so_5/nohandler_msg_tracing/main.cpp

/*
 * An example to show custom msg_tracing filter.
 * Only trace message for cases when no event handler found will be printed.
 */
 
#include <iostream>
#include <time.h>
 
// Main SObjectizer header file.
#include <so_5/all.hpp>
 
// Main example agent.
class a_example_t final : public so_5::agent_t
{
  // Several signals for demonstration.
  struct first final : public so_5::signal_t {};
  struct second final : public so_5::signal_t {};
  struct third final : public so_5::signal_t {};
 
  // Signal for finishing the example.
  struct finish final : public so_5::signal_t {};
 
  // Several agent's states.
  const state_t st_first{ this, "first" };
  const state_t st_second{ this, "second" };
  const state_t st_third{ this, "third" };
    
public :
  a_example_t( context_t ctx )
    : so_5::agent_t( std::move(ctx) )
  {
    st_first.event( &a_example_t::on_first );
    st_first.event( &a_example_t::on_finish );
 
    st_second.event( &a_example_t::on_second );
 
    st_third.event( &a_example_t::on_third );
  }
 
  void so_evt_start() override
  {
    // Change the state of the agent.
    this >>= st_first;
 
    // Send a serie of messages.
    so_5::send< first >( *this );
    so_5::send< second >( *this );
    so_5::send< third >( *this );
 
    so_5::send< finish >( *this );
  }
 
private :
  void on_first( mhood_t<first> ) {}
  void on_second( mhood_t<first> ) {}
  void on_third( mhood_t<first> ) {}
 
  void on_finish( mhood_t<finish> )
  {
    so_deregister_agent_coop_normally();
  }
};
 
int main()
{
  try
  {
    so_5::launch( []( so_5::environment_t & env ) {
        env.introduce_coop( []( so_5::coop_t & coop ) {
          coop.make_agent< a_example_t >();
        } );
      },
      []( so_5::environment_params_t & params ) {
        // Turn message delivery tracing on.
        params.message_delivery_tracer(
            so_5::msg_tracing::std_cout_tracer() );
        // Setup filter which enables only messages with
        // null event_handler_data_ptr.
        params.message_delivery_tracer_filter(
            so_5::msg_tracing::make_filter(
              [](const so_5::msg_tracing::trace_data_t & td) {
                const auto h = td.event_handler_data_ptr();
                return h && (nullptr == *h);
              } ) );
      } );
  }
  catch( const std::exception & ex )
  {
    std::cerr << "Error: " << ex.what() << std::endl;
    return 1;
  }
 
  return 0;
}