in reply to package DB penalty?

The @DB::args array is populated by copying the pointers from the actual @_ array, so the cost is a pretty negligible fraction of a caller() invocation - grep for the reference to PL_dbargs in pp_ctl.c to find the 20-odd line block of code involved (within pp_caller()).

I should stress that this is not intended for everyday use, and would suspect that overly imaginative use of this facility is likely to lead you to coredumps and JAPHs.

Hugo

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Re: Re: package DB penalty?
by Rhandom (Curate) on May 15, 2003 at 14:31 UTC
    Thank you. This is exactly the type of answer I was looking for.

    I agree with the "not intended for everyday use." Simple assignment of @args = @DB::args or @args = map {Carp::format_arg($_)} @DB::args can cause a blow up. A case we see a lot is when there is a single argument with a value of undef. It happens occasionally - but it does happen. Kind of frustrating when a cluck that is supposed to debug info takes the entire script down. Wish I had an easily duplicatable code snippet for you - but usually there is a bit of a caller trace involved.

    Thanks again.

    my @a=qw(random brilliant braindead); print $a[rand(@a)];
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