Go Coding Practice Repository

A comprehensive guide to Go programming with deep dives into concurrency concepts and system design patterns.

Repository Structure

├── concepts/                          # Core Go concepts
│   ├── 01-goroutines-concurrency/    # Goroutine lifecycle, scheduling, patterns
│   ├── 02-channels/                  # Buffered/unbuffered, select, deadlocks
│   ├── 03-synchronization/           # Mutex, RWMutex, sync.Once, WaitGroup
│   ├── 04-context/                   # Context, cancellation, deadlines
│   ├── 05-memory-management/         # Stack vs heap, escape analysis, GC
│   ├── 06-interfaces/                # Implicit implementation, segregation
│   └── 07-error-handling/            # Error wrapping, custom types, recovery
│
└── designs/                          # System design patterns
    ├── 01-high-throughput-api/       # Buffered channels, worker pool
    ├── 02-worker-pool/               # Task distribution, backpressure
    ├── 03-rate-limiter/              # Token bucket, sliding window, leaky bucket
    ├── 04-circuit-breaker/           # State machine, failure handling
    └── 05-cache-with-ttl/            # TTL expiration, thread safety

Concepts Covered

Goroutines & Concurrency

• Goroutine lifecycle and scheduling (GMP model)
• Blocking vs non-blocking operations
• Fan-in and Fan-out patterns

Channels

• Buffered vs unbuffered channels
• Channel closing rules
• Select statement for multiplexing
• Deadlock and starvation detection

Synchronization

• sync.Mutex for mutual exclusion
• sync.RWMutex for read-write separation
• sync.WaitGroup for goroutine coordination
• sync.Once for one-time initialization

Context Package (Very Important!)

• context.Background vs TODO
• Cancellation propagation
• Deadlines and timeouts
• Context values
• Avoiding context misuse patterns

Memory Management

• Stack vs heap allocation
• Escape analysis
• Garbage collector behavior
• Reducing GC pressure techniques

Interfaces

• Implicit interface implementation
• Interface segregation principle
• Empty interface vs generics
• Design-focused patterns

Error Handling

• Error wrapping with context preservation
• Sentinel errors
• Custom error types
• Panic and recover
• Multiple return values pattern

Design Patterns

1. High-Throughput API

Use Case: Handling many concurrent requests efficiently

Key Concepts:

• Buffered request channels
• Worker pool pattern
• Non-blocking statistics
• Request batching

2. Worker Pool

Use Case: Controlling resource consumption, limiting concurrency

Key Concepts:

• Fixed worker count
• Task queue management
• Result collection
• Graceful shutdown

3. Rate Limiter

Use Case: Controlling request rate, preventing system overload

Algorithms:

• Token Bucket: Allows burst with refill rate
• Sliding Window: Strict rate limiting with memory
• Leaky Bucket: Smooth output rate

4. Circuit Breaker

Use Case: Preventing cascading failures, graceful degradation

States:

• CLOSED: Normal operation
• OPEN: Fail fast
• HALF_OPEN: Testing recovery

5. Cache with TTL

Use Case: Reducing database load, improving response time

Features:

• Automatic expiration
• Manual eviction
• Cleanup goroutine
• Thread-safe access

Getting Started

Prerequisites

• Go 1.18 or higher (for generics examples)
• Basic understanding of goroutines and channels

Running Examples

Each concept and design folder has:

• basics.go or implementation file with code examples
• README.md with detailed explanations
• Runnable examples in the code

Compilation and Execution

# Check for compilation errors
go build ./...

# Run all tests
go test ./...

# Run specific package tests
go test ./concepts/01-goroutines-concurrency -v

Learning Path

Recommended Order

1. Start with Concepts: Understand fundamentals before patterns

   • Goroutines & Concurrency → Channels → Synchronization
   • Context Package → Memory Management
   • Interfaces → Error Handling

2. Progress to Designs: Apply concepts to real-world patterns

   • Worker Pool (uses goroutines + channels)
   • Rate Limiter (uses time + state management)
   • Circuit Breaker (uses state machine + sync)
   • Cache with TTL (uses goroutines + time)
   • High-Throughput API (combines all)

Exercises

Each folder includes exercises to reinforce learning:

• Concepts: Deep dives into each topic
• Designs: Real-world implementation challenges

Key Takeaways

Concurrency Best Practices

1. Don't share memory by communicating; share communication by memory
2. Context for cancellation, not configuration
3. Use channels for synchronization, sync.Mutex for shared state
4. Always pass context as first parameter
5. Handle errors explicitly

Design Patterns

1. Worker pools limit resource consumption
2. Rate limiting prevents system overload
3. Circuit breakers prevent cascading failures
4. Caching reduces latency and load
5. Separation of concerns (input, processing, output channels)

Performance Optimization

1. Pre-allocate slices with known capacity
2. Use buffered channels appropriately
3. Reduce GC pressure with object pooling
4. Profile before optimizing
5. Consider trade-offs (memory vs CPU, latency vs throughput)

Resources

• Effective Go
• Concurrency in Go
• Context Package
• sync Package Documentation

Notes

• All code examples are production-ready patterns
• Error handling is included in examples
• Thread safety is considered throughout
• Comments explain non-obvious implementation details

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Happy learning and coding in Go! 🚀