Limited wait group in Go (Golang)

limited_wait_group.go

type LimitedWaitGroup struct {
	limit     int
	count     int
	countChan chan int
}

func NewLimitedWaitGroup(limit int) *LimitedWaitGroup {
	wg := LimitedWaitGroup{limit: limit}
	wg.countChan = make(chan int)
	return &wg
}

func (wg *LimitedWaitGroup) Add(delta int) {
	if delta > wg.limit {
		panic("delta higher then limit")
	}
	if wg.count+delta > wg.limit {
		for <-wg.countChan+delta > wg.limit {
		}
	}
	wg.count += delta
}

func (wg *LimitedWaitGroup) Done() {
	wg.count--
	wg.countChan <- wg.count
}

func (wg *LimitedWaitGroup) Wait() {
	for <-wg.countChan > 0 {
	}
	close(wg.countChan)
}