SFML Network Multithreading - c++

Question

I need to create a thread to run the Networking portion of my game. I would prefer to use SFML threads as my compiler doesn't yet support C++11 threads. However the class which contains the thread is created with make_shared(). Here is the code:
Game.cpp (not all the code just the declaration of GameScreen)
std::shared_ptr<Screen> Game::screen = std::make_shared<GameScreen>();
Screen is just a base class containing pure virtual functions. You should be able to figure out which ones are virtual based off the override keywords.
GameScreen.h
#ifndef GAMESCREEN_H
#define GAMESCREEN_H
#include <SFML/Graphics.hpp>
#include "Events.h"
#include "Screen.h"
#include "Map.h"
#include "Network.h"
class GameScreen : public Screen
{
public:
GameScreen();
void handleInput(sf::RenderWindow&) override;
void update(sf::RenderWindow&, sf::View&) override;
void render(sf::RenderWindow&) override;
private:
Map m_map;
Network network;
Events eventManager;
sf::Thread networkThread;
};
#endif // GAMESCREEN_H
GameScreen.cpp
#include <memory>
#include <iostream>
#include "GameScreen.h"
#include "Game.h"
GameScreen::GameScreen()
: networkThread(network.receive(eventManager))
{
network.Connect();
}
void GameScreen::handleInput(sf::RenderWindow& window)
{
/*Code*/
}
void GameScreen::update(sf::RenderWindow& window, sf::View& view)
{
/*Code*/
}
void GameScreen::render(sf::RenderWindow& window)
{
/*Code*/
}
Network.cpp (receive function only)
void Network::Recieve(Events& eManager)
{
sf::Packet m_rPacket;
m_socket.receive(m_rPacket, m_serverIP, port);
m_rPacket >> /*Data*/
eManager.addEvent(tmp);
}

Answer 1

You can use this in the constructor's initialization list:
MyClass::MyClass()
: AClass(&MyFunction(*this))
{
/*do stuff*/
}
However, this doesn't make sense in your example, because you are trying to pass a pointer to MyFunction (or its non-existent return value) to AClass(), and you can't quality a pointer with parameters. You can only pass parameters to MyFunction() when actually calling MyFunction(). Are you sure you don't actually mean something more like this instead:
MyClass::MyClass()
: AClass()
{
/*do stuff*/
MyFunction(*this);
}
Without seeing what AClass() actually is, or what it expects as input, it is difficult to know for sure what you are trying to do.
Update clearly you have not read the SFML documentation or SFML Tutorial on threading. The Thread constructor takes a pointer to a function/method as one input parameter, and an optional input value for the function/method as a separate parameter. Try this instead:
class MyClass : public sf::Thread
{
private:
static void MyFunction(MyClass &cls);
public:
MyClass();
};
MyClass::MyClass()
: sf::Thread(&MyClass::MyFunction, *this)
{
/*do stuff*/
}
void MyClass::MyFunction(MyClass &cls)
{
/*do stuff with 'cls'*/
}
Or this, as you can use a non-static class method with an SFML thread:
class MyClass : public sf::Thread
{
private:
void MyFunction();
public:
MyClass();
};
MyClass::MyClass()
: sf::Thread(&MyClass::MyFunction, *this)
{
/*do stuff*/
}
void MyClass::MyFunction()
{
/*do stuff with 'this'*/
}
Update: based on your new code, you are still not even close to constructing the sf::Thread object correctly (did you read the documentation/tutorial I linked to?). Also, your thread needs access to multiple objects owned by GameScreen, so you can't pass them all to the sf::Thread constructor. You need to do something more like this instead:
class GameScreen : public Screen
{
public:
GameScreen();
...
private:
...
Network network;
Events eventManager;
sf::Thread networkThread;
void networkThreadFunc();
};
GameScreen::GameScreen()
: networkThread(&GameScreen::networkThreadFunc, *this)
{
network.Connect();
}
void GameScreen::networkThreadFunc()
{
network.Receive(eventManager);
}