Milleks kasutatakse WaitGroupi Go-s?

WaitGroup is used to synchronize the work of one or more goroutines. It allows the main goroutine to wait for the completion of other created goroutines. It consists of a counter that increases when a goroutine is created and decreases when it finishes.

Main methods:

• Add(delta int): Increases or decreases the goroutine counter.
• Done(): Decreases the counter by 1. Usually called at the end of a goroutine (often with defer).
• Wait(): Blocks execution until the counter reaches zero.

Example usage:

package main

import (
	"fmt"
	"sync"
)

func worker(id int, wg *sync.WaitGroup) {
	defer wg.Done() // Decreases the counter when goroutine finishes

	fmt.Printf("Goroutine %d starts\n", id)
	// Simulate work
	// time.Sleep(time.Second)
	fmt.Printf("Goroutine %d ends\n", id)
}

func main() {
	var wg sync.WaitGroup // Create a WaitGroup

	for i := 1; i <= 5; i++ {
		wg.Add(1) // Increment counter for each goroutine
		go worker(i, &wg) // Start goroutine, passing pointer to WaitGroup
	}

	wg.Wait() // Wait until counter is zero (all goroutines finish)
	fmt.Println("All goroutines completed")
}