nldsq_next_task
nldsq_next_task(dsq, NULL, false)))
first_task = nldsq_next_task(dsq, NULL, false);
n = nldsq_next_task(donor_dsq, n, false);
n = nldsq_next_task(donor_dsq, n, false);
for ((p) = nldsq_next_task((dsq), NULL, false); (p); \
(p) = nldsq_next_task((dsq), (p), false))
p = nldsq_next_task(kit->dsq, p, rev);