Week 13: Advanced Memory Management (Advanced)

Overview

Week 13 begins the advanced phase of the Rust learning journey, focusing on sophisticated memory management techniques. You’ll explore allocators, advanced smart pointer implementations, and complex ownership patterns that push the boundaries of Rust’s memory model while maintaining safety.

Day 1-2: The Allocator Interface

Topics

• Global allocator and the GlobalAlloc trait
• std::alloc module in depth
• Custom allocator implementations
• Allocator API and alignment requirements
• Layout calculations and optimizations
• Porting allocators from C/C++
• Using existing allocator libraries:
  • bumpalo
  • mimalloc
  • jemalloc
• Measuring allocator performance

Resources

• Rust Allocator Documentation
• Global Allocator API
• Custom Allocators in Rust
• Bumpalo Documentation
• Using jemalloc with Rust

Use Cases

• High-performance applications needing custom memory management
• Embedded systems with specialized allocation needs
• Gamedev with frame-based allocation strategies
• Memory-constrained environments
• Performance-critical applications

Day 3-4: Smart Pointers Deep Dive

Topics

• Implementing custom smart pointers
• Interior mutability patterns
• Shared ownership with Rc<T> and Arc<T>:
  • Implementation details
  • Memory layout
  • Reference counting mechanics
• Handling weak references with Weak<T>
• Breaking reference cycles
• Custom Deref and DerefMut implementations
• Smart pointer ergonomics and optimizations
• GC-like patterns in Rust

Resources

• Smart Pointers in Rust Book
• Arc/Rc Implementation Details
• Understanding Deref Coercion
• Interior Mutability in Rust
• Crust of Rust: Smart Pointers and Interior Mutability

Use Cases

• Building complex data structures (graphs, trees)
• Caching systems with weak references
• Reference-counted resource management
• Shared state in concurrent applications
• Custom containers with specific memory characteristics

Day 5-7: Advanced Ownership Patterns

Topics

• Self-referential structures:
  • Challenges and approaches
  • Using the Pin API
  • std::pin module in depth
• Ghost types and phantom data
• Borrowed and owned handles
• The Cow<T> (Clone on Write) pattern
• Arena allocation patterns:
  • Using crates like typed-arena
  • Region-based memory management
• Ownership in non-lexical contexts
• The ouroboros crate for safe self-referential types
• Working with uninitialized memory safely
• Advanced lifetime management

Resources

• Pin API documentation
• Pin and Suffering
• Self-referential Structs
• Ouroboros crate documentation
• Arena allocation in Rust
• Cow documentation

Use Cases

• Creating async state machines
• Building self-referential data structures
• Managing complex object graphs
• Zero-copy deserialization
• High-performance data processing
• Memory-efficient data manipulation

Exercises

1. Implement a custom allocator that tracks memory usage
2. Create a self-referential struct using the Pin API
3. Build a simple reference-counting smart pointer
4. Implement a memory pool/arena for object allocation
5. Create a data structure that uses Cow<T> for efficient cloning
6. Benchmark different allocator implementations for a specific use case

Advanced Challenges

1. Implement a slab allocator for fixed-size objects
2. Create a safe abstraction for a self-referential structure without external crates
3. Build a custom Rc<T> implementation with different trade-offs
4. Design a memory-efficient graph data structure
5. Implement a custom allocator that works in no_std environments

Next Steps

After completing Week 13, you’ll have a deep understanding of Rust’s memory management capabilities. Week 14 will build on this knowledge by exploring unsafe Rust and the foundational abstractions that make it safe.