Method close

net/kernel_socket.cpp:141–147

        return (Object*) (uint64_t) fd;
    }
    int close() final {
        if (fd < 0) return 0;
        get_vcpu()->master_event_engine->wait_for_fd(fd, 0, -1UL);
        auto ret = ::close(fd);
        fd = -1;
        return ret;
    }
    int getsockname(EndPoint& addr) override {
        return get_socket_name(fd, addr);
    }