ASYNC_CARR_ON
async->async_flags |= ASYNC_CARR_ON;
async->async_flags &= ~ASYNC_CARR_ON;
if ((!(async->async_flags & (ASYNC_CARR_ON|ASYNC_OUT)) &&
if ((async->async_flags & ASYNC_CARR_ON) != 0)
async->async_flags |= ASYNC_CARR_ON;
if ((async->async_flags & ASYNC_CARR_ON) == 0)
async->async_flags &= ~ASYNC_CARR_ON;
async->async_flags |= ASYNC_CARR_ON;
async->async_flags &= ~ASYNC_CARR_ON;
if (!(async->async_flags & (ASYNC_CARR_ON|ASYNC_OUT)) ||
if ((async->async_flags & ASYNC_CARR_ON) == 0) {
async->async_flags |= ASYNC_CARR_ON;
if ((async->async_flags & ASYNC_CARR_ON) &&
async->async_flags &= ~ASYNC_CARR_ON;