Actix Ws does not seem to shutdown worker when websocket route finishes

[soundprojects]

Expected Behavior

When a websocket route that contains some spawned tasks all finish, I expect the worker associated to shut down.

Current Behavior

My websocket route finishes, the spawned tasks finish but only when I shutdown the application do I see a "force shutdown worker, closing x connections" for all the connections that have finished way earlier

Possible Solution

Some pointers on how to diagnose this further

Steps to Reproduce (for bugs)

1. Use the default websocket example
2. Spawn some tasks inside the route
3. Close client
4. Close server -> see how many connections are closed

Context

Your Environment

• Rust version (output of rustc -V): 1.8.2
• actix-* crate versions: actix-ws 0.3.0, actix-web 4.9.0, actix-cors 0.7.0

[robjtede]

Spawned tasks might not be getting updates from a TCP socket that closed silently¹. You have to actually read or write to the socket to figure that out reliably. Thankfully, WebSockets have first-party support for ping/pong, which counts. The websocket examples also show this best practice and include a timeout that shuts down the lingering task if it becomes dormant.

I strongly suspect this is your problem, but if it isn't I'd be happy to look more at a complete reproduction case and re-open this issue.

Footnotes

1. https://github.com/tokio-rs/tokio/issues/3467 ↩