Exception on socket.send() - Solved! Thank you all!

[SlySherZ]

Hey guys! I'm writing down some code to use on a simple messaging server.

Whenever the server has to send some messages in a row, I get:  Access violation reading location 0xFEEEFEF6
I've been getting some errors for trying to modify free heap values too.

this is where I allocate the socket (Sorry if it's hard to read :S)

client_list.push_back(Client("", false, new sf::TcpSocket));  //I'm creating a client object, storing it
                                listener.accept(*(client_list[client_list.size() - 1].S.Socket));     //on a vector
                                selector.add(*(client_list[client_list.size() - 1].S.Socket));

And I free memory here.

delete client_list[i].S.Socket;
client_list.erase(client_list.begin() + i , client_list.begin() + i + 1);

Maybe this isn't enough to get a correct evaluation, but I don't really know from where else the bug could be coming from.

Thanks!

[eXpl0it3r]

You shouldn't use manual memory management.

If you get an Access Violation you're most likely try to access something out of bound or something that doesn't exist anymore. This is a very simple case to debug. Just set some break points, track different variables and step through youd application step by step.

[SlySherZ]

I tried to use unique_pt but... I get and error saying that unique_ptr is not a member of std.
Using VS2013 with c++11 flag and #include<memory.h>

[select_this]

#include<memory.h>

That should probably be #include<memory>

[SlySherZ]

Thanks! that fixed it!
But I still can't get this to work....

std::unique_ptr<sf::TcpSocket> Socket;
Socket = make_unique<sf::TcpSocket>();

this tries to copy a tcpsocket, which cannot be copied. How do I re-write this so that no copies occur?

[select_this]

How do I re-write this so that no copies occur?

Try this:

std::unique_ptr<sf::TcpSocket> Socket(new sf::TcpSocket());

[SlySherZ]

error C2280: 'std::unique_ptr<sf::TcpSocket,std::default_delete<_Ty>> &std::unique_ptr<_Ty,std::default_delete<_Ty>>::operator =(const std::unique_ptr<_Ty,std::default_delete<_Ty>> &)' :
attempting to reference a deleted function      c:\program files (x86)\microsoft visual studio 12.0\vc\include\xlocmon

Still not working. Thanks for your help anyway

[Laurent]

It's not this line (the construction) that triggers an assignment. Where else are you using the pointer?

[SlySherZ]

This pointer is declared inside an object Client.

client_list.push_back(Client("", false));

Every time I pass an object or the full list I do it as a reference. At least I think I do.
I only use that pointer to send and receive messages, like so:

Socket->send(buffer, x + 1);

And as a argument to selector functions:

selector.isReady(*client_list[i].S.Socket))

EDIT: I don't really know what the problem is, but it has something to do with vector push_back() and erase()
I tried to comment those lines and the program compiles without errors

EDIT2: I ended up changing my vector to store unique pointers to Clients instead of the clients themselves. Everything working as intended... for now. Thanks a lot guys, I REALLY appreciate your help.

[Nexus]

If you write your own class that is not copyable, you must make it movable in order to be stored in most containers.

By the way,

std::unique_ptr<sf::TcpSocket> Socket;
Socket = make_unique<sf::TcpSocket>();

can be written as

auto Socket = std::make_unique<sf::TcpSocket>();

There's never a  need to assign a variable one line after it has been declared...