edd922d6d0
`tokio::task` enforces a cooperative scheduling regime that can cause `oneshot::Receiver::poll` to return pending after the sender has sent an update. `ReadyCache` uses a oneshot to notify pending services that they should not become ready. When a cancelation is not observed, the ready cache return service instances that should have been canceled, which breaks assumptions and causes an invalid state. This branch replaces the use of `tokio::sync::oneshot` for canceling pending futures with a custom cancelation handle using an `AtomicBool` and `futures::task::AtomicWaker`. This ensures that canceled `Pending` services are always woken even when the task's budget is exceeded. Additionally, cancelation status is now always known to the `Pending` future, by checking the `AtomicBool` immediately on polls, even in cases where the canceled `Pending` future was woken by the inner `Service` becoming ready, rather than by the cancelation. Fixes #415 Signed-off-by: Oliver Gould <ver@buoyant.io> Co-authored-by: Eliza Weisman <eliza@buoyant.io>
Tower
Tower is a library of modular and reusable components for building robust networking clients and servers.
Overview
Tower aims to make it as easy as possible to build robust networking clients and servers. It is protocol agnostic, but is designed around a request / response pattern. If your protocol is entirely stream based, Tower may not be a good fit.
Supported Rust Versions
Tower will keep a rolling MSRV (minimum supported Rust version) policy of at least 6 months. When increasing the MSRV, the new Rust version must have been released at least six months ago. The current MSRV is 1.49.0.
Getting Started
If you're brand new to Tower and want to start with the basics we recommend you check out some of our guides.
License
This project is licensed under the MIT license.
Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Tower by you, shall be licensed as MIT, without any additional terms or conditions.