FIX_O_NONBLOCK
flags = FIX_O_NONBLOCK(flags);
flags = FIX_O_NONBLOCK(flags);
flags = FIX_O_NONBLOCK(flags);
flags = FIX_O_NONBLOCK(flags);
flags = FIX_O_NONBLOCK(flags);
flags = FIX_O_NONBLOCK(flags);
flags = FIX_O_NONBLOCK(flags);