I am considering authoring a webserver (think nginx, apache, cowboy, etc) in Rust. From a user point of view, mapping tasks (green) to web requests makes the most sense as the tasks could be long running, perform their own I/O, sessions, or what have you. It would also allow the user to do per-request in memory caching.
My main concern is obviously the cooperative scheduler. Given that the mantra of Rust seems to be safety, I'm curious about how feasible it would be to provide the option for task safety as well. Preemptive scheduling provides two things: 1. If preemption is used aggressively, the user can opt for a lower latency system (a la Erlang style round robin preemptive scheduling) 2. Preemption of any sort can be used as a safety net to isolate bugs or blocks in tasks for long running systems, or at least mitigate damage until the developer intervenes. I noticed in issue 5731[1] on the repo, it was pointed out that this was possible, albeit difficult. The issue was closed with a comment that the user should use OS threads instead. I really think this misses the point as it no longer allows preemption on a smaller granularity scale. Could any devs chime in on the scope and difficulty of this project? Could any users/devs chime in on any of the points above? tl;dr I think preemptive scheduling is a must for safe concurrency in long running executables at the bottom of the stack. Opinions? [1] https://github.com/mozilla/rust/issues/5731 _______________________________________________ Rust-dev mailing list Rust-dev@mozilla.org https://mail.mozilla.org/listinfo/rust-dev
