Using PQsocketPoll() for PIPELINE mode

Hi. I've now used successfully the new PQsocketPoll() API
in the context of waiting for notifications, using beta2 and 3.

But now I'm looking into using it in the context of PIPELINE mode.
Where I suppose both forRead and forWrite are 1, but the return
code only indicates whether the condition is met. The doc says nothing
about OR or AND semantic, when both forRead and forWrite are true.

Perhaps it's deemed obvious from the use of select() or poll()?
Or is one supposed to call it once with forRead=forWrite=1 and
a timeout, then call it again twice with just one forFlag set and
a 0 timeout, to know the "details" about which "side" is ready?

Or hasn't this use case been considered for PQsocketPoll(),
and thus the current return code isn't has precise as it could be?

Thanks for any precisions, --DD