Minor updates

Author: endurodave

example/sample-projects/databus-shapes/client/main.cpp

@@ -32,6 +32,7 @@ using namespace ftxui;
 struct GlobalState {
     std::mutex mutex;
     std::map<std::string, ShapeMsg> shapes;
+    ScreenInteractive* screen = nullptr;
 } g_state;
 
 int main() {
@@ -49,13 +50,22 @@ int main() {
         return -1;
     }
 
+    auto screen = ScreenInteractive::Fullscreen();
+    g_state.screen = &screen;
+
     // 2. Setup Participant and Handlers
     auto group = std::make_shared<dmq::Participant>(transport);
     static Serializer<void(ShapeMsg)> serializer;
 
     auto shapeHandler = [](const std::string& topic, ShapeMsg msg) {
-        std::lock_guard<std::mutex> lock(g_state.mutex);
-        g_state.shapes[topic] = msg;
+        {
+            std::lock_guard<std::mutex> lock(g_state.mutex);
+            g_state.shapes[topic] = msg;
+        }
+        // Data-Driven Refresh: Trigger UI redraw immediately on data arrival
+        if (g_state.screen) {
+            g_state.screen->PostEvent(Event::Custom);
+        }
     };
 
     group->RegisterHandler<ShapeMsg>(SystemTopic::SquareId, serializer, [&](ShapeMsg m) { shapeHandler(SystemTopic::Square, m); });
@@ -67,26 +77,21 @@ int main() {
     std::thread netThread([&]() {
         while (running) {
             group->ProcessIncoming();
-            std::this_thread::sleep_for(std::chrono::milliseconds(10));
+            std::this_thread::sleep_for(std::chrono::milliseconds(5)); // High-freq check
         }
     });
 
     // 4. FTXUI Render Loop
-    auto screen = ScreenInteractive::Fullscreen();
-
     auto renderer = Renderer([&] {
-        // Create a canvas that fills the available space
         auto c = Canvas(200, 100);
 
         {
             std::lock_guard<std::mutex> lock(g_state.mutex);
             for (auto const& [topic, shape] : g_state.shapes) {
                 if (topic == SystemTopic::Square) {
-                    // Draw Square (using block coordinates)
                     for(int x=0; x<10; ++x) 
                         for(int y=0; y<10; ++y) c.DrawBlock(shape.x * 2 + x, shape.y * 2 + y, true, Color::Blue);
                 } else if (topic == SystemTopic::Circle) {
-                    // Draw Circle
                     c.DrawBlockCircle(shape.x * 2, shape.y * 2, 10, Color::Red);
                 }
             }
@@ -99,34 +104,24 @@ int main() {
             canvas(std::move(c)) | flex | border,
             hbox({
                 filler(),
-                text("Newest data received via DataBus Multicast | 'q' to quit") | dim,
+                text("Data-Driven Rendering (Sync with DataBus) | 'q' to quit") | dim,
                 filler()
             })
         });
     });
 
-    // Handle 'q' to quit and sink all other events to prevent character artifacts
     auto component = CatchEvent(renderer, [&](Event event) {
         if (event == Event::Character('q')) {
             screen.Exit();
             return true;
         }
-        return true; // Sink all events
-    });
-
-    // Refresh UI at 20fps to reduce flickering
-    std::thread refresher([&] {
-        while (running) {
-            std::this_thread::sleep_for(std::chrono::milliseconds(50));
-            screen.PostEvent(Event::Custom);
-        }
+        return false;
     });
 
     screen.Loop(component);
 
     running = false;
     netThread.join();
-    refresher.join();
     transport.Close();
 
     std::cout << "\r" << std::flush; 

example/sample-projects/databus-shapes/server/main.cpp

@@ -36,7 +36,10 @@ int main() {
     std::cout << "Local Interface: " << localIP << std::endl;
 
 #ifdef DMQ_DATABUS_SPY
+    // Start Spy Bridge to export DataBus traffic to the Spy Console via Multicast
+    // Note: Use port 9999 to isolate spy traffic from app traffic on 8000.
     SpyBridge::StartMulticast("239.1.1.1", 9999, localIP);
+
     dmq::DataBus::RegisterStringifier<ShapeMsg>(SystemTopic::Square, [](const ShapeMsg& m) {
         return "Square X=" + std::to_string(m.x) + " Y=" + std::to_string(m.y);
     });
@@ -83,7 +86,7 @@ int main() {
         dmq::DataBus::Publish<ShapeMsg>(SystemTopic::Circle, circle);
 
         angle += 0.1f;
-        std::this_thread::sleep_for(std::chrono::milliseconds(50));
+        std::this_thread::sleep_for(std::chrono::milliseconds(33));
     }
 
     transport.Close();

src/delegate-mq/predef/transport/linux-udp/MulticastTransport.h

@@ -55,6 +55,12 @@ class MulticastTransport : public ITransport
                 return -1;
             }
 
+            // Disable loopback so we don't receive our own packets
+            int loop = 0;
+            if (setsockopt(m_socket, IPPROTO_IP, IP_MULTICAST_LOOP, &loop, sizeof(loop)) < 0) {
+                std::cerr << "IP_MULTICAST_LOOP failed." << std::endl;
+            }
+
             // Set the interface for outgoing multicast data
             struct in_addr localAddr;
             inet_aton(localInterface, &localAddr);

src/delegate-mq/predef/transport/win32-udp/MulticastTransport.h

@@ -41,12 +41,13 @@ class MulticastTransport : public ITransport
             m_addr.sin_port = htons(port);
             inet_pton(AF_INET, groupAddr, &m_addr.sin_addr);
 
+            // Disable loopback so we don't receive our own packets
+            int loop = 0;
+            setsockopt(m_socket, IPPROTO_IP, IP_MULTICAST_LOOP, (const char*)&loop, sizeof(loop));
+
             in_addr localAddr;
             inet_pton(AF_INET, localInterface, &localAddr);
             setsockopt(m_socket, IPPROTO_IP, IP_MULTICAST_IF, (const char*)&localAddr, sizeof(localAddr));
-
-            int ttl = 3; 
-            setsockopt(m_socket, IPPROTO_IP, IP_MULTICAST_TTL, (const char*)&ttl, sizeof(ttl));
 
             std::cout << "[Multicast] Created PUB on " << localInterface << ", Group: " << groupAddr << ":" << port << std::endl;
         }