use 5.16.2;
use threads;
use Thread::Queue;

my @serverList = qw(one two three four five six);

my $serverQueue = Thread::Queue->new( @serverList );
$serverQueue->end;

my @threads = map { threads->new( \&worker ) } 1..4;
$_->join for @threads;

say 'Back to main - Finished!';

sub worker {
    my $tid = threads->tid;
    while ( my $server = $serverQueue->dequeue_nb ) {
        say "I'm thread ID $tid and I'm processing server $server to copy a whole bunch of files";
        sleep 1;
    }
    say "Thread ID $tid finished";
}