rust-async-patterns

★ 37,559

by wshobson · part of wshobson/agents

Master Rust async programming with Tokio, async traits, error handling, and concurrent patterns. Use when building async Rust applications, implementing concurrent systems, or debugging async code.

🧩 One of 7 skills in the wshobson/agents package — works on its own, and pairs well with its siblings.

This is the playbook your agent receives when the skill activates — you don't need to read it to use the skill, but it's here to audit before installing.

Rust Async Patterns

Production patterns for async Rust programming with Tokio runtime, including tasks, channels, streams, and error handling.

When to Use This Skill

Building async Rust applications
Implementing concurrent network services
Using Tokio for async I/O
Handling async errors properly
Debugging async code issues
Optimizing async performance

Core Concepts

1. Async Execution Model

Future (lazy) → poll() → Ready(value) | Pending
                ↑           ↓
              Waker ← Runtime schedules

2. Key Abstractions

Concept	Purpose
`Future`	Lazy computation that may complete later
`async fn`	Function returning impl Future
`await`	Suspend until future completes
`Task`	Spawned future running concurrently
`Runtime`	Executor that polls futures

Detailed patterns and worked examples

Detailed pattern documentation lives in references/details.md. Read that file when the navigation tier above is insufficient.

Best Practices

Do's

Use tokio::select! - For racing futures
Prefer channels - Over shared state when possible
Use JoinSet - For managing multiple tasks
Instrument with tracing - For debugging async code
Handle cancellation - Check CancellationToken

Don'ts

Don't block - Never use std::thread::sleep in async
Don't hold locks across awaits - Causes deadlocks
Don't spawn unboundedly - Use semaphores for limits
Don't ignore errors - Propagate with ? or log
Don't forget Send bounds - For spawned futures

Copy & paste — that's it

npx skills add https://github.com/wshobson/agents --skill rust-async-patterns

Run this in your project — your agent picks the skill up automatically.

Quick Start

# Cargo.toml
[dependencies]
tokio = { version = "1", features = ["full"] }
futures = "0.3"
async-trait = "0.1"
anyhow = "1.0"
tracing = "0.1"
tracing-subscriber = "0.3"

use tokio::time::{sleep, Duration};
use anyhow::Result;

#[tokio::main]
async fn main() -> Result<()> {
    // Initialize tracing
    tracing_subscriber::fmt::init();

    // Async operations
    let result = fetch_data("https://api.example.com").await?;
    println!("Got: {}", result);

    Ok(())
}

async fn fetch_data(url: &str) -> Result<String> {
    // Simulated async operation
    sleep(Duration::from_millis(100)).await;
    Ok(format!("Data from {}", url))
}