use MCE::Hobo;
use MCE::Shared;
...
tie my $data_in, 'MCE::Shared', 0;
tie my $data_ret, 'MCE::Shared', '----';
tie my $button_control, 'MCE::Shared', 0;
tie my $go_control, 'MCE::Shared', 0;
tie my $die_control, 'MCE::Shared', 0;
...
my $thr = MCE::Hobo->create( \&worker );
...