Switch to eventpp

CMakeLists.txt

@@ -6,13 +6,10 @@ project(xbot
     LANGUAGES C CXX
 )
 
-find_package(PkgConfig REQUIRED)
-
-pkg_check_modules(LIBIDN IMPORTED_TARGET libidn)
 find_package(Boost REQUIRED)
-find_package(OpenSSL REQUIRED)
 
 include(FetchContent)
+
 FetchContent_Declare(
     tomlplusplus
     GIT_REPOSITORY https://github.com/marzer/tomlplusplus.git
@@ -20,5 +17,12 @@ FetchContent_Declare(
 )
 FetchContent_MakeAvailable(tomlplusplus)
 
-add_executable(xbot main.cpp ircmsg.cpp settings.cpp connection.cpp thread.cpp watchdog_thread.cpp irc_parse_thread.cpp write_irc.cpp ping_thread.cpp registration_thread.cpp)
+FetchContent_Declare(
-target_link_libraries(xbot PRIVATE Boost::headers OpenSSL::SSL tomlplusplus_tomlplusplus)
+    eventpp
+    GIT_REPOSITORY https://github.com/wqking/eventpp.git
+    GIT_TAG        v0.1.3
+)
+FetchContent_MakeAvailable(eventpp)
+
+add_executable(xbot main.cpp ircmsg.cpp settings.cpp connection.cpp thread.cpp snote_thread.cpp watchdog_thread.cpp write_irc.cpp ping_thread.cpp irc_parse_thread.cpp registration_thread.cpp)
+target_link_libraries(xbot PRIVATE Boost::headers tomlplusplus_tomlplusplus eventpp)

connection.cpp

@@ -6,16 +6,6 @@ Connection::Connection(boost::asio::io_context & io)
 {
 }
 
-auto Connection::add_thread(std::shared_ptr<Thread> thread) -> void
-{
-    dispatcher_.add_thread(std::move(thread));
-}
-
-auto Connection::add_event(std::shared_ptr<Event> event) -> void
-{
-    dispatcher_.dispatch(std::move(event));
-}
-
 auto Connection::writer_() -> void
 {
     std::vector<boost::asio::const_buffer> buffers;
@@ -100,7 +90,6 @@ auto Connection::connect(
 
 auto Connection::write_raw(std::string message) -> void
 {
-    std::cout << "Writing " << message;
     auto const need_cancel = write_strings_.empty();
     write_strings_.push_back(std::move(message));
     if (need_cancel)

connection.hpp

@@ -4,9 +4,13 @@
 #include "settings.hpp"
 #include "thread.hpp"
 
+#include <eventpp/eventdispatcher.h>
+#include <eventpp/utilities/argumentadapter.h>
+
 #include <boost/asio.hpp>
 
 #include <chrono>
+#include <functional>
 #include <concepts>
 #include <iostream>
 #include <list>
@@ -17,6 +21,8 @@
 #include <utility>
 #include <variant>
 #include <vector>
+#include <typeinfo>
+#include <typeindex>
 
 struct ConnectEvent : Event
 {
@@ -34,22 +40,60 @@ struct LineEvent : Event
 
 class Connection : public std::enable_shared_from_this<Connection>
 {
+    using EventDispatcher = eventpp::EventDispatcher<std::type_index, void(Event&)>;
+
+public:
+    template <typename T>
+    class Handle
+    {
+        EventDispatcher::Handle handle;
+        Handle(EventDispatcher::Handle handle) : handle{handle} {}
+    public:
+        Handle() : handle{} {}
+        friend Connection;
+    };
+
+private:
     boost::asio::ip::tcp::socket stream_;
     boost::asio::steady_timer write_timer_;
     std::list<std::string> write_strings_;
-    Dispatcher dispatcher_;
+    EventDispatcher dispatcher_;
 
     auto writer() -> void;
     auto writer_() -> void;
 
 public:
     Connection(boost::asio::io_context & io);
-    auto add_thread(std::shared_ptr<Thread> thread) -> void;
+
-    auto add_event(std::shared_ptr<Event> event) -> void;
+    template <typename T, typename F>
+    auto add_listener(F f) -> Handle<T>
+    {
+        return Handle<T>{dispatcher_.appendListener(
+            typeid(T),
+            eventpp::argumentAdapter<void(T&)>(f)
+        )};
+    }
+
+    template <typename T>
+    auto remove_listener(Handle<T> handle) -> void
+    {
+        dispatcher_.removeListener(typeid(T), handle.handle);
+    }
+
+    template <typename T>
+    auto dispatch(T& event) -> void
+    {
+        dispatcher_.dispatch(typeid(T), event);
+    }
+
+    auto get_executor() -> boost::asio::any_io_executor {
+        return stream_.get_executor();
+    }
 
     template <typename T, typename... Args>
     auto make_event(Args&& ... args) {
-        add_event(std::make_shared<T>(std::forward<Args>(args)...));
+        auto event = T{std::forward<Args>(args)...};
+        dispatch<T>(event);
     }
 
