my ($cnf,$thread) = @_;
    if ($thread && !$db_connections{$cnf}{$thread}) {
        my $control = "dbh".$cnf.$thread;
        #  ^^^^^^^^
        $$control = DBI->connect(
        #^^^^^^^^
            "dbi:Pg:database=dirotext;host=domain.com", 'user', 'pass' 
        ) or die $DBI::errstr;

##</code><code>##

sub dbconn() {
    my ($cnf,$thread) = @_;


##</code><code>##

my %response_hash = ();
...
return \%response_hash;
...
my %tr_res = %{$running_threads{$name}->join()};

##</code><code>##

my %response_hash; ## No need to initialise lexicals.
...
return %response_hash; ## Return a simple list of values
...
my %tr_res = $running_threads{$name}->join(); ## Assign the list to a local hash.

##</code><code>##

            $running_threads{$threadname} = threads->create(\&send_sms_message, $db_ids_in_progress{$id}{'uid'}, $db_ids_in_progress{$id}{'from'}, $db_ids_in_progress{$id}{'to'}, $db_ids_in_progress{$id}{'msg'}, $id, $db_ids_in_progress{$id}{'dlr_track_id'}, $processing);

##</code><code>##

( $running_threads{$threadname} ) = threads->create(
    \&send_sms_message, 
    $db_ids_in_progress{$id}{'uid'}, 
    $db_ids_in_progress{$id}{'from'}, 
    $db_ids_in_progress{$id}{'to'}, 
    $db_ids_in_progress{$id}{'msg'}, 
    $id, 
    $db_ids_in_progress{$id}{'dlr_track_id'}, 
    $processing
);