Method eventHandler

src/proxy/http/HttpSessionManager.cc:255–331

Called from the NetProcessor to let us know that a connection has closed down

//    connection has closed down
//
int
ServerSessionPool::eventHandler(int event, void *data)
{
  NetVConnection  *net_vc = nullptr;
  PoolableSession *s      = nullptr;

  switch (event) {
  case VC_EVENT_READ_READY:
  // The server sent us data.  This is unexpected so
  //   close the connection
  /* Fall through */
  case VC_EVENT_EOS:
  case VC_EVENT_ERROR:
  case VC_EVENT_INACTIVITY_TIMEOUT:
  case VC_EVENT_ACTIVE_TIMEOUT:
    net_vc = static_cast<NetVConnection *>((static_cast<VIO *>(data))->vc_server);
    break;

  default:
    ink_release_assert(0);
    return 0;
  }

  sockaddr const *addr  = net_vc->get_remote_addr();
  bool            found = false;

  for (auto spot = m_ip_pool.find(addr); spot != m_ip_pool.end() && spot->_ip_link.equal(addr, spot); ++spot) {
    if ((s = spot)->get_netvc() == net_vc) {
      // if there was a timeout of some kind on a keep alive connection, and
      // keeping the connection alive will not keep us above the # of max connections
      // to the origin and we are below the min number of keep alive connections to this
      // origin, then reset the timeouts on our end and do not close the connection
      if ((event == VC_EVENT_INACTIVITY_TIMEOUT || event == VC_EVENT_ACTIVE_TIMEOUT) && s->state == PoolableSession::KA_POOLED &&
          s->conn_track_group) {
        Dbg(dbg_ctl_http_ss, "s->conn_track_group->min_keep_alive_conns : %d", s->conn_track_group->_min_keep_alive_conns);
        bool connection_count_below_min = s->conn_track_group->_count <= s->conn_track_group->_min_keep_alive_conns;

        if (connection_count_below_min) {
          Dbg(dbg_ctl_http_ss,
              "[%" PRId64 "] [session_bucket] session received io notice [%s], "
              "resetting timeout to maintain minimum number of connections",
              s->connection_id(), HttpDebugNames::get_event_name(event));
          s->get_netvc()->set_inactivity_timeout(s->get_netvc()->get_inactivity_timeout());
          found = true;
          break;
        }
      }

      // We've found our server session. Remove it from
      //   our lists and close it down
      Dbg(dbg_ctl_http_ss, "[%" PRId64 "] [session_pool] session %p received io notice [%s]", s->connection_id(), s,
          HttpDebugNames::get_event_name(event));
      ink_assert(s->state == PoolableSession::KA_POOLED);
      // Out of the pool! Now!
      this->removeSession(s);
      // Drop connection on this end.
      s->do_io_close();
      found = true;