Issues with connection counting

[NicEastvillage]

1) It is possible to make the match start even though not all connections are ready. Steps:

• Start a match with 2 bots (that both need to be started manually),
• Connect the first bot
• Disconnect the first bot (Core still believes it is ready)
• Connect the second bot. Core then spawns the cars and the match starts.

2) It is also possible that the match does not start even though all connections are ready. Steps:

• Start a match with 1 bot which has close_between_matches=False.
• Let the bot connect
• ...
• Match does not start as connections where close_between_matches=False are not counted (assumed to be a match runner client).

[VirxEC]

Case 2 could be labeled as intentional behavior because we say that bots and scripts must close between matches.

[NicEastvillage]

Not quite. It needs to be counted as we should not start the match without it. Only on subsequent matches we don't need to count it (assuming it is a player in the match, but it might not be).

To me, it seems easiest to simply count up whenever a connection we need is ready, and count down if it disconnects. The id reservation system is pretty close to what we need. Maybe we can integrate it here. Connections with close_between_matches=False just need to reattempt to reserve an id when a new match starts, and then we get the expected behaviour.

[VirxEC]

I just don't like the idea of a bot that stays up between matches. Booting/shutting down is super fast in v5 anyways

[NicEastvillage]

I agree. Maybe we should rename the setting to something like orchestrator or observer to indicate that it is intended for match orchestrators. And we could additionally disallow such clients to participate in matches, which solves case 2. However, that may also limit the possibilities of what you can do with the framework.

[VirxEC]

The current system already prevents unintended connections from participating in the match (at least by sending player inputs)

And some "observers" at least would want to close between matches

[NicEastvillage]

The current system already prevents unintended connections from participating in the match

Yes. So the question is whether we want a connection with close_between_matches=False to fall in that category. Currently, they can reserve indexes if they have an agent id and they can send inputs - except that the match will not start because they cannot be counted as a ready connection. So they are somewhere in between.

E.g. we could disallow having a non-empty agent id and close_between_matches=False at the same time to fix that.

[VirxEC]

we could disallow having a non-empty agent id and close_between_matches=False at the same time to fix that.

I like this