Concurrency and Async Programming: async/await, Actors

In this module, we explore Swift's modern concurrency system, including async/await, actors, structured concurrency, and task groups. We'll compare these approaches with JavaScript's Promise-based and callback-based concurrency patterns.

Table of Contents

• Introduction: Concurrency Models
• Async/Await Basics
• Structured Concurrency
• Actors
• Task Groups
• Async Sequences
• Advanced Concurrency
• Exercises
• Key Takeaways

Introduction: Concurrency Models

Swift's modern concurrency system provides a safer and more efficient approach compared to traditional threading and JavaScript's event loop.

Async/Await Basics

Concurrent Execution

Structured Concurrency

Swift's structured concurrency ensures that child tasks are properly managed and cancelled when their parent is cancelled.

Actors

Swift actors provide thread-safe access to mutable state, preventing data races.

Task Groups

Swift task groups allow you to manage multiple concurrent tasks with shared cancellation and error handling.

Async Sequences

Swift async sequences provide a way to iterate over asynchronous data streams.

Advanced Concurrency

Continuations and Callback Integration

Custom Executors

Exercises

Exercise 1: Concurrent Data Processing

Exercise 2: Real-time Data Stream Processing

Key Takeaways

Swift Concurrency Advantages

1. Structured Concurrency: Automatic task lifecycle management
2. Data Race Prevention: Actors provide compile-time safety
3. Cancellation: Built-in cancellation support
4. Performance: Efficient task scheduling and execution
5. Memory Safety: Automatic memory management for concurrent code
6. Integration: Seamless integration with existing code

Key Differences from JavaScript

1. Task Management: Structured vs manual task management
2. Data Safety: Actors vs manual synchronization
3. Cancellation: Automatic vs manual cancellation
4. Performance: Native vs event loop-based execution
5. Memory Safety: Compile-time vs runtime safety
6. Integration: Native vs callback-based integration

Best Practices

1. Use structured concurrency for task management
2. Leverage actors for shared mutable state
3. Implement proper cancellation in long-running tasks
4. Use task groups for concurrent operations
5. Prefer async sequences for data streams
6. Handle errors appropriately in concurrent code

Next Steps

In the next module, we'll explore Swift's memory management and performance optimization techniques, including ARC, value types, and performance profiling, comparing them with JavaScript's garbage collection and optimization strategies.