Move a socket to a different thread?

[psy0rz]

I'm building a whiteboard that updates cursors and drawings in realtime, (as in 60fps), that should support 100s of "whiteboards" with 100s of clients at the same time. (demo at https://draw.cafe )

Since this amounts to lots of websocket messages/s, i'm trying to be efficient as possible:

• Let the javascript client do most of the work
• Use zero-copy flatbuffers to send messages to multiple clients.
• Bundle multiple events into a single websocket message.

Currently i'm using threading to support multiple CPU cores, and a separate IO and update thread. However i think the mutexes/atomics are generating too much overhead and are making things too complex.

So singlethreaded-async-everything should be much better for per-core efficiency and reduced complexity. (As has Alex advised in his documentation.)

Would it be possible to move a websocket to a different thread? This way i can have multiple independent threads, and move a client to the correct thread. (e.g. the thread that has the shared session in which a whiteboard exists)

So basically:

1. Client connects websocket and is assigned to a random thread. (this is how uwebsockets operates when using multiple threads)
2. Client creates a new shared session. (a "drawing")
3. Second client connects and is assigned to a different random thread.
4. Client wants to join shared session, but cant since its in a different thread.
5. Client socket is moved to the correct thread and can join the session.

(Off course step 4 and 5 would need some locking but since this occurs one time, the overhead doesn't matter.)

Is step 5 possible somehow?

Different ideas to solve this are welcome off course.

Edwin