How do I use WaitGroups in Go?

How do I use WaitGroups in Go?

WaitGroups in Go are used to wait for a collection of goroutines to finish executing. You can use the sync.WaitGroup type for this.

Can you show me a simple example?

Sure! Here's a basic example:

package main

import (
    "fmt"
    "sync"
)

func main() {
    var wg sync.WaitGroup

    for i := 1; i <= 3; i++ {
        wg.Add(1) // Increment the WaitGroup counter
        go func(i int) {
            defer wg.Done() // Decrement the counter when the goroutine completes
            fmt.Printf("Goroutine %d is running\n", i)
        }(i)
    }

    wg.Wait() // Block until the counter is zero
    fmt.Println("All goroutines finished.")
}

What happens if I forget to call Done()?

If you forget to call Done(), the WaitGroup's counter will never reach zero, and your program will hang indefinitely at the wg.Wait() call.

Are there any best practices for using WaitGroups?

Yes! Always ensure that Done() is called in a deferred manner within the goroutine, and avoid adding to the WaitGroup after starting the goroutine.