Thu Jan 16 20:04:02 CET 2020

External receive

This could implement a "pull" network as well.  It's completely
symmetric.  The counterpart read to synchronous send is obvious.

That also means there should be a conterpart to the buffered input,
but this is less obvious.  Maybe it's just a poll of a buffer?  Maybe
execute a network until a buffer is full?

A typical use case is an interrupt that will pick up something from a
buffer.  The interrupt should perform the read and signal the network
to fill the buffer again.

In general it seems something needs to be buffered, but it is not
really clear what.

Both input and output buffering might be necessary due to deadlines,
so a third element (WFI main loop) is actually essential if both need
buffering, otherwise advance the network from input or output