Added the possibility of shutting down the rendering processes remotely.

client/main_window.cpp

@@ -33,6 +33,10 @@ main_window::main_window(unsigned int port, QWidget* parent) :
     connect(rnd_btn, &QPushButton::clicked, this, &main_window::send_img_render);
     layout->addWidget(rnd_btn);
 
+    QPushButton* exit_btn = new QPushButton("Kill render processes", this);
+    connect(exit_btn, &QPushButton::clicked, this, &main_window::handle_kill_renderer);
+    layout->addWidget(exit_btn);
+
     server = new mandel_tcp_server(this);
     connect(server, &QTcpServer::newConnection, this, &main_window::handle_new_connection);
     server->listen(QHostAddress::Any, port);
@@ -79,6 +83,15 @@ void main_window::send_img_render()
     socket->send_data_packet(rnd_packet);
 }
 
+void main_window::handle_kill_renderer()
+{
+    if (!socket)
+        return;
+
+    data_packet kill_packet(op_codes::EXIT, 0, nullptr);
+    socket->send_data_packet(kill_packet);
+}
+
 void main_window::handle_new_connection()
 {
     socket = server->nextPendingConnection();
@@ -123,3 +136,4 @@ void main_window::handle_recv_data()
     
     delete packet;
 }
+

client/main_window.h

@@ -30,6 +30,7 @@ class main_window : public QWidget
     public slots:
         void show_image();
         void send_img_render();
+        void handle_kill_renderer();
 
     private slots:
         void handle_new_connection();

network/network_defines.h

@@ -11,7 +11,8 @@ enum op_codes : quint32
      * encoded as base64 using ImageMagicks
      * Blob-class. */
     IMG_DATA = 0x1,
-    RENDER_IMG = 0x2
+    RENDER_IMG = 0x2,
+    EXIT = 0x3
 };
 
 #endif

server/mandel_render_srv.cpp

@@ -102,19 +102,18 @@ void mandel_render_srv::mpi_event_loop()
     double recv_buf[8];
     while (true)
     {
-        cout << "Process " << id << " in event loop!";
         MPI_Status status;
 
         // Sending the opcode as a double as well to only have to use one transmission.
         MPI_Recv(&recv_buf, 8, MPI_DOUBLE, 0, 0, MPI_COMM_WORLD, &status);
 
-        cout << "Received opcode: " << recv_buf[0] << endl;
 
         mpi_opcodes op_code = static_cast<mpi_opcodes>(recv_buf[0]);
         switch (op_code)
         {
             case mpi_opcodes::EXIT:
             {
+                MPI_Finalize();
                 exit(0);
                 break;
             }
@@ -145,6 +144,7 @@ void mandel_render_srv::handle_recv_data()
     {
         case op_codes::RENDER_IMG:
         {
+            cout << "Dispatching and starting image rendering!" << endl;
             QByteArray payload;
             QDataStream stream(&payload, QIODevice::ReadWrite);
 
@@ -177,6 +177,20 @@ void mandel_render_srv::handle_recv_data()
             start_drawing();
             break;
         }
+        case op_codes::EXIT:
+        {
+            double mpi_data = 0;
+            // Send exit command.
+            if (procs >= 2)
+            {
+                for (int i = 1; i < procs; ++i)
+                    MPI_Send(&mpi_data, 1, MPI_DOUBLE, i, 0, MPI_COMM_WORLD);
+            }
+
+            MPI_Finalize();
+            exit(0);
+            break;
+        }
         default:
             qDebug() << "Unrecognised op code received: " << static_cast<quint32>(packet->get_op_code());
     }