Improve zero conf announce reliability.

* Make sure the even loop was entered before trying to announce
the TDM on zeron conf.

* Make sure the server are accepting connections by the TDM is
announced on zero conf.

* Refresh the announce every few seconds in case there
was some spurious failure.

This changes should make zero conf a bit more reliable and
avoid some of the issues where the launcher doesn't see the
TDM

aseba/thymio-device-manager/aseba_node_registery.cpp

@@ -16,8 +16,6 @@ aseba_node_registery::aseba_node_registery(boost::asio::execution_context& io_co
     , m_discovery_socket(static_cast<boost::asio::io_context&>(io_context))
     , m_nodes_service_desc("mobsya") {
     m_nodes_service_desc.name(fmt::format("Thymio Device Manager on {}", boost::asio::ip::host_name()));
-
-    //  update_discovery();
 }
 
 void aseba_node_registery::add_node(std::shared_ptr<aseba_node> node) {
@@ -114,48 +112,43 @@ void aseba_node_registery::set_ws_endpoint(const boost::asio::ip::tcp::endpoint&
     m_ws_endpoint = endpoint;
 }
 
-void aseba_node_registery::set_discovery() {
-    update_discovery();
+void aseba_node_registery::announce_on_zeroconf() {
+    // Make sure we have entered the event loop before announcing ourself
+    boost::asio::post(boost::asio::get_associated_executor(this),
+                      boost::bind(&aseba_node_registery::do_announce_on_zeroconf, this));
 }
 
-void aseba_node_registery::update_discovery() {
-
-    if(m_updating_discovery) {
-        m_discovery_needs_update = true;
-        return;
-    }
+void aseba_node_registery::do_announce_on_zeroconf() {
     m_nodes_service_desc.properties(build_discovery_properties());
-
-    m_discovery_needs_update = false;
-    m_updating_discovery = true;
     m_discovery_socket.async_announce(
         m_nodes_service_desc,
-        std::bind(&aseba_node_registery::on_update_discovery_complete, this, std::placeholders::_1));
+        std::bind(&aseba_node_registery::on_announce_complete, this, std::placeholders::_1));
 }
 
-void aseba_node_registery::on_update_discovery_complete(const boost::system::error_code& ec) {
+void aseba_node_registery::on_announce_complete(const boost::system::error_code& ec) {
     if(ec) {
         mLogError("Discovery : {}", ec.message());
-		m_discovery_needs_update = true;
     } else {
         mLogTrace("Discovery : update complete");		
     }
-	m_updating_discovery = false;
-    if(m_discovery_needs_update) {
-        boost::asio::post(boost::asio::get_associated_executor(this),
-                          boost::bind(&aseba_node_registery::update_discovery, this));
-    }
+
+    // Refresh the zeroconf info every few seconds in case they get lost
+    // or corrupted.
+    auto timer = std::make_shared<boost::asio::deadline_timer>(get_io_context());
+    timer->expires_from_now(boost::posix_time::seconds(5));
+    auto cb = boost::asio::bind_executor(get_io_context().get_executor(), [timer, this](const boost::system::error_code& ec) {
+        do_announce_on_zeroconf();
+    });
+    timer->async_wait(std::move(cb));
 }
 
 
 aware::contact::property_map_type aseba_node_registery::build_discovery_properties() const {
     aware::contact::property_map_type map;
     map["uuid"] = boost::uuids::to_string(m_service_uid);
-    map["_ws-port"] = "8597"; //HACK adding some unused description to correct bug in avahi
     if(m_ws_endpoint.port())
         map["ws-port"] = std::to_string(m_ws_endpoint.port());
     mLogTrace("=> WS port discovery on {}", map["ws-port"]);
-    map["_ws-port2"] = "8597"; //HACK adding some unused description to correct bug in avahi
     return map;
 }
 

aseba/thymio-device-manager/aseba_node_registery.h

@@ -30,7 +30,7 @@ class aseba_node_registery : public boost::asio::detail::service_base<aseba_node
 
     void set_tcp_endpoint(const boost::asio::ip::tcp::endpoint& endpoint);
     void set_ws_endpoint(const boost::asio::ip::tcp::endpoint& endpoint);
-	void set_discovery();
+    void announce_on_zeroconf();
 
     node_map nodes() const;
     std::shared_ptr<aseba_node> node_from_id(const node_id&) const;
@@ -48,8 +48,8 @@ class aseba_node_registery : public boost::asio::detail::service_base<aseba_node
     void save_group_affiliation(const aseba_node& node);
     void restore_group_affiliation(const aseba_node& node);
 
-    void update_discovery();
-    void on_update_discovery_complete(const boost::system::error_code&);
+    void do_announce_on_zeroconf();
+    void on_announce_complete(const boost::system::error_code&);
     aware::contact::property_map_type build_discovery_properties() const;
 
     node_map::const_iterator find(const std::shared_ptr<aseba_node>& node) const;
@@ -73,9 +73,6 @@ class aseba_node_registery : public boost::asio::detail::service_base<aseba_node
     // Endpoint of the WebSocket - So we can expose the port on zeroconf
     boost::asio::ip::tcp::endpoint m_ws_endpoint;
 
-    bool m_updating_discovery = false;
-    bool m_discovery_needs_update = false;
-
     boost::signals2::signal<void(std::shared_ptr<aseba_node>, node_id, aseba_node::status)>
         m_node_status_changed_signal;
     friend class node_status_monitor;

aseba/thymio-device-manager/main.cpp

@@ -50,25 +50,18 @@ void run_service(boost::asio::io_context& ctx) {
 
     [[maybe_unused]] mobsya::wireless_configurator_service& ws =
         boost::asio::make_service<mobsya::wireless_configurator_service>(ctx);
-    // ws.enable();
+    ws.enable();
 
     // Create a server for regular tcp connection
     mobsya::application_server<mobsya::tcp::socket> tcp_server(ctx, 0);
     node_registery.set_tcp_endpoint(tcp_server.endpoint());
-    tcp_server.accept();
 
     mobsya::aseba_tcp_acceptor aseba_tcp_acceptor(ctx);
 
     // Create a server for websocket
     mobsya::application_server<mobsya::websocket_t> websocket_server(ctx, 8597);
 	node_registery.set_ws_endpoint(websocket_server.endpoint());
-    websocket_server.accept();
-
-    // Enable Bonjour, Zeroconf 
-	node_registery.set_discovery();
 
-    mLogTrace("=> TCP Server connected on {}", tcp_server.endpoint().port());
-    mLogTrace("=> WS Server connected on {}", websocket_server.endpoint().port());
 
 #ifdef MOBSYA_TDM_ENABLE_USB
     mobsya::usb_server usb_server(ctx, {mobsya::THYMIO2_DEVICE_ID, mobsya::THYMIO_WIRELESS_DEVICE_ID});
@@ -79,6 +72,16 @@ void run_service(boost::asio::io_context& ctx) {
     serial_server.accept();
 #endif
     aseba_tcp_acceptor.accept();
+    websocket_server.accept();
+    tcp_server.accept();
+
+    mLogTrace("=> TCP Server started on {}", tcp_server.endpoint().port());
+    mLogTrace("=> WS Server started on {}", websocket_server.endpoint().port());
+
+    // Enable Bonjour/Zeroconf
+    // Make sure this is done after the different servers are started and accept connections
+    // So that clients can connect to discovered services
+    node_registery.announce_on_zeroconf();
 
     ctx.run();
 }