Crate async_rs 

A Rust async runtime abstraction library.

Provides a unified Runtime enum and a set of traits (Executor, Reactor, Dns, …) that abstract over Tokio, smol, and async-global-executor. Applications select exactly one runtime via feature flags; library crates depend on the trait objects and remain runtime-agnostic.

Feature flags

Flag	Notes
tokio (default)	Tokio runtime
smol	smol executor
async-global-executor	async-global-executor
async-io	async-io reactor (required by smol)
hickory-dns	Hickory DNS resolver (tokio only)

Example

use async_rs::{Runtime, TokioRuntime, traits::*};
use std::{io, time::Duration};

async fn get_a(rt: &TokioRuntime) -> io::Result<u32> {
    rt.spawn_blocking(|| Ok(12)).await
}

async fn get_b(rt: &TokioRuntime) -> io::Result<u32> {
    rt.spawn(async { Ok(30) }).await
}

async fn tokio_main(rt: &TokioRuntime) -> io::Result<()> {
    let a = get_a(rt).await?;
    let b = get_b(rt).await?;
    rt.sleep(Duration::from_millis(500)).await;
    assert_eq!(a + b, 42);
    Ok(())
}

fn main() -> io::Result<()> {
    let rt = Runtime::tokio()?;
    rt.block_on(tokio_main(&rt))
}

Modules

traits

A collection of traits to define a common interface across async runtimes

util

A collection of utilities to deal with IO, futures and runtimes

Structs

AsyncGlobalExecutor

Dummy object implementing executor common interfaces on top of async-global-executor

AsyncIO

Dummy object implementing reactor common interfaces on top of async-io

HickoryToSocketAddrs

Perform async DNS resolution using hickory-dns

Noop

A no-op RuntimeKit implementation that never actually executes tasks or I/O

Runtime

A full-featured async runtime that combines an executor and a reactor.

Smol

The RuntimeKit implementation backed by the smol async runtime

Tokio

The RuntimeKit implementation backed by the tokio async runtime

Type Aliases

AGERuntime

Type alias for the async-global-executor runtime

NoopRuntime

Type alias for the noop runtime

SmolRuntime

Type alias for the smol runtime

TokioRuntime

Type alias for the tokio runtime