An simple interface and implementation for concurrent queue in go

concurrentqueue.go

// Can be any backing type, even 'interface{}' if desired.
// See stackoverflow.com/q/11403050/3960399 for type conversion instructions.
type IntConcurrentQueue interface {
	// Inserts the int into the queue
	Enqueue(int)
	// Will return error if there is nothing in the queue or if Close() was already called
	DequeueNonBlocking() (int, error)
	// Will block until there is a value in the queue to return.
	// Will error if Close() was already called.
	DequeueBlocking() (int, error)
	// Close should be called with defer after initializing
	Close()
}

func GetIntConcurrentQueue() IntConcurrentQueue {
	return &intChannelQueue{c: make(chan int)}
}

type intChannelQueue struct {
	c chan int
}

func (q *intChannelQueue) Enqueue(i int) {
	q.c <- i
}

func (q *intChannelQueue) DequeueNonBlocking() (int, error) {
	select {
	case i, ok := <-q.c:
		if ok {
			return i, nil
		} else {
			return 0, fmt.Errorf("queue was closed")
		}
	default:
		return 0, fmt.Errorf("queue has no value")
	}
}

func (q *intChannelQueue) DequeueBlocking() (int, error) {
	i, ok := <-q.c
	if ok {
		return i, nil
	}
	return 0, fmt.Errorf("queue was closed")
}

func (q *intChannelQueue) Close() {
	close(q.c)
}