use Gtk3;
my $window = Gtk3::Window->new ('toplevel');
my $button = Gtk3::Button->new ('Quit');
$button->signal_connect (clicked => sub { Gtk3::main_quit });
$window->add ($button);
$window->show_all;
my $id = Gtk3->timeout_add(1000, \&handler, $data);
Gtk3::main;

sub handler {
    my ($data) = @_;
    print "timed out ... \n";
    # return 1 if you want the handler to be called again later
    # return 0 to stop the handler from being called again
    return 1;
}

result: perl test0.pl 
Segmentation fault (core dumped)