// Len returns the length of the queue.
Len returns the length of the queue.
// Len returns the length of the queue .
func (fifo *FIFO) Len() int {
	fifo.mu.Lock()
	defer fifo.mu.Unlock()
	return fifo.length
}
func ( fifo * FIFO ) Len ( ) int { fifo . mu . Lock ( ) defer fifo . mu . Unlock ( ) return fifo . length }
Len returns the length of the queue.
Len returns the length of the queue .