My first experience doing a computer system project was building a server using vanilla Java and then a client on an Android phone. Since then, I’ve found that there are a lot of frameworks to help manage scalability and remove the need to write boilerplate code.
I’m trying to understand what services like Tokio and Rayon enable.
I came across this paragraph on the Tokio tutorial page and I’m having a hard time understanding it
When you write your application in an asynchronous manner, you enable it to scale much better by reducing the cost of doing many things at the same time. However, asynchronous Rust code does not run on its own, so you must choose a runtime to execute it.
I first thought a "runtime" might refer to where the binary can run, but it looks like Tokio just provides functions that are already available in the Rust standard library while Rayon implements functions that aren’t in the standard library.
Are the standard implementations for asynchronous functions written poorly in the standard library or am I not understanding what service Tokio is providing?
>Solution :
Rust currently does not provide an async runtime in the standard library. For full details, see Asynchronous Programming in Rust, and particularly the chapter on "The Async Ecosystem."
Rust currently provides only the bare essentials for writing async code. Importantly, executors, tasks, reactors, combinators, and low-level I/O futures and traits are not yet provided in the standard library. In the meantime, community-provided async ecosystems fill in these gaps.
Rust has very strict backward compatibility requirements, and they haven’t chosen to lock-in a specific runtime. There are reasons to pick one over another (features versus size for example), and making it part of the standard library would impose certain choices that aren’t clearly the right ones for all projects. This may change in the future as the community projects better explore this space and help determine the best mix of choices without the strong backward compatibility promises.