fix

src/message_broker.cpp

@@ -0,0 +1,43 @@
+#include "message_broker.h"
+#include <iostream>
+
+void MessageBroker::publish(const std::string &message) {
+    std::lock_guard<std::mutex> lock(mutex);
+    messageQueue.push(message);
+    cv.notify_all();
+}
+
+void MessageBroker::subscribe(const MessageCallback &callback) {
+    std::lock_guard<std::mutex> lock(mutex);
+    subscribers.push_back(callback);
+}
+
+void MessageBroker::start() {
+    running = true;
+    brokerThread = std::thread([this]() { processMessages(); });
+}
+
+void MessageBroker::stop() {
+    running = false;
+    cv.notify_all();
+    if (brokerThread.joinable()) {
+        brokerThread.join();
+    }
+}
+
+void MessageBroker::processMessages() {
+    while (running) {
+        std::unique_lock<std::mutex> lock(mutex);
+        cv.wait(lock, [this]() { return !messageQueue.empty() || !running; });
+        if (!running) break;
+        while (!messageQueue.empty()) {
+            std::string message = std::move(messageQueue.front());
+            messageQueue.pop();
+            lock.unlock();
+            for (const auto &callback : subscribers) {
+                callback(message); 
+            }
+            lock.lock(); 
+        }
+    }
+}