     /// Write bytes into the socket. Messages should be properly newline terminated.

irc_parse_thread.cpp

@@ -2,20 +2,10 @@
 
 #include "connection.hpp"
 
-IrcParseThread::IrcParseThread(Connection * connection) noexcept
+auto irc_parse_thread(Connection * connection) -> void
-: connection_{connection} {}
-
-auto IrcParseThread::priority() const -> priority_type
 {
-    return 0;
+    connection->add_listener<LineEvent>([connection](LineEvent const& event)
-}
-
-auto IrcParseThread::on_event(Event const& event) -> callback_result
-{
-    if (auto line_event = dynamic_cast<LineEvent const*>(&event))
     {
-        connection_->make_event<IrcMsgEvent>(parse_irc_message(line_event->line));
+        connection->make_event<IrcMsgEvent>(parse_irc_message(event.line));
-        return { ThreadOutcome::Continue, EventOutcome::Consume };
+    });
-    }
-    return {};
 }

irc_parse_thread.hpp

@@ -10,11 +10,4 @@ struct IrcMsgEvent : Event
     IrcMsg irc;
 };
 
-struct IrcParseThread : Thread
+auto irc_parse_thread(Connection * connection) -> void;
-{
-    Connection * connection_;
-
-    IrcParseThread(Connection * connection) noexcept;
-    auto priority() const -> priority_type override;
-    auto on_event(Event const& event) -> callback_result override;
-};

main.cpp

@@ -1,15 +1,17 @@
 #include <boost/asio.hpp>
-#include <boost/asio/ssl.hpp>
 
 #include "connection.hpp"
 #include "ircmsg.hpp"
 #include "linebuffer.hpp"
 #include "settings.hpp"
 #include "thread.hpp"
+#include "write_irc.hpp"
 
 #include "irc_parse_thread.hpp"
-#include "ping_thread.hpp"
 #include "registration_thread.hpp"
+#include "ping_thread.hpp"
+#include "watchdog_thread.hpp"
+#include "snote_thread.hpp"
 
 #include <algorithm>
 #include <chrono>
@@ -30,40 +32,13 @@
 
 using namespace std::chrono_literals;
 
-
+auto unhandled_message_thread(Connection * connection) -> void
-struct ChatThread : public Thread
 {
-    auto priority() const -> priority_type override
+    connection->add_listener<IrcMsgEvent>([](IrcMsgEvent const& event)
     {
-        return 100;
+        if (not event.handled_)
-    }
-    auto on_event(Event const& event) -> callback_result override
-    {
-        if (auto const* irc_event = dynamic_cast<IrcMsgEvent const*>(&event))
         {
-            auto const& irc = irc_event->irc;
+            auto& irc = event.irc;
-            if (irc.command == "PRIVMSG" && 2 == irc.args.size())
-            {
-                std::cout << "Chat from " << irc.source << ": " << irc.args[1] << std::endl;
-                return { ThreadOutcome::Continue, EventOutcome::Consume };
-            }
-        }
-        return {};
-    }
-};
-
-struct UnhandledThread : public Thread
-{
-    auto priority() const -> priority_type override
-    {
-        return std::numeric_limits<Thread::priority_type>::max();
-    }
-
-    auto on_event(Event const& event) -> callback_result override
-    {
-        if (auto irc_event = dynamic_cast<IrcMsgEvent const*>(&event))
-        {
-            auto& irc = irc_event->irc;
             std::cout << "Unhandled message " << irc.command;
             for (auto const arg : irc.args)
             {
@@ -71,19 +46,19 @@ struct UnhandledThread : public Thread
             }
             std::cout << "\n";
         }
-        return {};
+    });
-    }
+}
-};
 
 auto start(boost::asio::io_context & io, Settings const& settings) -> void
 {
     auto connection = std::make_shared<Connection>(io);
 
