Actor framework rotor v0.09 (c ++) released

rotor is an unobtrusive C ++ actor microframework similar to its older brothers - caf and sobjectizer . In the new release, the inner core has been completely redesigned using plugin mechanisms , so this affects the life cycle of actors.

Linking Actors

, . . ( , ). , , (1); , A B, , B M.

v0.09 /, , . . , , , . v0.09 A B, (link), , .

:

namespace r = rotor;

void some_actor_t::on_start() noexcept override {
    request<payload::link_request_t>(b_address).send(timeout);
}

void some_actor_t::on_link_response(r::message::link_response_t &response) noexcept {
    auto& ec = message.payload.ec;
    if (!ec) {
        //  
    }
}

, … . A , . . some_actor_t . , :

namespace r = rotor;

void some_actor_t::configure(r::plugin::plugin_base_t &plugin) noexcept override {
    plugin.with_casted<r::plugin::link_client_plugin_t>(
        [&](auto &p) {
            p.link(B1_address);
            p.link(B2_address);
        }
    );
}

, link_client_plugin_t actor_base_t. , , , . . : 1) ( — )? 2) , ("") ? 3) , -?

.

(, state) : new (ctor) -> initializing -> initialized -> operational -> shutting down -> shut down.

, operational, , .

(I-, . . initializing -> initialized), : , , . rotor', I- , . . , (2).

(S-, . . shutting down -> shut down ) I-, . . , , .

, (composability) , - (. Trees of Supervisors). , , I- S-, . — (operational), (shut down).

( . , — ).

rotor . caf. , sobjectizer' shutdown helper, S- ; , , , "" () , Environment' stop. sobjectizer' ( ), I- S- rotor'a, , -. rotor' .

rotor' , I- (S-) () , , , , . , . , , .

rotor'? — , . . init_shutdown, () , . . , (); , , child_manager, , , , . . , , , .

, , link_client_plugin_t:

• : () ? : initializing (shutting down).
• : , ? : . . , -; , , , . . .
• : , , , -? : - , , - (3).

, (event loop), rotor', TCP-, . db_actor_t, acceptor_t. :

namespace r = rotor;

struct db_actor_t: r::actor_base_t {

    struct resource {
        static const constexpr r::plugin::resource_id_t db_connection = 0;
    }

    void configure(r::plugin::plugin_base_t &plugin) noexcept override {
        plugin.with_casted<r::plugin::registry_plugin_t>([this](auto &p) {
            p.register_name("service::database", this->get_address())
        });
        plugin.with_casted<r::plugin::resources_plugin_t>([this](auto &) {
            resources->acquire(resource::db_connection);
            //      
        });
    }

    void on_db_connection_success() {
        resources->release(resource::db_connection);
        ...
    }

    void on_db_disconnected() {
        resources->release(resource::db_connection);
    }

    void shutdown_start() noexcept override {
        r::actor_base_t::shutdown_start();
        resources->acquire(resource::db_connection);
        //         
    }
};

resource . , 0. , , registry_plugin_t , ( ). resources_plugin_t "" , . , db_actor_t . S- : , ; (4).

, , :

namespace r = rotor;
struct acceptor_actor_t: r::actor_base_t {
    r::address_ptr_t db_addr;

    void configure(r::plugin::plugin_base_t &plugin) noexcept override {
        plugin.with_casted<r::plugin::registry_plugin_t>([](auto &p) {
            p.discover_name("service::database", db_addr, true).link();
        });
    }

    void on_start() noexcept override {
        r::actor_base_t::on_start();
        //   , :
        // asio::ip::tcp::acceptor.async_accept(...);
    }

    void on_new_client(client_t& client) {
        // send<message::log_client_t>(db_addr, client)
    }
};

, configure. registry_plugin_t , service::database, db_actor_t db_addr, . service::database , acceptor_actor_t (. . on_start ). , .

, , . . rotor'. (payload), , .

main.cpp; , boost::asio .

namespace asio = boost::asio;
namespace r = rotor;
...
asio::io_context io_context;
auto system_context = rotor::asio::system_context_asio_t(io_context);
auto strand = std::make_shared<asio::io_context::strand>(io_context);
auto timeout = r::pt::milliseconds(100);
auto sup = system_context->create_supervisor<r::asio::supervisor_asio_t>()
               .timeout(timeout)
               .strand(strand)
               .create_registry()
               .finish();

sup->create_actor<db_actor_t>().timeout(timeout).finish();
sup->create_actor<acceptor_actor_t>().timeout(timeout).finish();

sup->start();
io_context.run();

, rotor' builder. sup, 3 : (db_actor_t acceptor_actor_t) -. , , . . ( ).

" " , , . , v0.09 .

: , , , (5). , - , , . get_registry_address() .

rotor' . : link_client_plugin_t, , registry_plugin_t, , resources_plugin_t, () .

,

builder .

.

P.S. Crazy Panda , sobjectizer' .

(1) , , (UB).

(2) , , , . . operational .

(3) , , ? , system_context_t::on_error(const std::error_code&), std::terminate(). , , - .

(4) registry_plugin_t , .

(5) , . API , , , . , API rotor'.