ring_cond.go

func (r *ring) EnqueueRequest(req request) chan response {
	s := &r.slots[atomic.AddUint64(&r.write, 1)&mask]
	s.cond.L.Lock()
	for s.mark != 0 {
		s.cond.Wait()
	}
	s.req = req
	s.mark = 1
	s.cond.L.Unlock()
	return s.ch
}

func (r *ring) NextRequestToSend() (req request, ok bool) {
	r.read1++
	s := &r.slots[r.read1&mask]
	s.cond.L.Lock()
	if ok = s.mark == 1; ok {
		s.mark = 2
		req = s.req
	} else {
		r.read1--
	}
	s.cond.L.Unlock()
	return
}

func (r *ring) ReplyToNextRequest(resp response) {
	r.read2++
	s := &r.slots[r.read2&mask]
	s.cond.L.Lock()
	if s.mark == 2 {
		s.mark = 0
		s.ch <- resp
	} else {
		panic("out-of-band response should not be passed in")
	}
	s.cond.L.Unlock()
	s.cond.Signal()
}