-    connection->add_thread(std::make_shared<IrcParseThread>(connection.get()));
+    watchdog_thread(connection.get());
-    connection->add_thread(std::make_shared<PingThread>(connection.get()));
+    irc_parse_thread(connection.get());
-    connection->add_thread(std::make_shared<RegistrationThread>(connection.get(), settings.password, settings.username, settings.realname, settings.nickname));
+    ping_thread(connection.get());
-    connection->add_thread(std::make_shared<ChatThread>());
+    registration_thread(connection.get(), settings.password, settings.username, settings.realname, settings.nickname);
-    connection->add_thread(std::make_shared<UnhandledThread>());
+    snote_thread(connection.get());
+    unhandled_message_thread(connection.get());
 
     boost::asio::co_spawn(
         io,

ping_thread.cpp

@@ -3,23 +3,15 @@
 #include "irc_parse_thread.hpp"
 #include "write_irc.hpp"
 
-PingThread::PingThread(Connection * connection) noexcept : connection_{connection} {}
+auto ping_thread(Connection * connection) -> void
-
-auto PingThread::priority() const -> priority_type
 {
-    return 1;
+    connection->add_listener<IrcMsgEvent>([connection](IrcMsgEvent& event)
-}
-
-auto PingThread::on_event(Event const& event) -> std::pair<ThreadOutcome, EventOutcome>
-{
-    if (auto const irc_event = dynamic_cast<IrcMsgEvent const*>(&event))
     {
-        auto& irc = irc_event->irc;
+        auto& irc = event.irc;
         if ("PING" == irc.command && 1 == irc.args.size())
         {
-            write_irc(*connection_, "PONG", irc.args[0]);
+            write_irc(*connection, "PONG", irc.args[0]);
-            return {ThreadOutcome::Continue, EventOutcome::Consume};
+            event.handled_ = true;
         }
-    }
+    });
-    return {};
 }

ping_thread.hpp

@@ -3,13 +3,4 @@
 #include "connection.hpp"
 #include "thread.hpp"
 
-class PingThread : public Thread
+auto ping_thread(Connection * connection) -> void;
-{
-    Connection * connection_;
-
-public:
-    PingThread(Connection * connection) noexcept;
-
-    auto priority() const -> priority_type override;
-    auto on_event(Event const& event) -> std::pair<ThreadOutcome, EventOutcome> override;
-};

registration_thread.cpp

@@ -1,13 +1,59 @@
 #include "registration_thread.hpp"
 
+#include <memory>
+#include <unordered_set>
+#include <unordered_map>
+
+namespace {
+struct RegistrationThread : std::enable_shared_from_this<RegistrationThread>
+{
+    Connection * connection_;
+    std::string password_;
+    std::string username_;
+    std::string realname_;
+    std::string nickname_;
+
+    std::unordered_map<std::string, std::string> caps;
+    std::unordered_set<std::string> outstanding;
+
+    Connection::Handle<ConnectEvent> connect_handle_;
+    Connection::Handle<IrcMsgEvent> message_handle_;
+
+    enum class Stage
+    {
+        LsReply,
+        AckReply,
+    };
+
+    Stage stage_;
+
+    RegistrationThread(
+        Connection * connection_,
+        std::string password,
+        std::string username,
+        std::string realname,
+        std::string nickname
+    );
+
+    auto on_connect() -> void;
+
+    auto send_req() -> void;
+
+    auto capack(IrcMsg const& msg) -> void;
+
+    auto capls(IrcMsg const& msg) -> void;
+
+    auto on_msg(IrcMsg const& msg) -> void;
+};
+
 RegistrationThread::RegistrationThread(
-    Connection * connection_,
+    Connection * connection,
     std::string password,
     std::string username,
     std::string realname,
     std::string nickname
 )
-    : connection_{connection_}
+    : connection_{connection}
     , password_{password}
     , username_{username}
     , realname_{realname}
@@ -15,24 +61,36 @@ RegistrationThread::RegistrationThread(
     , stage_{Stage::LsReply}
 {}
 
-auto RegistrationThread::priority() const -> priority_type
+auto RegistrationThread::on_connect() -> void
-{
-    return 2;
-}
-
-auto RegistrationThread::on_connect() -> Thread::callback_result
 {
     write_irc(*connection_, "CAP", "LS", "302");
     write_irc(*connection_, "PASS", password_);
     write_irc(*connection_, "USER", username_, "*", "*", realname_);
     write_irc(*connection_, "NICK", nickname_);
-    return {};
+
+    connection_->remove_listener(connect_handle_);
 }
 
