 type PollServer struct {
-       cr, cw *chan *FD;       // buffered >= 1
+       cr, cw chan *FD;        // buffered >= 1
        pr, pw *os.FD;
-       pending *map[int64] *FD;
+       pending map[int64] *FD;
        poll *Pollster; // low-level OS hooks
 }