## 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;