-auto RegistrationThread::send_req() -> Thread::callback_result
+auto RegistrationThread::send_req() -> void
 {
     std::string request;
-    char const* want[] = { "extended-join", "account-notify", "draft/chathistory", "batch", "soju.im/no-implicit-names", "chghost", "setname", "account-tag", "solanum.chat/oper", "solanum.chat/identify-msg", "solanum.chat/realhost", "server-time", "invite-notify", "extended-join" };
+    char const* const want[] = {
+        "extended-join",
+        "account-notify",
+        "draft/chathistory",
+        "batch",
+        "soju.im/no-implicit-names",
+        "chghost",
+        "setname",
+        "account-tag",
+        "solanum.chat/oper",
+        "solanum.chat/identify-msg",
+        "solanum.chat/realhost",
+        "server-time",
+        "invite-notify",
+        "extended-join"
+    };
+
     for (auto cap : want)
     {
         if (caps.contains(cap))
@@ -47,16 +105,15 @@ auto RegistrationThread::send_req() -> Thread::callback_result
         request.pop_back();
         write_irc(*connection_, "CAP", "REQ", request);
         stage_ = Stage::AckReply;
-        return {ThreadOutcome::Continue, EventOutcome::Consume};
     }
     else
     {
         write_irc(*connection_, "CAP", "END");
-        return {ThreadOutcome::Finish, EventOutcome::Consume};
+        connection_->remove_listener(message_handle_);
     }
 }
 
-auto RegistrationThread::capack(IrcMsg const& msg) -> Thread::callback_result
+auto RegistrationThread::capack(IrcMsg const& msg) -> void
 {
     auto const n = msg.args.size();
     if ("CAP" == msg.command && n >= 2 && "*" == msg.args[0] && "ACK" == msg.args[1])
@@ -72,20 +129,12 @@ auto RegistrationThread::capack(IrcMsg const& msg) -> Thread::callback_result
         if (outstanding.empty())
         {
             write_irc(*connection_, "CAP", "END");
-            return {ThreadOutcome::Finish, EventOutcome::Consume};
+            connection_->remove_listener(message_handle_);
         }
-        else
-        {
-            return {ThreadOutcome::Continue, EventOutcome::Consume};
-        }
-    }
-    else
-    {
-        return {};
     }
 }
 
-auto RegistrationThread::capls(IrcMsg const& msg) -> Thread::callback_result
+auto RegistrationThread::capls(IrcMsg const& msg) -> void
 {
     auto const n = msg.args.size();
     if ("CAP" == msg.command && n >= 2 && "*" == msg.args[0] && "LS" == msg.args[1])
@@ -105,7 +154,7 @@ auto RegistrationThread::capls(IrcMsg const& msg) -> Thread::callback_result
         }
         else
         {
-            return {};
+            return;
         }
 
         auto in = std::istringstream{std::string{*kvs}};
@@ -128,37 +177,37 @@ auto RegistrationThread::capls(IrcMsg const& msg) -> Thread::callback_result
 
         if (last)
         {
-            return send_req();
+            send_req();
         }
-
-        return {ThreadOutcome::Continue, EventOutcome::Consume};
     }
-    else
-    {
-        return {};
-    }
-
 }
 
-auto RegistrationThread::on_msg(IrcMsg const& msg) -> Thread::callback_result
+auto RegistrationThread::on_msg(IrcMsg const& msg) -> void
 {
     switch (stage_)
     {
-        case Stage::LsReply: return capls(msg);
+        case Stage::LsReply: capls(msg); return;
-        case Stage::AckReply: return capack(msg);
+        case Stage::AckReply: capack(msg); return;
-        default: return {};
     }
 }
 
-auto RegistrationThread::on_event(Event const& event) -> Thread::callback_result
+} // namespace
+
+auto registration_thread(
+    Connection * connection,
+    std::string password,
+    std::string username,
+    std::string realname,
+    std::string nickname
+) -> void
 {
-    if (auto const irc_event = dynamic_cast<IrcMsgEvent const*>(&event))
+    auto thread = std::make_shared<RegistrationThread>(connection, password, username, realname, nickname);
+    thread->message_handle_ = connection->add_listener<IrcMsgEvent>([thread](IrcMsgEvent const& event)
     {
-        return on_msg(irc_event->irc);
+        thread->on_msg(event.irc);
-    }
+    });
-    if (auto const connect_event = dynamic_cast<ConnectEvent const*>(&event))
+    thread->connect_handle_ = connection->add_listener<ConnectEvent>([thread](ConnectEvent const&)
     {
-        return on_connect();
+        thread->on_connect();
-    }
+    });
-    return {};
 }

registration_thread.hpp

@@ -5,47 +5,14 @@
 #include "irc_parse_thread.hpp"
 #include "write_irc.hpp"
 
