$self->{start_in_progress} = undef;
$self->{gui}->show_semaphore(0);
Glib::Timeout->add($SEMAPHORE_STEP, \&semaphore_step, $self);
$self->{start_in_progress} = undef;
$self->{gui}->show_semaphore(0);
Glib::Timeout->add($SEMAPHORE_STEP, \&semaphore_step, $self);