in reply to Re^2: Using SUPER in dynamically generated subs
in thread Using SUPER in dynamically generated subs

( Sorry, this post is completely wrong. )

That's a different problem, relating to threads and shared variables.

Is $alias_for a shared variable? I'm no threading expert, but it makes sense that captures do not remain shared. Perhaps you want to capture a reference to the shared variable instead of capturing the shared variable itself. 

    my $alias_for_ref = \$alias_for;

    eval "package $class;"<<'SUB';
        sub find_ids {
            my ($class,$params) = @_;
            # Do something with ${$alias_for_ref}
            return SUPER::find_ids->($class,\%params);
        });
SUB

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Re^4: Using SUPER in dynamically generated subs
by clinton (Priest) on Nov 13, 2006 at 17:53 UTC
    No - it has nothing to do with threads. It means that the deep binding, which I was relying on, has been broken : see Variable will not stay shared

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      Oops! I was thinking of another warning.

      It turns out the warning is spurious in this case. We want a class's find_ids to refer to $alias_for as it was when find_ids was compiled, which is to say we want $alias_for not to be "shared".

      The warning can be silenced by changing 

      sub find_ids {

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      to 
      *find_ids = sub {

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      Tested. 

      ...
my ($class, $alias_for) = @_;

my $sub = eval "package $class;" . <<'__EOI__';
   *find_ids = sub {
      my ($class, $params) = @_;
      do_something_with($alias_for);
      return $class->SUPER::find_ids($params);
   }
__EOI__
die $@ if $@;
...

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        Thanks ikegami - that works a treat.

        When I benchmarked the three methods, I got this: 

                  Rate super  eval  orig
super   7794/s    --  -88%  -93%
eval   67568/s  767%    --  -35%
orig  104167/s 1236%   54%    --

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        ... where super is using SUPER, eval is ikegami's method, and orig is the one in the original post.

        The eval method would be preferable because it checks the @ISA at runtime, while my method, although faster, would only check @ISA at compile time.

        UPDATE At ikegami's suggestion, I have added the benchmark code:

        Read more... (2 kB)
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