Hello.
While I looked around shutdown sequence, pmdie() uses
"BACKEND_TYPE_AUTOVAC | BACKEND_TYPE_BGWORKER" for sending signal
and PostmasterStateMachine counts them using
BACKEND_TYPE_WORKER. It is the only usage of the combined one. It
seems to me just a leftover of da07a1e856.
regards.
--
Kyotaro Horiguchi
NTT Open Source Software Center