Какова роль и назначение структуры WaitGroup при разработке на Go?

In Go, the WaitGroup structure is used for synchronizing multiple goroutines. It allows the main goroutine to wait for the completion of a group of other goroutines.

Main methods:

• Add(int): increases the counter of expected goroutines.
• Done(): decreases the counter by 1, called upon goroutine completion.
• Wait(): blocks execution until the counter reaches 0.

Example of usage:

var wg sync.WaitGroup
wg.Add(2) // expecting 2 goroutines

go func() {
    defer wg.Done()
    // goroutine 1 work
}()

go func() {
    defer wg.Done()
    // goroutine 2 work
}()

wg.Wait() // wait for both goroutines to finish

Thus, WaitGroup helps to correctly manage parallel execution and wait for task completion.