package test;
 
require Exporter;
                               
our @ISA        =qw(Exporter);
our @EXPORT     =qw(queuereader); ## You are exporting "queuereader"
our @VERSION    =1.0;
 
sub forthread{          ## Not the forthread function that is in the file!
        my ($arg)=@_;
        return 0;
} #forthread

## You have no module termination value,
1;

##</code><code>##

use threads;
use test;
 
my $argument=1;
##                          VVVVVVVVVV---- this is not a function reference, its a string! 
my $thread=threads->create("forthread", ($argument));
$thread->join();
exit(0);

##</code><code>##

## test.pl
use threads;
use Testit;

my $argument=1;

my $thread=threads->create( 'forthread', ($argument));
$thread->join();
exit(0);

## Testit.pm
package Testit;

require Exporter;

our @ISA        =qw(Exporter);
our @EXPORT     =qw(forthread);
our @VERSION    =1.0;

sub forthread{
        my ($arg)=@_;
        warn "$arg";
        return 0;
}

1;

##</code><code>##

C:\test>test.pl
1 at Testit.pm line 11.
Attempt to free unreferenced scalar: SV 0x194aa50, Perl interpreter: 0x18290c4 during global destruction.

##</code><code>##

use threads;
use Testit;

my $argument=1;

my $thread=threads->create( \&forthread, ($argument));
$thread->join();
exit(0);

__END__
C:\test>test.pl
1 at Testit.pm line 11.