class Raindrops::TCP_Info - raindrops-0.19.0 Documentation

# class Raindrops::TCP_Info

This is used to wrap “struct tcp_info” as described in tcp(7) and /usr/include/linux/tcp.h. The following readers methods are defined corresponding to the “tcpi_” fields in the tcp_info struct.

As of raindrops 0.18.0+, this is supported on FreeBSD and OpenBSD systems as well as Linux, although not all fields exist or match the documentation, below.

In particular, the `last_data_recv` field is useful for measuring the amount of time a client spent in the listen queue before +accept()+, but only if `TCP_DEFER_ACCEPT` is used with the listen socket (it is on by default in Unicorn).

- state

- ca_state

- retransmits

- probes

- backoff

- options

- snd_wscale

- rcv_wscale

- rto

- ato

- snd_mss

- rcv_mss

- unacked

- sacked

- lost

- retrans

- fackets

- last_data_sent

- last_ack_sent

- last_data_recv

- last_ack_recv

- pmtu

- rcv_ssthresh

- rtt

- rttvar

- snd_ssthresh

- snd_cwnd

- advmss

- reordering

- rcv_rtt

- rcv_space

- total_retrans

kernel.org/doc/man-pages/online/pages/man7/tcp.7.html

### Public Class Methods

Raindrops::TCP_Info.new(tcp_socket) → TCP_Info object click to toggle source

Reads a TCP_Info object from any given `tcp_socket`. See the tcp(7) manpage and /usr/include/linux/tcp.h for more details.

    static VALUE init(VALUE self, VALUE io)
    {
            int fd = my_fileno(io);
            struct tcp_info *info = DATA_PTR(self);
            socklen_t len = (socklen_t)sizeof(struct tcp_info);
            int rc = getsockopt(fd, IPPROTO_TCP, TCP_INFO, info, &len);

            if (rc != 0)
                    rb_sys_fail("getsockopt");

            return self;
    }

### Public Instance Methods

get!(tcp_socket) click to toggle source

Update an existing TCP_Info objects with the latest stats from the given socket. This even allows sharing TCP_Info objects between different sockets to avoid garbage.

    static VALUE init(VALUE self, VALUE io)
    {
            int fd = my_fileno(io);
            struct tcp_info *info = DATA_PTR(self);
            socklen_t len = (socklen_t)sizeof(struct tcp_info);
            int rc = getsockopt(fd, IPPROTO_TCP, TCP_INFO, info, &len);

            if (rc != 0)
                    rb_sys_fail("getsockopt");

            return self;
    }