The official doc is threads::shared, you can find info about this in the BUGS section.

Whether there is any online article about this, I am not sure. You may give a search, if find any, please post links here, thanks.

I created a short script to demo this, just uncomment either of the two commented lines. Compare the results from both cases. You will see that, if %hash itself is shared, you are not be able to assign $hash{VALUE} to an Object of Something correctly. Perl loses the object type, and simple coverts it into an unblessed hashref. Hence, you would not be able to call any method defined on that Object. 
use Something;

use threads;
use threads::shared;

use strict;
use warnings;

#my %hash : shared;
#my %hash;
$hash{VALUE} = &share(new Something(1));
print $hash{VALUE};


package Something;

sub new {
    shift;
    my $self = {};
    $self->{VALUE} = shift;
    bless($self);
    return $self;
}

1;

1;

[download]

In reply to Re: Re: Re: Re: Use thread with good care, but definitely keep using it by pg
in thread Use thread with good care, but definitely keep using it by pg

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.