so_5/ping_pong_minimal/main.cpp

#include <iostream>

#include <so_5/all.hpp>

// Types of signals for the agents.
struct msg_ping final : public so_5::signal_t {};
struct msg_pong final : public so_5::signal_t {};

// Class of pinger agent.
class a_pinger_t final : public so_5::agent_t
  {
  public :
    a_pinger_t( context_t ctx, so_5::mbox_t mbox, int pings_to_send )
      : so_5::agent_t{ ctx }
      , m_mbox{ std::move(mbox) }
      , m_pings_left{ pings_to_send }
      {}

    void so_define_agent() override
      {
        so_subscribe( m_mbox ).event( &a_pinger_t::evt_pong );
      }

    void so_evt_start() override
      {
        send_ping();
      }

  private :
    const so_5::mbox_t m_mbox;

    int m_pings_left;

    void evt_pong(mhood_t< msg_pong >)
      {
        if( m_pings_left > 0 )
          send_ping();
        else
          so_environment().stop();
      }

    void send_ping()
      {
        so_5::send< msg_ping >( m_mbox );
        --m_pings_left;
      }
  };

class a_ponger_t final : public so_5::agent_t
  {
  public :
    a_ponger_t( context_t ctx, const so_5::mbox_t & mbox )
      : so_5::agent_t( std::move(ctx) )
    {
      so_subscribe( mbox ).event(
        [mbox]( mhood_t<msg_ping> ) {
          so_5::send< msg_pong >( mbox );
        } );
    }
  };

int main()
  {
    try
      {
        so_5::launch( []( so_5::environment_t & env ) {
            env.introduce_coop( [&env]( so_5::coop_t & coop ) {
              // Mbox for agent's interaction.
              auto mbox = env.create_mbox();

              // Pinger.
              coop.make_agent< a_pinger_t >( mbox, 100000 );

              // Ponger agent.
              coop.make_agent< a_ponger_t >( std::cref(mbox) );
            });
          });

        return 0;
      }
    catch( const std::exception & x )
      {
        std::cerr << "*** Exception caught: " << x.what() << std::endl;
      }

    return 2;
  }