smol

A small and fast async runtime.

This crate simply re-exports other smaller async crates (see the source).

To use tokio-based libraries with smol, apply the async-compat adapter to futures and I/O types.

Examples

Connect to an HTTP website, make a GET request, and pipe the response to the standard output:

use smol::{io, net, prelude::*, Unblock};

fn main() -> io::Result<()> {
    smol::block_on(async {
        let mut stream = net::TcpStream::connect("example.com:80").await?;
        let req = b"GET / HTTP/1.1\r\nHost: example.com\r\nConnection: close\r\n\r\n";
        stream.write_all(req).await?;

        let mut stdout = Unblock::new(std::io::stdout());
        io::copy(stream, &mut stdout).await?;
        Ok(())
    })
}

There's a lot more in the examples directory.

Subcrates

• async-channel - Multi-producer multi-consumer channels
• async-executor - Composable async executors
• async-fs - Async filesystem primitives
• async-io - Async adapter for I/O types, also timers
• async-lock - Async locks (barrier, mutex, reader-writer lock, semaphore)
• async-net - Async networking primitives (TCP/UDP/Unix)
• async-process - Async interface for working with processes
• async-task - Task abstraction for building executors
• blocking - A thread pool for blocking I/O
• futures-lite - A lighter fork of futures
• polling - Portable interface to epoll, kqueue, event ports, and wepoll

TLS certificate

Some code examples are using TLS for authentication. The repository contains a self-signed certificate usable for testing, but it should not be used for real-world scenarios. Browsers and tools like curl will show this certificate as insecure.

In browsers, accept the security prompt or use curl -k on the command line to bypass security warnings.

The certificate file was generated using minica and openssl:

minica --domains localhost -ip-addresses 127.0.0.1 -ca-cert certificate.pem
openssl pkcs12 -export -out identity.pfx -inkey localhost/key.pem -in localhost/cert.pem

Another useful tool for making certificates is mkcert.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.