so-5.5.8: New variant of limit_then_abort

Method so_5::rt::agent_t::limit_then_abort allow to specify message limit with very tough overlimit reaction – application abortion. But there was an inconvenience in limit_then_abort usage: it was hard to detect what message/signal caused the abortion. To simplify this task a new variant of limit_then_abort was introduced in v.5.5.8. This variant allows to set an action to be preformed before calling std::abort(). This action can be used, for example, for logging:

class my_agent : public so_5::rt::agent_t
{
public :
  my_agent( context_t ctx )
    : so_5::rt::agent_t( ctx +
      // Specifying limit for a message and pre-abort action.
      limit_then_abort< request >( 10,
        // Pre-abort action as lambda.
        []( const so_5::rt::agent_t & agent, const request & req ) {
          std::cerr << "Overlimit of requests for: "
            << (dynamic_cast< const my_agent & >(agent)).query_name()
            << ", request ID: " << req.query_id() << std::endl;
        } ) )
  ...
  const std::string & query_name() const { ... }
};

That variant of limit_then_abort can be used for messages (as in example abort) and for signals. But for signals pre-abort action must have different format:

return_type action(const so_5::rt::agent_t &);

Attention

Pre-abort actions must be noexcept-functions or lambda.