Can you change the number of waiting threads in a synchronizing group in Go during program execution?

In Go, the number of goroutines waiting in a sync.WaitGroup can be changed during program execution using the methods Add, Done, and Wait.

• The Add(n int) method increases or decreases the counter of waiting goroutines by n. It can be called multiple times to dynamically change the number of waiters.
• The Done() method is equivalent to Add(-1) and decreases the counter by 1.
• The Wait() method blocks execution until the counter reaches zero.

Important: you cannot call Add with a negative value if the counter is already zero, otherwise a panic will occur.

Example:

var wg sync.WaitGroup

wg.Add(2) // expecting 2 goroutines

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

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

// You can add more waits during execution
wg.Add(1)
go func() {
    defer wg.Done()
    // additional work
}()

wg.Wait() // wait for all to finish

Thus, the number of waiters in WaitGroup can be changed dynamically, as long as Add and Done are used correctly.