#! perl -slw
use strict;
use threads;
use threads::shared;
use Thread::Queue;
use Data::Dump qw[ pp ];

sub helper {
    my $Q = shift;
    while( my $ref = $Q->dequeue ) {;
        lock $ref;
        $ref->{NEW_KEY} = 1;
    }
}

sub my_sub {
    my( $ref, $n ) = @_;
    my $Q = new Thread::Queue;
    my @threads = map async( \&helper, $Q ), 1 .. $n;
    $Q->enqueue( values %{ $ref } );
    $Q->enqueue( (undef) x $n );
    $_->join for @threads;
}

my $hoh = {
    A => { NAME => 'aa' },
    B => { NAME => 'bb' },
};

$hoh = shared_clone( $hoh );

pp $hoh;
my_sub( $hoh, 2 );
pp $hoh;

__END__
C:\test>junk39
{
  A => {
         # tied threads::shared::tie
         NAME => "aa",
       },
  B => {
         # tied threads::shared::tie
         NAME => "bb",
       },
}

{
  A => {
         # tied threads::shared::tie
         NAME => "aa",
         NEW_KEY => 1,
       },
  B => {
         # tied threads::shared::tie
         NAME => "bb",
         NEW_KEY => 1,
       },
}