0xb7b105a3 in Parrot_newclass_p_sc (cur_opcode=0x811cc98, interp=0x804f040)
at src/ops/object.ops:242
#40 0xb7ba755c in runops_slow_core (interp=0x804f040, pc=0x811cc98)
at src/runops_cores.c:222
#41 0xb7b78fa9 in runops_int (interp=0x804f040, offset=66)
at src/interpreter.c:937
#42 0xb7b79883 in runops (interp=0x804f040, offs=66) at src/inter_run.c:101
#43 0xb7b79b4f in runops_args (interp=0x804f040, sub=0x80e9068, obj=0x80b1058,
meth_unused=0x0, sig=0xb7e47cb8 "vP", ap=0xbffd309c "\030\217\016\bn6")
at src/inter_run.c:236
#44 0xb7b79c9c in Parrot_runops_fromc_args (interp=0x804f040, sub=0x80e9068,
sig=0xb7e47cb8 "vP") at src/inter_run.c:300
#45 0xb7b622c7 in Parrot_ex_throw_from_c (interp=0x804f040,
exception=0x80e8f18) at src/exceptions.c:291
#46 0xb7b6239e in Parrot_ex_throw_from_c_args (interp=0x804f040, ret_addr=0x0,
exitcode=20, format=0xb7e4afa0 "Class %Ss already registered!\n")
at src/exceptions.c:338
#47 0xb7b9b13a in fail_if_type_exists (interp=0x804f040, name=0x80e9030)
at src/oo.c:556
#48 0xb7b9b1a4 in Parrot_oo_register_type (interp=0x804f040, name=0x80e9030)
at src/oo.c:587
#49 0xb7d7d8aa in init_class_from_hash (interp=0x804f040, self=0x80e9014,
info=0x80e8f34) at ./src/pmc/class.pmc:222
#50 0xb7d7f338 in Parrot_Class_init_pmc (interp=0x804f040, pmc=0x80e9014,
init_data=0x80e9030) at ./src/pmc/class.pmc:512
#51 0xb7ba6b41 in pmc_new_init (interp=0x804f040, base_type=50, init=0x80e9030)
at src/pmc.c:368
#52 0xb7b105a3 in Parrot_newclass_p_sc (cur_opcode=0x811cc98, interp=0x804f040)
at src/ops/object.ops:242
#53 0xb7ba755c in runops_slow_core (interp=0x804f040, pc=0x811cc98)
at src/runops_cores.c:222
#54 0xb7b78fa9 in runops_int (interp=0x804f040, offset=0)
at src/interpreter.c:937
#55 0xb7b79883 in runops (interp=0x804f040, offs=0) at src/inter_run.c:101
#56 0xb7b79b4f in runops_args (interp=0x804f040, sub=0x80e9538, obj=0x80b1058,
meth_unused=0x0, sig=0xb7e47977 "vP", ap=0xbffd340c "")
at src/inter_run.c:236
#57 0xb7b79c9c in Parrot_runops_fromc_args (interp=0x804f040, sub=0x80e9538,
sig=0xb7e47977 "vP") at src/inter_run.c:300
#58 0xb7b5f8f7 in Parrot_runcode (interp=0x804f040, argc=1, argv=0xbffd3578)
at src/embed.c:959
#59 0xb7e21aa2 in imcc_run_pbc (interp=0x804f040, obj_file=0, output_file=0x0,
argc=1, argv=0xbffd3578) at compilers/imcc/main.c:791
#60 0xb7e224c2 in imcc_run (interp=0x804f040, sourcefile=0xbffd46ff "x.pir",
argc=1, argv=0xbffd3578) at compilers/imcc/main.c:1079
#61 0x08048938 in main (argc=1, argv=0xbffd3578) at src/main.c:61
(gdb)
If there's something I need to add to the PIR code to properly
trap and handle the exception, or if this particular pattern for
handling exceptions isn't intended to work this way, let me know.
We can also now fix PGE and other tools to work around this issue
by avoiding calls to newclass for existing classes, but there still
seems something odd about exception handling here.
Hope this helps,
Pm
