Re: Multiple perl interpreters and Module::Runtime (-d)

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Re^2: Multiple perl interpreters and Module::Runtime (-d) by daneus (Initiate) on Feb 07, 2011 at 09:43 UTC
Thanks for the hint. I've tried the Perl debugger and found the following: It is crashing in the module Exporter, line 64: `[31499->31499] DB<1> Exporter::import(/export/packages/perl-5.12.3/li +b/5.12.3/Exporter.pm:64): 64: *{"$callpkg\::$_"} = \&{"$pkg\::$_"} foreach @_;` [download] where the variables are: `$callpkg = "Module::Runtime" @_ = ("is_string") $_ = "is_string" $pkg = "Params::Classify"` [download] When I tried to feed the debugger with this: `&{"$pkg\::$_"}` [download] the debugger crashed. So there is probably something bad going on in Params::Classify. The generated core dump shows, that it crashed in `lib/params/Classify.xs:635`. The backtrace is very high and starts like this: ... #87243 0x00007fd820981b7a in myck_entersub (my_perl=0x2143000, op=0x26 +0b250) at lib/Params/Classify.xs:635 #87244 0x00007fd820981b7a in myck_entersub (my_perl=0x2143000, op=0x26 +0b250) at lib/Params/Classify.xs:635 #87245 0x00007fd820981b7a in myck_entersub (my_perl=0x2143000, op=0x26 +0b250) at lib/Params/Classify.xs:635 #87246 0x00007fd820981b7a in myck_entersub (my_perl=0x2143000, op=0x26 +0b250) at lib/Params/Classify.xs:635 #87247 0x00007fd826cae142 in Perl_convert (my_perl=0x2143000, type=173 +, flags=192, o=0x260b250) at op.c:2652 #87248 0x00007fd826cb351c in Perl_utilize (my_perl=0x2143000, aver=1, +floor=147, version=0x0, idop=0x2617d20, arg=0x264e210) at op.c:3979 #87249 0x00007fd826d4d17c in Perl_yyparse (my_perl=0x2143000) at perly +.y:674 #87250 0x00007fd826ef2d6d in S_doeval (my_perl=0x2143000, gimme=2, sta +rtop=0x0, outside=0x0, seq=2054) at pp_ctl.c:3112 #87251 0x00007fd826efa35e in Perl_pp_require (my_perl=0x2143000) at pp +_ctl.c:3690 #87252 0x00007fd826da5fc8 in Perl_runops_debug (my_perl=0x2143000) at +dump.c:2049 #87253 0x00007fd826cdadb6 in Perl_eval_sv (my_perl=0x2143000, sv=0x216 +0e28, flags=4) at perl.c:2705 #87254 0x0000000000401a47 in perl_load_module_1 () #87255 0x00000000004040f9 in main () [download] The function "myck_entersub" is calling itself ad infinitum, which is not good. My guess is there's something wrong with Classify.xs. Unfortunately, I don't know how to fix it. Do you have any ideas?	[reply] [d/l] [select]
Re^3: Multiple perl interpreters and Module::Runtime (&) by tye (Sage) on Feb 07, 2011 at 14:20 UTC
`{"$callpkg\::$_"} = \&{"$pkg\::$_"} foreach @_;` [download] ... When I tried to feed the debugger with this: `&{"$pkg\::$_"}` [download] \&... would never do what &... does. \&... takes a reference to a subroutine while &... invokes a subroutine. So what `&{"$pkg\::$_"}` does is rather irrelevant. It is indeed unfortunate that Params::Classify::is_string() stupidly produces an endless recursive loop when not given any parameters. But that likely has nothing to do with your original problem. The author of that module even included: `sub is_string($);` [download] Which makes it fatal to call is_string() with no arguments... unless you use the prefix `&` to disable sub prototype checking, as you did. So even a bug report against the module might not yield anything. It is crashing in the module Exporter, line 64:* How does it crash? - tye	[reply] [d/l] [select]
Re^4: Multiple perl interpreters and Module::Runtime (&) by daneus (Initiate) on Feb 08, 2011 at 09:43 UTC
How does it crash? Sorry, I should have been more specific. The program crashes with SEGFAULT after executing this line (Exporter.pm, line 64): `64: *{"$callpkg\::$_"} = \&{"$pkg\::$_"} foreach @_;` [download] \&... would never do what &... does. \&... takes a reference to a subroutine while &... invokes a subroutine. So what &{"$pkg\::$_"} does is rather irrelevant. It is indeed unfortunate that Params::Classify::is_string() stupidly produces an endless recursive loop when not given any parameters. But that likely has nothing to do with your original problem. Indeed, you are right. However the expression `\&{"$pkg\::$_"}` entered into the perl debugger yields the same result - SEGFAULT crash. I've been trying to find the part of the line 64 that causes problems - and it shows that the bad part is the expression `\&{"$pkg\::$_"}`. Perl somehow cannot correctly resolve the function `Params::Classify::is_string`. My previous post followed with a GDB backtrace generated from the core dump of the crashed program. It shows where exactly the segfaulted. Btw. have you tried that program? Does it work on your computer?	[reply] [d/l] [select]
Re^5: Multiple perl interpreters and Module::Runtime (XS--) by tye (Sage) on Feb 08, 2011 at 15:02 UTC
Re^6: Multiple perl interpreters and Module::Runtime (XS--) by Anonymous Monk on Nov 28, 2011 at 12:40 UTC
Re^6: Multiple perl interpreters and Module::Runtime (XS--) by daneus (Initiate) on Feb 09, 2011 at 08:31 UTC