+#include <eventpp/eventdispatcher.h>
+
 #include <string>
-#include <unordered_set>
-#include <unordered_map>
 
-struct RegistrationThread : Thread
+auto registration_thread(
-{
+    Connection * connection,
-    Connection * connection_;
+    std::string password,
-    std::string password_;
+    std::string username,
-    std::string username_;
+    std::string realname,
-    std::string realname_;
+    std::string nickname
-    std::string nickname_;
+) -> void;
-
-    std::unordered_map<std::string, std::string> caps;
-    std::unordered_set<std::string> outstanding;
-
-    enum class Stage
-    {
-        LsReply,
-        AckReply,
-    };
-
-    Stage stage_;
-
-    RegistrationThread(
-        Connection * connection_,
-        std::string password,
-        std::string username,
-        std::string realname,
-        std::string nickname
-    );
-
-    auto priority() const -> priority_type override;
-    auto on_connect() -> Thread::callback_result;
-
-    auto send_req() -> Thread::callback_result;
-
-    auto capack(IrcMsg const& msg) -> Thread::callback_result;
-
-    auto capls(IrcMsg const& msg) -> Thread::callback_result;
-
-    auto on_msg(IrcMsg const& msg) -> Thread::callback_result;
-
-    auto on_event(Event const& event) -> Thread::callback_result override;
-};

snote_thread.cpp

@@ -0,0 +1,24 @@
+#include "snote_thread.hpp"
+
+#include "irc_parse_thread.hpp"
+#include "connection.hpp"
+
+#include <cstring>
+
+
+auto snote_thread(Connection * connection) -> void
+{
+    static char const* const prefix = "*** Notice -- ";
+    connection->add_listener<IrcMsgEvent>([connection](IrcMsgEvent& event)
+    {
+        auto& irc = event.irc;
+        if ("NOTICE" == irc.command
+         && 2 == irc.args.size()
+         && "*" == irc.args[0]
+         && irc.args[1].starts_with(prefix))
+        {
+            event.handled_ = true;
+            connection->make_event<SnoteEvent>(irc.args[1].substr(strlen(prefix)));
+        }
+    });
+}

snote_thread.hpp

@@ -0,0 +1,14 @@
+#pragma once
+
+#include "thread.hpp"
+
+class Connection;
+
+// WIP: Use much finer granularity
+struct SnoteEvent : Event
+{
+    SnoteEvent(std::string_view raw) : raw{raw} {}
+    std::string_view raw;
+};
+
+auto snote_thread(Connection * connection) -> void;

thread.cpp

@@ -1,46 +1 @@
 #include "thread.hpp"
-
-auto Dispatcher::add_thread(std::shared_ptr<Thread> thread) -> void
-{
-    threads_.push_back(std::move(thread));
-}
-
-auto Dispatcher::dispatch(std::shared_ptr<Event> event) -> void
-{
-    if (dispatching_)
-    {
-        events_.push_back(std::move(event));
-        return;
-    }
-
-    dispatching_ = true;
-    std::vector<std::shared_ptr<Event>> events{std::move(event)};
-    while (not events.empty())
-    {
-        for (auto && event : events)
-        {
-            std::vector<std::shared_ptr<Thread>> work;
-            work.swap(threads_);
-            std::sort(work.begin(), work.end(), [](auto const& a, auto const& b) { return a->priority() < b->priority(); });
-
-            std::size_t const n = work.size();
-            for (std::size_t i = 0; i < n; i++)
-            {
-                auto const [thread_outcome, msg_outcome] = work[i]->on_event(*event);
-                if (thread_outcome == ThreadOutcome::Continue)
-                {
-                    threads_.push_back(std::move(work[i]));
-                }
-                if (msg_outcome == EventOutcome::Consume)
-                {
-                    std::move(work.begin() + i + 1, work.end(), std::back_inserter(threads_));
-                    break;
-                }
-            }
-        }
-
-        events = std::move(events_);
-        events_.clear();
-    }
-    dispatching_ = false;
-}

