size      int
	r         int // next position to read
	w         int // next position to write
	isFull    bool
	err       error
	block     bool
	mu        sync.Mutex
	wg        sync.WaitGroup
	readCond  *sync.Cond // Signaled when data has been read.
	writeCond *sync.Cond // Signaled when data has been written.
}

// New returns a new RingBuffer whose buffer has the given size.
func New(size int) *RingBuffer {