if (!$queue->lock($mach, $jid)) {
print "### Skipping locked $jid on $mach ###\n";
update_status($mach, $jid, 'LOCKED', undef);
if (!$queue->lock($mach, $jid)) {
print "### Skipping locked $jid on $mach ###\n";
update_status($mach, $jid, 'LOCKED', undef);