// Transport is tracking conns-per-host.
		// Increment connection count to account
		// for new persistConn created below.
		t.connsPerHostMu.Lock()
		if t.connsPerHost == nil {
			t.connsPerHost = make(map[connectMethodKey]int)
		}
		t.connsPerHost[key]++
		t.connsPerHostMu.Unlock()
	}

	return t.tryPutIdleConn(&persistConn{
		t:        t,
		conn:     c,                   // dummy

	defer t.connsPerHostMu.Unlock()

	if t.MaxConnsPerHost <= 0 {
		t.startDialConnForLocked(w)
		return
	}

	if n := t.connsPerHost[w.key]; n < t.MaxConnsPerHost {
		if t.connsPerHost == nil {
			t.connsPerHost = make(map[connectMethodKey]int)
		}
		t.connsPerHost[w.key] = n + 1
		t.startDialConnForLocked(w)
		return
	}

	if t.connsPerHostWait == nil {