+ /* + * Only signal regular backends, since those need to notify + * their clients using a GoAway message. + */ + if (bp->bkend_type == B_BACKEND)
This condition is slightly different to how SignalChildren works, is that intentional? I don't think it causes any practical difference, and I don't see an easy way to reuse SignalChildren for this, but maybe it could still follow the same pattern. Otherwise I don't see any other issues, and this also doesn't seem to be an important comment. Since the pytest framework seems unlikely to be included in PG19, have you considered a different test implementation, to have at least some minimal coverage?
