Week 10: Async Rust (Intermediate)

Overview

Week 10 explores asynchronous programming in Rust using the async/await syntax. You’ll learn how Rust’s approach to async programming enables highly concurrent, non-blocking code without sacrificing safety or performance. This week forms a critical foundation for modern Rust server-side development.

Day 1-4: Intro to Async/Await

Topics

• Async programming fundamentals:
  • Blocking vs non-blocking I/O
  • Concurrency vs parallelism
  • Event loops and polling
• The Future trait
• Async/await syntax:
  • async fn and async blocks
  • The .await operator
• Understanding zero-cost futures
• Pinning and self-referential structs
• Async lifecycle and state machines
• Cancellation and dropping futures
• Common async patterns:
  • Sequential execution
  • Concurrent execution (join!)
  • Select and race (select!)
• Task spawning and executors
• Async closures (unstable feature)
• Comparing with JavaScript’s Promises and async/await

Resources

• Rust Async Book
• Async Programming in Rust
• Understanding Rust Futures
• Tokio Tutorial: Getting Started
• std::future documentation
• Async in Depth

Use Cases

• Non-blocking I/O operations
• Handling many concurrent connections
• Building responsive UIs
• Creating highly scalable services
• Processing streams of data
• Implementing timeouts and cancellation

Day 5-7: Tokio Runtime and Futures

Topics

• Async runtimes in Rust:
  • Tokio
  • async-std
  • smol
• Tokio runtime features:
  • Multi-threaded scheduler
  • I/O driver
  • Timer system
• tokio::spawn and task management
• Synchronization primitives:
  • Mutex
  • RwLock
  • Semaphore
  • Notify
• Streams and async iterators
• Backpressure handling
• Channel types in Tokio:
  • mpsc
  • oneshot
  • broadcast
  • watch
• Resource management in async code
• Error handling in async contexts
• Testing async code
• Tracing and debugging async workflows
• Performance considerations

Resources

• Tokio Documentation
• Tokio Tutorial
• Streams in Rust
• Async Tracing
• Testing Async Code
• Tokio by Example

Use Cases

• Building high-performance network services
• Creating async APIs and libraries
• Implementing complex concurrent workflows
• Handling real-time data processing
• Building web servers and APIs
• Creating resilient distributed systems

Exercises

1. Convert a synchronous file processing program to use async I/O
2. Build a concurrent TCP server with Tokio
3. Implement a rate-limited API client using async/await
4. Create an async data processing pipeline with backpressure
5. Develop a simple chat server using Tokio channels
6. Implement timeouts and cancellation for async operations

Advanced Challenges

1. Build an async web crawler with concurrent requests
2. Implement a simple HTTP server from scratch using async Rust
3. Create a distributed task processing system with Tokio
4. Develop an async stream processing library
5. Build a real-time notification system using broadcast channels

Next Steps

After completing Week 10, you’ll have a strong foundation in async Rust programming. Week 11 will apply these skills to build a complete command-line application using the Clap library.