I am expecting some low-level hack here. :-)

The low level hacks are found here

I was hoping Devel::Peek might reveal something but it doesn't :) 

$ perl -Mthreads -MDevel::Peek -e"my $locked=1; my $unlocked=1; Dump($
+unlocked); lock($locked); Dump($locked)"

SV = IV(0x98a490) at 0x98a494
  REFCNT = 1
  FLAGS = (PADMY,IOK,pIOK)
  IV = 1
SV = IV(0x3e8c10) at 0x3e8c14
  REFCNT = 1
  FLAGS = (PADMY,IOK,pIOK)
  IV = 1

[download]
http://cpansearch.perl.org/src/JDHEDDEN/threads-shared-1.33/shared.xs says 
/* User-level locks:
   This structure is attached (using ext magic) to any shared SV that

[download]
so you might have luck using Variable::Magic to peek at the magic

In reply to Re^3: Debugging lock ownership by Anonymous Monk
in thread Debugging lock ownership by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.