What is the difference between Go's goroutines and threads for concurrent and parallel programming in Go programs?

Table of Contents

• Introduction
• Goroutines in Go
  • • Characteristics of Goroutines
    • Example of a Goroutine
• Threads in Traditional Programming
  • • Characteristics of Threads
• Key Differences: Goroutines vs Threads
• Parallelism vs Concurrency in Go
• Conclusion

Introduction

Go provides efficient concurrency handling through goroutines, which are lightweight and managed by the Go runtime. Unlike traditional threads, goroutines allow high-performance, scalable applications with minimal overhead.

Goroutines in Go

Goroutines are functions that run independently and concurrently, managed by the Go runtime.

Characteristics of Goroutines

• Extremely lightweight (uses a few KB of memory).
• Created using the go keyword before a function call.
• Efficiently scheduled by Go's runtime scheduler.
• Can run thousands or even millions in a single program.

Example of a Goroutine

Output:

Threads in Traditional Programming

Threads are system-level execution units managed by the OS kernel.

Characteristics of Threads

• Have a significant memory overhead (~1MB per thread).
• Managed by the operating system.
• More expensive in terms of context switching and resource usage.
• Number of threads is limited by system resources.

Key Differences: Goroutines vs Threads

Feature	Goroutines	Threads (OS-Level)
Memory Usage	Few KB per goroutine	~1MB per thread
Creation Cost	Very low (Go runtime)	High (OS-level)
Scheduling	Handled by Go runtime	Handled by OS scheduler
Concurrency	Supports thousands easily	Limited by system resources
Context Switching	Fast (M:N scheduling)	Slow (1:1 scheduling)
Performance	Highly efficient	Higher overhead

Parallelism vs Concurrency in Go

• Concurrency: Multiple tasks make progress without necessarily running at the same time.
• Parallelism: Multiple tasks run simultaneously on multiple CPU cores.

Goroutines enable concurrency. For parallelism, Go uses GOMAXPROCS to control the number of OS threads used.

Conclusion

Goroutines provide a more efficient alternative to OS threads in Go. They are lightweight, scalable, and managed by the Go runtime, making them ideal for concurrent programming. Threads, on the other hand, are heavyweight and managed by the OS, leading to higher resource consumption.