Introduction

Go is known for its built-in support for concurrency, making it a powerful language for writing concurrent programs. In this guide, we'll introduce the concept of Goroutines, one of Go's key features for handling concurrency, and provide sample code to demonstrate their usage.


What Is Concurrency?

Concurrency is the ability of a program to perform multiple tasks simultaneously. It's not the same as parallelism, which involves executing multiple tasks at the exact same time on multiple CPUs or cores. Concurrency in Go is achieved through Goroutines.


Goroutines

Goroutines are lightweight threads managed by the Go runtime. They make it easy to write concurrent code in a clean and efficient way. To create a Goroutine, you prefix a function call with the "go" keyword. Here's an example:

package main
import (
    "fmt"
    "time"
)
func sayHello() {
    for i := 0; i < 5; i++ {
        fmt.Println("Hello")
        time.Sleep(100 * time.Millisecond)
    }
}
func main() {
    go sayHello() // Start a new Goroutine
    for i := 0; i < 5; i++ {
        fmt.Println("World")
        time.Sleep(100 * time.Millisecond)
    }
}

In this code, we create a Goroutine using "go sayHello()" while the main program continues to execute. This results in interleaved "Hello" and "World" messages, showing concurrent execution.


Concurrency Features in Go

Go provides several features for working with Goroutines and managing concurrency effectively:

  • **Channel**: A built-in communication mechanism for synchronizing Goroutines and sharing data.
  • **Select**: A control structure for handling multiple channels and timeouts.
  • **Wait Groups**: A way to wait for a collection of Goroutines to finish.
  • **Mutex**: A synchronization primitive for protecting shared data in a thread-safe manner.

Further Resources

To continue learning about Go concurrency and Goroutines, consider these resources: