S_KEEPALIVEIDLE
#define V_KEEPALIVEIDLE(x) ((x) << S_KEEPALIVEIDLE)
#define G_KEEPALIVEIDLE(x) (((x) >> S_KEEPALIVEIDLE) & M_KEEPALIVEIDLE)
#define V_KEEPALIVEIDLE(x) ((x) << S_KEEPALIVEIDLE)
#define G_KEEPALIVEIDLE(x) (((x) >> S_KEEPALIVEIDLE) & M_KEEPALIVEIDLE)