thread.hpp

@@ -5,38 +5,7 @@
 #include <memory>
 #include <vector>
 
-enum class EventOutcome
-{
-    Pass,
-    Consume,
-};
-
-enum class ThreadOutcome
-{
-    Continue,
-    Finish,
-};
-
 struct Event {
     virtual ~Event() {}
+    bool handled_ = false;
 };
-
-struct Thread
-{
-    using priority_type = std::uint64_t;
-    using callback_result = std::pair<ThreadOutcome, EventOutcome>;
-    virtual ~Thread() {}
-    virtual auto on_event(Event const& event) -> callback_result { return {}; };
-    virtual auto priority() const -> priority_type = 0;
-};
-
-struct Dispatcher
-{
-    std::vector<std::shared_ptr<Thread>> threads_;
-    std::vector<std::shared_ptr<Event>> events_;
-    bool dispatching_;
-
-    /// Apply a function to all the threads in priority order
-    auto dispatch(std::shared_ptr<Event> event) -> void;
-    auto add_thread(std::shared_ptr<Thread> thread) -> void;
-};

watchdog_thread.cpp

@@ -2,41 +2,92 @@
 
 #include "connection.hpp"
 #include "irc_parse_thread.hpp"
+#include "write_irc.hpp"
+
+#include <boost/asio/steady_timer.hpp>
 
 #include <chrono>
+#include <memory>
 
 using namespace std::chrono_literals;
 
-WatchdogThread::WatchdogThread(Connection * connection) noexcept
+namespace {
-: connection_{connection}
-{
-}
 
-auto WatchdogThread::priority() const -> priority_type
+struct WatchdogThread : std::enable_shared_from_this<WatchdogThread>
 {
-    return 0;
+    WatchdogThread(Connection * connection)
-}
+    : connection_{connection}
-
+    , timer_{connection->get_executor()}
-auto WatchdogThread::on_event(Event const& event) -> std::pair<ThreadOutcome, EventOutcome>
+    , tried_ping{false}
-{
-    if (auto const irc_event = dynamic_cast<LineEvent const*>(&event))
     {
-        timer_.expires_from_now(30s);
-        return {};
     }
-    if (auto const connect_event = dynamic_cast<ConnectEvent const*>(&event))
+
+    Connection * connection_;
+    boost::asio::steady_timer timer_;
+    bool tried_ping;
+
+    auto on_activity() -> void
     {
+        tried_ping = false;
         timer_.expires_from_now(30s);
-        timer_.async_wait([weak = weak_from_this()](auto error)
+    }
+
+    auto timeout_token() 
+    {
+        return [weak = weak_from_this()](auto const& error)
         {
             if (not error)
             {
                 if (auto self = weak.lock())
                 {
-                    self->connection_->close();
+                    self->on_timeout();
                 }
             }
-        });
+        };
     }
-    return {};
+
+    auto on_timeout() -> void
+    {
+        if (tried_ping)
+        {
+            connection_->close();
+        }
+        else
+        {
+            write_irc(*connection_, "PING", "watchdog");
+            tried_ping = true;
+            timer_.expires_from_now(30s);
+            timer_.async_wait(timeout_token());
+        }
+    }
+
+    auto on_connect() -> void
+    {
+        on_activity();
+        timer_.async_wait(timeout_token());
+    }
+
+    auto on_disconnect() -> void
+    {
+        timer_.cancel();
+    }
+};
+
+} // namespace
+
+auto watchdog_thread(Connection * connection) -> void
+{
+    auto const thread = std::make_shared<WatchdogThread>(connection);
+    connection->add_listener<ConnectEvent>([thread](auto&)
+    {
+        thread->on_connect();
+    });
+    connection->add_listener<DisconnectEvent>([thread](auto&)
+    {
+        thread->on_disconnect();
+    });
+    connection->add_listener<IrcMsgEvent>([thread](auto&)
+    {
+        thread->on_activity();
+    });
 }

watchdog_thread.hpp

@@ -1,18 +1,4 @@
 #pragma once
 
-#include "thread.hpp"
-#include <boost/asio/steady_timer.hpp>
-
 class Connection;
-
+auto watchdog_thread(Connection * connection) -> void;
-class WatchdogThread : public Thread, public std::enable_shared_from_this<WatchdogThread>
-{
-    Connection * connection_;
-    boost::asio::steady_timer timer_;
-
-public:
-    WatchdogThread(Connection * connection) noexcept;
-
-    auto priority() const -> priority_type override;
-    auto on_event(Event const& event) -> std::pair<ThreadOutcome, EventOutcome> override;
-};