fix: implement proper thread locking for serial manipulations

implemented serial_mutex to lock serial changes when receiving data or when ConnectionWindow changes the connection. Furthermore, port is now automatically closed when error occurs, e.g. when disconnecting device while receiving.

src/ConnectionWindow.cpp

@@ -1,14 +1,16 @@
 #include "ConnectionWindow.hpp"
 
-ConnectionWindow::ConnectionWindow(Serial *sp) : Window(ICON_FA_NETWORK_WIRED "  Connection", nullptr), _sp(sp)
+ConnectionWindow::ConnectionWindow(DataHandler *data_handler, Serial *sp) : Window(ICON_FA_NETWORK_WIRED "  Connection", data_handler), _sp(sp)
 {
     _com_ports.push_back("COM-");
 }
 
 void ConnectionWindow::update_content()
 {
+    std::lock_guard<std::mutex> lock(_data_handler->get_serial_mutex());
 
     ImGui::SeparatorText("Settings");
+    _port_open = _sp->get_open();
 
     if (_port_open)
     {
@@ -170,6 +172,7 @@ void ConnectionWindow::update_content()
         std::cout << "Closing COM port ..." << std::endl;
 
         _sp->close();
+
         ImGui::InsertNotification({ImGuiToastType::Success, SPARQ_NOTIFY_DURATION_OK, "COM port closed successfully!"});
         _port_open = false;
     }

src/ConnectionWindow.hpp

@@ -14,7 +14,7 @@
 class ConnectionWindow : public Window
 {
 public:
-    ConnectionWindow(Serial *sp);
+    ConnectionWindow(DataHandler *data_handler, Serial *sp);
 
     void update_content();
 

src/DataHandler.cpp

@@ -22,10 +22,14 @@ void DataHandler::receiver_loop()
 {
     while (_running)
     {
+        std::unique_lock<std::mutex> serial_lock(_serial_mutex);
         sparq_message_t message = receive_message();
+        serial_lock.unlock();
+
         if (message.valid)
         {
-            std::unique_lock<std::mutex> lock(_data_mutex);
+
+            std::lock_guard<std::mutex> data_lock(_data_mutex);
 
             if (message.message_type == sparq_message_type_t::STRING)
             {
@@ -35,8 +39,6 @@ void DataHandler::receiver_loop()
             {
                 add_to_datasets(message);
             }
-
-            lock.unlock();
         }
 
         std::this_thread::sleep_for(SPARQ_RECEIVE_LOOP_DELAY);
@@ -256,6 +258,12 @@ sparq_message_t DataHandler::receive_message()
 
     // Read everything thats available
     int len = _sp->read(_serial_buffer.data(), SPARQ_MAX_MESSAGE_LENGTH * 2);
+
+    if (len <= 0)
+    {
+        return message;
+    }
+
     // Append to message buffer
     _message_buffer.insert(_message_buffer.end(), _serial_buffer.begin(), _serial_buffer.begin() + len);
 

src/DataHandler.hpp

@@ -61,6 +61,7 @@ class DataHandler
     sparq_plot_settings_t plot_settings;
 
     std::mutex &get_data_mutex() { return _data_mutex; }
+    std::mutex &get_serial_mutex() { return _serial_mutex; }
 
 private:
     uint32_t current_absolute_sample = 0;
@@ -82,5 +83,5 @@ class DataHandler
 
     std::thread _receive_thread;
     std::atomic<bool> _running = true;
-    std::mutex _data_mutex;
+    std::mutex _data_mutex, _serial_mutex;
 };

src/sparq.cpp

@@ -29,7 +29,7 @@ void SPARQ::object_init()
     static ConsoleWindow console_window;
     static DataHandler data_handler(&serial_port, &console_window);
 
-    static ConnectionWindow connection_window(&serial_port);
+    static ConnectionWindow connection_window(&data_handler, &serial_port);
     static PlottingWindow plotting_window(&data_handler);
     static DataWindow data_window(&data_handler);
     static MeasureWindow measure_window(&data_handler);

src/sparq_config.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#define SPARQ_VERSION "v0.4.0"
+#define SPARQ_VERSION "v0.4.1"
 
 #define SPARQ_MAX_FPS 120
 #define SPARQ_FONT "./assets/roboto.ttf"