Without this, the Follower would see data for subchannel 0 before it had a
chance to create the SubChannel object that could accept it. We already have
a mechanism for inbound data to be queued inside the SubChannel until the
endpoint has had a chance to create the Protocol object: we rely on that
mechanism here. We just need to create the SubChannel before telling the
Manager to start, even though we don't reveal the SubChannel to the
caller (via the control endpoint) until the connection is known to succeed.
This helps a manual test get data from one side to the other without throwing
exceptions.
When the follower's connection is accepted, they'll observe a single
dataReceived chunk containing both the leader's KCM and the leader's first
actual data record. The state machine considers the KCM for an eventual-turn
before selecting the connection, so the data record will arrive while the
connection isn't quite ready for it (if consider() were immediate, this
wouldn't be a problem, but Automat doesn't deal with reentrant calls very
well). So we queue any records that arrive before we're selected.
If we had multiple potential connections, the act of cancelling the losing
ones was putting an error into log.err(), which flunked the tests. This
happened to appear on windows because the appveyor environment has different
interfaces than travis hosts.
Dilator.stop() now shuts everything down, and returns a Deferred when it all
stops moving. This needed some Manager state machine changes (to notify
Dilator when it enters the STOPPED state). This also revealed problems in the
delivery of connector_connection_made() (which was misnamed) and
connector_connection_lost() (which wasn't being called at all).
This is only used by tests so far (and will simplify the integration test
that hasn't landed yet), but is not yet wired up to Boss, so there's no way
for applications to enable it yet.
I mistakenly believed that Noise handshakes are simultaneous. In fact, the
Responder waits until it sees the Initiator's handshake before sending its
own. I had to update the Connection state machines to work this way (the
Record machine now has set_role_leader and set_role_follower), and update the
tests to match.
For debugging I added a `_role` property to Record, but it should probably be
removed.
only install 'noiseprotocol' (which is necessary for dilation to work) if the
"dilate" feature is requested (e.g. `pip install magic-wormhole[dilate]`)
