in reply to Re^3: mod_perl debugging help
in thread mod_perl debugging help

[error] Undefined subroutine &FormGenerator::handler called

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Originaly I did think this was a globals issue, it seems to be the most common cause of it, however i've gone through and removed any globals (running in strict).

As for the code, I know it's not terribly helpfull but I cant really put it up, a) it's work b) it's about 680 lines :)

What I really need at this point is new ideas on how to actualy locate the bug, much easier to fix when I actualy know what im looking for :)

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Re^5: mod_perl debugging help
by Joost (Canon) on Jun 22, 2006 at 19:53 UTC
    Hmm... are you using funky stuff like INIT handlers to load the FormGenerator module, or is the handler generated at runtime somewhere?

    My first guess would be that a new apache child gets started that doesn't load all required modules, (in other words, you're not sharing all the modules you think you do).

    Ofcourse, it's possible you're deleting the method somewhere, or it might be a nasty bug in some other method. Any special modules (especially C/XS) you're using?

    "What should it profit a man, if he should win a flame war, yet lose his cool?"
[reply]
      Nope, it's just a standard module, the usual "package Blah" and the subroutines below!

      As for the modules, I am using quite a few, have a gander and see if you see anything suspect!

      Data::Dumper
      Apache
      DBI
      HTML::EasyTags
      Apache::Reload
      XML::TreePP
      Apache::Request
      Apache::Constants qw(:response)
      Sort::Naturally

      Im also using 2 other modules which exist soley to service the 2 main FormGenerator modules.
      FormGenerator::Common
      FormGenerator::FormSubs
      Also it doesnt happen just on the first load, it's quite inconsistant, I can go hours without seeing it and then get it over and over!
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Re^5: mod_perl debugging help
by jhourcle (Prior) on Jun 23, 2006 at 12:24 UTC

    Is there anything else on the server that uses the 'FormGenerator' namespace?

    It's WAY too generic. If some other CGI running under mod_perl uses that namespace, when your script runs, it'll see that a module with that name is loaded, and not bother loading anything. You'll then get strange error messages about functions not found.

    (or worse, they both use the same subroutines names, and you end up with odd behaviour that is almost impossible to track down on larger systems)

[reply]
      The only other thing in that namespace are the subordinate modules.

      And as for the name, I do plan to devise a less generic name for it however for the time being FormGenerator fits, tis one of those "does what it says on the tin" names, consider it a development name :)
[reply]

        You might think so, but you're the one asking for help here, and have said you're not sure what's going on.

        I'd suggest looking for occurances of 'FormGenerator' in every perl module and mod_perl file that you have, and make sure you're correct.

        Or, if you don't want to go to that trouble, switch every occurance that you know should be 'FormGenerator' to something more specific. After all, if you have multiple people working on a system, someone else might've thought that 'FormGenerator' made a good 'development name' as well, or you might've done it months/years ago, and forgotten you still had a file sitting around.

        Because you can declare a package in ANY file, it is very, very, easy for the problem I've describe to occur if you're sloppy in your naming. (and I speak from experience.) Mod_perl is much, much less forgiving than a simple CGI.

        ps. 'paint' makes a good label for a can -- but it's not of much use when you're specifically looking for white semigloss latex paint

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