Class data & preloading modules

[Adriano Nagelschmidt Rodrigues]

Hi,

I have some modules that use the idiom

package Foo;

use Bar;

{
  my $bar = Bar->new(args);
  sub bar { return $bar }
}

which works fine until one tries to preload them in startup.pl.

I realized that, by preloading, I was innocently sharing the same DBI
object between Apache children (nothing strange happened during
testing, but I guess it was only a question of time & stress).

I also happen to have Foo subclasses that need the DBI connection to
produce otherwise shareable (read only) class data.

My question is about good programming practice in this case. I guess
I have three options:

(init once per MaxRequestsPerChild)

* initialize the class data externally, from within a method.

* do something like

  {
    my $bar;

    sub bar {
      $bar = BAR->new(args) unless $bar; # too ugly? performance loss small?
      return $bar;
    }
  }

(init only once)

* initialize everything in the parent Apache, just make sure to create
  new DBI connections in the children.


What do you think?

Thanks,

--
Adriano