IC_BUFFER_WAITER
sc->ic_flags |= IC_BUFFER_WAITER;
sc->ic_flags &= ~IC_BUFFER_WAITER;
if ((sc->ic_flags & (IC_BUFFERS_BUSY | IC_BUFFER_WAITER)) ==
IC_BUFFER_WAITER)
if ((sc->ic_flags & (IC_BUFFERS_BUSY | IC_BUFFER_WAITER)) ==
IC_BUFFER_WAITER)