(doc) Add more doc to SocketServer

ixwebsocket/IXSocketServer.h

@@ -25,6 +25,7 @@ namespace ix
     public:
         using ConnectionStateFactory = std::function<std::shared_ptr<ConnectionState>()>;
 
+        // Each connection is handled by its own worker thread.
         // We use a list as we only care about remove and append operations.
         using ConnectionThreads = std::list<std::pair<std::shared_ptr<ConnectionState>,
                                                       std::thread>>;
@@ -36,6 +37,9 @@ namespace ix
         virtual ~SocketServer();
         virtual void stop();
 
+        // It is possible to override ConnectionState through inheritance
+        // this method allows user to change the factory by returning an object
+        // that inherits from ConnectionState but has its own methods.
         void setConnectionStateFactory(const ConnectionStateFactory& connectionStateFactory);
 
         const static int kDefaultPort;
@@ -65,15 +69,19 @@ namespace ix
 
         std::mutex _logMutex;
 
+        // background thread to wait for incoming connections
         std::atomic<bool> _stop;
         std::thread _thread;
 
+        // the list of (connectionState, threads) for each connections
         ConnectionThreads _connectionsThreads;
 
+        // used to have the main control thread for a server
+        // wait for a 'terminate' notification without busy polling
         std::condition_variable _conditionVariable;
         std::mutex _conditionVariableMutex;
 
-        //
+        // the factory to create ConnectionState objects
         ConnectionStateFactory _connectionStateFactory;
 
         // Methods