package Testit;
require Exporter;

our @ISA        = qw[ Exporter ];
our @EXPORT     = qw[ forthread ];
our @VERSION    = 1.0;

sub forthread{
    my ($arg)=@_;
    warn "forthread called with argument: '$arg'";
    return 0;
}

1;

##</code><code>##

#! perl -w
use strict;

use threads;
use XML::Simple;
use Data::Dumper;

my $data = '
<cde>
 <thread>
  <module>Testit</module>
  <subroutine>forthread</subroutine>
 </thread>
</cde>
';
my $ref = XMLin( $data );
print Dumper $ref;

my $argument=1;

require $ref->{thread}{module} . '.pm';  ## Line A

my $thread=threads->create(
    \&{ $ref->{thread}{module} . '::' . $ref->{thread}{subroutine} }, # Line B
    $argument
);

$thread->join();

exit(0);

##</code><code>##

c:\test>test
$VAR1 = {
          'thread' => {
                      'subroutine' => 'forthread',
                      'module' => 'Testit'
                    }
        };
forthread called with argument: '1' at Testit.pm line 11.

##</code><code>##

&{ 'Testit::forthread' }

##</code><code>##

\ &{ 'Testit::forthread' }

##</code><code>##

require $ref->{thread}{module} . '.pm';

my $thread=threads->create(
    do{
        no strict 'refs';
        \ &{
            $ref->{thread}{module} . '::' . $ref->{thread}{subroutine}
        }
    },
    $argument
);

##</code><code>##

require $ref->{thread}{module} . '.pm';

my $subname = $ref->{thread}{module} . '::' . $ref->{thread}{subroutine};

my $thread=threads->create(
    do{ no strict 'refs'; \ &{ $subname } },
    $argument
);